Chemical constituents from Piper hainanense and their cytotoxicities

Abstract

Two new compounds, (Z,R)-1-phenylethylcinnamate (1) and (1R,2R,3R,6S)-pipoxide (2) were isolated from the aerial part of Piper hainanense, along with 12 known compounds, including nine benzene derivatives (4–11), one isobutylamide (12), and two polyoxygenated cyclohexene derivatives (13–14). Their structures were elucidated on the basis of the HRESIMS, 1D and 2D NMR spectroscopic analyses, and ECD in cases of 2 and 3. The absolute configuration of ellipeiopsol B (3) was determined for the first time. All these compounds 1–14 were reported from the titled plant for the first time. Most of the isolates were tested for their cytotoxicities against five human cancer cell lines. Four of which, 2, 3, 9, 14 showed moderate bioactivities. Among them, the new compound 2 showed potential cytotoxicity against SMMC-7721, MCF-7, and SW-480 with IC₅₀ values of 9.7, 15.0, and 13.2 μM, respectively.

Keywords:

• Piperaceae
• Piper hainanense
• cytotoxicity
• polyoxygenated cyclohexene derivatives
• benzene derivatives
• pipoxide

Acknowledgments

The authors are grateful to the analytical center and bioactivity screening center of Kunming Institute of Botany, Chinese Academy of Sciences, for measuring the spectrospic data and cytotoxic assay, respectively.