The binding of the different compounds to Moreover, H-Styr illustrated the most significant effects on the BSA fluorescence intensity, with red shifting from 340 to 350 nm (supplementary fig. ). These changes in the BSA fluorescence spectrum were confirmed through absorption spectroscopy, where the more the hydrophobic properties of the Fe(III)-PPIX complex, as evidenced from the dipole moment calculations (table ), the more complexation with BSA was observed. In brief, H-Styr caused the most significant enhancement in the absorption peak at 279 nm, followed by H-Tyra, then H-Tyros and finally hemin.