Monoamine oxidase and succinate dehydrogenase inhibitory properties of substituted 1,3,4‐oxadiazole‐2‐thiones

Fifteen new 3‐arylaminomethyl‐5‐(2‐hydroxy‐3,5‐dibromophenyl)‐1,3,4‐oxadiazole‐2‐thiones were synthesized and characterized by their sharp melting points, elemental analyses and ir spectra. These substituted oxadiazolylthiones were evaluated for their enzyme inhibitory activity. All compounds inhibited in vitro monoamine oxidase and succinate dehydrogenase activity of rat brain homogenates. The degree of monoamine oxidase inhibition ranged from 59‐93% at a final concentration of 1 × 10−4 M whereas the inhibition of succinate dehydrogenase was 49‐100% at a final concentration of 5 × 10−5 M.