The State of Knowledge of the Primary and Secondary Metabolites of the <i>Iris</i> Genus

The genus Iris L. is one of the largest in the Iridaceae Juss. family, comprising more than 320 species. These plants are widespread across the Northern Hemisphere, particularly in temperate and subtropical climate zones. The greatest species diversity occurs in the Mediterranean region, as well as in Southwest and Central Asia. Throughout history, Iris species have had horticultural, cultural, and medicinal value. The rhizomes of several Iris species have long been used for treating various diseases and as a source of essential oils for the cosmetic industry. Phytochemical studies of plants have revealed a rich diversity of primary and secondary metabolites, including phenolic compounds, stilbenes, triterpenoids, quinones, amino acids, and organic acids. These specialised metabolites exhibit a wide range of biological activities, such as antitumor, antimicrobial, estrogenic, antioxidant, and other effects. Modern chromatographic and spectroscopic techniques have enabled precise structural characterisation and quantification of these compounds, thereby providing chemotaxonomic and pharmacological research. This review highlights the chemical diversity of key compounds in Iris species and examines the ecological and chemotaxonomic relationships underlying their distribution. This article aims to consolidate current phytochemical knowledge of the genus Iris and identify gaps in chemical analysis and ecological adaptation.