New aurone epoxide and auronolignan from the heartwood of <i>Cotinus coggygria</i> Scop

Abstract

New aurone epoxide, 2,10-oxy-10-methoxysulfuretin (<b>14</b>), and new auronolignan (<b>15</b>), named cotinignan A, were isolated by silica gel column and semipreparative HPLC chromatography from the methylene chloride/methanol extract of <i>Cotinus coggygria</i> Scop. heartwood. In addition, thirteen known secondary metabolites namely sulfuretin, 2,3-<i>trans</i>-fustin, fisetin, butin, butein, taxifolin, eriodictyol, 3',5,5',7-tetrahydroxyflavanone, 3',4',7-trihydroxyflavone, 3-<i>O</i>-methyl-2,3-<i>trans</i>-fustin, 3-<i>O</i>-galloyl-2,3-<i>trans</i>-fustin, <i>β</i>-resorcylic acid and 3-<i>O</i>-<i>β</i>-sitosterol glucoside were isolated as well. Their structures were elucidated by 1D and 2D NMR, HR-ESI-MS, IR and UV. Ten out of eleven isolated flavonoids possess 7, 3' and 4' hydroxy groups. These structural features could be considered as chemotaxonomic characteristic of flavonoids from <i>C. coggygria</i>. Cotinignan A (<b>15</b>) represents new subclass of secondary metabolites - auronolignans.