Phytochemical constituents from dietary plant Citrus hystrix

Abstract

Chemical investigation of the fruit peel of dietary plant Citrus hystrix offered two new flavones 5,6,4'-trihydroxypyranoflavone I and 5,4'-dimethyl-6-prenylpyranoflavone XIII besides 11 known compounds. The structures of all compounds were elucidated with the aid of suitable analytical methods like 1D, 2D-NMR, mass and single crystal X-ray analysis. An X-ray crystal study of compound II was done for the first time and the compounds I-VI, XI and XII are hitherto not reported from this plant. Biological studies revealed that compound I found to have a good antidiabetic and antiacetylcholinesterase activities meanwhile compounds II, III and V showed a significant free radical scavenging ability as well as antioxidant capacity. In addition, compounds I, IV, V and VI showed cytotoxicity against U87, A549 and MCF-7 cells. Overall, the new compound I showed valuable bioactive properties. Due to insufficient quantity of compound XIII, biological studies were not done.

Keywords: Citrus hystrix; Pyranoflavones; acetylcholinesterase inhibitory activities; antioxidant; cytotoxicity; α-amylase.