High resolution LC-MS/MS characterization of polyphenolic composition and evaluation of antioxidant activity of Sambucus ebulus fruit tea traditionally used in Bulgaria as a functional food

The purpose of this study was to perform phytochemical analysis of tea from Sambucus ebulus fruits concerning hydroxycinnamic acids, flavonol glucosides, stilbenes and proanthocyanidin mono-, di- and trimers content. In total, 33 compounds were identified and quantified using UPLC-DAD-ESI/MS/MS system and the results are presented in mg/g dry weight (DW). Among analyzed hydroxycinnamic acids, 5-Caffeoylquinic acid (114.17 mg/g) was most abundant, followed by 3-p-Coumaroylquinic acid (50.33 mg/g) and 3-p-Feruloylquinic acid, p-Coumaric acid glucoside and 4-p-Coumaroylquinic acid (31.36 mg/g, 29.78 mg/g and 27.70 mg/g, respectively). Flavonol glucosides were represented predominantly by Quercetin-3-O-galactoside, Quercetin-3-O-rhamnosyl-galactoside Quercetin-3-O-glucoside and Quercetin-3-O-rhamnosyl-glucoside (3.68 mg/g, 3.22 mg/g, 2.87 mg/g and 2.56 mg/g, respectively). trans-Resveratrol-3-O-glucoside, epicatechin (40.62 mg/g) and proanthocyanidin di- and -trimers (19.90 mg/g - 31.42 mg/g) also were present in the tea. ABTS cation decolorization assay revealed 1.248 mM UAE activity and the percent of DPPH radical scavenging was 14.25%, corresponding to 39.07 mu M Trolox equivalents.

Automated summary

This study conducted phytochemical analysis of tea from Sambucus ebulus fruits, revealing the presence of hydroxycinnamic acids, flavonol glucosides, stilbenes, and proanthocyanidin mono-, di- and trimers. The tea was found to contain high levels of 5-caffeoylquinic acid and epicatechin, indicating potential antioxidant properties.