Inhibitory mechanism of anthocyanin B-ring substituents on advanced glycation end-product formation through bovine serum albumin binding: Insights from multispectral, molecular docking and proteomics approaches.

This study demonstrated that the inhibitory effect of anthocyanins on AGEs formation is highly dependent on the substitution pattern of the B-ring. Among the four anthocyanins, delphinidin-3-O-glucoside (D3G) exhibited the most potent antiglycation activity across BSA-fructose, MGO, and GO models with half-maximal inhibitory concentration (IC50) of 30.77, 200.29 and 269.97 μM. This superior performance was attributed to the presence of three hydroxyl groups on the B-ring, which facilitates a high-affinity, spontaneous binding interaction with BSA primarily through hydrophobic forces and hydrogen bonding. Spectroscopic and computational analyses revealed that D3G effectively stabilizes the protein scaffold, specifically recovering α-helix content and shielding critical subdomains (IB, IIA, and IIIA). Proteomics data are consistent with a protective binding mechanism, suggesting that D3G reduces the accessibility of key lysine and arginine residues to glycation-induced modifications. These findings provide a structural basis for developing D3G-rich extracts as targeted, structure-based functional ingredients to mitigate glycation-associated food quality degradation and related health issues.