A New Flavonoid Derivative and Inhibitory Effects on Xanthine Oxidase and α-glucosidase from Glinus oppositifolius

In previous studies on bioactivities, some extracts from Glinus oppositifolius possessed antimicrobial, antifungal, antiplasmodial, anti-inflammatory, anti-diarrhoeic, antihyperlipidemic, and hepatoprotective. However, information on the xanthine oxidase inhibitors' properties of G. oppositifolius is still limited. For the purpose of discovering new leads with potential α-glucosidase inhibition, the less explored plant G. oppositifolius has been investigated. A new apigenin flavone glucoside, named apigenin-5-O-β-D-glucopyranosyl-8-C-β-Dglucopyranoside (7), together with seven known compounds (spergulacin (1), glinoside C (2), spergulacin A (3), spergulin B (4), spergulin A (5), vitexin (6), vicenin 2 (8)) were identified from Glinus oppositifolius (L.) Aug. DC. aerial parts. The identification of their structures involved a comprehensive analysis utilizing extensive 1D and 2D NMR techniques, mass spectrometry, and in comparison with those from references. Compound 7 (IC50 =257.90 ± 1.00 μM) showed better inhibition of α- glucosidase than acarbose (IC50 = 1021.47 ± 10.79 μM). Compound 8 (IC50 = 56.82 ± 1.95 μM) indicated a good XO inhibitory effect.