Composition and Antilipase Activity of C,O-glycosylflavones from Yellow-Skinned Varieties of Cucumis sativus L. (Cucurbitaceae)
摘要
Plant waste from greenhouse production of Cucumis sativus L. (Cucurbitaceae) contains various groups of biologically active compounds including C, O-glycosylflavones identified in the most common green-skinned cucumber varieties. The present work shows for the first time that the leaf extracts of yellow-skinned varieties of C. sativus are also characterized by high flavonoid contents (14.02 – 32.87 mg/g) and have an inhibitory effect on human pancreatic lipase (IC50 53.15 – 175.52 μg/mL). Thirty two flavonoids, including derivatives of isovitexin, isoscoparin, and isoorientin in the form of non-acylated and acylated C, O-glycosides, were detected using liquid-chromatography-mass-spectrometry. Three new isoscoparin glycosides were isolated from the leaves of C. sativus cultivar Chinese Yellow and identified by UV and NMR spectroscopy and mass spectrometry as isoscoparin 4′,2″-di-O-glucoside (cucumoside L), isoscoparin 4′-O-glucoside (cucumoside M), and isoscoparin 2″-O-caffeate (cucumoside N). Astudy of the antilipase activity of the individual compounds showed that the presence of a caffeyl fragment in the structure increased the activity of the compounds, while 4′-O-glucosylation decreased it. The results obtained indicate the possibility of using waste from cultivation of yellow-skinned varieties of C. sativus as a source for producing flavonoids with antilipase activity.