Myricadiol and other taraxerenes from Scaevola spinescens

Scaevola spinescens R. Br. (Coodeniaceae), a West Australian semi-arid native plant, has been found to contain a number of pentacyclic triterpenoid compounds of the taraxerene type in high yield compared with other species in which these compounds are known to occur. Isolation of these molecules, which are potential lead compounds for synthetic anti-cancer drugs, was achieved by partitioning the diethyl ether-soluble fraction, of the methanol Soxhlet extract, between hexane and aqueous methanol, followed by base extraction of minor components from the methanol isolate and recrystallisation or column chromatography. The major component isolated from the extract, and main subject of this report, is the pentacyclic triterpenoid,14-taraxerene-3,28-diol (1; myricadiol).