Noscapine hydrochloride (Nos), an opium derived anticancer agent manifests therapeutic applications and is compliant to beneficial modifications. In this paper, we study its interaction with human serum albumin (HSA) by different spectroscopic methods including UV–vis, fluorescence, circular dichroism and thermal denaturation and molecular docking. Using corrected fluorescence data, the binding constant and Stern-Volmer constant were found out to be 3.14 × 10⁴ M⁻¹ and 1.04 × 10⁵ M⁻¹ respectively. Further, type of interactions between Nos and HSA were also elucidated. The energy transfer and distance between donor and acceptor were computed in accordance with Förster mechanism as 0.654 nm and 2.17 nm respectively. The average lifetime of HSA decreased from 6.11 ns to 3.87 ns in presence of two equivalents of Nos. Through Job’s plot, a 1:1 binding stoichiometry was also elucidated for interaction between Nos and HSA. It was finally demonstrated both experimentally using site markers and computationally that Nos binds HSA at Sudlow’s Site II.

鸦片衍生的抗癌药盐酸诺卡汀（Nos）具有治疗用途，并且符合有益的修饰方法。在本文中，我们通过不同的光谱方法，包括紫外可见，荧光，圆二色性，热变性和分子对接，研究了它与人血清白蛋白（HSA）的相互作用。使用校正的荧光数据，发现结合常数和Stern-Volmer常数分别为3.14×10 ⁴ M ^-1和1.04×10 ⁵ M ^-1分别。此外，还阐明了Nos和HSA之间的相互作用类型。根据福斯特（Förster）机理计算出供体和受体之间的能量转移和距离分别为0.654nm和2.17nm。在存在两个当量Nos的情况下，HSA的平均寿命从6.11 ns降至3.87 ns。通过Job's图，还阐明了Nos与HSA之间相互作用的1：1结合化学计量。最终在实验上证明了使用位点标记和Nos结合Sudlow's Site II上的HSA。