Two new flavonoid glycosides from the fruits of Lycium ruthenicum Murr.

Nine flavonoid glycosides were isolated from water extract of the fruits of Lycium ruthenicum Murr. by using various chromatographic methods, including D-101 macroporous adsorption resin, silica gel, ODS, Sephadex LH-20 and semi-preparative HPLC. The structures of the isolated compounds were identified as laricetrin-3-O-β-D-glucopyranoside-7-O-4′′′′-O-(E)-p-coumaroyl-α-L-rhamnopyranosyl-(1′′′′→6′′′)-β-D-glucopyranoside (1), (2S)-naringenin-5-O-α-L-rhamnopyranosyl(1′′′→6′′)-β-D-glucopyranoside (2), kaempferol-3-O-robinobioside (3), quercetin-3-O-rutinose (4), isorhamnetin-3-rutinoside (5), kaempferol-3-β-D-glucopyranosyl(1→4)-α-L-rhamnopyranoside (6), prunin (7), (2S)-helichrysin A (8), 2′-O-β-D-glucopyranoside (9) by spectroscopy methods (1D NMR, 2D NMR, MS, etc.). Compounds 1 and 2 were new flavonoid glycosides, named lyciuflavonoid A and lyciuflavonoid B. Compounds 6 and 9 were isolated from L. ruthenicum for the first time. Compound 9 has an inhibitory effect on α-glucosidase with an IC₅₀ of (76.14 ± 4.64) μmol·L^-1.