Chemical Constituents from Soft Coral Clavularia spp. Demonstrate Antiproliferative Effects on Oral Cancer Cells
Ming-Ya Cheng, Ya-Ting Chuang, Hsueh‐Wei Chang, Zhengyu Lin, Ching‐Yeu Chen, Yuan‐Bin Cheng
Abstract
Five new eudensamane-type sesquiterpene lactones, clasamanes A–E (1–5), three new dolabellane-type diterpenes, clabellanes A–C (6–8), and fifteen known compounds (9–23) were isolated from the ethanolic extract of Taiwanese soft coral Clavularia spp. The structures of all undescribed components (1–8) were determined by analysis of IR, mass, NMR, and UV spectroscopic data. The absolute configuration of new compounds was determined by using circular dichroism and DP4+ calculations. The cytotoxic activities of all isolated marine natural products were evaluated. Compound 7 showed a significant cytotoxic effect against oral cancer cell line (Ca9-22) with an IC50 value of 7.26 ± 0.17 μg/mL.