Bioactive compounds profile, enzyme inhibitory and antioxidant activities of water extracts from five selected medicinal plants

Abstract

Medicinal plants are a potentially renewable source of biomolecules. The aim of the current study was to investigate the bioactive compounds, the antioxidant capacity and the enzyme inhibitory effects of aqueous extracts from Camellia sinensis L., Erica arborea L., Ilex paraguariensis A. St. Hilaire, Rosmarinus officinalis L., and Thymus vulgaris L. The extraction yields were between 8.54 and 32.62 %. The contents of total phenolic compounds varied from 31.55 to 199.06 mg GAEs/g extract. Thirteen bioactive compounds were identified using liquid chromatography-electrospray tandem mass spectrometry and fifteen compounds were detected in the five species (Protocatechuic acid, 3,4-dihydroxyphenylacetic acid, ( + )-catechin, chlorogenic acid, 4-hydroxybenzoic acid, vanillic acid, caffeic acid, syringic acid, 3-hydroxybenzoic acid, verbascoside, p-coumaric acid, ferulic acid, hesperidin, hyperoside, and rosmarinic acid). Ilex paraguariensis and R. officinalis showed the highest alpha-amylase and alpha-glucosidase inhibitory activities. The correlation analysis showed that caffeic acid and pinoresinol were significantly correlated with alpha-amylase and alpha- glucosidase inhibitory activities, respectively. Principal component analysis and cluster analysis grouped the studied species into three main clusters: the first group included E. arborea, the second group included I. paraguariensis, and the third group included C. sinensis, R. officinalis, and T. vulgaris.