Phytochemistry and Biological Activities of Iris Species Growing in Iraqi Kurdistan and Phenolic Constituents of the Traditional Plant <i>Iris postii</i>

• Main Authors: Hawraz Ibrahim M. Amin, Faiq H. S. Hussain, Soran K. Najmaldin, Zaw Min Thu, Mohammed Farhad Ibrahim, Gianluca Gilardoni, Giovanni Vidari
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Molecules
• Subjects: phenolics; terpenoids; isoflavones; swertisin 6-<i>C</i>-glycosides; resveratrol 3,4′-<i>O</i>-diglucoside; <i>Iris postii</i>
• Online Access: https://www.mdpi.com/1420-3049/26/2/264

A dozen <i>Iris</i> species (Iridaceae) are considered traditional remedies in Kurdistan, especially for treating inflammations. Phytochemical studies are still scarce. The information reported in the literature about <i>Iris</i> species growing in Kurdistan has been summarized in the first part of this paper, although, except for <i>Iris persica</i>, investigations have been performed on vegetal samples collected in countries different from Kurdistan. In the second part of the work, we have investigated, for the first time, the contents of the methanolic extracts of <i>Iris postii</i> aerial parts and rhizomes that were collected in Kurdistan. Both extracts exhibited a significant dose-dependent free radical scavenging and total antioxidant activities, comparable to those of ascorbic acid. Medium-pressure liquid chromatographic separations of the two extracts afforded <span style="font-variant: small-caps;">l</span>-tryptophan, androsin, isovitexin, swertisin, and 2″-<i>O</i>-α-<span style="font-variant: small-caps;">l</span>-rhamnopyranosyl swertisin from the aerial parts, whereas ε-viniferin, <i>trans</i>-resveratrol 3,4′-<i>O</i>-di-β-<span style="font-variant: small-caps;">d</span>-glucopyranoside, and isotectorigenin were isolated from the rhizomes. This is the first finding of the last three metabolites from an <i>Iris</i> species. The various remarkable biological activities of isolated compounds scientifically sustain the traditional use of <i>I. postii</i> as a medicinal plant.