Investigation of Phytochemical Variability, Antioxidant Activity and Ecological Conditions of Native Iranian Glycyrrhiza glabra L.

Licorice (Glycyrrhiza glabra L.) as a strategic and highly valuable medicinal plant in Iran with numerous beneficial pharmaceutical properties contributes substantially to Iranian herbs exports. In the present study, a variation on the phytochemical and antioxidant activity of 25 populations of valuable and profitable medicinal plant of G. glabra was investigated. The climate variables and soil properties were evaluated in various habitates of G. glabra. Total phenol (Folin–Ciocalteu method), total flavonoid (Aluminum Chloride method), anthocyanin (pH difference method) and antioxidant activity (DPPH method) were studied. Glycyrrhizic acid, glabridin, liquiritigenin and liquiritin content of root were evaluated by liquid chromatography. The content of major components in G. glabra varied in different regions. Outstanding quantitative variability of glycyrrhizic acid, glabridin, liquiritin and liquiritigenin content were observed in roots of licorice from different regions of Iran. Glycyrrhizic acid content was varied from 93.89 (mg/g dry weight) for the Sepidan population to 20.68 (mg/g dry weight) for the Ahar population. The maximum and minimum amounts of glabridin were recorded in Kashmar and Bajgah populations, respectively. The highest levels of liquritin and liquiritigenin were in the population of Kazerun and Yasuj, respectively, and the lowest was observed in Kashmar. Also, the highest antioxidant activity (the lowest IC50) for licorice root was associated with Semirom population. In conclusion, The populations with high amount of each active ingredient in licorice root and those with considerable antioxidant activity can be exploited depending on the purpose of breeding and cultivation.