Sesquiterpenes with anti-inflammatory activity from the stems and branches of <i>Melicope patulinervia</i>

Five new sesquiterpenes comprising three zieranes, melicopatulones A–C (<b>1</b>–<b>3</b>) and two guaianes, melicopatulones D–E (<b>5</b>–<b>6</b>), were isolated from the stems and branches of <i>Melicope patulinervia</i>, together with melicodenones B (<b>4</b>), C (<b>7</b>) and D (<b>8</b>). Their structures with absolute configurations were elucidated on the basis of analysis of MS, NMR, and TDDFT-ECD calculations. Sesquiterpenes <b>1</b>, <b>2</b> and <b>6</b> exhibited significant inhibitory effect at 10 µM on lipopolysaccharide-induced NO production in BV-2 microglial cells.