Phytochemical profiling, polyphenol composition, and antioxidant activity of the leaf extract from the medicinal halophyte Thespesia populnea reveal a potential source of bioactive compounds and nutraceuticals

The present study evaluated the phytochemical constituents, nutritional attributes, and the antioxidant capacity of the medicinal halophyte Thespesia populnea. The metabolite profiling by GC-QTOF-MS analysis identified 37 metabolites among which sucrose, malic acid, and turanose were the most abundant. A total of 18 polyphenols and 17 amino acids were identified by the HPLC-DAD analysis. The most abundant polyphenols in T. populnea were gallic acid, catechin, and myricetin. Other polyphenols like protocatechuic acid, epigallocatechin gallate, rosmarinic acid, ellagic acid, rutin, and naringenine were also detected in ample amounts. The leaf extract demonstrated higher antioxidant as well as lipid peroxidation inhibition activities. A correlation analysis revealed a positive correlation between the antioxidant capacity and the phenolic compounds viz. gallic acid, catechin, myricetin, quercetin, apigenin, cinnamic acid, and coumarin which indicates that these phenolic compounds are the main contributors of the antioxidant potential of T. populnea. The results of this study establish T. populnea as a potential source of nonconventional functional food.