Metabolite Profiling of Commiphora wightii (Guggul) with Respect to Seasons

Abstract

Aim of the study was to undertake comprehensive metabolic profiling of plant parts of Commiphora wightii during two contrasting seasons i.e. summer and winter; compared seasonal metabolic variations; and assess antioxidant activity of fractions for commercial applications. Leaves, young stems and gum-resin extracts from summer and winter seasons were analyzed using GC-MS, HPLC and NMR spectroscopy. The antioxidant activity on each set was determined by DPPH free radical scavenging assay. Complete metabolic profiling from two contrasting seasons identified one hundred and four major known and unknown metabolites. Also, two alkylated phenols, 2,4-di- tert-butyl phenol and 3-(3,5-di- tert-butyl-4-hydroxyphenyl) propanoic acid not reported earlier from this taxon were isolated from the vegetative part. Comparative analysis of seasonal metabolic profiles of leaves, young stems and gum-resin revealed significant variations in concentrations of several metabolites. Multivariate principal component analysis (PCA) showed significant qualitative and quantitative variations in the polar (glycine, quinic acid and myo-inositol) and non-polar metabolites (alkylated phenols, guggulsterones and α-tocopherol) between the two seasons. Variation amongst metabolites such as myo-inositol, quinic acid α- tocopherol and alkylated phenols that are important for nutraceutical industry in the two contrasting seasons is a useful finding. These metabolites are of medicinal and nutraceutical importance and are commonly used in nutraceuticals and dietary supplement industry. DPPH radical scavenging activity (IC50 values) of polar and non-polar extracts varied significantly between summer and winter seasons. The antioxidant activity can be attributed to major polar metabolite, quinic acid biosynthesized in excess during winter, and to non-polar metabolites like alkylated phenols and α-tocopherol present during the summer season. The study shall be useful for medicinal, nutraceutical and dietary supplement industry for selection of polar or non-polar extracts from a particular season for obtaining targeted products with optimized functionality.