Secondary metabolites from endemic species Iris adriatica Trinajstić ex Mitić (Iridaceae)

Abstract

© 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. This manuscript describes the first detailed chemical investigation of endemic species Iris adriatica, including isolation and structure elucidation. Chemical analyses of the rhizome CH2Cl2/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-O-β-D-glucopyranoside) and nigricin-4′-(1-O-β-D-glucopyranosyl (1–6)-β-D-glucopyranoside) with 2.5, 10 and 1% of the total extract, respectively. Irisxanthone–xanthone C-glucoside, β-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. adriatica. 5,3′,5′-Trimethoxy-6,7-methylenedioxyisoflavone-4′-(1-O-β-D-glucopyranoside) and benzophenone have been isolated from Iris species for the first time.