新三氮唑并嘧啶型除草剂的合成及其与人血清白蛋白的相互作用

Synthesis of a novel triazolopyrimidine herbicide and its interaction with HSA

合成了一种新型除草剂3-(4-氯苯基)-5-[(3-氯苯基)-氨基]-6-[(3-三氟甲基苯氧基甲基)-氨基]-3,6-二氢-[1,2,3]三唑并[4,5-d]嘧啶-7-酮(TAPO),并对其进行了表征。在模拟生理(pH 7.4)条件下,采用紫外光谱、荧光光谱、圆二色谱法(CD)和傅里叶红外光谱研究了TAPO与人血清白蛋白(HSA)的相互作用。结果表明:TAPO对HSA的内源荧光产生了有规律的猝灭,通过Stern-Volmer方程和紫外吸收光谱确定其猝灭过程主要为静态猝灭;由热力学公式计算出相关热力学参数ΔH,ΔS,ΔG的值分别为-100.92 KJ/mol,-234.35 J/(mol·K),-30.40KJ/mol,推断二者间的作用力主要为氢键和范德华力;根据Frster非辐射能量转移理论求得二者的结合距离r为4.02 nm(298 K)。同步荧光结果表明结合位点更接近于色氨酸残基;傅里叶红外光谱和曲线拟合数据显示,α-螺旋含量下降,β-转角结构和无规则卷曲结构上升;圆二色谱法进一步验证TAPO使HSA的二级结构发生了不可逆的变化。

A novel herbicide,3-（4-chlorophenyl）-5-[（3-chlorophenyl）-amido） ]-6-[（3-trifluoromethyl-phenoxymethyl）-amido]-3,6-dihydro-1,2,3-triazolo[4,5-d]pyri-midine-7-one（TAPO）,was synthesized and characterized by ^1H NMR,^13C NMR FT-IR,and elemental analysis.The interaction between TAPO and human serum albumin（HSA） under physiological conditions was studied by using four spectral methods,including fluorescence spectroscopy,ultraviolet absorption spectroscopy,FT-IR spectroscopy and circular dichroism spectroscopy.Spectroscopic analysis of the emission quenching indicated that the quenching mechanism of human serum albumin by TAPO was mainly static quenching procedure,which was in good agreement with the result from ultraviolet absorption spectroscopy.The thermodynamic parameters ΔH,ΔS and ΔG were calculated to be -100.92 KJ/mol,-234.35 J·mol^-1·K^-1,and -30.40 KJ/mol respectively by the thermodynamic equations.From the above data,it could be inferred that the action forces were mainly van der Waals force and hydrogen bonds.The binding average distancer between HSA and TAPO was obtained to be 4.02 nm（298 K）.In addition,synchronous fluorescence spectroscopy indicated the binging site was closer to the tryptophan residues.The FT-IR and fourier self-deconvolution,second derivative and curve-fitting showed that the content of α – helix decreased while those of β-turn and random coil increased,which were in accordance with the results from circular dichroism spectroscopy.