Anti-inflammatory and cytotoxic neoflavonoids and benzofurans from Pterocarpus santalinus

Five new benzofurans, pterolinuses A-E (1-5), six new neoflavonoids, pterolinuses F-J (8-13), and five known compounds (6, 7, 14-16) were isolated from an extract of Pterocarpus santalinus heartwood. All new structures were elucidated by spectroscopic methods, and configurations were confirmed by CD spectral data and optical rotation values. The isolates were evaluated for anti-inflammatory and cytotoxic activities. Six compounds (1, 2, 4, 6, 7, and 15) showed significant inhibition in at least one anti-inflammatory assay. Compound 2 showed the best selective effect against superoxide anion generation in human neutrophils with, an IC50 value of 0.19 μg/mL, and was 6.2-fold more potent than the positive control LY294002. Compound 14 showed the highest cytotoxicity against Ca9-22 cancer cells, with an IC50 value of 0.46 μg/mL.