FLAVONOIDES E ÁCIDOS FENÓLICOS ISOLADOS DOS EXTRATOS METANÓLICOS DAS FOLHAS E GALHOS DE Macrolobium acaciifolium (FABACEAE)

Abstract

FLAVONOIDS AND PHENOLIC ACIDS ISOLATED FROM Macrolobium acaciifolium (FABACEAE) LEAVES AND BRANCHES METHANOLIC EXTRACTS. The phytochemical study of Macrolobium acaciifolium extracts allowed the isolation and identification of 18 substances, 15 of which are reported for the first time in this species. From the methanolic extract of the leaves, the flavonoids luteolin-3’-O-α-L-rhamnoside (1), neoastilbin (2), astilbin (3), neoisoastilbin (4), isoastilbin (5), quercetin-3-O-α-L-rhamnoside (6), quercetin-3-O-rutinoside (7), kaempferol-3-O-rutinoside (8), quercetin-3-O-glicoside (9) and kaempferol-7-O-rutinoside (10) were isolated. From the methanolic extract of branches, the flavonoids chrysoeriol (13), apigenin (14), 7,4’-dihydroxyflavone (16), eriodictyol (17) and luteolin (18), in addition to the phenolic acids 3,4-dihydroxybenzoic acid (11), 3-methoxy,4-hydroxybenzoate (12) and methyl 3,4-dihydroxybenzoate (15) were isolated. The structural identification of the compounds was established by proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond correlation (HMBC) and correlated spectroscopy (COSY) analyses. In this paper, we also discuss about the anisotropic effects on H-1’’, H-2’’, H-5’’ and H-6’’ rhamnose of isomers dihydroflavonoids.