Isopimarane diterpenes and flavan derivatives from the twigs of Caesalpinia furfuracea

Abstract The first phytochemical investigation of Caesalpinia furfuracea twigs led to the isolation and identification of four new compounds including two isopimarane diterpenes, caesalfurfuric acids A ( 1 ) and B ( 2 ), and two flavans, (2 R )-caesalflavans A ( 5 ) and B ( 6 ), together with four known compounds, 4- epi -isopimaric acid ( 3 ), methyl ( E )-3-(3,4-dihydroxyphenyl)acrylate ( 4 ), ( E )-resveratrol ( 7 ) and oxyresveratrol ( 8 ). Their structures were elucidated by intensive spectroscopic analysis. Compound 1 was found to exhibit antibacterial activity against MRSA SK1 with an MIC value of 16 μg/mL.