Styloguanidines, new chitinase inhibitors from the marine sponge Stylotella aurantium

Abstract Three potent new chitinase inhibitors, styloguanidines 1, 2 and 3, were isolated from the sponge. Stylotella aurantium collected from the Y ap sea. Their structures were determined by spectral means. These were a new type of inhibitor from natural sources and were proved to inhibit the moulting of cyprid larvae of barnacles.