Phytochemical constituents from dietary plant <i>Citrus hystrix</i>

<p>Chemical investigation of the fruit peel of dietary plant <i>Citrus hystrix</i> offered two new flavones 5,6,4′-trihydroxypyranoflavone <b>I</b> and 5,4′-dimethyl-6-prenylpyranoflavone <b>XIII</b> 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 <b>II</b> was done for the first time and the compounds <b>I–VI, XI</b> and <b>XII</b> are hitherto not reported from this plant. Biological studies revealed that compound <b>I</b> found to have a good antidiabetic and antiacetylcholinesterase activities meanwhile compounds <b>II, III</b> and <b>V</b> showed a significant free radical scavenging ability as well as antioxidant capacity. In addition, compounds <b>I, IV, V</b> and <b>VI</b> showed cytotoxicity against U87, A549 and MCF-7 cells. Overall, the new compound <b>I</b> showed valuable bioactive properties. Due to insufficient quantity of compound <b>XIII,</b> biological studies were not done.</p>