USCHARIN, THE MOST POTENT MOLLUSCICIDAL COMPOUND TESTED AGAINST LAND SNAILS

Calotropis procera. is a shrub with broad ovate fleshy leaves that gro ws wild in the Egyptian deserts. The plant was discovered to be highly toxic to the land snails Thepa pisana. The active ingredient responsi ble for the molluscicidal activity was isolated from its latex by solv ent extraction and partitioning and was finally purified by fractional crystallization from 95% aqueous ethanol. The purity of the isolated material was monitored by TLC. Chemical identification was carried out using mass, infrared, and proton magnetic resonance spectroscopic met hods. The active compound was found to be uscharin, and its identity w as confirmed by comparing its spectroscopic data with the literature v alues. The isolated compound was 128 times more toxic than methomyl to the snails tested.