Acylated Flavonoids from Cucumis sativus Inhibit the Activity of Human Pancreatic Lipase

Abstract

Lipid metabolism disorders are a large group of diseases for the treatment of which various strategies are used, including the use of pancreatic lipase inhibitors that reduce the intake and adsorption of lipids. This study was the first that shows that agricultural wastes of cucumber (Cucumis sativus) can be a source of the effective lipase inhibitors. As a result of the chromatographic separation of metabolites in C. sativus leaves, seven acylated flavonoids were identified, including three new derivatives of isovitexin characterized by UV, NMR spectroscopy and mass spectrometry data as isovitexin-2"-O-glucoside-6"-O-ferulate (1), isovitexin-2"-O-glucoside-6"-O-p-coumarate (2), and isovitexin-2"-O-(6"-O-feruloyl)-glucoside-6"-O-ferulate (3). The quantitative HPLC data showed that the total content of the acylated flavonoids in the leaves of Russian varieties of C. sativus amounted to 3.78–7.44 mg/g of dry plant weight. Isolated compounds demonstrated the ability to inhibit the human pancreatic lipase; the effectiveness of compound 3 was the greatest and exceeded the activity of the reference compound Orlistat. This study has shown that C. sativus leaves can be a useful source of biologically active phytocomponents with hypolipidemic activity.