Flavonoid Constituents and Antimicrobial Activity of Date (Phoenix dactylifera L.) Seeds Growing in Egypt

Abstract

The methanolic extract of date palm (Phoenix dactylifera L.) seeds cultivated in El-Dakhla Oases, Egypt, was investigated for their phenolics and antimicrobial activity. Seven flavonoids were isolated and identified as isoquercetrin (1), luteolin 7-O--D-neohesperopyranoside 3-O-methylether (2), luteolin 7-O--D-neohesperopyranoside (3), acacetin 7-O--D-neohesperopyranoside (4), apigenin 7-O�-D-apiofuranoside (5), apigenin 7- O-�-D-apiofuranosyl-(1 2)-O--D-glucopyranoside (6) and genistein 8-C--D-glucopyranoside (7). The structures were determined mainly by spectroscopic methods (UV, 1 H-, 13 C-NMR, 2D-NMR). Results of an antimicrobial test showed that the methanolic extract of the P. dactylifera seeds moderately inhibited the growth of Gram-positive and Gram-negative bacteria.