An organic small-molecular drug, 4-(1H-indol-3-yl)-2-(p-tolyl)quinazoline-3-oxide 1a was synthesized. It was employed to investigate the binding interaction and mechanism with human serum albumin (HSA). The experimental results indicated that the fluorescence quenching of HSA by 1a is a static quenching process and formation 1a-HSA complex. The site competition experiments revealed that the combination of 1a on HSA are hydrophobic interactions in the IIA domain and hydrogen bonds in IIIA domain of HSA, and the hydrophobic interactions of 1a on HSA are stronger than that of hydrogen bonds. These results were also confirmed by molecular docking theoretic analysis and ANS-hydrophobic fluorescent probe experiment. Synchronous fluorescence experiments showed that the polarity of HSA microenvironment was increase in the interaction process of 1a with HSA. The results of binding distance explored indicated that the combination distance between 1a and HSA is 3.63 nm, which is between 0.5R₀ and 1.5R₀, revealing the energy transfer between HSA and 1a is non-radiative. These results are very helpful for people to screen out high efficient indoloquinazoline drugs.

合成了有机小分子药物4-（1H-吲哚-3-基）-2-（对甲苯基）喹唑啉-3-氧化物1a。它被用来研究与人血清白蛋白（HSA）的结合相互作用和机理。实验结果表明，该荧光猝灭的HSA由图1A是一个静态猝灭过程和形成图1A-HSA复合物。站点竞争实验显示的组合1A上HSA是在IIA域疏水相互作用和在第IIIA域氢键HSA，和的疏水性相互作用1A上HSA比氢键强 分子对接理论分析和ANS-疏水荧光探针实验也证实了这些结果。同步荧光实验表明，在1a与HSA的相互作用过程中，HSA微环境的极性增加。结合距离的结果表明，1a与HSA的结合距离为3.63 nm，介于0.5R ₀与1.5R _0之间，揭示了HSA与1a之间的能量转移。是非辐射的。这些结果对人们筛选高效吲哚喹唑啉药物非常有帮助。