PROJUVENOIDS - SYNTHESIS AND BIOLOGICAL EVALUATION OF SULFENYLATED, SULFINYLATED, AND SULFONYLATED CARBAMATES

Applying the proinsecticide principle developed earlier for neurotoxic carbamate insecticides, a series of new N-sulfenylated, N-sulfinylate d, and N-sulfonylated derivatives of fenoxycarb were synthesized and e valuated for juvenile hormone mimicking activity. Laboratory evaluatio ns of the compounds using Pieris brassicae and Sitophilus oryzae, as w ell as field experiments using Bemisia tabaci, showed that several sym metrical biscarbamates with either a sulfenyl or sulfinyl bridge posse ssed higher activity than the parent carbamate. From the unsymmetrical compounds containing biologically inert derivatizing moieties, one of the sulfenylated biscarbamates also showed improved activity against P. brassicae. The changes in the biological activity of the sulfur-con taining derivatives compared to that of the parent compound are attrib uted to the modified physicochemical characteristics, i.e., increased lipophilicity facilitating penetration, transport, as well as protecti on of the compound from metabolism. (C) 1996 Wiley-Liss, Inc.