New Isoflavanes from and Their Cytotoxicity against Human Breast Cancer Cell Lines.

The rattans of Dunn are a traditional Chinese medicine activating blood circulation and removing stasis. They have often been used for the traditional Chinese medicinal treatment of breast cancer in modern China. In this study, four novel isoflavanes (- and ) and four known analogues ( and -) were isolated from an ethanolic extract of the rattans of . Their structures were elucidated by extensive spectroscopic analyses and electronic circular dichroism studies. MCF-7 and MDA-MB-231 human breast cancer cell lines were used to evaluate the cytotoxic effects of the isolates. Interestingly, compounds and only inhibited the proliferation of MCF-7 cells, while compound showed a selective cytotoxicity against MDA-MB-231 cells. However, compound had significant cytotoxicity against both MCF-7 and MDA-MB-231 cell lines.