A synthesized and promising biologically hypoglycemic compound 5,6-Dichloro-2-[2-(pyridin-2-yl)ethyl]isoindoline-1,3-dione (5e) was studied for its binding to a model protein (bovine serum albumin; BSA) by spectroscopic and molecular simulation approaches. Fluorescence studies revealed that 5e quenched BSA’s intrinsic fluorescence by static quenching. The experiments were performed at three different temperatures and the quenching constants and binding constants were evaluated. Stern-Volmer constant (K_sv) values decreased from 1.36 × 10⁴ to 1.20 × 10⁴ as the temperature increased suggesting static quenching involvement in the interaction. Decreased binding constants from 1.70 × 10⁴ to 4.57 × 10³ at higher temperatures indicated instability of the complex at rising temperatures. Site I (subdomain IIA) of BSA was found to interact with 5e. The thermodynamic results showed the binding interaction was spontaneous and enthalpy driven. The secondary structure alterations in BSA due to interaction with 5e were studied by UV–visible, synchronous fluorescence, and three-dimensional fluorescence spectra. The results indicate the 5e binds effectively to the BSA and thus, this study can be useful in further exploring the pharmacokinetics and pharmacodynamics of 5e.

研究了一种合成的、有前景的生物降血糖化合物 5,6-二氯-2-[2-(吡啶-2-基)乙基]异吲哚啉-1,3-二酮 ( 5e ) 与模型蛋白（牛血清白蛋白）的结合; BSA）通过光谱和分子模拟方法。荧光研究表明， 5e通过静态猝灭来猝灭 BSA 的固有荧光。实验在三种不同的温度下进行，并评估了猝灭常数和结合常数。随着温度升高，Stern-Volmer 常数 (K _sv ) 值从 1.36 × 10 ⁴降低至 1.20 × 10 ⁴ ，表明相互作用中涉及静态猝灭。较高温度下结合常数从 1.70 × 10 ⁴降低至 4.57 × 10 ³表明复合物在温度升高时不稳定。发现 BSA 的位点 I（子域 IIA）与5e相互作用。热力学结果表明结合相互作用是自发的且由焓驱动。通过紫外-可见光、同步荧光和三维荧光光谱研究了由于与5e相互作用而引起的 BSA 二级结构变化。结果表明5e与BSA有效结合，因此本研究可用于进一步探索5e的药代动力学和药效学。