Kalshiolin A, new lignan from Kalimeris shimadai

The Asian plant Kalimeris shimadai has been used as food and ethnologic medicine for over a thousand years. In this study, we isolated and identified one new lignan, kalshiolin A (1), and 12 known lignans (2-13). The structures were characterized by the comprehensive analyses of spectroscopic data (HR-ESI-MS, IR, 1D, and 2D-NMR) and the absolute configuration of 1 was determined from ECD calculations. The new compound 1 was also screened for cytotoxic activity but did not show significant potency (IC₅₀ 35.9-43.3 μM) against A549, MDA-MB-231, MCF7, KB, and KB-VIN cell lines.