Identification of specific flavonoids and their diversity in four subspecies of Teucrium orientale from Iran

Teucrium orientale L. belonging to the genus Teucrium L., Lamiaceae family is widely distributed in Asia and North America. It has different medicinal properties and a great source of metabolites. This study aimed to recognize specific flavonoid markers and their diversity in subspecies of T. orientale. A total of ۲۶ accessions of four subspecies (subsp. orientale, taylori (Boiss.) Rech.f., glabrescens (Hausskn. ex Bornm.) Rech. f., and gloeotrichum Rech. f.) were collected from southwest, south and center of Iran. The flavonoid was extracted from air-dried leaves (۱۵gr, ۹۰% CH۳OH) and concentrated using a rotary evaporator at ۴۰°C. Flavonoid isolation and purification were performed by thin layer chromatography, column chromatography and CHCl۳-CH۳OH-H۲O (۵۰:۴۰:۱۰). Subsequently, ۱۲ methanol fractions were analyzed using HPLC-MQ-API-MS/MS. In order to investigate flavonoid diversity, principle component analysis (PCA) was applied using PAST ۴.۰۳. According to our findings, ۲۶ flavonoid compounds were recognized as subspecies indicators including diglucoside, rhamnoside, arabinoside, manoyl-glucoside, and glucosyl acetate substitutions. PCA analysis also showed that the highest flavonoid diversity was observed in subsp. orientale (۱۳ compounds) and the lowest was found in subsp. taylori (five compounds). Compared with south regions, center and south-west of Iran strongly influenced sub-specific levels of T. orientale. Consequently, these findings are mainly used in industrial productions, chemotaxonomic and pharmaceutical purposes.