ISOLATION, IDENTIFICATION AND QUANTIFICATION OF BIOACTIVE COMPOUNDS FROM AMARANTHUS HYPOCHONDRIACUS LEAF EXTRACT: A VITAL SOURCE OF POTENT NATURAL ANTIOXIDANTS

In this study we aimed at isolation, identification, and quantification of two phenolic compounds reported for the first time in leaves of Amaranthus hypochondriacus. A non targeted GC-MS metabolite profiling of hexane extracts of amaranth leaves was done which indicated the presence of major phenolic compounds. Two alkylated phenols namely 2,4-di-tert-butyl phenol (A) and 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoic acid (B) were isolated for the first time from the hexane extract of A. hypochondriacus leaves. Structure elucidation of both the compounds was done using ¹H NMR and purity was checked by GC-MS. Quantitative estimation of purified compounds in leaves extract was carried out using RP-analytical HPLC. The antioxidant potential of the isolated compounds (A), (B) and the hexane extract of leaves were investigated using in-vitro 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radicals scavenging bioassay. Hexane leaf extract (IC₅₀ = 385.34 ± 37.11 µg/mL), 2,4-di-tert-butyl phenol (A) (IC₅₀ = 253.76 ± 24.67 µg ml^-1) and 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoic acid (B) (IC₅₀ = 174.09 ± 16.89 µg ml^-1) exhibited significant free radicals scavenging activity. Thus, our study reports high content of two alkylated phenols for the first time in Amaranthus hypochondriacus leaves extract. It substantiates the usage of amaranthus leaves as a prominent source of antioxidant bioactive potent enough to substitute synthetic toxic antioxidants in food and pharmaceutical industries.