Experimental Paper. Intrapopulation variability of flavonoid content in roots of Baikal skullcap (Scutellaria baicalensis Georgi)

Abstract

Summary Introduction: Baikal skullcap (Scutellaria baicalensis Georgi) is an important medicinal plant, indigenous to Asia. Due to a wide range of pharmacological activities, its roots has been used for ages in Traditional Chinese Medicine. Recently, the species has become an object of interest of Western medicine, as well. Objective: The aim of the study was to determine the variability of Baikal skullcap population originated from Mongolia and cultivated in Poland, in terms of content and composition of flavonoids in the roots. Methods: The objects of the study were 15 individual plants, selected within examined population and cloned in order to obtain a sufficient amount of raw material. The total content of flavonoids in roots was determined according to Polish Pharmacopeia 6th. The qualitative analysis of flavonoids was carried out using HPLC, Shimadzu chromatograph. Results: The dry mass of roots ranged from 25.88 to 56.14 g × plant-1. The total content of flavonoids (expressed as a quercetin equivalent) varied between 0.17 and 0.52% dry matter (DM). Nine compounds were detected within the group, with oroxylin A 7-Oglucuronide (346.90-1063.00 mg × 100 g-1 DM) as a dominant, which differentiated investigated clones at the highest degree (CV=0.27). Baicalin (391.40-942.00 mg × 100 g-1 DM), wogonoside (324.00-641.10 mg × 100 g-1 DM) and hesperetine 7-O-glucoside (163.00-346.32 mg × 100 g-1 DM) were also present in a considerable amounts. Clone 7 was distinguished by the highest content of all investigated compounds, except wogonin and oroxylin A 7-O-glucuronide. Conclusions: Results obtained in present study show a high variability within Baical skullcap investigated population in respect of flavonoid compounds detected in roots. Thus, the results may be used in future investigations concerning the selection and breeding of this species.