New Cadinane Sesquiterpenes from the Stems of Kadsura heteroclita

Abstract

As part of our continual efforts to exploit 'Tujia Ethnomedicine' for their pharmacophoric functionalities, we herein investigated <i>Kadsura heteroclita</i> collected from a deep Wulin mountain area in northern Hunan province. The current study resulted in the isolation of three new sesquiterpenes: 6α,9α,15-trihydroxycadinan-4-en-3-one (<b>1</b>), (+)-3,11,12-trihydroxycalamenene (<b>2</b>), (-)-3,10,11,12-tetrahydroxy-calamenene (<b>3</b>), along with four known sesquiterpenes (<b>4</b>-<b>7</b>), and a cytochalasin H (<b>8</b>). Their chemical structures were elucidated by 1D-, and 2D-NMR spectroscopy, and HRESI-MS, CD spectrometry. The antioxidant, and cytotoxic activities of the compounds were evaluated. Compound <b>8</b> exhibited a strong antioxidant effect with an IC₅₀ value of 3.67 µM on isolated human polymorphonuclear cells or neutrophils.