Heterocyclic N-dithiocarboxylates as cadmium antagonists: 4-Hydroxypiperidine- and 4-carboxamidopiperidine-N-dithiocarboxylate

Sodium 4-hydroxypiperidine-N-dithiocarboxylate(HP-N-DTC) and sodium 4-carboxamidopiperidine-N-dithiocarboxylate (CAP-N-DTC) were synthesized by the reaction of each piperidine analog with CS₂ in the presence of NaOH. Following isolation and characterization, each dithiocarboxylate (DTC) when added to an aqueous solution of CdCl₂ formed a water-insoluble complex with Cd which was shown by elemental analyses to consist of DTC:Cd in a 2:1 molar ratio. HP-N-DTC was a highly effective antagonist of acute Cd toxicity in mice, while CAP-N-DTC was less effective. When seven equimolar doses of each DTC were administered to mice which had received a non-lethal dose of CdCl₂ along with 1.0 μCi of ¹⁰⁹CdCl₂ 50 days earlier, both effected marked reductions of renal Cd levels. CAP-N-DTC was much more effective than HP-N-DTC in reducing the whole body Cd burden, apparently due to its more rapid depletion of hepatic Cd accompanied by an enhanced rate of Cd excretion. The data illustrate that subtle structural modifications of this class of heavy metal binding agents can yield compounds with impressive differences in pharmacologic activity.