Flavonoids of Zizyphus jujuba L. and Zizyphus spina-christi (L.) Willd (Rhamnaceae) fruits

The ripe edible fruits of jujube, Zizyphus jujuba Miller (syn. Z. sativa Gaertner, Z. vulgaris Lam.) and Christ’s thorn jujube Zizyphus spina-christi (L.) Willd (Rhamnaceae family) were phytochemically investigated, comparing their quali-quantitative flavonoids profile. Twelve compounds from both methanol extracts have been recognized as quercetin, kaempferol, and phloretin derivatives by means of HPLC/ESI-MS analyses. Six major compounds have been purified by Sephadex LH-20 column chromatography followed by HPLC and were characterized using NMR spectroscopy. One C-glycoside, 3′,5′-di-C-β-d-glucosylphloretin, was detected in Z. spina-christi. The quantitative analysis of all compounds was also reported showing a higher content of flavonoids in Z. jujuba.