Phytochemical characterization of South African bush tea (Athrixia phylicoides DC.)

A methanolic extract of bush tea (Athrixia phylicoides, Asteraceae) was evaluated sensorially. A High Temperature Liquid Chromatography (HTLC)-coupled sensory-guided analysis was performed on bush tea extract to identify potential taste modulating compounds. One fraction showed bitter enhancing effects on caffeine. Fractionation using Fast Centrifugal Partition Chromatography (FCPC) and preparative HPLC followed by structure elucidation using NMR and LC NMR led to the identification of three polymethoxylated flavones, quercetin-3′-O-glucoside (1), as well as a methoxylated derivative (2). In addition, two dicaffeoyl quinic acids and one coumaric acid ester (3) were isolated. Sensory evaluation of isolated compounds led to the identification of quercetin-3′-O-glucoside as bitterness enhancing principle.

► Athrixia phylicoides extract was separated by HTLC and FCPC followed by ESI-TOF-HRMS.
► Two novel compounds, a flavone-3′-O-glucoside and a coumaric acid ester were found.
► Sensory evaluation revealed bitter enhancing effects for quercetin-3′-O-glucoside.