Secondary metabolites from endemic species <i>Iris adriatica</i> Trinajstić ex Mitić (Iridaceae)

<p>This manuscript describes the first detailed chemical investigation of endemic species <i>Iris adriatica</i>, including isolation and structure elucidation. Chemical analyses of the rhizome CH<sub>2</sub>Cl<sub>2</sub>/MeOH (2:1) extract revealed fourteen secondary metabolites, mainly isoflavonoids. Among isoflavonoids, two groups have been found: nigricin-type and tectorigenin-type. Dominant group of the isolated compounds has been nigricin-type isoflavones: nigricin, nigricin-4′-(1-<i>O</i>-<i>β</i>-D-glucopyranoside) and nigricin-4′-(1-<i>O</i>-<i>β</i>-D-glucopyranosyl (1–6)-<i>β</i>-D-glucopyranoside) with 2.5, 10 and 1% of the total extract, respectively. Irisxanthone – xanthone C-glucoside, <i>β</i>-sitosterol, benzophenone and one of its derivatives have also been found. Nigricin-type isoflavonoids and irisxanthone can be considered as possible chemotaxonomic markers for <i>I. adriatica</i>. 5,3′,5′-Trimethoxy-6,7-methylenedioxyisoflavone-4′-(1-<i>O</i>-<i>β</i>-D-glucopyranoside) and benzophenone have been isolated from <i>Iris</i> species for the first time.</p>