Total synthesis of both enantiomers of melodorinol. Redetermination of their absolute configurations
作者:Xiyan Lu、Guoying Chen、Lijun Xia、Guangzhong Guo
DOI:10.1016/s0957-4166(97)00373-x
日期:1997.9
Both enantiomers of the natural products, melodorinol and acetylmelodorinol, have been synthesized by a palladium catalyzed enyne coupling methodology. Their absoluteconfiguration aare redetermined.
the first time from this plant species. The structures of the isolated compounds were characterized by spectroscopic techniques and by comparison of the spectroscopic data with the literature values and the stereochemistry at the asymmetric carbon was determined by the modified Mosher’s method. Among them, compound 2 displayed potent cytotoxic activity against human small cell lung cancer (NCI-H187)
Furthermore, the melanogenesis inhibitory activities of S- and R-1–4 were evaluated, with all shown to be potentinhibitors with IC50 values in the range 0.29–2.9 μM, regardless of differences in the stereochemistry at C-6. In particular, S-4 (IC50 = 0.29 μM) and R-4 (0.39 μM) showed potent inhibitory activities compared with that of reference standard arbutin (174 μM).