Untargeted metabolomic analysis of Randia echinocarpa cell cultures treated with L-Tyrosine

Abstract

The addition of precursors, like tyrosine (Tyr), can increase the biomass and specialized metabolite production in plant cell suspensions. There is a need for natural compounds with inhibitory activity against α-amylase and α-glucosidase to decrease the intestinal absorption of simple carbohydrates. It has been previously reported that soluble melanins from the Randia echinocarpa fruit inhibit the enzymatic activity of α-glucosidase. Thus, the objective of this study was to analyze the metabolomic profiles of R. echinocarpa cell suspensions when treated with different concentrations of Tyr and to assess the inhibitory activities of the cell extracts against α-amylase and α-glucosidase. Methanolic extracts (1 mg/mL) of R. echinocarpa cell suspensions inhibited the activity of α-amylase similarly to acarbose at 50 µM. Nevertheless, no inhibition of α-glucosidase by the extracts was observed. Further purification of the methanolic extracts is required to prevent antagonist effects of the compounds. Four specific chemical profiles were determined by Hierarchical Cluster and Principal Components Analysis. Galactose metabolism and starch/sucrose metabolism were among the main modulated metabolic pathways. Molecular docking showed that compounds Tyr_100 and 200 treatments had an estimated free binding energy of -2.4 to -5.6 kcal/mol and can interact with key amino acids involved with the catalytic activity of α-amylase. The addition of Tyr to the cell suspensions of R. echinocarpa can be used to produce α-amylase inhibitory extracts.