Cong Yang

This study comparatively evaluated how solvent polarity affects the chemical antioxidant capacity, preliminary hyaluronidase inhibition, and supportive chemical features of Buddleja officinalis Maxim. Six extracts prepared with petroleum ether, ethyl acetate, n-butanol, water, 60% ethanol, and 95% ethanol were assessed using DPPH·, ABTS⁺·, ferric reducing power, and hyaluronidase inhibition assays, together with total flavonoid and linarin determinations. The 60% ethanol extract showed the strongest overall radical-scavenging activity, reaching 95% DPPH· scavenging and 95% ABTS⁺· scavenging at 2 mg/mL, whereas the 95% ethanol extract showed the highest ferric reducing power under the tested conditions. Total flavonoid and linarin contents were highest in the ethanol-rich fractions, especially the 95% ethanol and 60% ethanol extracts. In the hyaluronidase assay, both the petroleum ether and 60% ethanol extracts showed relatively strong inhibition at 2.5 mg/mL, with inhibition rates of 74% and 68%, respectively, suggesting that different chemical classes may contribute to this endpoint. Supportive ¹H NMR and UPLC–QTOF–MS data indicated clear polarity-dependent compositional differences; the 60% ethanol extract was enriched in phenylethanoid glycosides and flavonoid glycosides, whereas the petroleum ether extract showed predominantly lipophilic features. Overall, medium-polarity phenolic-rich fractions were more closely associated with chemical antioxidant capacity, while hyaluronidase inhibition may involve contributions from both non-polar and medium-polarity constituents. The present extract-level comparison provides a useful basis for fraction selection, extract standardization, and follow-up activity-guided studies.

This work was designed as a comparative extract-level study to clarify how solvent polarity influences antioxidant activity, preliminary hyaluronidase inhibition, and supportive chemical features in Buddleja officinalis Maxim.. Six extracts prepared with petroleum ether, ethyl acetate, n-butanol, water, 60% ethanol, and 95% ethanol were independently prepared in triplicate and evaluated for DPPH· radical scavenging, ABTS⁺· radical scavenging, ferric reducing power, and hyaluronidase inhibitory activity, together with total flavonoid and linarin contents. The 60% ethanol extract showed the strongest overall radical-scavenging activity, reaching 95% DPPH· scavenging and 95% ABTS+· scavenging at 2 mg/mL, whereas the 95% ethanol extract showed the highest ferric reducing power under the tested conditions. Total flavonoid and linarin contents were highest in the ethanol-rich fractions, especially the 95% ethanol and 60% ethanol extracts. In the hyaluronidase assay, the petroleum ether and 60% ethanol extracts showed relatively strong inhibition at 2.5 mg/mL, with inhibition rates of 74% and 68%, respectively. Supportive ¹H NMR and UPLC–QTOF–MS data, including representative chromatographic profiles and representative compound assignments for the 60% ethanol extract, indicated clear polarity-dependent differences in extract composition; the 60% ethanol fraction was enriched in phenylethanoid glycosides and flavonoid glycosides, whereas the petroleum ether fraction was characterized mainly by lipophilic constituents. Overall, the results support a comparative and exploratory interpretation in which medium-polarity phenolic-rich fractions are associated with stronger antioxidant effects, while non-polar fractions may contribute more strongly to hyaluronidase inhibition. Because the present work was based on in vitro assays and preliminary enzyme screening, further studies with positive inhibitor controls, potency evaluation, and activity-guided isolation are still required.

Macroporous adsorption resins (MARs) are widely used for preparative-scale flavonoid purification, yet rational resin selection remains difficult because flavonoids differ substantially in hydrophobicity, hydrogen-bonding capacity, molecular size, and planarity. This review reorganizes the available literature into a structure-guided and data-supported selection aid rather than a fully predictive model. A systematic search of Web of Science, Scopus, PubMed, and CNKI (January 2000 to February 2026) identified 55 studies for qualitative synthesis. Because many reports describe total flavonoids or mixed extracts rather than explicit single-compound adsorption data, only the subset with sufficiently clear compound-level or narrowly interpretable adsorption information was used for cautious comparative interpretation. Across the compiled evidence, non-polar resins generally favored less polar aglycones and methoxylated flavonoids, whereas medium-polar and polar resins more often performed well for glycosylated or more hydrophilic targets. On this basis, flavonoids were organized into four operational classes linked to recommended resin polarity, indicative adsorption capacity ranges, and typical ethanol-elution windows. A retrospective comparison with independent literature cases suggests practical value for initial resin prioritization, but the framework should be interpreted primarily as a heuristic, trend-based guide rather than as a strictly predictive model, because mixed-matrix effects, pore accessibility, and competitive adsorption can override simple polarity matching. A generalized operating window for adsorption and desorption is also summarized. Overall, this review provides a mechanism-informed starting point for resin screening while making explicit the conditions under which case-specific experiments remain necessary.