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

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.