RESUMEN
Bioassay-guided fractionation of an ethanolic extract of Ochrosia borbonica led to the isolation of two known pyridocarbazole alkaloids, ellipticine (1) and 9-methoxyellipticine (2), and six known monoterpenoid indole alkaloids (3-8). Lipid-lowering assay in 3T3-L1 cell model revealed that 1 and 2 could significantly inhibit the lipid droplet formation (EC = 0.41 and 0.92 μmol·L, respectively) and lower triglyceride levels by 50%-60% at the concentration of 1 μmol·L, being more potent than the positive drug luteolin (EC = 2.63 μmol·L). A mechanistic study indicated that 1 and 2 could intercalate into supercoiled DNA, which consequently inhibited the mitotic clonal expansion of 3T3-L1 cells at the early differentiation phase, leading to the retardance of following adipogenesis and lipogenesis. These findings suggest that 1 and 2 may serve as promising leads for further development of anti-obesity drugs.
RESUMEN
To study the non-alkaloid constituents from the stems and leaves of Ochrosia borbonica. The chemical constituents were separated and purified by silica gel, Sephadex LH-20, ODS column chromatographies, and preparative HPLC. Their structures were determined by physicochemical properties, spectral data, as well as comparison with the data in literature. Fifteen compounds were isolated from the petroleum ether fraction of 70% ethanol extract from the stems and leaves of O. borbonica, and identified as lupeol (1), lupine ketone (2), betulinic alcohol (3), betulinic acid (4), ursolic acid (5), 2α, 3β-dihydroxy-ursolic acid (6), 11, 12-dehydroursolic acid lactone (7), β-amyrin (8), oleanolic lactone (9), alphitolic acid (10), friedelin (11), cholesterol (12), 24R-ethyl-5α-cholestane-3β, 6α-diol (13), stigmast-7-en-3β-ol (14), and β-sitosterol (15). All the compounds are isolated from the plants of Ochrosia Juss. for the first time.