Oliveridepsidones A-D, antioxidant depsidones from Garcinia oliveri.

Four new prenylated depsidones, oliveridepsidones A-D, were isolated from the bark of Garcinia oliveri collected in Vietnam. Their structures were elucidated using mainly NMR techniques ((1)H and (13)C NMR, HMQC, HMBC and NOE experiments).

Cytotoxic geranylated xanthones and O-alkylated derivatives of alpha-mangostin.

Two new geranylated xanthones, 6-O-methylcowanin (4) and oliverixanthone (5), along with five known compounds, cowanin, rubraxanthone, cowaxanthone, cowanol, and beta-mangostin, have been isolated from the bark of Garcinia oliveri. For comparison of their biological activities, one mono- and seven di-O-alkylated alpha-mangostin derivatives were synthesized from alpha-mangostin. The structures of all compounds were assigned by spectroscopic methods (1D and 2D NMR and MS).