2-吡咯类酰腙的合成、晶体结构及与小牛胸腺DNA的相互作用

以2-吡咯甲酰肼与2,4-二羟基苯甲醛和2-羟基-3-甲氧基苯甲醛经缩合反应合成2,4-二羟基苯甲醛-2-吡咯甲酰腙C_(12)H_(11)N_3O_3(Ⅰ)和2-羟基-3-甲氧基苯甲醛-2-吡咯甲酰腙C_(13)H_(15)N_3O_4(Ⅱ),并利用红外光谱、元素分析、~1H NMR、X射线单晶衍射和热重分析进行表征,结果表明晶体Ⅰ属单斜晶系,空间群为P21/c,Z=4,晶胞参数为a=1.2586(4)nm,b=0.8050(3)nm,c=1.1914(4)nm;晶体Ⅱ为正交晶系,空间群为P2_12_12_1,Z=4,晶胞参数为a=0.4756(2)nm,b=1.2491(6)nm,c=2.2145(11)nm。热重结果显示,化合物Ⅰ和Ⅱ最大热分解峰分别出现在267.59和284.79℃,表观活化能分别为176.6和122.9 k J/mol,表明化合物Ⅰ和Ⅱ具有较高的热稳定性。利用粘度实验和微量热实验研究了化合物Ⅰ和Ⅱ与CT-DNA的相互作用,均显示两种化合物均与CT-DNA发生了插入作用,且相互作用过程放热,焓变值分别为ΔH(Ⅰ)=4.67 k J/mol和ΔH(Ⅱ)=4.40 k J/mol。

Synthesis,Crystal Structures and Calf Thymus DNA Binding of Acylhydrazone Bearing Pyrrole Ring

Two hydrazone componds(E)-N'-(2,4-dihydroxybenzylidene)-pyrrole-2-carbohydrazide C₁₂H₁₁N₃O₃(Ⅰ) and (E)-N'-(2-hydroxy-3-methoxybenzylidene)-pyrrole-2-carbohydrazide C₁₃H₁₄N₃O₄(Ⅱ) have been synthesized from 2,4-dihydroxybenzaldehyde and 2-hydroxy-3-methoxybenzaldehyde with pyrrole-2-carbohydrazide, respectively. The compounds have been characterized by IR spectroscopy, elemental analysis, ¹H NMR spectroscopy, single-crystal X-ray diffraction and thermogravimetric analysis. The crystal of compound Ⅰ belonged to monoclinic crystal lattice, space group P2₁/c, Z=4, with unit cell parameters a=1.2586(4) nm, b=0.8050(3) nm, c=1.1914(4) nm, and compound Ⅱ crystallized in the orthorhombic system, space group P2₁2₁2₁, Z=4, with unit cell parameters a=0.4756(2) nm, b=1.2491(6) nm, c=2.2145(11) nm. The TG-DTG result shows that the compounds Ⅰ and Ⅱ display good thermal stability, the maximum decomposition peaks are at the temperature of 267.59 ℃ and 284.79 ℃, and their apparent activation energy values are 176.6 kJ/mol and 122.9 kJ/mol, respectively. The thermogenic curves of the compounds Ⅰ and Ⅱ reacting with calf thymus DNA(CT-DNA) measured by viscosity and microcalorimetry, indicate that the interactions of compounds Ⅰ and Ⅱ with CT-DNA belong to the intercalation mode, and the interacting processes are all endothermic, their enthalpies are ΔH(Ⅰ)=4.67 kJ/mol and ΔH(Ⅱ)=4.40 kJ/mol, respectively.