Flavonoids from Urena lobata / 中草药

ABSTRACT

Objective: To study the chemical constituents of Urena lobata. Methods: Compounds were isolated and purified using various column chromatographies such as silica gel, Sephadex LH-20, and prep HPLC. Their structures were identified by physicochemical properties and various spectroscopic experiments, including HRESIMS, 1H-NMR, 13C-NMR, HSQC, and HMBC. Results: Fourteen flavonoids were obtained from the ethyl acetate extract of U. lobata, including apigenin-6-C-(6″-O-trans- caffeoyl)-β-D-glucopyranoside (1), tiliroside (2), kaempferol-3-O-(6″-O-cis-p-coumaroyl)-β-D-glucopyranoside (3), kaempferol-3- O-β-D-glucopyranosyl-(1→2)-β-D-galactopyranoside (4), rutin (5), astragalin (6), baicalin (7), myricetrin (8), isoquercitrin (9), baicalein (10), luteolin (11), apigenin (12), kaempferol (13), and quercetin (14). Conclusion: Compound 1 is a new compound named urenalobside A, compounds 3, 4, 7, and 8 are firstly obtained from the family Malvaceae, and compound 10 is firstly isolated from genus Urena Linn.