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Updated: Sep 10, 2025

A Generalized Method for Determining Free Soluble Phenolic Acid Composition and Antioxidant Capacity of Cereals and Legumes
Published on: June 10, 2022
Study on the correlation between proton transfer of phenolic hydroxyl groups of 6 flavonoid compounds and their
Gong Shuangmei1, Yang Changying2, Li Min3
1Research Center for Preparation and Properties of New Functional Materials, Hanjiang Normal University, Shiyan 442000, Hubei, PR China.
Abstract:
This study investigated six flavonoids' photophysical properties in various environments, revealing their pKa variations (e.g., quercetin: 7.364 in water vs 9.329 in vesicles) and demonstrating vesicle/liposome systems' protective effects by slowing proton transfer and oxidation. Metal ion complexation occurred preferentially at specific hydroxyl-keto sites (3-OH-4-keto for quercetin/kaempferol, 5-OH-4-keto for apigenin/baicalein), while structural features like phenolic hydroxyl arrangement and double bonds significantly influenced these interactions. Importantly, the work established that vesicular systems provide superior protection against proton transfer and oxidation compared to liposomes.ANS fluorescence quenching studies further characterized their molecular behaviors, providing key insights into flavonoid stabilization mechanisms and pharmacological activity foundations.
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