Studies of the chemistry of dithiocarbamates and their metal complexes : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science with Honours in Chemistry at Massey University, New Zealand

Abstract

The studies of the chemistry of dithiocarbamates and its related compounds have been undertaken. It is hoped that such studies would shed light on the interaction betwe n such compounds and the thiol-enzyme, aldehyde dehydrogenase. The facts of previous publication revealed that metabolism of alcohol occurs chiefly in the liver and involves several different enzyme systems. The major pathway, however, is oxidation of ethanol to acetaldehyde, catalysed by alcohol dehydrogenase, followed by oxidation of acetaldehyde to acetate, catalysed by aldehyde dehydrogenase. This normal pathway can be disrupted by the ingestion of certain compound, the famous of which is disulfiram or Antabuse, prior to the drinking of alcohol. The compound 4-nitro-phenyl di-methyldithiocarbamate has a close structural similarity to both the inactivator, disulfiram, and the substrate, 4-nitro-phenyl acetate. It turns out that the dithiocarbamate ester is in fact an inactivator of aldehyde dehydrogenase. The chemical reaction resulted in the formation of an inactivated enzyme. The extent of the inhibition can be measured by the release of 4-nitrothiophenoxide ion and upon the treatment of di-methyldithiocarbamate ion with acid to form carbon disulphide gas. However, the analysis is not fully understood, due to further complex reactions occured in the system. Two other suggestions have been put forward to account for the gap. Nevertheless, the study of the chemistry of dithiocarbamate is a step further towards understanding. The study of metal complexes of some substituted dithiocarbamates has found considerable use in analytical methods for heavy metals. The complexes gave approximately the correct metal analysis based on the expected stoichiometry of a 2:1 ratio of dithiocarbamate to metal.