The ability of drugs to diffuse through the lipid bilayer of cell membranes is important for their metabolism, distribution, and efficacy. In this study, the interaction between phloretin and human serum albumin (HSA) in an L-egg lecithin phosphatidylcholine (PC) liposome suspension was investigated by fluorescence and absorbance spectroscopy. The spectroscopic and fluorescence quenching experiments show that phloretin molecules penetrated into the lumen of the liposome. The partition coefficient of phloretin in the PC liposome suspensions was calculated from fluorescence quenching measurements. The results show that phloretin efficiently quenches the intrinsic fluorescence of HSA through a combination of dynamic and static quenching. The values of Gibbs free energy, and the enthalpy and entropic change in the binding process of phloretin with HSA in the PC liposome suspensions were negative, suggesting that the binding process of phloretin and HSA was spontaneous. Hydrogen bonding and van der Waals force interactions play an important role in the interaction between the two molecules. In addition, binding of phloretin to HSA in liposome suspensions was investigated by synchronous fluorescence spectroscopy.

药物通过细胞膜脂质双层扩散的能力对其代谢，分布和功效至关重要。在这项研究中，通过荧光和吸收光谱研究了L-卵磷脂卵磷脂磷脂酰胆碱（PC）脂质体悬浮液中促视紫红质素与人血清白蛋白（HSA）之间的相互作用。光谱和荧光猝灭实验表明，荧光素分子渗透到脂质体的内腔中。从荧光猝灭测量值计算出PC脂质体悬浮液中促视紫红质的分配系数。结果表明，荧光素通过动态和静态猝灭相结合，有效地猝灭了HSA的固有荧光。吉布斯自由能的价值 PC脂质体悬浮液中促胰泌素与HSA结合过程的焓变和熵变均为负，表明促胰泌素与HSA的结合过程是自发的。氢键和范德华力相互作用在两个分子之间的相互作用中起重要作用。此外，通过同步荧光光谱研究了荧光素与脂质体悬液中HSA的结合。