Abstract:
A new prenylated xanthone, 1,3,5,8-tetrahydroxy-2-(3-methybut-2-enyl)-4-(3,7-
dimethylocta-2,6-dienyl) xanthone (1), and a new benzophenone (2), together with four
known xanthone derivatives, cheffouxanthone (3), smeathxanthone A (4), smeathxanthone
B (5), ananixanthone (6), and two pentacyclic triterpenes, epi-friedelinol (7) and friedelin (8),
were isolated from the stem bark of Garcinia smeathmannii. The structures of the
compounds were elucidated on the basis of 1D and 2D NMR experiments, and compound 2
was further characterized and confirmed by single X-ray analysis. Compounds 1, 2, and 3
exhibited the most prominent Garcinia activity against gram-positive Enterococcus faecalis
with minimal inhibitory concentration values of 8, 8, and 2 μg/mL, respectively, while
compounds 1, 3, 4, and 6 showed the capacity to scavenge free radicals.
