Bioactive cardinane sesquiterpenes from the stems of Alangium salviifolium

A dichloromethane extract of the stems of Alangium salviifolium afforded twelve cardinane sesquiterpenes, seven of which are new alangenes A-G (1-7) and five known compounds (8-12). Their structures were elucidated on the basis of spectroscopic techniques including UV, IR, and NMR spectroscopies, and mass spectrometry. Most of the tested compounds exhibited very potent aromatase inhibition properties, especially in the case of the cardinane sesquiterpenes 1, 5-8, and 10 (IC50 values of 0.09, 0.13, 0.30, 0.06, 2.05, and 1.19 μM, respectively), which are significantly better than that of the positive control (ketoconazole, IC50 of 2.4 μM). Compounds 1 and 4 exhibited selective cytotoxicity against the MOLT-3 cancer cell line with IC50 values of 7.9 and 2.1 μg mL(-1) , respectively.