Nervisides I–J: Unconventional Side-Chain-Bearing Cycloartane Glycosides from <i>Nervilia concolor</i>

Abstract

Two new cycloartane glycosides, nervisides I−J, were isolated from Nervilia concolor whole plants. Their structures were unambiguously established by interpretation of their HRESIMS and 1D and 2D NMR data. These cycloartanes comprised a stereogenic center at C-24, the R configuration of which was assigned based on DFT-NMR calculations and the subsequent DP4 probability score. These compounds were tested for cytotoxicity against K562 and MCF-7 tumor cell lines, revealing mild cytotoxic activity.

Keywords

• <i>Nervilia concolor</i>
• triterpene
• saponoside
• cycloartane
• xylopyranose