Novel Prenylated Xanthones from Garcinia gerrardii HARVEY

Abstract
Three novel prenylated xanthones, 1–3, have been isolated from the root bark of Garcinia gerrardii HARVEY ex T. R. SIM (G. natalensis SCHLECHTER; G. transvaalensis BURTT DAVY; Guttiferae). Structure elucidation was achieved by a combination of one‐ and two‐dimensional NMR spectroscopic techniques, including long‐range HETCOR, mass spectroscopy, and chemical methods. Garcigerrin A (1) and B (2) are pyrano derivatives of 3. They all show a rare 1,4,5 oxygenation pattern of the xanthone nucleus. Xanthone 3 is fungicidal against Cladosporium cucumerinum.