RESUMO
Naringin is the natural chief bitter flavonoid found in Citrus species. Herein, bitter naringin was treated with atmospheric pressure plasma to afford two new converted flavonoids, narinplasmins A (2) and B (3), along with the known compound, 2R-naringin. The structures of the two new naringin derivatives were elucidated on the basis of spectroscopic methods. The antioxidant activity of all isolates was evaluated based on 1,1-diphenyl-2-picrylhydrazyl and peroxynitrite (ONOO(-)) scavenging assays. The new flavanone glycoside 2 containing a methoxyalkyl group exhibited significantly improved antioxidant properties in these assays relative to the parent naringin.
Assuntos
Antioxidantes/química , Dissacarídeos/química , Flavanonas/química , Pressão Atmosférica , Dicroísmo Circular , Citrus/química , Citrus/metabolismo , Flavonoides/química , Espectroscopia de Ressonância Magnética , Conformação Molecular , Ácido Peroxinitroso/químicaRESUMO
Activity-guided fractionation of a methanolic extract of the leaves of Eremochloa ophiuroides (centipede grass) using a pancreatic lipase inhibitory assay led to the isolation and identification of a new C-glycosidic flavone, luteolin 6-C-ß-D-boivinopyranoside (1), as well as eight known compounds. The structures of these compounds were established on the basis of interpretation of their spectroscopic data. Among these isolates, the C-glycosidic flavones 1-5 showed potent inhibitory effects on pancreatic lipase, with IC50 values ranging from 18.5 ± 2.6 to 50.5 ± 3.9 µM.