Kazemi Zahra, Amiri Rudbari Hadi, Sahihi Mehdi, Mirkhani Valiollah, Moghadam Majid, Tangestaninejad Sharam, Mohammadpoor-Baltork Iraj, Azimi Gholamhassan, Gharaghani Sajjad, Kajani Abolghasem Abbasi
Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Iran.
Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Iran.
J Photochem Photobiol B. 2016 Oct;163:246-60. doi: 10.1016/j.jphotobiol.2016.08.035. Epub 2016 Aug 25.
A racemic mixture of a new chiral Schiff base ligand (HL: R/S-(1-phenylethylimino)methylnaphtalen-2-ol) has been utilized to prepare Pd(II) complex. Crystallization technique has been employed to separate diastereomeric pairs of Pd(II) complex: (mesoPdL2) and (racPdL2) that in this paper are known as PdL2(1) and PdL2(2), respectively. The synthesized complexes have been characterized by means of elemental analysis (CHN), FT-IR, (1)H and (13)C NMR spectroscopies. Moreover, PdL2(1) has been structurally characterized by single-crystal X-ray diffraction. The geometry around the metal center is square-planar. The interaction of two diastereomers of Pd(II) complex with FS-DNA has been explored, using UV-vis spectroscopy, fluorescence quenching, chemometrics and viscosity measurement methods. The PdL2(1) exhibited higher binding constant, about 10-fold, (1.0×10(6)M(-1)) as compared to PdL2(2) (1.51.5×10(5)M(-1)). Moreover, the human serum albumin (HSA) binding ability has been monitored by absorption, quenching of tryptophan fluorescence emission and circular dichroism (CD) studies. The slight difference is observed between HSA binding affinity with the complexes: PdL2(1) (6.2×10(4)M(-1)) and PdL2(2) (3.3×10(4)M(-1)). Also, the thermodynamic parameters were determined at three different temperatures (298, 308 and 318K). In this study, molecular docking was also carried out to confirm and illustrate the specific DNA- and HSA-binding of the Pd(II) complexes. In the PdL2(1)-HSA system a T-shaped π-π interaction with PHE206 was observed. While in the PdL2(2)-HSA system there are a hydrogen bond, a π-cation and two T-shaped π-π interactions with ASB324, LYS212 and PHE228, respectively. The groove binding mode of DNA interaction has been proposed for both diastereomers.
一种新型手性席夫碱配体（HL：R/S-(1-苯乙基亚氨基)甲基萘-2-醇）的外消旋混合物已被用于制备钯（II）配合物。采用结晶技术分离钯（II）配合物的非对映异构体对：（内消旋PdL2）和（外消旋PdL2），在本文中分别称为PdL2(1)和PdL2(2)。通过元素分析（CHN）、傅里叶变换红外光谱（FT-IR）、核磁共振氢谱（1H）和核磁共振碳谱（13C）对合成的配合物进行了表征。此外，通过单晶X射线衍射对PdL2(1)进行了结构表征。金属中心周围的几何形状为平面正方形。使用紫外可见光谱、荧光猝灭、化学计量学和粘度测量方法研究了钯（II）配合物的两种非对映异构体与FS-DNA的相互作用。与PdL2(2)（1.5×105 M-1）相比，PdL2(1)表现出更高的结合常数，约为其10倍（1.0×106 M-1）。此外，通过吸收、色氨酸荧光发射猝灭和圆二色性（CD）研究监测了人血清白蛋白（HSA）的结合能力。观察到配合物与HSA的结合亲和力存在细微差异：PdL2(1)（6.2×104 M-1）和PdL2(2)（3.3×104 M-1）。此外，在三个不同温度（298、308和318K）下测定了热力学参数。在本研究中，还进行了分子对接以确认和说明钯（II）配合物与DNA和HSA的特异性结合。在PdL2(1)-HSA体系中，观察到与PHE206的T形π-π相互作用。而在PdL2(2)-HSA体系中，分别与ASB324、LYS212和PHE228存在一个氢键、一个π-阳离子相互作用和两个T形π-π相互作用。已提出两种非对映异构体与DNA相互作用的沟槽结合模式。
