Flavonoids and Xanthones From the Genus Iris: Phytochemistry, Relationships with Flower Colors and Taxonomy, and Activities and Function

Abstract

The genus Iris consists of approximately 360 species and is distributed to Eurasia, North Africa, and North America. Belamcanda chinensis was incorporated into the genus Iris by APG III as Iris domestica. Iris species have also been cultivated as ornamentals since ancient times. Many flavonoids are isolated and identified from the flowers, leaves, and rhizomes. So far as we know, 6 anthocyanidins, 13 flavones, 20 flavonols, 20 C-glycosylflavones, 14 flavanones, 11 dihydroflavonols, 6 flavan and proanthocyanidins, and 85 isoflavonoids were reported as aglycones and glycosides. However, chalcones, dihydrochalcones, aurones, biflavonoids, and neoflavonoids are not found in the genus Iris. Fifteen xanthones that are related to flavonoids were also isolated from Iris species. In this review, we describe the flavonoids and xanthones that were isolated and characterized from Iris species. Moreover, their phytochemistry, contribution to the flower colors, relationships with taxonomy, and activities and functions are also discussed.