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.

研究了合成的有前途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。实验是在三个不同的温度下进行的，并评估了淬灭常数和结合常数。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。结合常数从1.70×10 ^4降低在较高的温度下达到4.57×10 ³表示复合物在升高的温度下不稳定。发现BSA的站点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和焓驱动的。通过紫外可见光谱，同步荧光和三维荧光光谱研究了与5e相互作用引起的BSA中的二级结构变化。结果表明5e与BSA有效结合，因此，该研究可用于进一步探索5e的药代动力学和药效学。