首页> 外文学位 >Probing the interactions between sterically demanding ferrihemes and histidine analogues. I. 2-D NMR studies of nonplanar ferriheme/bis(N-/2-methylimidazole) complexes; II. Synthesis of a trans-disubstituted tetraarylporphyrin with a bulky group near each potential axial ligation site.

【24h】

Probing the interactions between sterically demanding ferrihemes and histidine analogues. I. 2-D NMR studies of nonplanar ferriheme/bis(N-/2-methylimidazole) complexes; II. Synthesis of a trans-disubstituted tetraarylporphyrin with a bulky group near each potential axial ligation site.

机译：探索空间需求的亚铁和组氨酸类似物之间的相互作用。 I.非平面亚铁血红素/双（N- / 2-甲基咪唑）配合物的2-D NMR研究；二。在每个潜在的轴向连接位点附近具有大体积基团的反式二取代四芳基卟啉的合成。

获取原文

获取原文并翻译 | 示例

页面导航

摘要
著录项
相似文献
相关主题

摘要

In a hemoprotein, histidine and other aromatic amines that ligate to the heme may encounter steric interactions from the following: (1) the peptide chains that form the pocket; or (2) the porphyrin ring that may have been distorted by the protein matrix or a distal ligand. Models that mimic these steric interactions need to be synthesized and studied in detail. The results of two research projects—both dealing with porphyrins that interact sterically with the axially ligated aromatic amines—are presented in this dissertation.;In the first part, variable-temperature 2-D NMR studies of nonplanar ferriheme complexes are presented. Hemes are surprisingly flexible, and a significantly distorted conformation is accessible by the forces exerted by surrounding proteins and ligands. Iron(III) octaethyltetraphenylporphyrin ([Fe(III)OETPP]+) is a saddled macrocycle that could serve as a model for distorted hemes. Two low-spin [Fe(III)OETPP]+ complexes, one with two N-methylimidazole (N-MeIm) molecules as the axial ligands and the other with two 2-methylimidazole (2-MeImH), have been made, and their NMR spectra recorded as a function of temperature. Spectral assignment for the bis(N-MeIm) complex has been made through 2-D techniques. The NOESY spectra indicate that at about –40°C, the ring inversion halts while the axial ligand dissociation remains prevalent. The spectra of the bis(2-MeImH) complex at –85°C indicate that the dominant internal dynamics consists of ring inversion and a concerted rotation of the axial ligands.;In the second part, the synthesis of a porphyrin with two sterically large groups near the potential sites of axial ligation is presented. In a bis(aromatic amine)/iron(III) complex of the αβ-atropisomer of 5,15-di-p-tolyl-10,20-bis[2,3-[(((hydrotris(3,5-dimethylpyrazolyl)borato)oxomolybdenio)dioxy]phenyl]porphyrin (1), the axial ligands are expected to be rotationally fixed. The synthesis of 1 is described. The corresponding trans -ditolylbis(dimethoxyphenyl)porphyrin (2) was synthesized from p-tolualdehyde and 2,3- dimethoxyphenyldipyrromethane in acidified aqueous sodium dodecyl sulfate in 16–25% yield. The demethylation of 2 and the subsequent reaction with HB(3,5-Me2Pyz) 3(OCH2CH2O) afforded 1, characterized with FAB-MS (cation detection mode). The product most likely consists entirely of the αβ-atropisomer because of the steric constraint during the formation.

机译：在血红蛋白中，与血红素连接的组氨酸和其他芳香胺可能会遇到以下空间相互作用：（1）形成口袋的肽链;或（2）卟啉环可能已被蛋白质基质或远端配体扭曲。模仿这些空间相互作用的模型需要进行综合和详细研究。本文提出了两个研究项目的结果-均与与轴向连接的芳族胺发生空间相互作用的卟啉-；第一部分，非平面亚铁血红素络合物的可变温度二维NMR研究。血红素具有出人意料的柔韧性，并且周围蛋白质和配体所施加的力可显着扭曲构象。铁（III）八乙基四苯基卟啉（[Fe（III）OETPP] +）是一个鞍形大环，可以用作变形血红素的模型。制备了两种低旋转[Fe（III）OETPP] +配合物，一种配合物以两个N-甲基咪唑（N-MeIm）分子为轴向配体，另一种配合物以两个2-甲基咪唑（2-MeImH）作为其配体。 NMR光谱记录为温度的函数。 bis（N-MeIm）络合物的光谱分配已通过2-D技术完成。 NOESY光谱表明，在约–40°C时，环反转停止，而轴向配体解离仍然普遍。 bis（2-MeImH）络合物在–85°C的光谱表明，主要的内部动力学由环反转和轴向配体的协调旋转组成。;第二部分，合成了两个空间上大的卟啉轴向结扎潜在位点附近的组。在5,15-二-对甲苯基-10,20-双[2,3-[（（（氢三（3,5-二甲基吡唑基））的αβ-阻转异构体的双（芳香胺）/铁（III）络合物中）硼酸酯）（羰基）（1）预期轴向配体被旋转固定。描述1的合成。相应的反式-二甲苯基双（二甲氧基苯基）卟啉（2）由对甲苯甲醛和酸化的十二烷基硫酸钠水溶液中的2,3-二甲氧基苯基二吡咯甲烷，收率16–25％。2的去甲基化以及与HB（3,5-Me2Pyz）3（OCH2CH2O）的后续反应产生1，用FAB-MS（阳离子检测）表征由于形成过程中的空间限制，产物很可能完全由αβ-阻转异构体组成。

著录项

作者
Ogura, Hiroshi.;
展开▼
作者单位

The University of Arizona.;

展开▼
授予单位 The University of Arizona.;
学科 Chemistry Inorganic.;Chemistry Physical.;Chemistry Organic.
学位 Ph.D.
年度 2000
页码 265 p.
总页数 265
原文格式 PDF
正文语种 eng
中图分类
关键词

相似文献

外文文献

1. I.~Synthesis and characterization of nitrogen containing heterocycles with potential antiviral and anti-PCP activity. II.~Synthesis of a series of phenylacetamides and study of their intramolecular hydrogen bonding interactions by oxygen-17 NMR spectroscopy. [D] . Santiago Troche, Daphne. 1993

机译：I.具有潜在抗病毒和抗PCP活性的含氮杂环的合成与表征II。〜一系列苯乙酰胺的合成以及通过氧17 NMR光谱研究它们的分子内氢键相互作用。
2. Probing the interactions between sterically demanding ferrihemes and histidine analogues. I. 2-D NMR studies of nonplanar ferriheme/bis(N-/2-methylimidazole) complexes; II. Synthesis of a trans-disubstituted tetraarylporphyrin with a bulky group near each potential axial ligation site [O] . Ogura Hiroshi 2000

机译：探索空间需求的亚铁和组氨酸类似物之间的相互作用。 I.非平面亚铁血红素/双（N- / 2-甲基咪唑）配合物的2-D NMR研究；二。在每个潜在的轴向连接位点附近具有大体积基团的反式二取代四芳基卟啉的合成

Probing the interactions between sterically demanding ferrihemes and histidine analogues. I. 2-D NMR studies of nonplanar ferriheme/bis(N-/2-methylimidazole) complexes; II. Synthesis of a trans-disubstituted tetraarylporphyrin with a bulky group near each potential axial ligation site.

摘要

著录项

相似文献

相关主题

期刊订阅