Antibacterial xanthones from the leaves of Garcinia nigrolineata.

Ten new 1,3,5-trioxygenated xanthones, nigrolineaxanthones J-S (1-10), one new quinone derivative, nigrolineaquinone A (11), and one new isoflavone-like compound, nigrolineaisoflavone A (12), were isolated from the leaves of Garcinia nigrolineata along with four known xanthones and friedelin. Among the xanthones, only nigrolineaxanthone N (5) showed significant antibacterial activity against methicillin-resistant Staphylococcus aureus.