ABSTRACT
Objective: To study the chemical constituents of the aerial parts of Siegesbeckia pubescens. Methods: A systematic separation of chemical constituents was conducted. Detailed chemical investigation of S. pubescens led to the isolation of six compounds by comprehensive chromatographic Methods: (Extraction, Silic gel C.C, Sephadex LH-20, ODS C. C). The structures of them were fully determined based on spectroscopic analysis including IR, HR-ESI-MS, ESI-MS, 1H-NMR, 13C-NMR, DEPT, HSQC, and HMBC spectrum. Results: A total of six compounds were isolated from the fraction of n-butanol extract of S. pubescens including one new monoterpenoid glycoside named (2Z,5E)-7-hydroxy-3,7-dimethyl-2,5-octadiene-1-O-[α-L-rhamnpyranosyl (1→6)]-β-D-glucopyranoside (1), four known diterpenoid glucosides named pubeside D (2), ent-15,16,19-trihydroxypimar- 8(14)-en-2-one-19-O-β-glucopyranoside (3), ent-15,16-dihydroxypimar-8(14)-en-2-one-19-oic-β-glucopyranoside (4), and neodarutoside (5), and eleutherazine B (6). Conclusion: Compound 1 is a new compound, named as siegeside F, and compound 6 is isolated from this species for the first time.
