Composition for alkylation and method for detoxifying a harmful compound by using the composition

TECHNICAL FIELD

The present invention relates to a composition for the alkylation and a method for detoxifying a harmful compound by using the composition.

BACKGROUND ART

The heavy metal material such as arsenic, antimony and selenium is widely used as an industrial material, for example, semiconductor, but the influence on the organism by being flowed it out into an environment is concerned, since it is harmful material for the organism.

In the past, as a method for treating these heavy metal, a method wherein a flocculating agent such as polychlorinated aluminum (PAC) is added into the wastewater containing an inorganic arsenic such as a harmful arsenous acid, and then the inorganic arsenic is removed by the filtration after the inorganic arsenic is aggregated, adsorbed to the flocculating agent and iron contained in a raw water and then precipitated, or a method wherein an arsenic compound etc. is adsorbed by using an activated alumina, cerium based flocculating agent, are generally known.

On the other hand, it is known in nature that an inorganic arsenic is stored in sea food such as a seaweed, and then a part of the inorganic arsenic is converted to an organic arsenic compound such as dimethyl arsenic by the physiological response-(Nonpatent literature 1: Kaise et al., 1998, Organomet. Chem., 12 137-143). And it is generally known that these organic arsenic compound has lower toxicity than that of the inorganic arsenic for the mammal.

Nonpatent literature 1: Kaise et al., 1998, Organomet. Chem., 12 137

DISCLOSURE OF THE INVENTION

Problems to be Resolved by the Invention

However, in the above method of removing the heavy metal characterized by the use of the filtration and adsorption, it is necessary to store or reclaim a polluted sludge containing the harmful compound such as the inorganic arsenic which is still harmful, and an absorbent to which the harmful compound is absorbed, under the condition of sealing off the harmful compound with the use of the concrete etc., in order to prevent it from being leaked to the outside. Therefore, there is problem that the mass disposal is difficult since a storage place or a large space for a reclaimed area are required.

Moreover, it is internationally recognized that an arsenic contained in the sea food is a harmless arsenobetaine, in the present invention, it is possible to attain the detoxification by chemically converting the highly toxic inorganic arsenic to the harmless arsenobetaine.

Therefore, it is an object of the present invention to provide a beneficial composition in order to detoxify the harmful compound containing arsenic etc. effectively and systematically and a method for detoxifying a harmful compound by using the composition.

Means of Solving the Problems

In order to accomplish the above objects, the present inventors made strenuous studies on the methylating reaction of the harmful compound, specifically, the methylation, especially dimethylation, and more preferably trimethylation of the harmful compound containing arsenic etc., by chemical reactions with the use of an organic metal complex having cobalt-carbon bond. As a result, the inventors discovered the present invention.

That is, the composition for the alkylation according- to the present invention is characterized in that the composition contains a cobalt complex.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the harmful compound containing at least one element selected from the groups comprising arsenic, antimony and selenium is alkylated by using the cobalt complex.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized by further containing a reducing agent to reduce at least one metal selected from the groups comprising arsenic, antimony and selenium.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the reducing agent is a material having SH group.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the material having SH group is at least one selected from the groups comprising glutathione, reduced glutathione (GSH), cysteine, S-adenosyl cysteine, sulforaphane, homocysteine and thioglycol.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the composition further contains a methylating additive factor having S-Me group.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the methylating additive factor is at least one selected from the groups comprising methionine and S-adenosyl methionine.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the composition further contains a buffer solution.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that a pH of the buffer solution is in the range of 5-10.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that a pH of the composition for the alkylation is less than 9.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the composition further contains H₂O₂.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the composition further contains an organic halide compound.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the organic halide compound is methyl halide.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the methyl halide is at least one selected from the groups comprising methyl iodide, methyl bromide and methyl chloride.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the organic halide compound is halogenated acetic acid.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the halogenated acetic acid is at least one selected from the groups comprising chloroacetic acid, bromoacetic acid and iodoacetic acid.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the organic halide compound is at least one selected from the groups comprising methyl chloride, methyl bromide, methyl iodide, chloroacetic acid, bromoacetic acid, iodoacetic acid, chloroethanol, bromoethanol, iodoethanol, chloropropionic acid, bromopropionic acid, iodopropionic acid, chloroacetic acid ethyl ester, bromoacetic acid ethyl ester and iodoacetic acid ethyl ester.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the organic halide compound is the Grignard reagent represented by the following chemical formula 1:

RMgX  Chemical formula 1:

(wherein R=Me, CH₂COOH, or CH₂COOC₂H₅, X=Cl, Br or I).

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the organic halide compound is derived from a persistent organic material selected from the groups comprising a pesticide, a fire retardant, dioxin, PCB, DDT, trihalomethane, trichloroethyl and chloroform.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the composition further contains a reducing agent to reduce the cobalt complex.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the reducing agent is at least one selected from the groups comprising titanium oxide and ruthenium complex.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the cobalt complex is methyl complex comprising at least one compound selected from methylcobalamin (methylated vitamin B12, official name: Coα-[α-5,6-dimethylbenz-1H-imidazole-1-yl-Coβ-methylcobamide]), vitamin B12 such as cyanocobalamin, cobalt(II) acetyl acetonate, cobalt(III) acetyl acetonate, cobalt carbonyl (dicobalt octacarbonyl), cobalt(II)1,1,1,5,5,5-hexafluoro acetyl acetonate, cobalt(II) meso-tetra phenyl porphin, hexafluoro phosphoric acid bis(pentamethyl cyclopenta dienyl) cobalt, N,N′-bis(salicylidene) ethylene diamine cobalt(II), bis(2,2,6,6-tetramethyl-3,5-heptanedionato)cobalt(II), (chlorophthalocyaninnato)cobalt(II), chlorotris (triphenylphosphine) cobalt(I), methyl complex of cobalt(II) acetate, cobalt(II) benzoate, cobalt(II) cyanide, cyclohexane cobalt(II) butyrate, 2-cobalt(II) ethylhexanoate, meso-tetramethoxyphenyl porphyrin cobalt(II), cobalt naphthenate, cobalt(II) phthalocyanine, methyl cobalt(III) protoporphyrin IX, cobalt stearate, cobalt(II) sulfamate, (1R,2R)-(−)-1,2-cyclohexanediamino-N,N′-bis(3,5-di-t-butylsalicylidene)cobalt(II), (1S,2S)-(+)-1,2-cyclohexanediamino-N,N′-bis(3,5-di-t-butylsalicylidene)cobalt(II), cyclopentadienyl bis (triphenylphosphine) cobalt(I), cyclopentadienyl cobalt dicarbonyl, dibromo bis(triphenylphosphine)cobalt(II), (tetraminochloro phthalocyaninnato)cobalt(II), (tetra-t-butyl phthalocyaninnato) cobalt(II), or at least one selected from the groups comprising cobalt-methyl complex formed by allowing the cobalt compound to coexist with the alkyl halide, especially methyl halide.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that a ratio between a molarity [Reducing Agent] of the reducing agent to reduce at least one metal selected from the groups comprising arsenic, antimony and selenium and a molarity [Metal] of the metal selected from arsenic, antimony and selenium, that is, a [Reducing Agent]/[Metal] is greater or equal to 1000.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the ratio is greater or equal to 10000.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that a ratio between a molarity [Co complex] of the cobalt complex and a molarity [Metal] of the metal selected from arsenic, antimony and selenium, that is, a [Co complex]/[Metal] is greater or equal to 100.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition is characterized in that the ratio is greater or equal to 1000.

The method of detoxifying the harmful compound according to the present invention, the method is characterized in that a harmful compound containing at least one element selected from the groups comprising arsenic, antimony and selenium is detoxified by the alkylation of the harmful compound, in the presence of the above composition.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the detoxification is attained by increasing the oxidation number of a valence of the one element.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that at least one bond of the one element is alkylated.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the element is arsenic.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that 50% of a lethal dose (LD₅₀) of the compound detoxified by the alkylation is greater or equal to 1000 mg/kg.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that 50% of an inhibition of cell growth concentration (IC₅₀) of the compound detoxified by the alkylation is greater or equal to 1000 μM.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the harmful compound is selected from the groups comprising arsenic trioxide, arsenic pentoxide, arsenic trichloride, arsenic pentachloride, arsenic sulfide compound, cyano arsenic compound, chloro arsenic compound, and the other arsenic inorganic salt.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the alkylation is a methylation.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the harmful compound is converted to a dimethyl compound, or trimethyl compound by the methylation.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the dimethyl compound is dimethyl arsonyl ethanol (DMAE), dimethyl arsonyl acetate (DMAA), dimethylarsinic acid or arseno sugar.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the trimethyl compound is arsenocholine, arsenobetaine, trimethyl arseno sugar or trimethyl arsine oxide.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that an organic halide selected from the groups comprising a pesticide, a fire retardant, dioxin, PCB, DDT, trihalomethane, trichloroethyl and chloroform is detoxified by the dehalogenation of the organic halide in the presence of the above composition.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the organic halide selected from the groups comprising a pesticide, a fire retardant, dioxin, PCB, DDT, trihalomethane, trichloroethyl and chloroform is detoxified by the dehalogenation of the organic halide in the presence of the above composition, and then in the presence of cobalt complex obtained by the reaction, the harmful compound containing at least one element selected from the groups comprising arsenic, antimony and selenium is detoxified by the alkylation of the harmful compound.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the method further comprises the step of exposing to the light in the presence of the reducing agent to reduce the cobalt complex.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized in that the reducing agent is at least one selected from the groups comprising titanium oxide and ruthenium complex.

EFFECT OF INVENTION

The present invention has an advantageous effect that it is possible to alkylate the harmful compound, in particular, the harmful compound containing arsenic, antimony and selenium etc., easily and simply. Furthermore, according to the method of the present invention, it has an advantageous effect that a large space such as storage place is not required since it is possible to detoxify the harmful compound without limit. Furthermore, according to the method of the present invention, it has an advantageous effect that the unnecessary byproduct is not generated since it does not use a biological material in itself in a viable condition. Furthermore, according to the present invention, it has an advantageous effect that it is possible to decrease the harmful inorganic arsenic even more with a simple method.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 gives a HPLC-ICP-MS analysis of a chlorella extract (Upper: standard sample, Lower: sample).

FIG. 2 gives a HPLC-ICP-MS analysis of a chlorella extract (Upper: standard sample, Middle: GSH addition (NE 14-7), Lower: MeCo+GSH+MIAA addition (NE 15-7)).

FIG. 3 shows a condition in the case that GSH (NE 14-4), GSH+MeCo +MIAA (NE 15-4) are added to the chlorella extract, respectively, and NaOH treatment (Lower) are subject to the chlorella extract.

FIG. 4 shows a condition in the case that GSH+MeCo+MIAA are added to DMA (NE 9-4).

FIG. 5 gives a HPLC-ICP-MS chromatogram. A No. on the graph corresponds to a No. on the table 7.

FIG. 6 gives a HPLC-ICP-MS chromatogram. A No. on the graph corresponds to a No. on the table 7.

FIG. 7 shows a variation per hour of the concentration of an arsenic compound in the reaction solution. It is in a graph form as to the result of the table 7.

FIG. 8 shows a variation per hour of the percentage of an arsenic compound in the reaction solution.

FIG. 9 shows a variation per hour of the percentage an arsenic compound in the reaction solution.

FIG. 10 gives a HPLC-ICP-MS chromatogram. A No. on the graph corresponds to a No. on the table 8.

FIG. 11 gives a HPLC-ICP-MS chromatogram. A No. on the graph corresponds to a No. on the table 8.

FIG. 12 gives a HPLC-ICP-MS chromatogram. A No. on the graph corresponds to a No. on the table 8.

FIG. 13 gives a HPLC-ICP-MS chromatogram. A No. on the graph corresponds to a No. on the table 8.

FIG. 14 shows a variation per hour of the concentration of an arsenic compound in the reaction solution.

FIG. 15 shows a variation per hour of the concentration of an arsenic compound in the reaction solution (After hydrogen peroxide solution treatment).

FIG. 16 shows a variation per hour of the percentage of an arsenic compound in the reaction solution (Before hydrogen peroxide treatment).

FIG. 17 shows a variation per hour of the percentage of an arsenic compound in the reaction solution (After hydrogen peroxide treatment).

FIG. 18 shows a variation per hour of the concentration of an arsenic compound in the reaction solution (No. 1-4 of the table 9).

FIG. 19 shows a variation per hour of the concentration of an arsenic compound in the reaction solution (No. 5-8 of the table 9, after hydrogen peroxide solution treatment).

FIG. 20 shows a variation per hour of the concentration of an arsenic compound in the reaction solution (No. 9-12 of the table 9).

FIG. 21 shows a variation per hour of the concentration of an arsenic compound in the reaction solution (No. 13-16 of the table 9, after hydrogen peroxide solution treatment).

FIG. 22 shows a variation per hour of the concentration of an arsenic compound in the reaction solution (No. 17-20 of the table 9, before hydrogen peroxide solution treatment).

FIG. 23 shows a variation per hour of the concentration of an arsenic compound in the reaction solution (No. 21-24 of the table 9, before hydrogen peroxide solution treatment).

FIG. 24 shows a variation per hour of the percentage of an arsenic compound in the reaction solution (No. 1-4 of the table 9, before hydrogen peroxide treatment).

FIG. 25 shows a variation per hour of the percentage of an arsenic compound in the reaction solution (No. 5-8 of the table 9, after hydrogen peroxide solution treatment).

FIG. 26 shows a variation per hour of the percentage of an arsenic compound in the reaction solution (No. 9-12 of the table 9, before hydrogen peroxide solution treatment).

FIG. 27 shows a variation per hour of the percentage of an arsenic compound in the reaction solution (No. 13-16 of the table 9, after hydrogen peroxide solution treatment).

FIG. 28 shows a variation per hour of the percentage of an arsenic compound in the reaction solution (No. 17-20 of the table 9, before hydrogen peroxide solution treatment).

FIG. 29 shows a variation per hour of the percentage of an arsenic compound in the reaction solution (No. 21-24 of the table 9, after hydrogen peroxide solution treatment).

FIG. 30 shows a mechanism concerning the methylation of arsenic trioxide in the case of vitamin B12 as an example.

FIG. 31 gives a HPLC-ICP-MS chromatogram of the methylation reaction of selenious acid [Se(IV)] by MC.

FIG. 32 gives a HPLC-ICP-MS chromatogram (measurement element Sb, m/z 121).

FIG. 33 gives a reaction condition in the production of trimechyl arsenic (TMA) from arsenic trioxide according to methylcobalamin.

BEST MODE FOR CARRYING OUT THE INVENTION

The composition for the alkylation according to the present invention contains a cobalt complex. The cobalt complex used herein is not particularly limited, but an organometallic complex having a cobalt-carbon bond etc., may be recited as an example.

As an example of the organometallic complex having a cobalt-carbon bond may be mentioned below. That is, methylcobalamin (methylated vitamin B12, official name: Coα-[α-5,6-dimethylbenz-1H-imidazole-1-yl-Coβ-methylcobamide]) is preferably used. Furthermore, mention may be made of at least one selected from the groups comprising the methyl complex of at least one compound selected from vitamin B12 such as cyanocobalamin, cobalt(II) acetyl acetonate, cobalt(III) acetyl acetonate, cobalt carbonyl (dicobalt octacarbonyl), cobalt(II)1,1,1,5,5,5-hexafluoro acetyl acetonate, cobalt(II) meso-tetra phenyl porphin, hexafluoro phosphoric acid bis(pentamethyl cyclopenta dienyl)cobalt, N,N′-bis(salicylidene) ethylene diamine cobalt(II), bis(2,2,6,6-tetramethyl-3,5-heptanedionato)cobalt(II), (chlorophthalocyaninnato) cobalt(II), chlorotris (triphenylphosphine) cobalt(I), methyl complex of cobalt(II) acetate, cobalt(II) benzoate, cobalt(II) cyanide, cyclohexane cobalt(II) butyrate, 2-cobalt(II) ethylhexanoate, meso-tetramethoxyphenyl porphyrin cobalt(II), cobalt naphthenate, cobalt(II) phthalocyanine, methyl cobalt(III) protoporphyrin IX, cobalt stearate, cobalt(II) sulfamate, (1R,2R)-(−)-1,2-cyclohexanediamino-N,N′-bis(3,5-di-t-butylsalicylidene)cobalt(II), (1S,2S)-(+)-1,2-cyclohexanediamino-N,N′-bis(3,5-di-t-butylsalicylidene)cobalt(II), cyclopentadienyl bis(triphenylphosphine) cobalt(I), cyclopentadienyl cobalt dicarbonyl, dibromo bis(triphenylphosphine)cobalt(II), (tetraminochloro phthalocyaninnato)cobalt(II), (tetra-t-butyl phthalocyaninnato)cobalt(II), or at least one selected from the groups comprising cobalt-methyl complex formed by allowing the cobalt compound to coexist with the alkyl halide, especially methyl halide. Methylcobalamin is preferable as the organometallic complex having a cobalt-carbon bond, from the viewpoint that it is possible to make it relatively easy to alkylate the harmful compound containing a harmful inorganic arsenic etc., and covert it to an organic material which has a less toxic.

That is, in the composition for the alkylation according to the present invention, it is possible to alkylate the harmful compound containing at least one element selected from the groups comprising arsenic, antimony and selenium by using the organometallic complex. The term “the harmful compound” used herein means a compound which gives any adverse affect to the organism when it is flowed out into the environment and exposed to the organism.

As a harmful compound containing arsenic among the harmful compound, mention may be made of arsenious acid, arsenic pentoxide, arsenic trichloride, arsenic pentachloride, arsenic sulfide compound, cyano arsenic compound, chloro arsenic compound, and other arsenic inorganic salt and or the like. In these arsenic, for example, LD₅₀ (50% of the fatal dose in mouse) is less or equal to 20, and therefore, it is generally a poisonous value for the organism.

Further, as a harmful compound containing antimony, mention may be made of antimony trioxide, antimony pentoxide, antimony trichloride, and antimony pentachloride and or the like.

Further, as a harmful compound containing selenium, mention may be made of selenium dioxide and selenium trioxide.

In a preferred embodiment, the composition of the present invention may further contain a reducing agent to reduce at least one metal selected from the groups comprising arsenic, antimony and selenium. The presence of the reducing agent makes it possible to further accelerate the alkylation. Although it is thought that a reducing ability for the arsenic or the transmethylation reaction are likely to be a rate controlling in the conversion to the arsenobetaine, it is thought that the conversion to the arsenobetaine etc., may be accelerated by adding those reducing agents. As the reducing agent like this, for example, a material having the SH group may be mentioned, which may be specifically at least one selected from the groups comprising glutathione, reduced glutathione (GSH), cysteine, S-adenosyl cysteine, sulforaphane, homocysteine and thioglycol. Moreover, any combination of these materials having the SH group may be used. For example, combinations of glutathione+homocysteine, or glutathione+thioglycol etc., may be mentioned.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, a ratio between a molarity [Reducing Agent] of the reducing agent to reduce at least one metal selected from the groups comprising arsenic, antimony and selenium and a molarity [Metal] of the metal selected from arsenic, antimony and selenium, that is, a [Reducing Agent]/[Metal] is greater or equal to 1000. More preferably, the ratio is greater or equal to 10000. This is because in such conditions, it is possible to attain the alkylation in a high rate, and then to attain the detoxification of the harmful compound containing arsenic etc., effectively when the composition of the present invention is applied to the method of detoxifying the harmful compound as mentioned later.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, a ratio between a molarity [Co complex] of the Co complex and a molarity [Metal] of the metal selected from arsenic, antimony and selenium, that is, a [Co complex]/[Metal] is greater or equal to 100. More preferably, the ratio is greater or equal to 1000. This is because in such conditions, it is possible to attain the alkylation in a high rate, and then to attain the detoxification of the harmful compound containing arsenic etc., effectively when the composition of the present invention is applied to the method of detoxifying the harmful compound as mentioned later.

According to the molarity ratio as mentioned above, it is possible to attain one of the primary objective of the present invention, that is, which an extremely-poisonous inorganic arsenic (Acute toxicity value: LD50 0.03 g/kg) etc., can be converted high-efficiently to a methylated arsenic etc., having a lower toxicity by the methylation of the inorganic arsenic. The methylated arsenic etc., having a lower toxicity which is an objective product are trimethylarsineoxide (Acute toxicity value: LD50 10.6 g/kg) or arsenobetaine (Acute toxicity value: LD50 10.0 g/kg) etc. It is possible to reduce a toxicity up to 1/300 compared with that of the inorganic arsenic etc., these harmless arsenic etc., can be obtained at 10% or more, preferably at 50% or more, more preferably at 90% or more at relative yield.

Furthermore, in a preferred embodiment of the composition for the alkylation according to the present invention, the composition further contains a methylating additive factor having S-Me group. The presence of the methylating additive factor having S-Me group makes it possible to produce more alkyl groups, and thereby, to attain more alkylation, and consequently more detoxification. As the methylating additive factor, mention may be made of at least one selected from the groups comprising methionine and S-adenosyl methionine.

Furthermore, the composition for the alkylation according to the present invention may further contain a buffer solution. Those generally used for the isolation, purification or preservation of the biomedical materials may be used for the buffer solution, and those are not particularly limited, but mention may be made of the buffer solution such as a tris buffer, a phosphate buffer, a carbonic acid buffer, and a boric acid buffer. Furthermore, in a viewpoint that it is possible to attain the detoxification more safely, a pH of the buffer solution is preferably in the range of 5-10. A pH of the composition for the alkylation is more preferably less than 9. The composition for the alkylation of the present invention may further contain H₂O₂. That is, H₂O₂ may be added in a viewpoint that an acute toxicity can be decreased by enhancing the oxidation state (from trivalent to pentavalent).

Furthermore, the composition for the alkylation according to the present invention may further contain an organic halide compound. In a viewpoint that it is possible to make it easy to convert a dimethyl compound and/or a trimethyl compound to arsenobetaine, methyl halide may be recited as the organic halide compound. In a viewpoint of a high reactivity of the methylation, as the methyl halide mention may be made of at least one selected from the groups comprising

• • methyl iodide, methyl bromide and methyl chloride.

In addition, in a viewpoint of a high reactivity of the alkylation, as the organic halide mention may be made of at least one selected from the groups comprising iodoacetic acid, iodoethanol, bromoacetic acid, bromoethanol and iodopropionic acid.

In a preferred embodiment, the organic halide is the halogenated acetic acid. As an example of the halogenated acetic acid, mention may be made of at least one selected from the groups comprising chloroacetic acid, bromoacetic acid and iodoacetic acid.

Furthermore, in a preferred embodiment, as the organic halide compound, mention may be made of at least one selected from the groups comprising methyl chloride, methyl bromide, methyl iodide, chloroacetic acid, bromoacetic acid, iodoacetic acid, chloroethanol, bromoethanol, iodoethanol, chloropropionic acid, bromopropionic acid, iodopropionic acid, chloroacetic acid ethyl ester, bromoacetic acid ethyl ester and iodoacetic acid ethyl ester.

Furthermore, in the present invention, the organic halide compound may be the Grignard reagent represented by the following chemical formula 1:

RMgX  Chemical formula 1:

(wherein R=Me, CH₂COOH or CH₂COOC₂H₅, X=Cl, Br or I).

Moreover, the use of the organic halide compound as mentioned above is mainly explained in a viewpoint that it is possible to methylate the harmful compound, in more detail, to make it easy to convert dimethyl compound and/or trimethyl compound to stable arsenobetaine.

On the other hand, an organic halide compound as mentioned below is exemplified as those capable of being object for the detoxification by the dehalogenation in a method of detoxifying the organic halide compound according to the present invention as described later.

That is, as an organic halide compound which may be intended for the detoxification, mention may be made of those selected from the groups comprising a pesticide, a fire retardant, dioxin, PCB, DDT, trihalomethane, trichloroethyl and chloroform. In the case that these materials are not purified, these materials may be used as appropriate forms (regardless of a liquid, a gas or a solid) capable of introducing them into the reaction system in the conventional procedure such as an extraction and the separation etc. Since the cobalt complex is existed in the composition for the alkylation according to the present invention, the catalytic action of the cobalt complex makes it possible to dehalogenate the above harmful organic halide, and thereby, to detoxify the harmful organic halide by the dehalogenation.

The composition for the alkylation according to the present invention may further contain a reducing agent to reduce the cobalt complex. This has an advantageous effect that it is possible to convert the oxidation state of the cobalt complex to an active oxidation state thereof by the presence of the reducing agent, as described later.

The reducing agent like this is not particularly limited as long as it can make the cobalt complex become activated, but for example, mention may be made of at least one selected from the groups comprising titanium oxide and ruthenium complex.

Next, the method of detoxifying the harmful compound according to the present invention is explained. Namely, the method of detoxifying the harmful compound according to the present invention is characterized in that a harmful compound containing at least one element selected from the groups comprising arsenic, antimony and selenium is detoxified by the alkylation of the harmful compound, in the presence of the composition for the alkylation according to the present invention as described above. The composition for the alkylation according to the present invention, and the harmful compound used herein mean those explained above, these explanation may be applicable for the method of detoxifying the harmful compound according to the present invention.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, in the viewpoint that the 50% of an inhibition of cell growth concentration (IC₅₀) or the 50% of a lethal dose (LD₅₀) is greater, and therefore it is possible to attain more detoxification, the detoxification of the harmful compound is preferably attained by increasing the oxidation number of a valence of the one element contained in the above harmful compound. Specifically, it is possible to increase the oxidation number of a valence of the one element by the alkylation with the use of the composition of the present invention as described above as a catalyst for the reaction. Moreover, it is preferable to convert a trivalent of the oxidation number of a valence to a pentavalent in the case that the element is arsenic or antimony, and it is preferable to convert a tetravalent of the oxidation number of a valence to a hexavalent in the case of selenium.

In the present invention, the detoxification of the harmful compound is carried out by alkylating the harmful compound. At this moment, the present invention may attain the detoxification by alkylating at least one bond of the one element contained in the above harmful compound.

Specifically, it is possible to alkylate at least one bond of the one element by carrying out the reaction with the use of the composition for the alkylation of the present invention as described above. As an alkyl group added to the one element, mention may be made of a methyl group, an ethyl group, a propyl group etc. In a viewpoint that it is possible to attain the detoxification more effectively, a methyl group is preferable as an alkyl group.

In the method of detoxifying the harmful compound according to the present invention, in a viewpoint of the safety for the living organism, the 50% of a lethal dose (LD₅₀) (an oral toxicity which render a 50% of the fatal dose in mouse) of the compound detoxified by the above alkylation is preferably greater or equal to 1000 mg/kg, more preferably greater or equal to 5000 mg/kg.

Furthermore, in the method of detoxifying the harmful compound according to the present invention, in a viewpoint of the safety for the living organism, the 50% of an inhibition of cell growth concentration (IC₅₀) of the compound detoxified by the above alkylation or arylation is preferably greater or equal to 1000 μM, more preferably greater or equal to 300 μM. The term “the 50% of an inhibition of cell growth concentration (IC₅₀)” used herein means a numerical value which gives a necessary concentration of certain substance in order to block or inhibit a 50% of the 100 cell proliferation with the use of the substance. It shows that the smaller the numerical value of IC₅₀, the larger the cytotoxicity. Moreover, IC₅₀ was calculated from a result of the examination of the cytotoxicity which gives a plasmid DNA damage under the condition at 37° C., for 24 hours.

At this moment, IC₅₀ of each arsenic compound is shown in table 1

TABLE 1

IC₅₀ value (μM)

Arsenic(III) compound

Arsenic(V) compound

Arsenious acid

10

Arsenic acid

100

MMA(III)

1

MMA(V)

>6000

DMA(III)

1

DMA(V)

3000

TMAO

>6000

Arseno sugar(III)

500

Arseno sugar(V)

>6000

24 h, 37° C.

From the table 1, it is revealed that arseno sugar(III) having a trivalent arsenic(III) has higher cytotoxicity than those of monomethylated arsenic (MMA) and dimethylated arsenic (DMA) having a pentavalent arsenic, but has lower cytotoxicity than those of monomethylated arsenic (MMA), dimethylated arsenic (DMA) having a trivalent, and arsenious acid. On the other hand, it is recognized that monomethylated arsenic (MMA), dimethylated arsenic (DMA) having a trivalent arsenic has higher cytotoxicity than that of arsenious acid (trivalent and pentavalen), but as a whole, the arsenic(V) compound having a pentavalent arsenic has higher safety for the living organism than that of the arsenic(III) compound having a trivalent arsenic in a viewpoint of the cytotoxicity.

Moreover, LD₅₀ of each arsenic compound is shown in table 2

TABLE 2

Chemical

species of the arsenic

LD₅₀ (mg/kg)

As(III)

Inorganic arsenic(III(valency))

4.5

As(V)

inorganic arsenic(V(valency))

14-18

MMA

monomethyl arsonic acid

1,800

DMA

dimethylarsinic acid

1,200

AC

arsenocholine

6,000

TMAO

trimethylarsineoxide

10,600

AB

arsenobetaine

10,000

Furthermore, in the method of detoxifying the harmful compound according to the present invention, a biological half-life of the compound detoxified by the above alkylation is preferably less or equal to 8 hours in a viewpoint of the safety for the living organism. In the method of detoxifying the harmful compound according to the present invention, it is preferable to convert the harmful compound to the dimethyl compound or the trimethyl compound by means of the methylation in a viewpoint that they are safer and has a lower toxicity. As the dimethyl compound mention may be made of dimethyl arsonyl ethanol (DMAE), dimethyl arsonyl acetate (DMAA), dimethylarsinic acid or arseno sugar. As the trimethyl compound mention may be made of arsenocholine, arsenobetaine, trimethyl arseno sugar or trimethyl arsine oxide.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method is characterized that the organic halide selected from the groups comprising a pesticide, a fire retardant, dioxin, PCB, DDT, trihalomethane, trichloroethyl and chloroform is detoxified by the dehalogenation of the organic halide in the presence of the composition according to the present invention as mentioned above.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, it is possible to detoxify the organic halide selected from the groups comprising a pesticide, a fire retardant, dioxin, PCB, DDT, trihalomethane, trichloroethyl and chloroform by the dehalogenation of the organic halide in the presence of the composition according to the present invention as mentioned above, and then to detoxify the harmful compound containing at least one element selected from the groups comprising arsenic, antimony and selenium by the alkylation thereof in the presence of cobalt complex obtained by the reaction.

That is, if an inherently harmful organic halide, such as a pesticide, a fire retardant, dioxin, PCB, DDT, trihalomethane, trichloroethyl and chloroform is reacted in the presence of the composition for the alkylation according to the invention, the dehalogenation of the organic halide comes about, whereas an organic cobalt complex is also came about by the reaction, as a result, an organic material in the organic cobalt complex may be one of the resource of the alkyl groups for the alkylation of the harmful heavy metal. In other words, it is possible to convert the harmful compound such as the inorganic arsenic to harmless substances, that is, the organic arsenic, with the use of the resource of the alkyl groups thus obtained.

Furthermore, in a preferred embodiment of the method of detoxifying the harmful compound according to the present invention, the method further comprises the step of exposing to the light in the presence of the reducing agent to reduce the cobalt complex. The exposure to the light makes it possible to convert the cobalt(II) complex to a cobalt(I) complex with an active oxidation state. The cobalt complex(I) has an advantageous effect that the organic halide compound is detoxified by the dehalogenation by reacting the complex with the harmful organic halide compound to be dehalogenated, whereas the organic material may be also obtained which may become the resource of the alkyl groups.

The reducing agent like this, is not particularly limited as long as it can make the cobalt complex active, but for example, mention may be made of at least one selected from the groups comprising titanium oxide and ruthenium complex.

Next, the explanation of the method of detoxifying the organic halide according to the present invention is as follows.

That is, the method of detoxifying the organic halide according to the present invention is characterized in that an organic halide selected from the groups comprising a pesticide, a fire. retardant, dioxin, PCB, DDT, trihalomethane, trichloroethyl and chloroform is detoxified by the dehalogenation of the organic halide in the presence of the composition according to the present invention as described above. In the case that the organic halide selected from the groups comprising a pesticide, a fire retardant, dioxin, PCB, DDT, trihalomethane, trichloroethyl and chloroform is some forms which can not be introduced into the reaction system, these materials may be used as appropriate forms (regardless of a liquid, a gas or a solid) capable of introducing them into the reaction system according to the conventional procedure such as an extraction, the separation and purification etc. According to the present method, cobalt complex in the composition of the present invention makes a contribution to the alkylation as well as the dehalogenation of the organic halide, and then makes it possible to attain the detoxification of the organic halide. As just described, the composition of the present invention is extremely valuable. As is the case with the method of detoxifying the harmful compound of the present invention as described above, the composition may be exposed to the light in the presence of the reducing agent to reduce the cobalt complex. The explanation of the method of detoxifying the harmful compound may be also directly applicable for an explanation about the reducing agent etc., used in the method of detoxifying the organic halide.

Moreover, FIG. 30 shows a mechanism concerning the methylation of arsenic trioxide in the case of vitamin B12 (methylcobalamin: CH₃-Cob(III)) as an example. In the FIG. 30, iAs(V), iAs(III), ATG, MADG and DMAG stand for pentavalent inorganic arsenic, trivalent inorganic arsenic, triglutathione arsenic complex, monomethyldiglutathione arsenic complex and dimethyl glutathione arsenic complex, respectively.

EXAMPLE

The present invention will be concretely explained in more detail with reference to Examples, but the invention is not intended to be interpreted as being limited to Examples.

At first, the explanation concerning the brevity code used in the Example is as follows:

<Brevity Code>

• iAs(III): Trivalent inorganic arsenic
• MMA: Monomethylated arsenic acid
• DMA: Dimethylated arsinic acid
• TMAO: Trimethylarsineoxide
• AB: Arsenobetaine (Trimethyl arsonium acetic acid)
• DMAA: Dimethyl arsonium acetic acid
• MeCo: Methylcobalamin
• GSH: Glutathione (Reduced form)
• iSe(IV): Inorganic selenium (Tetravalent)
• MIAA: Monoiodoacetic acid

Example 1

<Reacting Operation>

Into a 1.5 mL of Eppendorf tube 740 μL of a reaction buffer solution (20 mM Tris-HCl (pH7.6)) was added. To this was added 220 μL of 100 mM GSH aqueous solution, stirred for 30 seconds with Voltex, and then allowed at 37° C. for 30 minutes. To this was added 20 μL of 100 ppm inorganic arsenic (III) standard solution (for the atomic absorption) and stirred for 30 seconds. To this was added 20 μL of 7.4 mM methylcobalamin (MeCo) aqueous solution (composition A). This was reacted in a constant temperature bath maintained at 37° C., the increasing amount of the product obtained with sampling at regular intervals was examined.

<Analysis of the Product>

The qualitative and quantitative analysis was carried out by using the inductively-coupled plasma ion mass spectroscope (Agilent 7500 ce) directly connected to the high-performance liquid chromatography (Agilent 1100) online with the retention time of the standard sample compared with that of the reaction product.

Example 2

<Reacting Operation>

The experiment was carried out in the same manner as in Example 1, except that 20 μL of 1000 ppm inorganic Se (IV) standard solution (for the atomic absorption) was added to the composition A of Example 1 (Composition B).

Comparative Example 1

The experiment was carried out in the same manner as in Example 1, except for no addition of MeCo in Example 1 (Composition C). The table 3 shows a detoxification of the inorganic arsenic to MMA (Example 1) and DMA (Example 2).

TABLE 3

reaction

As (V)

As (III)

MMA

DMA

Total

time (h)

ppm

ppm

ppm

ppm

ppm

comparative exa.

77

0.002

1.073

—

—

1.074

example 1-1

2

0.002

1.242

0.002

—

1.246

example 1-2

7

0.003

1.048

0.005

—

1.056

example 1-3

24

2.102

0.022

—

—

2.124

example 2-1

2

0.002

1.073

0.001

—

1.075

example 2-2

7

0.001

0.333

0.007

—

0.341

example 2-3

24

1.684

0.037

—

0.006

1.727

As shown in Examples 1-2, methyl arsenic (MMA) was generated as time advances compared with the comparative example. It was confirmed that the methylation was further proceeded, as a result, dimethylated arsenic (DMA) was also generated in Example 2. The remarkable effects was confirmed that the harmful inorganic arsenic was detoxified by being converted it to methylated arsenic having a lower toxicity in the presence of MeCo.

Further, the methylation of selenium was also examined. FIG. 31 gives a HPLC-ICP-MS chromatogram of the methylation reaction of selenious acid [Se(IV)] by MC. In the Figure, A: standard sample, B: samples after the reaction, Se (IV): selenious acid and DMSe: dimethyl selenium, respectively.

As shown in FIG. 31, it was confirmed that selenious acid was converted to dimethyl selenium having a lower, toxicity.

Example 3

<Reacting Operation>

The experiment was carried out in the same manner as in Example 2, except that 20 μL of 1000 ppm MMA was added to the composition B of Example 2 (Composition D).

Comparative Example 2

The experiment was carried out in the same manner as in Example 3, except for no addition of MeCo in Example 3.

Example 4

<Reacting Operation>

The experiment was carried out in the same manner as in Example 2, except that 20 μL of 1000 ppm DMA was added to the composition B of Example 2 (Composition E).

Comparative Example 3

The experiment was carried out in the same manner as in Example 4, except for no addition of MeCo in Example 4. The table 4 shows a detoxification of MMA to DMA (Example 3) and a detoxification of DMA to TMAO (Example 4).

TABLE 4

reaction

time

As (V)

As (III)

MMA

DMA

TMAO

Total

(h)

(ppm)

(ppm)

(ppm)

(ppm)

(ppm)

(ppm)

comparative example 2

2

—

0.010

14.315

—

—

14.325

example 3-1

2

—

0.010

14.304

0.011

—

14.324

example 3-2

7

—

2.054

1.651

0.054

—

3.759

example 3-3

22

0.507

1.374

4.748

0.125

—

6.753

comparative example 3

2

—

0.006

0.007

9.014

—

9.028

example 4-1

2

—

0.006

0.007

9.008

0.006

9.028

example 4-2

7

—

0.029

0.009

2.243

0.019

2.300

example 4-3

22

0.879

0.297

—

5.104

0.020

6.300

As shown in Examples 3-1 to 3-3, the concentration of dimethyl arsenic (DMA) increased as time advances. The generation of DMA was not observed in the comparative example 2. As shown in Examples 4-1 to 4-3, the concentration of trimethyl arsenic (TMAO) increased, it was revealed that an arsenic substrate was converted to the most harmless trimethyl arsenic. The generation of trimethyl arsenic was not observed in the comparative example 3.

Example 5

<Reacting Operation>

The experiment was carried out in the same manner as in Example 2, except that 20 μL of 1000 ppm TMAO instead of inorganic arsenic was added to the composition B of Example 2 (Composition F).

Example 6

<Reacting Operation>

The experiment was carried out in the same manner as in Example 5, except for no addition of MeCo in the composition F of Example 5 (Composition G).

Example 7

<Reacting Operation>

The experiment was carried out in the same manner as in Example 5, except for the use of DMA instead of TMAO in the composition F of Example 5 (Composition H). Table 5 shows a conversion to arsenobetaine.

TABLE 5

reaction

DMA

DMAA

TMAO

AB

Total

time (h)

(ppm)

(ppm)

(ppm)

(ppm)

(ppm)

example 5-1

2

0.005

—

13.956

1.183

15.144

example 5-2

8

0.004

—

8.889

1.655

10.548

example 5-3

22

0.005

—

8.716

1.680

10.401

example 6-1

2

0.004

—

18.536

1.698

20.238

example 6-2

8

0.007

—

17.814

2.530

20.351

example 6-3

22

0.007

—

16.881

2.438

19.326

example 6-4

94

0.013

—

17.424

2.607

20.044

example 7-1

2

12.771

0.015

0.012

—

12.798

example 7-2

22

17.141

0.434

0.018

0.007

18.200

example 7-3

94

10.847

0.230

0.015

0.017

11.109

As shown in Example 5, the conversion of TMAO which is one of the arsenic substrate to AB under the presence of both MeCo and MIAA was confirmed. As shown in Example 6, the conversion of TMAO to AB under the presence of only MIAA was confirmed too. As shown in Example 7, the conversion of DMA which is one of the arsenic substrate to AB under the presence of both MeCo and MIAA was confirmed.

Example 8

At first, the explanation concerning the brevity code used in the following Example is as follows:

<Brevity Code>

• iAs(III): Trivalent inorganic arsenic
• MMA: Monomethylated arsenic acid
• DMA: Dimethylated arsinic acid
• TMAO: Trimethylarsineoxide
• AB: Arsenobetaine (trimethyl arsonium acetic acid)
• DMAA: Dimethyl arsonium acetic acid
• MeCo: Methylcobalamin
• GSH: Glutathione (reduced form)
• MIAA: Monoiodoacetic acid
• AS: Arseno sugar
• iSe(IV): Inorganic selenium (tetravalent)

  
  
  

  (1) Culture of the Microalgae

The microalgae, chlorella (Chlorella vulgaris IAM C-629 strain) cultivated in advance until a logarithmic growth phase was inoculated so as to obtain a 1×10⁶ cells/mL in 150 mL Bold's Basal (BB) medium and was cultured with static culture method under exposure to the fluorescent light (4000 Lux, 24 hr illumination), at 25° C. In this case, a culture medium was prepared by adding 10 mM of glucose or 10 mM of sodium acetate as a carbon source to the culture.

(2) Accumulation Test of the Arsenic

The accumulation test of the arsenic was carried out by adding arsenous acid to the culture medium to obtain 1 ppm as a metal arsenic after the inoculation, and then culturing the microalgae for 284 hours after the addition of arsenic.

(3) Measurement of the Content of Arsenic

The qualitative and quantitative analysis concerning inorganic arsenic and organic arsenic contained in alga body was carried out by using the inductively-coupled plasma ion mass spectroscope (Agilent 7500 ce) directly connected to the high-performance liquid chromatography (Agilent 1100) online with the retention time of the standard sample compared with that of the reaction product.

(4) Condition of the Analysis

As the standard sample of the organic arsenic compound, MMA, DMA, TMAO, TeMA, AB and AC which are commercially available reagent from Optronics Co., Ltd. (Trichemical research institution) and as the standard sample of the inorganic arsenic compound, sodium salt of As(III), As(V) which are commercially available high quality reagent from Wako Pure Chemical Industries, Ltd., were used. The standard solution of 100 mg/100 mL of each arsenic compound was prepared by diluting it with an ultrapure water (Millipore).

<Condition of ICP-MS Apparatus>

• RF forward power: 1.6 kW
• RF reflect power: <1 W
• Carrier gas flow: Ar 0.75 L/min
• Sampling 8.5 mm
• Monitoring mass: m/z=75 and 35 internal standard m/Z=71
• Dwell time: 0.5 sec 0.01 sec 0.1 sec
• Times of scan: 1 time

  
  
  

  <Condition of H P L C>

  
  
  

  Eluent: 5 mM nitric acid/6 mM ammonium nitrate/1.5 mM pyridine dicarboxylic acid

• Flow rate of eluent: 0.4 mL/min.
• Injection volume: 20 μL
• Column: Cation-exchange column Shodex RSpak N,N-414 (150 mm×4.6 mm i.d.)
• Column temperature: 40° C.

<Extraction of the Arsenic Compound from the Microalgae in which Arsenic is Accumulated>

A microalgae extract (wherein chlorella is treated to extract it with methanol, and then methanol is removed by the evaporation) was prepared. To this added a purified water to dilute it and to obtain a solution having a concentration described in the following table 6. Moreover, the component of an UN (Unknown) 1 and UN6 was belonged as a compound corresponding to arseno sugar (FIG. 1). FIG. 1 gives a HPLC-ICP-MS analysis of a chlorella extract (Upper: standard sample, Lower: sample). Table 6 shows a concentration (ppm) of arsenic compound of the chlorella extract.

TABLE 6

As (V)

As (III)

MMA

DMA

UN1

UN6

total

2.65

0.175

0.62

0.035

1.14

1.22

5.83

<Conversion to AB>

Into an Eppendorf tube with 1.5 mL volume 740 μL of a reaction buffer solution (20 mM Tris-HCl (pH7.6)) was added. To this was added 220 μL of 20 mM GSH aqueous solution, stirred with Voltex for 30 seconds, and then allowed at 37° C. for 30 minutes. To this was added 100 μL of the chlorella extract and stirred for 30 seconds. To this was added 135 μL of 7.4 mM methylcobalamin (MeCo) aqueous solution. To this was added 68 mg of MIAA (0.35 μM) to dissolve them. This was reacted in a constant temperature bath maintained at 37° C., the increasing amount of the product obtained with sampling at regular intervals was examined. As shown in FIG. 2, the generation of AB could be confirmed in the case that GSH, MeCo and MIAA are existed. FIG. 2 gives a HPLC-ICP-MS analysis of a chlorella extract (Upper: standard sample, Middle: GSH addition (NE 14-7), Lower: MeCo+GSH+MIAA addition (NE 15-7)).

Example 9

<Conversion of Arseno Sugar to DMA>

100 μL of the chlorella extract was mixed with 4N of NaOH aqueous solution (1 mL), and allowed at 80° C. overnight. The conversion of arseno sugar to DMA was confirmed since DMA was generated(FIG. 3).

<Conversion of DMA to AB>

The experiment was carried out in the same manner as in Examples 1-7. FIG. 3 shows a condition in the case that GSH (NE 14-4), GSH+MeCo+MIAA (NE 15-4) are added to the chlorella extract, respectively, and NaOH treatment (lower) are subject to the chlorella extract. Furthermore, FIG. 4 shows a condition in the case that GSH+MeCo +MIAA are added to DMA (NE 9-4).

Example 10

Further, the experiment was carried out by using methylcobalamin as a cobalt complex. At first, into a 1.5 mL of Eppendorf tube 10 mg of methylcobalamin (Wako Pure Chemical Industries, Ltd.) was added. To this was added 1 mL of an ultrapure water (18 MΩ/cm) to dissolve methylcobalamin (7.4 mmol/L) (Solution A). Into a 1.5 mL of Eppendorf tube 30.7 mg of glutathione (reduced form) was added to dissolve it with 1 mL of the ultrapure water (100 mmol/L) (Solution B). Arsenous acid aqueous solution (for an atomic absorption: 100 ppm: as metal arsenic) was prepared (Solution C). Selenious acid aqueous solution (for an atomic absorption: 1000 ppm: as metal selenium) was prepared (Solution D). 100 mmol/L of Tris-HCl buffer solution (pH 7.8, 0.01 mol/L, pH was adjusted by using hydrochloric acid solution) was prepared (Solution E). Into a 1.5 mL of Eppendorf tube 720 μL of the solution E, 20 μL of the solution C, 220 μL of the solution B were added respectively, and allowed at 37° C. for 1 hour. To this were added 20 μL of the solution A and 20 μL of the solution D, and then reacted in a constant temperature bath maintained at 37° C. The condition of the reaction is as follows:

<Condition of the Reaction>

• Concentration of the substrate: [As]=30 μmmol/L
• Concentration of native vitamin B12 (methylcobalamin): [MeCo]=150 μmol/L
• Concentration of glutathione (reduced form): [GSH]=22 mmol/L
• Concentration of selenium: [Se]=760 μmol/L
• Buffer solution: 100 mMTris-HCl buffer solution (pH7.8), reaction temperature: 37° C., reaction solution: pH 3

A qualitative and quantitative analysis was carried out by using a HPLC-ICP-MS method at regular time intervals with sampling 50 mL to dilute it by ten times with the ultrapure water (No. 1-8 of the table 7).

TABLE 7

Time

Concentration (μmol/L)

No.

(hr)

As (V)

MMA

MMA (III)

As (III)

DMA

Total

1

0.5

0.173

0.000

0.000

26.120

0.000

1.972

2

1

0.163

1.171

0.213

23.799

0.075

1.907

3

2

0.152

2.305

0.440

22.651

0.109

1.924

4

4

0.156

2.900

0.915

21.545

0.129

1.923

5

21

0.361

4.383

0.588

19.311

0.153

1.860

6

48

0.712

4.869

0.000

17.565

0.187

1.750

7

72

0.605

3.621

0.000

12.469

0.160

1.264

8

360

2.481

6.659

0.000

19.316

0.860

2.199

9

21

13.609

6.973

0.000

0.000

0.165

1.556

10

48

13.333

6.741

0.000

0.000

0.224

1.522

11

12

9.477

4.099

0.000

0.000

0.176

1.031

12

360

19.261

8.264

0.000

0.000

0.873

2.130

FIG. 7 shows a variation per hour of the concentration of the arsenic compound in the reaction solution (which is in graph form of the result of the table 7). Moreover, with sampling 50 μL from the reaction solution to obtain a sample, and the obtained sample was treated with 50 mL of hydrogen peroxide solution (37° C., 1 hour) to dilute it by ten times with the ultrapure water so that the reaction product could be analyzed in a similar way (No. 9-11 of the table 7). FIGS. 5 and 6 give a HPLC-ICP-MS chromatogram.

Example 11

The experiment was carried out in the same manner as in Example 10, except that the solution B was adjusted to a pH 7 in 100 mM Tris-HCl buffer solution in Example 10.

The table 8 and FIGS. 8-17 show the results. Approximately 50% of arsenous acid was methylated. The table 8 shows the concentration of the arsenic compound in the reaction solution.

TABLE 8

Concentration (μmol/L)

Time

MMA

No.

(hr)

As (V)

MMA (V)

(III)

As (III)

DMA (V)

Total

1

0.5

0.00

0.00

0.01

15.46

0.00

15.47

2

1

0.00

0.03

0.66

17.09

0.00

17.77

3

2

0.00

0.18

1.91

15.29

0.12

17.50

4

3

0.00

0.22

3.45

13.40

0.16

17.22

5

4

0.02

0.45

5.10

11.28

0.19

17.04

6

24

0.20

4.44

2.09

9.40

0.25

16.38

7

96

0.25

9.07

0.55

13.63

0.21

23.71

8

0.5

14.46

0.00

0.00

0.12

0.00

14.57

9

1

9.84

4.63

0.00

0.01

0.08

14.56

10

2

7.03

6.27

0.00

0.00

0.18

13.48

11

3

6.66

7.04

0.00

0.00

0.21

13.91

12

4

6.08

7.70

0.00

0.00

0.23

14.00

13

24

6.20

7.83

0.00

0.00

0.26

14.29

14

96

9.73

11.39

0.00

0.15

0.23

21.50

*No. 1-7: before H₂O₂ treatment.

**No. 8-14: after H₂O₂ treatment.

As it is clear from the table 8, it was revealed that it is possible to render them harmless by means of converting As(III) into As(V) with a high oxidation number, that is, increasing an oxidation number, by using H₂O₂ treatment.

Example 12

The experiment was carried out in the same manner as in Example 10, except that it was carried out under the condition that a pH of the reaction solution after preparation was a value shown in table 9.

The table 9 and FIGS. 18-29 show the results. Approximately 50% of arsenous acid in the case of a pH 6.7 was methylated. On the other hand, in the case of a pH 9, the methylation was not progressed. The table 9 shows the concentration of the arsenic compound in the reaction solution.

TABLE 9

Time

H₂O₂

Concentration (μmol/L)

No.

pH

(hr)

treatment

As (V)

MMA (V)

MMA (III)

As (III)

DMA (V)

UN6

TMAO

Total

1

4.3

1

before

1.0

1.0

0.0

22.8

0.0

0.0

0.0

24.9

2

4.3

2

before

1.0

1.6

0.8

21.3

0.9

1.0

0.0

26.6

3

4.3

4

before

1.0

2.2

1.1

20.1

1.0

1.0

0.0

26.4

4

4.3

24

before

1.1

3.3

1.5

13.6

1.0

0.9

0.0

21.4

5

4.3

1

after

17.8

0.0

0.0

0.0

0.0

0.0

0.0

17.8

6

4.3

2

after

17.7

1.1

0.0

0.0

0.9

0.0

0.0

19.7

7

4.3

4

after

12.7

5.3

0.0

0.0

1.0

0.0

0.0

18.9

8

4.3

24

after

8.9

6.3

0.0

0.0

1.0

0.0

0.0

16.2

9

6.7

1

before

1.6

1.8

0.6

21.4

0.0

0.0

0.0

25.3

10

6.7

2

before

1.5

4.0

0.6

18.5

0.9

0.0

0.0

25.4

11

6.7

4

before

1.3

6.3

0.6

15.2

1.0

0.0

0.0

24.5

12

6.7

24

before

1.3

5.1

1.4

11.1

1.0

0.0

0.0

19.9

13

6.7

1

after

18.1

0.0

0.0

0.0

0.0

0.0

0.0

18.1

14

6.7

2

after

12.9

5.3

0.0

0.0

0.9

0.0

0.0

19.1

15

6.7

4

after

10.1

8.1

0.0

0.0

1.0

0.0

0.0

19.3

16

6.7

24

after

8.2

6.8

0.0

0.0

1.0

0.0

0.0

16.0

17

9

1

before

8.2

0.0

0.0

12.9

0.0

1.0

0.0

22.1

18

9

2

before

10.0

0.0

0.0

10.8

0.0

1.0

0.0

21.9

19

9

4

before

10.9

0.0

0.0

9.6

0.0

1.1

0.0

21.6

20

9

24

before

13.0

0.0

0.0

1.8

0.0

0.0

0.0

14.9

21

9

1

after

18.3

0.0

0.0

0.0

0.0

0.0

0.0

18.3

22

9

2

after

18.0

0.0

0.0

0.0

0.0

0.0

0.0

18.0

23

9

4

after

18.1

0.0

0.0

0.0

0.0

0.0

0.0

18.1

24

9

24

after

14.4

0.0

0.0

0.0

0.0

0.0

0.0

14.4

Example 13

Next, the synthesis of [Cob(II)]ClO₄ from cyanocobalamin was attempted.

1. Oxidation-Reduction of the Cobalt Complex, and the Reaction of the Methylation

(1) The Synthesis of [Cob(II)]ClO₄ from Cyanocobalamin

<Reaction Scheme 1>

<Experiment Procedure>

50 mg of cyanocobalamin (which is Cob(III) shown in the above [chemical 1]) is dissolved in 100 mL of methanol, and then it is deaerated by a nitrogen bubbling. To this is added 400 mg of NaBH₄ (1.05 mol) to confirm a green color originated from Co(I). To this is added 3 mL of 60% HClO_4aq. To this is added 50 mL of water to extract with methylene chloride. After washed it with water, it is dried with anhydrous sodium sulfate so that it might be solidified under reduced pressure. This is re-precipitated with benzene/n-hexane to obtain a powder with an orange color.

(2) Reduction of [Cob(II)] to [Cob(I)]

<Reaction Scheme 2>

<Experiment Procedure>

30 mg of [Cob(II)]ClO₄ is dissolved in 100 mL of methanol, and then it is deaerated by a nitrogen bubbling. To this is added 300 mg of NaBH₄ (0.788 mol) to confirm a green color originated from Co(I). It is recognized that in a viewpoint of the reaction of Cob(II) to Cob(I) shown in reaction scheme 2 [Chemical 2], the cobalt(III) complex existing in the composition for the alkylation of the present invention may convert to cobalt(II) complex, thereby cobalt(II) complex thus obtained is reduced by a photocatalyst or a chemical reducing agent as described in the following Example 14 to obtain a cobalt(I) complex. The cobalt (I) complex may be utilized as the substrate of the reaction of the dehalogenation. That is to say, it is possible to detoxify the organic halide compound by using the cobalt (I) complex thus obtained.

Example 14

Next, the synthesis of [MeCob(II)] by reacting [Cob(I)] with CH₃I (the reaction of the dehalogenation of the halide) was examined.

(3) The Synthesis of [MeCob(II)] by Reacting [Cob(I)] with CH₃I (the Reaction of the Dehalogenation of the Halide)

<Reaction Scheme 3>

37 mg of CH₃I (2.6×10⁻⁴ mol) is added under the dark place, and stirred for 5 minutes. In this manner, the reaction of the dehalogenation is caused by the cobalt complex and the organic halide compound. That is, not only the organic halide compound which has been a harmful compound is detoxified by the dehalogenation, but the obtained cobalt (III) complex may become a preferable substrate to detoxify the harmful compound such as arsenic by the methylation.

(4) The Synthesis of [MeCob(III)] from [MeCob(II)]

<Reaction Scheme 4>

<Experiment Procedure>

2 mL of 60% HCl_4aq is added to the Cob(II). To this is added 50 mL of water to be extracted with methylene chloride. After washed them with water, they are dried with anhydrous sodium sulfate so as to be solidified under reduced pressure. They are re-precipitated with benzene/n-hexane to obtain a powder with an orange color, that is, methylcobalamin.

In this manner, it is possible to detoxify the organic halide compound or the harmful compound such as arsenic by utilizing the oxidation state of the cobalt complex existing in the composition for the alkylation of the present invention. In other words, it is also possible to detoxify the harmful compound by the methylation through the reaction of the cobalt (III) complex with the harmful compound (which contains arsenic etc.) with the use of the cobalt (III) complex obtained by the dehalogenation reaction of the organic halide compound with cobalt (I) complex.

On the other hand, if the generated cobalt (II) complex is reduced through any reaction, a cobalt (I) complex may be obtained, thereby the use of the cobalt complex thus obtained making it possible to detoxify the organic halide compound again.

Example 15

Next, under given conditions, with the use of GSH and methylcobalamin, the most efficient case capable of converting to TMAO was examined.

At first, into a 0.2 mL of Eppendorf tube GSH (60 mg, 0.195 mmol), 10 mg of methylcobalamin (MC) (7.44 μmol), Tris-HCl buffer solution (pH 8, 50 μL) were added. To this was added 2 mL of arsenic standard solution (for an atomic absorption: 100 ppm as arsenic), thereby set on an aluminium block heater heated at 125° C. to react them for predetermined time. The product of a reaction was diluted with 10% of hydrogen peroxide solution by 10-30 folds so that the product might be analyzed by the HPLC-ICP-MS. The result of this is shown in tables 10 and 11.

TABLE 10

concentration

GSH

MC

reaction temp.

reaction time

(ppm)

Sample

(mg)

(mg)

pH

(° C.)

(h)

As (III)

As (V)

MMA

DMA

TMAO

TeMA

Total

MC111-1p

10

5

8

125

2

0.00

0.00

0.00

0.00

0.54

0.05

0.59

MC112-1p

20

5

8

125

2

0.00

0.00

0.00

0.02

0.50

0.00

0.52

MC113-1p

30

5

8

125

2

0.00

0.00

0.00

0.02

0.43

0.00

0.46

MC114-1p

20

10

8

125

2

0.00

0.00

0.00

0.00

1.79

0.04

1.83

MC115-1p

40

10

8

125

2

0.00

0.00

0.00

0.00

1.56

0.01

1.57

MC116-1p

60

10

8

125

2

0.00

0.00

0.00

0.03

1.73

0.00

1.77

MC117-1p

20

10

8

100

2

0.00

0.03

0.09

0.02

2.83

0.00

2.97

MC118-1p

40

10

8

100

2

0.00

0.00

0.00

0.00

0.00

0.00

0.00

MC119-1p

60

10

8

100

2

0.00

0.00

0.29

0.38

5.14

0.02

5.83

MC120-1p

0

10

8

125

2

0.06

1.27

0.36

0.04

0.13

1.59

3.46

MC117-2p

10

10

8

100

over night

0.00

0.03

0.01

0.00

3.35

0.00

3.39

MC118-2p

20

10

8

100

over night

0.00

0.00

0.00

0.00

0.00

0.00

0.00

MC119-2p

30

10

8

100

over night

0.00

0.00

0.02

0.07

2.68

0.00

2.78

TABLE 11

Sample

GSH (mg)

MC (mg)

pH

reaction temp. (° C.)

reaction time (h)

As (III)

As (V)

MMA

DMA

TMAO

TeMA

Total

MC111-1p

10

5

8

125

2

0.0

0.0

0.0

0.0

91.1

8.9

100

MC112-1p

20

5

8

125

2

0.0

0.0

0.0

3.6

96.4

0.0

100

MC113-1p

30

5

8

125

2

0.0

0.0

0.0

5.1

94.9

0.0

100

MC114-1p

20

10

8

125

2

0.0

0.0

0.0

0.0

97.8

2.2

100

MC115-1p

40

10

8

125

2

0.0

0.0

0.0

0.1

99.2

0.7

100

MC116-1p

60

10

8

125

2

0.0

0.0

0.0

1.9

98.1

0.0

100

MC117-1p

20

10

8

100

2

0.0

1.0

3.0

0.6

95.4

0.0

100

MC119-1p

60

10

8

100

2

0.0

0.0

5.0

6.6

88.2

0.3

100

MC120-1p

0

10

8

125

2

1.7

36.9

10.3

1.2

3.9

46.1

100

MC117-2p

10

10

8

100

over night

0.0

0.8

0.3

0.0

98.9

0.0

100

MC119-2p

30

10

8

100

over night

0.0

0.0

0.9

2.6

96.5

0.0

100

The tables 10 and 11 show a result of the HPLC-ICP-MS analysis in the case that the concentration of GSH, the concentration of arsenic and temperature etc., are changed. The table 10 is expressed in the concentration, and the table 11 is expressed in the percentage.

As a result, under the condition of the present Example, it is revealed that MC115 of the table 10 and 11 is the best data which makes it possible to convert the harmful compound into approximately 100% of TMAO by using GSH.

Example 16

Next, the effect was examined with the use of cysteine (Cys) instead of GSH. At first, into a 0.2 mL of Eppendorf tube, cysteine (20 mg, 0.165 mmol) as the reducing agent instead of GSH, methylcobalamin (MC) (20 mg, 14.9 μmol.), phosphate buffer solution (pH 6, 100 μL) were added. To this was added 4 μL of arsenic standard solution (for an atomic absorption: 100 ppm as arsenic), thereby set on an aluminium block heater heated at 110° C. to react them for predetermined time. The product of a reaction was diluted with 10% of hydrogen peroxide solution by 10-30 folds so that the product might be analyzed by the HPLC-ICP-MS. The result of this is shown in table 12.

TABLE 12

reaction conditions

reaction

reaction

content of the arsenic

TMAO

Cys

MC

Buffer

temperature

time

compound (ng As/mL)

ratio

Sample

(mg)

(mg)

pH

(mL)

(° C.)

(h)

As (V)

MMA

DMA

TMAO

TeMA

Total

(g)

MC151-1p

30

20

8

0.1

120

1.5

4.5

9.3

6.9

33.9

0.0

54.6

62.1

MC152-1p

20

20

8

0.1

120

1.5

0.3

2.7

1.2

3.9

0.9

9.0

43.3

MC153-1p

10

20

8

0.1

120

1.5

13.2

5.1

5.4

25.2

5.1

54.0

46.7

MC154-1p

30

20

8

0.1

110

1.5

5.4

10.5

7.8

55.5

8.1

87.3

63.6

MC155-1p

20

20

8

0.1

110

1.5

2.1

4.5

4.5

20.1

4.5

35.7

56.3

MC156-1p

10

20

8

0.1

110

1.5

2.4

0.0

0.0

0.0

0.0

2.4

0.0

MC157-1p

20

20

6

0.1

110

1.5

2.7

3.3

0.0

26.1

3.6

35.7

73.1

MC158-1p

20

20

7

0.1

110

1.5

1.5

5.7

6.0

15.9

3.3

32.4

49.1

MC159-1p

20

20

8

0.1

110

1.5

3.0

12.9

12.3

27.6

3.3

59.1

46.7

MC160-1p

0

20

8

0.1

110

1.5

115.5

0.0

0.0

0.0

0.0

115.5

0.0

MC151-2p

30

20

8

0.1

120

14

16.8

29.4

26.4

132.6

5.7

210.9

62.9

MC152-2p

20

20

8

0.1

120

14

15.3

12.9

26.7

180.3

17.4

252.6

71.4

MC153-2p

10

20

8

0.1

120

14

13.2

8.7

34.5

173.1

21.6

251.1

68.9

MC154-2p

30

20

8

0.1

110

14

6.6

16.8

15.0

130.5

8.4

177.3

73.6

MC155-2p

20

20

8

0.1

110

14

10.2

13.2

18.9

192.3

22.2

256.8

74.9

MC156-2p

10

20

8

0.1

110

14

17.1

0.0

14.4

186.9

21.0

239.4

78.1

MC157-2p

20

20

6

0.1

110

14

8.4

10.8

12.6

261.6

19.2

312.6

83.7

MC158-2p

20

20

7

0.1

110

14

7.8

9.9

18.3

192.9

15.3

244.2

79.0

MC159-2p

20

20

8

0.1

110

14

13.2

19.8

62.1

223.8

14.1

333.0

67.2

MC160-2p

0

20

8

0.1

110

14

431.4

0.0

0.0

5.1

23.1

459.6

1.1

MC151-3p

30

20

8

0.1

120

26

14.4

0.0

78.0

129.6

0.0

222.0

58.4

MC152-3p

20

20

8

0.1

120

26

90.3

45.3

371.7

1883.7

120.9

2511.9

75.0

MC153-3p

10

20

8

0.1

120

26

171.3

96.0

391.2

1985.7

195.3

2839.5

69.9

MC154-3p

30

20

8

0.1

110

26

0.0

0.0

72.3

295.2

0.0

367.5

80.3

MC155-3p

20

20

8

0.1

110

26

72.9

0.0

155.1

1089.0

1.8

1318.8

82.6

MC156-3p

10

20

8

0.1

110

26

52.2

27.6

84.9

1118.1

65.1

1347.9

83.0

MC157-3p

20

20

6

0.1

110

26

0.0

21.0

50.7

497.7

0.0

569.4

87.4

MC158-3p

20

20

7

0.1

110

26

3.9

13.5

169.8

1140.0

85.8

1413.0

80.7

MC159-3p

20

20

8

0.1

110

26

13.8

35.1

366.6

1066.2

14.4

1496.1

71.3

MC160-3p

0

20

8

0.1

110

26

1587.0

0.0

0.0

0.0

4.5

1591.5

0.0

The table 12 shows a result of the HPLC-ICP-MS analysis in the case that the concentration of cysteine, the concentration of arsenic and temperature etc., are changed. It is revealed that an excellent result is produced in the same as GSH even if cysteine instead of GSH is used. Especially, if the ratio of TMAO is noted, MC157-3p of the table 12 has an excellent result.

Example 17

Next, the effect was also examined with the use of homocysteine instead of GSH. At first, into a 0.2 mL of Eppendorf tube, homocysteine (HCys) (5 mg, 16.3 μmol.) as the reducing agent instead of GSH, methylcobalamin (MC) (20 mg, 14.9 μmol.), phosphate buffer solution (pH 6, 100 μL) were added. To this was added 4 μL of an arsenic standard solution (for an atomic absorption: 100 ppm as arsenic), thereby set on an aluminium block heater heated at 120° C. to react them for predetermined time. The product of a reaction was diluted with 10% of hydrogen peroxide solution by 10-30 folds so that the product might be analyzed by the HPLC-ICP-MS. The result of this is shown in table 13.

TABLE 13

reaction conditions

content of the arsenic compound (ng As/mL)

TMAO

HCys

MC

Buffer

reaction temp.

reaction time

As

ratio

Sample

(mg)

(mg)

pH

(mL)

(° C.)

(h)

(V)

MMA

DMA

TMAO

TeMA

Total

(%)

MC161-1p

10

20

8

0.1

120

1.5

27.3

20.1

6.6

78.9

11.1

132.9

59

MC162-1p

7.5

20

8

0.1

120

1.5

13.2

8.4

4.2

73.8

16.5

99.6

74

MC163-1p

5

20

8

0.1

120

1.5

19.2

8.7

7.5

142.8

61.8

178.2

80

MC164-1p

10

20

8

0.1

110

1.5

17.7

13.8

4.5

78.3

8.1

114.3

69

MC165-1p

7.5

20

8

0.1

110

1.5

28.2

13.8

8.4

86.7

12.6

137.1

63

MC166-1p

5

20

8

0.1

110

1.5

23.7

9.9

7.2

112.8

27.9

153.6

73

MC167-1p

7.5

20

6

0.1

110

1.5

46.5

21.3

8.1

110.4

20.1

186.3

59

MC168-1p

7.5

20

7

0.1

110

1.5

16.5

9.0

6.3

80.4

20.7

112.2

72

MC169-1p

7.5

20

8

0.1

110

1.5

22.2

9.0

10.8

68.4

16.5

110.4

62

MC170-1p

0

20

8

0.1

110

1.5

367.2

0.0

0.0

0.0

0.0

367.2

0

MC161-2p

10

20

8

0.1

120

14

9.6

7.2

22.5

203.1

18.3

242.4

84

MC162-2p

7.5

20

8

0.1

120

14

14.7

16.2

18.6

298.5

51.3

348.0

86

MC163-2p

5

20

8

0.1

120

14

10.8

9.0

13.2

227.7

99.0

260.7

87

MC164-2p

10

20

8

0.1

110

14

12.3

7.5

16.8

191.1

17.4

227.7

84

MC165-2p

7.5

20

8

0.1

110

14

36.6

24.6

23.7

264.3

23.1

349.2

76

MC166-2p

5

20

8

0.1

110

14

18.3

18.6

19.8

328.5

60.3

385.2

85

MC167-2p

7.5

20

6

0.1

110

14

21.3

10.5

13.8

222.6

23.4

268.2

83

MC168-2p

7.5

20

7

0.1

110

14

15.3

11.7

20.1

248.4

23.7

295.5

84

MC169-2p

7.5

20

8

0.1

110

14

12.6

8.7

18.3

141.0

12.6

180.6

78

MC170-2p

0

20

8

0.1

110

14

214.2

0.0

0.0

0.0

6.6

214.2

0

MC161-3p

10

20

8

0.1

120

26

146.1

124.8

138.0

1245.3

84.3

1654.2

75

MC162-3p

7.5

20

8

0.1

120

26

183.9

123.0

107.4

1655.1

205.3

2059.4

80

MC163-3p

5

20

8

0.1

120

26

82.2

51.6

50.1

940.2

343.2

1124.1

84

MC164-3p

10

20

8

0.1

110

26

385.8

201.6

104.1

1437.3

36.0

2128.8

68

MC165-3p

7.5

20

8

0.1

110

26

264.0

121.2

88.8

1056.6

14.4

1530.6

69

MC166-3p

5

20

8

0.1

110

26

69.0

79.2

50.7

1035.9

135.9

1234.8

84

MC167-3p

7.5

20

6

0.1

110

26

126.6

90.0

58.5

1204.5

65.4

1479.6

81

MC168-3p

7.5

20

7

0.1

110

26

170.4

87.0

94.2

1163.4

51.0

1515.0

77

MC169-3p

7.5

20

8

0.1

110

26

104.1

84.3

126.0

1110.9

42.3

1425.3

78

MC170-3p

0

20

8

0.1

110

26

2700.3

0.0

0.0

0.0

0.0

2700.3

0

The table 13 shows a result of the HPLC-ICP-MS analysis in the case that the concentration of homocysteine, the concentration of arsenic and temperature etc., are changed. It is revealed that an excellent result is obtained in the same as GSH even if homocysteine instead of GSH is used. Especially, if the ratio of TMAO is noted, MC163-2p of the table 13 has an excellent result.

Example 18

Next, the effect was also examined with the use of thioglycol in addition to GSH. That is, the effect in the case of the addition of a high boiling point solvent was examined. Specifically, thioglycol (TG, HSCH₂CH₂OH, boiling point: 157° C.) with the SH group and dimethyl sulfoxide (DMSO, (CH₃)₂SO, boiling point: 189° C.) with no SH group were used.

At first, into a 0.2 mL of Eppendorf tube, GSH (4 mg, 13 μmol.) as the reducing agent, methylcobalamin (MC) (1 mg, 0.74 μmol.), TG (5 μL), Tris-HCl buffer solution (pH 8, 5 μL) were added. To this was added 2 μL of an arsenic standard solution (10 ppm as arsenic), thereby set on an aluminium block heater heated at 120° C. to react them for predetermined time. The product of a reaction was diluted with 10% of hydrogen peroxide solution by 10-30 times so that the product might be analyzed by the HPLC-ICP-MS (the explanation of MC179 etc., of the tables 14 and 15).

Moreover, concerning MC180 of tables 14 and 15, into a 0.2 mL of Eppendorf tube, GSH (4 mg, 13 μmol.) as the reducing agent, methylcobalamin (MC) (1 mg, 0.74 μmol.), DMSO (5 mL), Tris-HCl buffer solution (pH 8, 5 μL) were added. To this was added 2 mL of the arsenic standard solution (10 ppm as arsenic), thereby set on an aluminium block heater heated at 120° C. to react them for predetermined time. The product of a reaction was diluted with 10% of hydrogen peroxide solution by 10-30 folds so that the product might be analyzed by the HPLC-ICP-MS. The results of these are shown in tables 14 and 15.

TABLE 14

conditions of the recation

content of the arsenic compound (mg As/L)

GSH

MC

Buffer

TG

DMSO

reaction

reaction

As

As

Sample

(mg)

(mg)

(μL)

(μL)

(μL)

time (h)

temp. (° C.)

UN

(III)

(V)

MMA

DMA

TMAO

TeMA

Total

MC179

4

1

5

5

0

2

120

0.084

0.010

0.000

0.982

0.452

0.171

0.027

1.725

MC180

4

1

5

0

5

2

120

0.572

0.000

0.000

0.969

0.117

0.083

0.000

1.740

TABLE 15

onditions of the reaction

ratio of the arsenic compound (%)

GSH

MC

Buffer

TG

DMSO

reaction

reaction

As

As

Sample

(mg)

(mg)

(μL)

(μL)

(μL)

time (h)

temp. (° C.)

UN

(III)

(V)

MMA

DMA

TMAO

TeMA

Total

MC179

4

1

5

5

0

2

120

4.9

0.6

0.0

56.9

26.2

9.9

1.5

100.0

MC180

4

1

5

0

5

2

120

32.9

0.0

0.0

55.7

6.7

4.8

0.0

100.0

The tables 14 and 15 show a result of the HPLC-ICP-MS analysis in the case of the use of TG, DMSO in addition to GSH (in tables 14 and 15, GSH: glutathione (reduced form), MC: methylcobalamin, TG: thioglycol, DMSO: dimethyl sulfoxide.). The table 14 is those expressed in the concentration, and the table 15 is those expressed in the percentage. It is revealed that an excellent result can be obtained in the same as the case of the use of GSH by itself, even if in the case that TG and DMSO are used.

Example 19

Next, the effect was further examined with the use of Cysteine (Cys) as the reducing agent in the same manner as the above example. The table 16 shows a methylation reaction (Acid condition) (Reacting substance) of arsenic trioxide [iAs (III)] by MC.

TABLE 16

reactant

solvent

ration of stoichiometry