A study on some secondary metabolites of Glycyrrhiza glabra L. in autumn and spring conditions in Khuzestan province

Medicinal plant licorice (Glycyrrhiza glabra L.) has been used by the pharmaceutical industries for its important secondary metabolites. This study was carried out to determine the best harvest time for obtaining the highest content of extract, glycyrrhizin, total phenols, total flavonoids, and phenolic compounds of licorice rhizome of the Behbahan area in Khuzestan province in two seasons of autumn and spring. The results of this study showed that the extract content of rhizomes and also glycyrrhizin, total phenols, and flavonoids content in autumn were higher than those in spring. The results of the independent T-test for glycyrrhizin, as an important and valuable secondary metabolite of licorice, showed a significant difference between autumn and spring seasons. Among the phenolic compounds studied, the highest amount was given to ferulic and coumaric acids in autumn, and the lowest one to caffeic acid in spring. Considering the importance of these secondary metabolites in the pharmaceutical, health and food industries, as well as the widespread use of phenolics, glycyrrhizin, and flavonoids of licorice in herbal drugs, it is necessary to determine the best time for the highest production and accumulation of these metabolites in the licorice rhizomes to take an effective step to enrich the industries mentioned.