Comparative metabolic profiling and quantitative analysis of metabolites in different tissues of Ajuga turkestanica by ESI-UHPLC-QqTOF-MS and NMR

Abstract

Abstract Ajuga turkestanica preparations are used as anti-aging cosmeceuticals and for medicinal purposes. Herein we describe the characterization and quantification of its metabolites in different organs using UHPLC-MS and NMR spectroscopy. A total of 51 compounds belonging to various phytochemical classes (11 flavonoids, 10 ecdysteroids, 9 diterpenes, 6 fatty acids, 5 iridoids, 3 phenylpropanoids, 3 sugars, 2 phenolics, 1 coumarin, 1 triterpene) were annotated and tentatively identified by UHPLC-ESI-QqTOF-MS/MS of methanolic extracts obtained separately from the organs. 1D and 2D NMR spectroscopy independently confirmed the identity of six major compounds. The abundances of these main constituents in flowers, fruits, leaves, roots, seeds, and stems were compared and quantified using 1H NMR. The results showed that 8-O-acetylharpagide, 20-hydroxyecdysone (ecdysterone) and ajugachin B were the most abundant constituents in the species. The two major compounds, 8-O-acetylharpagide and 20-hydroxyecdysone, were chosen as the markers for the quality assessment of A. turkestanica material. The methanolic extract of the aerial parts of A. turkestanica showed no noteworthy anthelmintic (antihelmintic), antifungal, or cytotoxic effect in in vitro assays.

Keywords

• Ajuga turkestanica
• UHPLC-MS
• NMR
• Metabolite profiling
• Metabolite annotation
• Biological activity