New Cadinane Sesquiterpenes from the Stems of <i>Kadsura heteroclita</i>

As part of our continual efforts to exploit &#8216;Tujia Ethnomedicine&#8217; for their pharmacophoric functionalities, we herein investigated Kadsura heteroclita collected from a deep Wulin mountain area in northern Hunan province. The current study resulted in the isolation of three new sesquiterpenes: 6&#945;,9&#945;,15-trihydroxycadinan-4-en-3-one (1), (+)-3,11,12-trihydroxycalamenene (2), (&#8722;)-3,10,11,12-tetrahydroxy-calamenene (3), along with four known sesquiterpenes (4&#8722;7), and a cytochalasin H (8). 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 8 exhibited a strong antioxidant effect with an IC50 value of 3.67 &#181;M on isolated human polymorphonuclear cells or neutrophils