Anatomy, trichome micromorphology and phytochemical profile of Stachys rizeensis R.Bhattacharjee from Turkey

In recent years, the popularity of natural products and natural product formulations has increased due to their beneficial effects on health. As a part of this trend, Lamiaceae family members have attracted attention due to their rich bioactive properties. Although the Stachys rizeensis R.Bhattacharjee plant is an endemic plant species in Turkey, no studies focus on its characterization. Hence, the present study aims to demonstrate the anatomical, morphological and phytochemical characterization of S. rizeensis in Turkey. In the first stage of the study, anatomical and trichome morphological characterization was performed to contribute to the taxonomic definition of S. rizeensis was found to be anatomically different from some other previously studied Stachys sp. by showing lacunar collenchyma type, uncertain cambium at the corners, two or three rows of endodermis in certain areas in the stem and two rows of palisade parenchyma, capitate and peltate glandular trichomes in the leaf. In the second stage, the phenolic profile, total phenolic/flavonoid content and antioxidant activity of the plant extracts prepared using solvents with different polarities (ethanol, methanol, water, ethyl acetate and hexane) were tested to determine the phytochemical content of the plant. The phytochemical analysis supported by chemometric analysis (PCA and HCA) revealed that methanol was the most efficient organic solvent for the extraction of the phytochemical compounds of the plant. Additionally, it was observed that chlorogenic acid (1842.40–217,086.19 mg/kg), verbascoside (2591.43–204,429.81 mg/kg), luteolin (3579.56–88,636.14 mg/kg) and kaempferol (9706.30–50,340.93 mg/kg) compounds were present at maximum levels in this plant, in which 31 different phenolic compounds were scanned using LC-MS/MS. In addition, results obtained from the phytochemical analysis revealed that S. rizeensis is a valuable plant that can be used for medical protection/treatment and that it could also have a variety of culinary applications. The present study served as the first original report regarding the chemical profile and anatomical characteristics of S. rizeensis (Lamiaceae) from Turkey.