Secondary metabolites from endemic species Iris adriatica Trinajs']jstic ex Mitic (Iridaceae)

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-beta-D- glucopyranoside) and nigricin-4'-(1-O-beta-D-glucopyranosyl (1-6)-beta-D-glucopyranoside) with 2.5, 10 and 1% of the total extract, respectively. Irisxanthone - xanthone C-glucoside, beta-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-beta-D-glucopyranoside) and benzophenone have been isolated from Iris species for the first time. Left-hand image of Iris adriatica (Adriatic potato) with redditsh purple flowers (C) Miroslav Mitic. All Rights Reserved.