Sinulodurins A and B, antiproliferative and anti-invasive diterpenes from the soft coral Sinularia dura

Two new diterpenes, sinulodurin A (1) and sinulodurin B (2), along with two known sterols, 24S-methyl cholesterol and 24-methylene cholesterol, were isolated from the Palau soft coral Sinularia dura. The structures of the new metabolites were determined on the basis of spectroscopic methods and by comparison of NMR data with those of related metabolites. Sinulodurin A (1) and sinulodurin B (2) showed antiproliferative activity against highly malignant +SA mammary epithelial cells with an IC(50) range of 20-30 mu M. They also displayed anti-invasive activity against human highly metastatic prostate cancer PC-3M-CT+ cells in the spheroid disaggregation assay. Furthermore, the antimicrobial activities of the isolates were tested.