An investigation of the binding of two cinnamate UV filters to bovine serum albumin separately and simultaneously

A study of the separate/simultaneous interaction mechanism between two common cinnamate ultraviolet filters (UVFs), Octtocrylene (OC) and 2-ethylhexyl 4-methoxycinnamate (EHMC), with bovine serum albumin (BSA) was conducted. Both OC and EM can bind to BSA. A more obvious fluorescence quenching effect was observed with EHMC on BSA, as well as a stronger affinity for BSA and a greater effect on the amino acid microenvironment. UVFs and BSA's binding constants were decreased when EHMC and OC interacted simultaneously with BSA, while the distance between UVFs and BSA was increased. Coexistence affected both OC and EHMC, making them less able to binding to BSA. While binding simultaneously to EHMC and OC, BSA's secondary structure underwent significant changes.