Solanum incanum and S. heteracanthum as sources of biologically active steroid glycosides: Confirmation of their synonymy

A new spirostanol saponin (1), along with four known saponins, dioscin (2), protodioscin (3), methyl-protodioscin (4), and indioside D (5), and one known steroid glycoalkaloid solamargine (6) were isolated from the two synonymous species, Solanum incanum and S. heteracanthum. The structure of the new saponin was established as (23S,25R)-spirost-5-en-3β,23-diol 3-O-{β-d-xylopyranosyl-(1→2)-O-α-l-rhamnopyranosyl-(1→4)-[O-α-l-rhamnopyranosyl-(1→2)]-β-d-glucopyranoside}, by using a combination of 1D and 2D NMR techniques including 1H, 13C, COSY, TOCSY, NOESY, HSQC and HMBC experiments and by mass spectrometry. The compounds 1, 3, 4 and 5 were evaluated for cytotoxicity against five cancer cell lines and for antioxidant and cytoprotective activity.

Graphical abstractA new spirostanol saponin, along with four known saponins, and one known steroid glycoalkaloid solamargine were isolated from the two synonymous species, Solanum incanum and S. heteracanthum. Compounds 1 and 3-5 were evaluated for cytotoxicity against human cancer cell lines and for antioxidant and cytoprotective activity.Download high-res image (242KB)Download full-size image