Virginianoside A, a new steroidal alkaloid saponin from Solanum virginianum: Isolation, structure elucidation and anti-adipogenic activity

Abstract

A previously unreported 16β-H spirosolane saponin, virginianoside A (1), along with three known compounds; diosgenin (2), solasodine (3) and prosapogenin B (4) were isolated from the whole plant of Solanum virginianum. The rare 16β-H configuration of 1 was established through detailed ROESY and HMBC analysis. All compounds were evaluated for anti-adipogenic activity, with 1 and 2 showing significant reduction in lipid accumulation on 3T3-L1 cell line. Virginianoside A (1) was the most potent, exhibiting dose-dependent activity, suppressing the expression of PPARγ, C/EBPα, FASN and FABP4, without notable cytotoxicity indicating its action during the early phase of adipocyte differentiation.