Chemical examination of Anacardium occidentale. Isolation and structure determination of a novel biflavonoid-C-glycoside

A new biflavonoid-C-glycoside named occidentoside, also the known (-)salipurposide and β-sitosterol, have been isolated from the nut shells of Anacardium occidentale L. (Anacardiaceae). The structure of occidentoside has been established as tetrahydroninokiflavone-C-glucoside (III) from spectral and chemical evidence. This is the first biflavonoid to occur with one flavanone and one chalcone unit and also the first C-glycoside in the biflavonoid series. Identification of (-)salipurposide is also reported since it has been isolated for the first time from cashew nut shells