A forensic pathologist needs to choose a chelating agent whose metal-binding action depends entirely on its sulfhydryl groups and which is effective against arsenic and inorganic mercury. Which agent fulfils both criteria?

• A Calcium disodium edetate
• B Deferoxamine
• C D-penicillamine
• D Dimercaprol (British anti-Lewisite) ✓

Explanation

Dimercaprol was developed in the Second World War as British anti-Lewisite against the arsenical war gas Lewisite. Its two vicinal sulfhydryl groups form stable ring complexes with arsenic, mercury and other soft metals, mobilising them for excretion. Edetate chelates lead via carboxylate and amine groups, deferoxamine is specific for iron through hydroxamate groups, and penicillamine is mainly a copper chelator used in Wilson disease.

Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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