Comprehensive evaluation and antioxidant activities of different medicinal materials based on HPLC-UVD and...

A comprehensive assessment of the total flavonoid content and antioxidant activities of 13 medicinal materials was conducted utilizing high-performance liquid chromatography with ultraviolet-visible detector (HPLC-UVD) and spectral-effect relationship analysis. The contents of seven flavonoids were quantified, and chemometric methods including hierarchical cluster analysis (HCA), principal component analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA) were applied to differentiate the samples. One-way analysis of variance (ANOVA) identified specific herbs for which both flavonoid profiles and antioxidant capacity varied significantly with geographical origin, underscoring the impact of provenance on bioactive quality. The results revealed significant variations in flavonoid composition, with isoquercitrin, quercetin, kaempferol, isorhamnetin, and hyperoside being identified as the key contributors to quality. A structure-activity relationship analysis was employed to elucidate how specific molecular features, such as hydroxylation and glycosylation patterns, influenced antioxidant efficacy. In vitro antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging) ranked Houttuyniae Herba as the most potent, followed by Rubi Fructus and Albiziae Flos. Grey relational analysis (GRA) identified isoquercitrin, astragalin, and hyperoside as the primary flavonoids correlated with antioxidant capacity. This work provides a scientific basis for quality assessment and bioactive component screening in multi-source medicinal materials.