Dimethylthioarsenicals as Arsenic Metabolites and Their Chemical Preparations

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• 作者：Kazuo T. Suzuki ; Badal K. Mandal ; Akio Katagiri ; Yoko Sakuma ; Ayumi Kawakami ; Yasumitsu Ogra ; Kentaro Yamaguchi ; Yoshihisa Sei ; Kenzo Yamanaka ; Kazunori Anzai ; Masayoshi Ohmichi ; Hiromitsu Takayama ; a
• 刊名：Chemical Research in Toxicology
• 出版年：2004
• 出版时间：July 2004
• 年：2004
• 卷：17
• 期：7
• 页码：914 - 921
• 全文大小：128K
• 年卷期：v.17,no.7(July 2004)
• ISSN：1520-5010

文摘

Two unidentified arsenic metabolites were detected in the liver of rats on a gel filtrationcolumn by HPLC inductively coupled argon plasma mass spectrometry after an injection ofdimethylarsinic (DMA^V), dimethylarsinous (DMA^III), monomethylarsonic (MMA^V), or monomethylarsonous (MMA^III) acid. The same arsenicals were also produced in vitro by incubationof DMA^III in the liver supernatant but not by DMA^V. The two arsenic metabolites eluted atthe same retention times as those of the two arsenicals prepared by reaction of DMA^V witheither thiosulfate plus disulfite or hydrogen sulfide or sodium sulfide plus sulfuric acid. Thefaster and slower eluting products on a gel filtration column were assigned as dimethyldithioarsinic acid (dimethylarsinodithioic acid) (DMTA^V) and dimethylthioarsinous acid (DMTA^III)from mass spectrometric data at m/z = 170 and 138 by electrospray ionization massspectrometry with negative and positive ion modes, respectively. They were prepared selectivelyby reacting DMA^V with hydrogen sulfide or sodium sulfide plus sulfuric acid under differentreaction conditions. DMA^III but not DMA^V was transformed to DMTA^III and DMTA^V in thepresence of sodium sulfide in vitro, suggesting that DMA^V is reduced to DMA^III with hydrogensulfide, thiolated to DMTA^III, and then further thiolated oxidatively to DMTA^V. Metabolically,it is assumed that DMA^III is transformed to DMTA^III in the presence of sulfide ions, and then,DMTA^III is oxidatively thiolated to DMTA^V. As the chemical species produced by reductionwith the Reay and Asher method are DMTA^III and DMTA^V, and different from DMA^III, thestudies carried out with DMA^III with the Reay and Asher method have to be reexamined.