Quantitative Identification of Antioxidant Basis for Dendrobium Nobile Flower by High Performance Liquid Chromatography-Tandem Mass Spectrometry

Dendrobium nobile is a beautiful orchid and a widely used medicinal plant. In vitro antioxidant assays suggested that D. noblie �ower extracts showed signi�cantly higher 2, 2′-azinobis-3-ethylbenzthiazoline-6-sulfonate (ABTS) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging rates and much more ferric-reducing power than those of root, stem, leaf and fruit. To better understand the antioxidant basis of D. nobile ower, high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) was used for metabolic identi�cation and quanti�cation. Finally, there were 72 metabolites among the total of 712 identi�ed components showed signi�cant association (coe�cient >0.8, p < 0.05) with ABTS scavenging rates, DPPH scavenging rates, and ferric-reducing power. �e three enriched classes of ower metabolites, including amino acids and their derivatives, organic acids and their derivatives, and avonoids, formed the main antioxidant basis. �e signi�cantly accumulated rutin, astragalin, isomucronulatol-7-Oglucoside, quercetin 4′-O-glucoside, methylquercetin O-hexoside, ca¡eic acid, ca¡eic acid O-glucoside, and p-coumaric acid (Log2(fold change) >2, p < 0.01, distribution in ower >0.1%) made a key contribution to the higher antioxidant activities in ower. �e relative quanti�cation results of HPLC-MS/MS were veri�ed by the common quanti�cation methods. �e antioxidant basis revealed of D. nobile ower will be helpful in the production of healthy or beauty products.