Cardanols from leaves of Rhus thyrsiflora

A mixture of 3-substituted alkyl- and alkenylphenols including nine new compounds (cardanols) was isolated from leaves of the Yemenian plant Rhus thyrsiflora (Anacardiaceae) and identified by GC-MS. The position of the double bond in the compounds bearing a monolefinic side chain was determined by their typical MS fragmentation patterns after hydroxylation and trimethylsilylation.