BENZYL, FLAVONOID, AND IRIDOID CONSTITUENTS FROM THE LEAVES OF PSYCHOTRIA SERPENS WITH NITRIC OXIDE INHIBITORY ACTIVITY

Tóm tắt

Six metabolites (1–6) were isolated from the leaves of Psychotria serpens L. through extensive chromatographic separation. Their structures were elucidated as fisetinidol 3-O-β-D-glucoside (1), camelliaside B (2), potalioside A (3), benzyl gentiobioside (4), 10-O-β-D-glucosylborreriagenin (5), and borreriagenin (6) by comprehensive spectroscopic analyses, including 1D and 2D NMR and HRESIMS data, together with comparisons to reported literature values. The absolute configuration of compound 1 was established by an experimental ECD spectrum. Remarkably, compound 1 is reported here for the first time as a naturally occurring metabolite, and its complete NMR spectroscopic data are described for the first time. Evaluation of their anti-inflammatory activity revealed that compounds 1, 5, and 6 effectively suppressed LPS-induced nitric oxide (NO) production in RAW264.7 macrophages, displaying IC₅₀ values of 53.37, 60.82, and 50.97 μM, respectively, compared with dexamethasone (IC₅₀ = 13.12 μM). Furthermore, the taxonomic occurrence of these metabolites was comprehensively examined and discussed in the context of phylogenetic relationships, providing further insight into their potential chemotaxonomic significance.