HPLC-Q-Orbitrap-MS/MS phenolic profiles and biological activities of extracts from roxburgh rose (Rosa roxburghii Tratt.) leaves

Abstract

Rosa roxburghii Tratt. leaves (RRLs) have been exploited as a alternative tea product in China owing to its various biological properties. A comparative study was performed for the first time on high-performance liquid chromatography quadrupole orbitrap tandem mass spectrometry (HPLC-Q-Orbitrap-MS/MS) phenolic profiles, antioxidant, α-glucosidase inhibitory (α-GIA) and anti-bacterial activities of the RRLs extracts extracted by traditional and eco-friendly solvents. The RRLs extracts extracted with four screened deep eutectic solvents (DES) showed higher total phenolic content (TPC, 167.48–190.14 mg GAE/g DW) and moderate total flavonoid content (TFC, 3.78–4.11 mg RE/g DW), while the RRLs extracts extracted with choline chloride-1,2-propanediol, choline chloride-levulinic acid, and 50% methanol/ethanol extracts had the highest TFC. Ethyl acetate extracts had the lowest TPC and TFC. Additionally, the phenolic constituents of the RRLs extracts were identified and quantified via HPLC-Q-Orbitrap-MS/MS and HPLC-DAD methods. A total of 30 phenolic compounds were identified in RRLs extracts. Among them, arbutin, gallic acid, (+)-catechin, 3-hydroxybenzoic acid, quercetin-3-O-galactoside and myricetin were the representative ones. The selected DES (especially for choline chloride-lactic acid and choline chloride-levulinic acid) extracts exhibited higher 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS+•) and 2,2-diphenyl-1-picrylhydrazyl (DPPH•) scavenging activities, cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP) except for reducing power, α-GIA and anti-bacterial activity as compared with the extracts extracted with other solvents. Multivariate analysis results revealed that the extraction solvents significantly affected the phenolic constituents and biological activities of the RRLs extracts. The present study presented eco-friendly solvents for high-efficient extraction of the phenolic metabolites from RRLs. RRLs as a potential source enriched in phenolic constituents can be applied in the health, cosmetic and pharmaceutical industries.