Chelation in Metal Intoxication XXVII: Chelating Agents Containing Vicinal Thioether Groups as Antidotes of Lead Toxicity

ABSTRACTThe chelating agents containing vicinal thioether groups viz. 4.5-dicarboxy-3.6-dithiaoctanedioic acid (DMSA), disodium-3.6-dithia - 1.8-octanediol-4,5 dicarboxylate (DMES) and 2,9 diamino- 5.6 dicarboxy-4,7 dithiadecanedioic acid (DCSA) were about equally effective but far more effective than α-mercapto-β -(2-thienyl) acrylic acid (MTA) in enhancing excretion of lead, reversing certain Pb induced biochemical alterations and mobilizing tissue Pb in poisoned rats. The results indicate that vicinal thioether groups participate in chelation of Pb. However, none of them could decrease brain Pb. Owing to their water solubility, low toxicity and ability to chelate toxic metals, the chelators with vicinal thioether groups appear as promising antidotes of Pb intoxication.