吡嗪类碳酰肼化合物与CT-DNA相互作用及体外抑菌

以5-氯吡嗪-2-羧酸甲酯和水合肼为原料,经亲核取代和脱水缩合反应合成了3种新型吡嗪类碳酰肼化合物C13H14N6O(a)、C13H14N6O2(b)和C12H12N6O2(c)。采用元素分析与核磁共振氢谱对化合物a~c进行了表征,结果表明合成的产物即为目标化合物。通过溶剂挥发法培养得到了化合物a的单晶并利用X-射线单晶衍射测定化合物a的晶体结构为单斜晶系。根据紫外-可见光谱可知,化合物a~c均以插入模式与CT-DNA作用。利用微量热实验测定了化合物a~c与CT-DNA的相互作用,发现反应过程放热,热效应ΔH依次为-5.77×103、 -5.50×103和-5.96×103 kJ·moL-1,反应时间均小于40 min。通过分子对接模拟计算明确了化合物a和b与DNA的具体结合位点包括A链DC4和DG5以及B链DC4、 DG5和DA6,化合物c与DNA的具体结合位点包括A链DC4和DG5以及B链DC4和DG5。采用牛津杯法测定了化合物a~c对枯草芽孢杆菌、金黄色葡萄球菌、铜绿假单胞菌以及大肠杆菌四种细菌的抑菌活性,结果表明化合物a~c均对铜绿假单胞菌表现出优于阳性对照组四环素的抑菌活性。     

2-甲酰基呋喃苯乙酰腙及其Ni(Ⅱ)配合物的晶体结构及热化学性质

以苯乙酸甲酯、水合肼和呋喃甲醛为原料,合成了配体2-甲酰基呋喃苯乙酰腙(H₂L:C₁₃H₁₂N₂O₂),再与六水氯化镍反应,制得配合物Ni(HL)₂ (1),并对配体及配合物进行了元素分析和X射线单晶衍射结构表征,结果表明,配体晶体属单斜晶系,P2₁/c空间群,晶胞参数为:a=1.161 9(3) nm,b=1.359 8(3) nm,c=0.792 16(19) nm,β=109.307(4)°;Ni(Ⅱ)配合物晶体属三斜晶系,P1空间群,晶胞参数为:a=0.455 70(14) nm,b=1.094 7(3) nm,c=1.204 8(4) nm,β=98.302(5)°。利用热重实验研究了H₂L和1的热稳定性,并计算了各自热分解过程的表观活化能(E_a),发现配合物的热稳定性要远高于配体。采用微量热法研究了H₂L及1与小牛胸腺DNA(CT-DNA)的相互作用,实验结果表明,配合物的作用焓值(ΔH)要大于配体的焓值,说明配合物与CT-DNA的作用要比配体与CT-DNA的作用更强。     

RD496微热量计的研制及其应用

简要回顾了热导式微热量计的建立和发展,着重介绍了RD496微热量计的研制历程.归纳并介绍了RD496微热量计在化学和材料研究中的应用,包括物质晶型转化温度和转化热、溶解热和混合热、生成反应焓的测定,化学反应热动力学、稀释结晶动力学的研究,比热容和固体材料导热系数的测定,材料原位生长的量热研究和材料的微量吸附量热研究等;另外,对于其在高分子化学及物理、生物化学及农业科学等方面的应用进行了叙述.     

2-呋喃甲醛-4-羟基苯甲酰腙及其Cu(Ⅱ)配合物的晶体结构及与CT-DNA的结合性能

通过2-呋喃甲醛与4-羟基苯甲酰肼缩合得到2-呋喃甲醛-4-羟基苯甲酰腙(H2L),并以其为配体与Cu(Ⅱ)配位得到了配合物[Cu(HL)2]·2H2O(1),采用元素分析和X射线单晶衍射对配体和配合物进行结构表征,结果表明配体属于正交晶系,Pna21空间群。配合物属于单斜晶系,P21/c空间群。利用热重实验研究了H2L和1的热稳定性,并计算了它们主要热分解过程的表观活化能,发现H2L和1的热稳定性都较高。通过紫外吸收光谱研究了H2L和1与CT-DNA的相互作用方式,并利用微量热计测量了其作用过程的热效应,结果表明H2L和1均以插入方式与CT-DNA结合,且作用过程放出的热量1大于H2L,说明配合物与CTDNA的结合能力强于配体。     

含卤素原子酰腙化合物的合成、表征及与CT-DNA的相互作用

以4-羟基苯乙酸甲酯、水合肼为原料合成4-羟基苯乙酰肼,再与卤代苯甲醛(X=F、Cl、Br)反应,获得3种含有卤素原子的新型酰腙化合物4-氟苯甲醛-4-羟基苯乙酰腙(Ⅰ)、4-氯苯甲醛-4-羟基苯乙酰腙(Ⅱ)和4-溴苯甲醛-4-羟基苯乙酰腙(Ⅲ),并培养得到上述化合物的单晶。通过元素分析和X-射线单晶衍射对它们进行了表征。结果表明,它们均属三斜晶系,P1空间点群,分子之间通过氢键相互作用,交错排列堆积。利用热重分析研究了它们的热稳定性,并分别计算了它们热分解过程的表观活化能(Ea),结果显示它们的热稳定性都较高。采用紫外光谱研究了它们与ct-DNA的相互作用,发现它们均是以插入模式与ct-DNA作用。通过微量热实验研究了化合物与ct-DNA相互作用过程的热效应(ΔH),化合物Ⅰ、Ⅱ和Ⅲ的ΔH分别为1.87、2.86和5.54 k J·mol-1,说明它们与ct-DNA相互作用的大小为:ⅢⅡⅠ。     

PDA作为ICP—AES元素定量分析检测器的性能评价

引言PDA(photodiode Array),即光敏二极管陈列是近年来发展起来的一种新型光探测器。国外已经有不少光谱工作者将PDA用于ICP的特性的研究,但很少见有用PDA作为ICP-AES元素定量分析的检测器,至今还很少有用PDA作为探测器的ICP-AES商品仪器。我们用PDA作为ICP-AES的检测器,测定了几个元素的检测限和工作曲线的线性范围。初步评价了这样一个用PDA作为检测器ICP-AES系统的性能。     

Crystal Structures,Thermal Behaviors and Biological Activities of Acylhydrazone Compounds Containing Pyrazine Rings and Halogen Atoms

Three new kinds of acylhydrazone compounds(C_(12)H_(10)FN_5O·H_2O,1;C_(12)H_(10)Cl N_5O·2CH_3COOH,2;C_(12)H_(10)Br N_5O,3)were synthesized by the reaction of 2-amino-3-pyrazinecarbohydrazide(C_5H_7N_5O)with halogenated benzaldehyde(C_7H_5OX,X=F,Cl,Br).The structures of the three compounds were characterized by elemental analysis,~1H NMR,IR and X-ray diffraction.X-ray single-crystal diffraction presents that the three compounds all belong to triclinic system,P1 space group.Thermal gravity analyses show that three compounds have excellent thermal stabilities and all the thermal decomposition temperature of maximum weight loss was around 300°C.The interactions of the compounds with CT-DNA were investigated by UV-Vis spectrum,fluorescence spectrum and viscosity measurement.All the results suggest that three compounds could bind with CT-DNA through intercalation.The fluorescence spectrum was also used to study the interactions of three compounds with BSA.It was proved that all the compounds could quench the intrinsic fluorescence of BSA via a static quenching process.Compound 2 displays the strongest binding ability both in the reaction with CT-DNA or BSA.Antimicrobial test was carried on Escherichia coli,Staphylococcus aureus and Salmonella,and 2 is more effective against S.aureus.But in MTT assay,1 shows better cytotoxity activity against A549cells.     

Crystal Structures,ct-DNA/BSA Binding Properties and Antibacterial Activities of Halogenated Pyridyl Hydrazones

Three new halogenated pyridyl hydrazones, namely 4-chlorobenzaldehyde-4-chloropyridine-2-formyl acylhydrazone(C(13)H9Cl2N3O, 3 a), 4-bromobenzaldehyde-4-chloropyridine-2-formyl acylhydrazone(C(13)H9BrClN3O, 3 b) and 4-iodobenzaldehyde-4-chloropyridine-2-formyl acylhydrazone(C(13)H9ClIN3O, 3 c), have been synthesized and characterized by elemental analysis, IR, 1 H NMR, and single-crystal X-ray diffraction. The X-ray diffraction analysis revealed that 3 a^3 c crystallize in monoclinic with space group Cc. The units of 3 a ~ 3 c were linked by intermolecular N–H...X(X = Cl, Br, I) hydrogen bonds into 2 D layered structures, which were further extended into 3 D networks by a series of π-π stacking interactions. Thermogravimetric analysis showed that all of them possessed higher thermal stabilities. The reactivities toward calf thymus DNA(ct-DNA) and bovine serum albumin(BSA) of 3 a^3 c were investigated by UV-vis and fluorescent spectroscopy as well as molecular docking simulation. Both theoretical and experimental results indicated that 3 a^3 c bound to ct-DNA in the mode of minor groove binding, and interacted with BSA through the hydrophobic cavity near TRP213. Besides, the orders of binding affinities of 3 a^3 c to ct-DNA and BSA were both 3 c > 3 b > 3 a, which were the same as that of antibacterial activities. Thus, the interactions of iodinated acylhydrazone with biological targets were stronger than that of chlorinated and brominated acylhydrazones, which provided a representative case for halogenation of lead compounds in rational drug design.     

Ag/g-C3N4纳米片的制备及可见光催化抗菌性能研究

在液相超声剥离制备g-C3 N4纳米片的基础上,通过光照还原法负载Ag纳米颗粒,成功构筑Ag/g-C3 N4纳米片,通过透射电子显微镜(TEM)、红外光谱仪(FT-IR)、X-射线衍射仪(XRD)、比表面积和孔分析仪(BET)和瞬态光电流等方法对制备的样品进行表征,考察可见光下杀灭E.coli能力以表征其光催化活性,并通过改进的Hom模型对样品的光催化抗菌动力学进行研究.研究结果表明,3;Ag/g-C3 N4纳米片具有最优的光催化抗菌活性,光催化抗菌曲线拟合的k2值是体相g-C3 N4的2.99倍,是3;Ag/体相g-C3 N4的1.45倍.大的比表面积和良好的光生载流子分离效率是3;Ag/g-C3 N4纳米片具有优异光催化抗菌活性的主要原因.     

Structure of Copper Chelate of 2-Hydroxy-4-methylthiobutanoic Acid as Trace Mineral Additive in Animal Feeding

The chelate complex of Cu2+ with 2-hydroxy-(4-methylthio)butanoate(MHA-H, the anion derived from the so-called methionine hydroxy-analogue, largely used in animal nutrition as a source of methionine, MHA) is an efficient, bioavailable trace mineral additive for animal feeding. The structure of MHA-H copper chelate was investigated by single-crystal X-ray diffraction. The crystal structure(C10H18Cu O6S2, 1, monoclinic, space group P21/c, Z = 2, a = 16.158(4), b = 4.9733(12), c = 9.159(2) ?, β = 104.786(4)°) exhibits that two MHA-H ligands coordinate with a CuII ion to form a square-planar environment completed to an octahedron through interaction with carbonyl oxygens of neighboring molecules, which expand to constitute a two-dimensional sheet coordination network. And a separation between the hydrophilic and lipophilic moieties like micelles was found in the packing structure. X-ray powder diffraction and thermogravimetric analysis were used to study the phase purity of the bulk sample and thermostability of complex 1, respectively.