ABSTRACT
OBJECTIVE: To study the flavonoid glycosides of Urena lobata. METHODS: Compounds were isolated and purified using various column chromatographies such as D101 macroporous adsorption resin, silica gel, Sephadex LH-20, and prep HPLC. Their structures were identified on the basis of their physicochemical properties and various spectroscopic experiments, including HRESIMS, 1H-NMR, 13C-NMR, HSQC, and HMBC. RESULTS: Ten flavonoid glycosides were obtained from the n-BuOH extract of U. lobata including quercetin-3-O-β-D-glucopyranosyl-(1→2)-β-D-galactopyranoside(1), kaempferol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside(2), quercetin-3-O-β-D-apiofuranosyl-(1→2)-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside(3), kaempferol-4'-O-β-D-apiofuranosyl-3-O-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside(4), kaempferol-3-O-β-D-apiofuranosyl-(1→2)-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside(5), quercetin-3-O-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside(6), quercetin-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside(7), kaempferol-3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside(8), kaempferol-3-O-β-D-glucopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside(9) and kaempferol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside(10). CONCLUSION: Compounds 1-3 and 6-10 are firstly obtained from U. lobata.