C₂₈ sterols with a cyclopentane ring at C-22 and 26 from cape gooseberry (berries of Physalis pubeacens L.)

Abstract

Two new C₂₈ sterols with a cyclopentane ring at C-22 and 26, alkesterol A (1) and alkesterol B (2), along with β-sitosterol (3), were isolated from the berries of Physalis pubeacens L. (cape gooseberry). The structures of the new compounds were established by HR-EI-MS, 1D and 2D (¹H–¹H COSY, HSQC, HMBC) NMR experiments. The known compound was identified by comparison of spectral data with published references. The two new compounds showed some cytotoxic activities by MTT assay.

Keywords:

• Physalis pubeacens L.
• C₂₈ sterols
• alkesterol A
• alkesterol B
• cytotoxic activities

Acknowledgements

This paper was funded by the National Sciences Foundation of China (No. 30873362) and Pre-research Project of Soochow University. We want to express our thanks to Mrs Li-Ping Shi in the Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences for the determination of NMR spectral data.