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• NGDC/NHDC bound to BSA through a static quenching, and NGDC had stronger binding affinity to BSA compared with NHDC. • Hydrophobic interactions and hydrogen bonds played a major role in the binding of NGDC/NHDC to BSA. • The interaction between NGDC/NHDC and BSA induced some conformational changes of BSA. • NGDC/NHDC showed obvious anti-glycation activities in a dose-dependent manner. The interactions of two dihydrochalcones (naringin dihydrochalcone (NGDC) and neohesperidin dihydrochalcone (NHDC)) with bovine serum albumin (BSA) and their anti-glycation effects were studied utilizing multiple spectral methods and molecular simulation technique. The findings proved that NGDC/NHDC could use a static quenching mechanism to reduce the intrinsic fluorescence of BSA, and the interaction between NGDC/NHDC and BSA was a spontaneous behavior with the binding constant ranging from 104 to 105 M −1. Furthermore, NGDC and NHDC mainly interacted with the site I (subdomain IIA) of BSA via hydrophobic interactions and hydrogen bonds, endorsed by molecular docking study. A conjoint analysis of circular dichroism, three-dimensional fluorescence, dynamic light scattering, and UV-vis absorption spectra confirmed that NGDC/NHDC could induce some alterations in the spatial conformation and microenvironment of BSA. Additionally, NGDC and NHDC inhibited the non-enzymatic glycation of BSA by decreasing the contents of advanced glycation end products (AGEs), trapping methylglyoxal/glyoxal and maintaining the stability of the natural conformation of the protein. Overall, these findings were highly beneficial in disclosing the interaction mechanisms between dihydrochalcones and BSA and providing valuable information for the application of dihydrochalcones as functional food ingredients. [Display omitted] [ABSTRACT FROM AUTHOR]

• In vitro the binding study of monascin to BSA was carried out. • Multi-spectral techniques and molecular modeling were adopted. • Monascin could bind to site I of BSA through static quenching mechanism. • Structural changes of BSA were demonstrated by fluorescence, DLS and CD methods. • The antioxidant activity of monascin might be reduced when binding to BSA. Monascin (MS) is a yellow lipid-soluble azaphilonoid pigment identified from Monascus -fermented products with promising biological activities. This work studied interactions between MS and bovine serum albumin (BSA) as well as their influences on the antioxidant activity of MS. Experimental results demonstrated that the fluorescence emission of BSA was quenched by MS via static quenching mechanism and the formed BSA-MS complex was mainly maintained by hydrophobic and hydrogen bond interactions. Meanwhile, the probable binding pocket of MS located near site I of BSA and the corresponding conformational and structural alterations of BSA were determined. Furthermore, the molecular modeling approach was performed to understand the visual representation of binding mode between BSA and MS. It was noticeable that the BSA-MS complex exhibited reduced DPPH radical-scavenging ability, which might be attributed to the restraining effect of BSA on the relevant reaction pathways involved in antioxidation by MS. [ABSTRACT FROM AUTHOR]