Cytotoxic Constituents From the Stem Bark and Leaves of Cinnamomum Bejolghota: Isolation, Structure Elucidation, and Molecular Docking Studies

Abstract

The genus Cinnamomum (Lauraceae) is a rich source of bioactive metabolites, yet the Vietnamese species Cinnamomum bejolghota remains incompletely characterised. This study aimed to characterise the constituents of the stem bark and leaves of C. bejolghota, evaluate their cytotoxicity, and explore their molecular targets by docking. Compounds were isolated by chromatographic methods and identified by spectroscopic analysis. Cytotoxicity was assessed against KB, HepG2, MCF-7 and SK-LU-1 cell lines using the MTT assay. Molecular docking against five protein targets and in silico ADME profiling were performed. Sixteen compounds were obtained, including the steroid ergosta-4,6,8(14),22-tetraen-3-one and the flavonol glycoside afzelin, both reported for the first time in this species. Of the 16 compounds, 14 had been reported by our group in two preliminary communications; only the steroid and the flavonol glycoside are newly described from this species. The bis(dimethoxyphenyl)pyridine alkaloid showed moderate cytotoxicity (IC50 31.1 to 45.9 µM), whereas the steroid was weakly active. Docking indicated that the active alkaloid bound topoisomerase IIα and tubulin more strongly than its inactive analogue, and the β-carboline alkaloid bound monoamine oxidase A as strongly as harmine. C. bejolghota produces a structurally diverse set of metabolites; the integrated cytotoxicity, docking and ADME data provide a rationale for the observed bioactivities and candidates for further study.