Flavonoid glycosides from Pouteria obovata (R. Br.) fruit flour

Three unknown dihydroflavanol glycosides: 2R,3R-4′O-methyl dihydrokaempferol 7-O-[3″-O-acetyl]-β-d-glucopyranoside (1), 2R,3R-4′-O-methyl dihydrokaempferol 7-O-β-d-β-l-xylopyranosyl-(1″′ → 6″)-[3″-O-acetyl]-β-d-glucopyranoside (2), 2R,3R-4′-O-methyl dihydrokaempferol 3-O-β-d-β-l-xylopyranosyl-(1″′ → 6″)-[3″-O-acetyl]-β-d-glucopyranoside (3), together with gallic acid (4) were isolated from the n-butanol fraction of Pouteria obovata fruit flour by chromatographic methods and their structures were elucidated on the basis of CD, UV, MS, monodimensional NMR (1H and 13C) and bidimensional NMR (COSY, HSQC and HMBC). The quantitative analysis of flavonoids and phenols were also reported. Total phenolic amount (51.1 ± 14.1 mg GAE/1000 g; p < 0.0006) and flavonoid content (153.2 ± 3.5 mg CE/100 g; p < 0.004) were detected spectrophotometrically.