New isohemigossypol related conjugates and caffeoylated oleanane triterpenoids from Hibiscus syriacus roots with...

Phytochemical investigation of the dried roots of Hibiscus syriacus L. led to the isolation of six previously undescribed compounds, including three rare benzo[1,4]dioxane-fused isohemigossypol conjugates (1-3) and three caffeoylated oleanane-type triterpenoids (4-6), together with 11 known compounds (7-20). Comprehensive spectroscopic analyses, combined with electronic circular dichroism (ECD) calculations, enabled the full structural elucidation of these metabolites and revealed isohemigossypol-derived phenylpropanoid conjugates and caffeoylated oleanane-type triterpenoids. Notably, Cell based screening identified selected compounds that suppressed p16^INK4A (p16) promoter activity, and follow up assays in senescent fibroblasts showed reduced senescence associated readouts, including SASP related cytokine transcripts. These findings highlight H. syriacus as a good source of structural diversity and pharmacological potential for the discovery of previously undescribed anti aging scaffolds.