NMR studies of the conjugation of mechlorethamine with glutathione
作者:Michael P. Gamcsik、Terence G. Hamill、Michael Colvin
DOI:10.1021/jm00165a019
日期:1990.3
nonenzymatic conjugation of mechlorethamine with glutathione. Several intermediates along the pathway to the doubly glutathione substituted mustard, including both mustard-aziridinium adducts, can be observed. The assignment of the 1H NMR spectrum of these adducts are presented. At 30 degrees C, pH 7.0, no hydrolyzed mustard was detectable. With the use of 13C-labeled mustard, the conjugation reaction
许多癌细胞对用甲氧乙胺和其他烷基化剂的化学疗法治疗具有抗性。与敏感细胞相比,这些耐药细胞通常显示出细胞内谷胱甘肽浓度的增加和谷胱甘肽-S-转移酶活性的增加。据认为,这两种成分都通过与谷胱甘肽结合或水解而与药物失活有关。NMR光谱用于监测甲乙胺与谷胱甘肽的非酶结合。可以观察到沿谷胱甘肽双倍取代芥末途径的几种中间体,包括两种芥末-叠氮鎓加合物。给出了这些加合物的1 H NMR谱图。在30摄氏度,pH 7.0下,未检测到水解芥末。
Synthesis and spectroscopic characterisation of <sup>13</sup>
C-labelled ubiquinone-0 and ubiquinone-10
作者:W.B.S. van Liemt、W.F. Steggerda、R. Esmeijer、J. Lugtenburg
DOI:10.1002/recl.19941130305
日期:——
(3-13C)-, (3-13CH3)-, (4-13C), and (13CH3O)2- ubiquinone-10 and the corresponding (1-13C)-, (6-13C)-, (5-13C)-, (5-13CH3)-, (4-13C)-, and (13CH3O)2-ubiquinone-0 have been synthesised from simple labelled starting materials via a single reaction scheme. The ubiquinones have been characterised using mass spectrometry, 1H NMR and 13C NMR. The spectroscopic results indicate that, within experimental error
Preparation of [1,2,3,4,5-13C5]-5-Amino-4-oxopentanoic Acid (ALA)− Design of a Synthetic Scheme to Prepare Any13C- and15N-Isotopomer with High Isotopic Enrichment
作者:Prativa Bade Shrestha-Dawadi、Johan Lugtenburg
DOI:10.1002/ejoc.200300408
日期:2003.12
5-Amino-4-oxopentanoic acid (5-aminolevulinic acid) is a precursor in the biosynthesis of the biologically active porphyrins such as chlorophyll, bacteriochlorophyll, heme, etc. These systems are central in photosynthesis, oxygen transport, electron transport, etc. In this paper we describe a simple scheme to prepare any isotopomer of 5-aminolevulinic acid in a few steps in high yield. Using a similar scheme, levulinic
applied in several NMRstudies to study the E/Z ratio in different matrices. In solution, such as DMSO, a dynamic equilibrium between E/Z-isomers (ratio of 8:92) was determined by initial 13 C-carbon NMR experiments. To get insights into the E/Z ratio of teriflunomide under "in-vivo" conditions, advanced heteronuclear NMR (HOESY) in D2 O and mixtures of D2 O/plasma were performed. While NMR experiments in
Synthesis of (12,13-13C2)retinal and (13,1413C2)retinal: A strategy to prepare multiple-13C-labeled conjugated systems
作者:M. Groesbeek、G. A. Rood、J. Lugtenburg
DOI:10.1002/recl.19921110307
日期:——
(12,13-13C2)Retinal, (13,14-13C2)retinal, (19-13C)retinal and (20-13C)retinal (1) were prepared in a simple fashion in high yield via a consecutive strategy. The key step is the reaction of a N-methoxy-N-methylamide with an alkyllithium or a Grignard reagent. The preparation of the required N-methoxy-N-methylamide is discussed. In this scheme, only three commercially available 13C-labeled starting