Effects of sorbitol on the production of phenolic compounds and terpenoids in the cell suspension cultures of Ocimum basilicum L.

Abstract

Ocimum basilicum L. contains secondary metabolites such as alkaloids, flavonoids, phenolics, and terpenoids, which are valuable metabolites for the food, cosmetic and pharmaceutical industries. The aim of this study was to evaluate the effects of sorbitol treatments applied to Ocimum basilicum L. cell suspension cultures on cell viability (%), cell number and cell dry weight (g/L), total phenolic content (TPC), flavonoid content (TFC), and secondary metabolites accumulations. Antioxidant capacities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. Phenolic compounds and terpenoids were recognized by reversed phase-high-performance liquid chromatography (RP-HPLC) and headspace solid-phase microextraction-gas-chromatographic-mass-spectrometry (HS-SPME–GC/MS), respectively. Among sorbitol treatments, 50 mg/L treatment was most effective in terms of TPCs and antioxidant activity, while 200 mg/L treatment was most effective in terms of TFCs. RP-HPLC analysis indicated that the highest accumulations of rosmarinic acid (12.32 mg/g DW, 25 mg/L treatment) and chicoric acid (4.52 mg/g DW, 100 mg/L treatment) were obtained in sorbitol treatments which were 30% and 35% greater than control (9.47 mg/g DW, 3.35 mg/g DW), respectively. The optimum biosynthesis of rutin and isoquercetin was obtained in the treatment of sorbitol 50 mg/L, with an increase of 2.01-fold (6.78 mg/g DW) and 2.17-fold (4.12 mg/g DW), respectively, compared to the control culture. The highest values of linalool and methyl chavicol compared to the control culture were 4.58 μg/g DW and 4.40 μg/g DW in 50 mg/L sorbitol treatment, respectively. Results indicate that application of sorbitol can enhance phenolic compounds and terpenoids production in O. basilicum cell suspension cultures.