Rich Phenolic Structure of Flavone Glycosides and Feruloylquinic Acid: Evaluation of Their Bioactivity in the Natural Plant Acer palmatum var. amoenum

Abstract

Objective: Flavonoid glycosides and feruloylquinic acid, which contain rich phenolic structures, are widely used in food and medicine, particularly in antioxidant research. Methods: Dry and ground leaf powder was extracted using 80% aqueous methanol in a sonicator. Partition extraction was performed using solvents of varying polarities. Active compounds from the ethyl acetate fraction were isolated via precipitation and chromatographic methods, including reversed-phase Sephadex LH-20 and repeated Silica gel separation, yielding vitexin, quercetin-3-O-glucoside, and 5-O-feruloylquinic acid. Results and Discussion: The structures of the compounds were confirmed by NMR spectroscopy in comparison with reference data. Total phenolic and flavonoid content were determined to assess bioactivity. Antioxidant activity was evaluated using the DPPH radical scavenging assay and reducing power method, with comparisons to standards (BHA, BHT, and α-tocopherol). Anti-inflammatory properties were tested using the RAW 264.7 cell line in a nitric oxide inhibition assay. Conclusions: Vitexin, quercetin-3-O-glucoside, and 5-O-feruloylquinic acid were successfully extracted and isolated from Acer palmatum var. amoenum (APV.a), demonstrating significant antioxidant and biological activity. These findings further support the potential of Acer palmatum var. amoenum as a source of bioactive flavonoids for natural medicine applications.