[A new cassane diterpenoid from fresh Caesalpinia decapetala pods]

One new cassane diterpenoid(1) and six known compounds(2-7) were isolated from the 95% ethanol extract of fresh Caesalpinia decapetala pods by silica gel column chromatography, gel filtration chromatography, and semi-preparative HPLC. Compound 1 was identified as a highly oxidized cassane diterpenoid, and its absolute configuration was determined by comprehensive spectroscopic analysis and electronic circular dichroism(ECD) calculations, being named caesalpin L. The known compounds were characterized as caesalsappanin K(2), bonducellin(3), 4-hydroxy-3,5-dimethoxybenzaldehyde(4), thellungianin C(5), p-hydroxybenzoyl coumaric acid anhydride(6), and gallic acid(7). Compounds 2 and 4-7 were obtained from this plant species for the first time. The anti-inflammatory activity of compounds 1 and 2 was comparable to that of the positive control.