Mass spectrometric studies of the path of carbon in photosynthesis: Positional isotopic analysis of13C-labelled 2-octulose phosphates
摘要:
AbstractThe electron impact mass spectrometric fragmentation patterns of the per‐O‐trimethylsilyl (TMS) and alkoxime‐TMS derivatives of D‐glycerol‐D‐altro and D‐glycerol‐D‐ido‐octuloses were fully analysed using seven specifically labelled 13C analogues. Many of the more intense‐ ions in the spectra of the per‐O‐TMS furanose and pyranose derivatives have more than one origin. On the other hand, the mass spectra of the straight‐chain methoxime and ethoxime hepta‐O‐TMS derivatives contain ions each of which in general originares from a single cleavage process. This makes gas chromatography/mass spectrometry of the aikoxime‐TMS derivatives a suitable method for monitoring 13C incorporations at individual carbon atoms in the corresponding octulose phosphates during photosynthesis experiments with 13CO2.
Successive C1–C2 bond cleavage: the mechanism of vanadium(<scp>v</scp>)-catalyzed aerobic oxidation of <scp>d</scp>-glucose to formic acid in aqueous solution
作者:Muge Niu、Yucui Hou、Weize Wu、Shuhang Ren、Ru Yang
DOI:10.1039/c8cp02352b
日期:——
carbohydrates can also proceed to make the reaction a much more complicated mixture. However, the fundamental reaction, C1–C2 bond cleavage, can drive all the intermediates to form the common product FA. Based on the detected intermediates, isotope-labelling experiments, the kinetic isotope effect study and kinetic analysis, this mechanism is proposed. D-Glucose first reacts with a vanadium(V) species
钒(V)催化的水溶液中的好氧氧化在碳水化合物的碳-碳键裂解领域对具有较少碳原子的化学物质显示出很高的选择性。然而,从糖中裂解碳键的途径和转化机理尚不清楚。在这项工作中,我们研究了以同位素标记的葡萄糖为底物的NaVO 3 -H 2 SO 4水溶液中D-葡萄糖氧化为甲酸(FA)的途径和机理。D-葡萄糖首先通过C1-C2键断裂转化为FA和D-阿拉伯糖。D-阿拉伯糖经历类似的C1-C2键裂解形成FA和相应的D-赤藓糖,可通过C1-C2键断裂进一步降解。碳水化合物之间的二聚和醛醇缩合也可以使反应变得更加复杂。但是,基本反应C1-C2键断裂可驱动所有中间体形成共同产物FA。基于检测到的中间体,同位素标记实验,动力学同位素效应研究和动力学分析,提出了该机理。D-葡萄糖首先与钒(V)物质反应形成五元环络合物。然后,发生电子转移和C1-C2键变弱,随后C1-C2键断裂(无C-H键断裂),以产生为H 3 COO
Analysis of metabolic pathways via quantitative prediction of isotope labeling patterns: a retrobiosynthetic 13C NMR study on the monoterpene loganin
作者:D Eichinger
DOI:10.1016/s0031-9422(98)00733-x
日期:1999.5
biosynthetic pathways of numerous indole alkaloids. In contrast to earlier studies, we present evidence that the biosynthesis of loganin in Rauwolfia serpentina cells proceeds mainly via the deoxyxylulose pathway and not by the mevalonate pathway. This conclusion is based on experiments using a R. serpentina cellculture supplied with 13C -labeled samples of glucose, ribose/ribulose, pyruvate or glycerol
摘要 单萜马钱素是多种吲哚生物碱生物合成途径中的前体。与早期的研究相反,我们提供的证据表明,蛇麻草细胞中马钱素的生物合成主要通过脱氧木酮糖途径进行,而不是通过甲羟戊酸途径进行。该结论基于使用蛇纹藻细胞培养物的实验,该细胞培养物提供有 13 C 标记的葡萄糖、核糖/核酮糖、丙酮酸或甘油样品。马钱素从生物质中分离出来,细胞蛋白质水解得到氨基酸。通过核磁共振光谱分析分离的代谢物。然后使用分离氨基酸的 13 C-标记模式重建磷酸烯醇丙酮酸、丙酮酸和乙酰辅酶A的标记模式。这些标记模式随后用于分别通过甲羟戊酸和脱氧木酮糖途径预测二甲基烯丙基焦磷酸和异戊烯焦磷酸的标记模式。马钱素中萜类化合物部分的观察标记模式与脱氧木酮糖预测非常一致。在早期研究中观察到的甲羟戊酸少量掺入马钱素中可归因于两种萜类化合物途径之间的代谢物交换。植物和植物细胞培养中两种途径之间可能存在串扰,这强调需要对一般碳代谢进行定量分析,以
Mass spectrometric studies of the path of carbon in photosynthesis: Positional isotopic analysis of13C-labelled 2-octulose phosphates
作者:Robert W. Irvine、Ian L. Flanigan、John K. MacLeod、J. Grant Collins、John F. Williams
DOI:10.1002/oms.1210271015
日期:1992.10
AbstractThe electron impact mass spectrometric fragmentation patterns of the per‐O‐trimethylsilyl (TMS) and alkoxime‐TMS derivatives of D‐glycerol‐D‐altro and D‐glycerol‐D‐ido‐octuloses were fully analysed using seven specifically labelled 13C analogues. Many of the more intense‐ ions in the spectra of the per‐O‐TMS furanose and pyranose derivatives have more than one origin. On the other hand, the mass spectra of the straight‐chain methoxime and ethoxime hepta‐O‐TMS derivatives contain ions each of which in general originares from a single cleavage process. This makes gas chromatography/mass spectrometry of the aikoxime‐TMS derivatives a suitable method for monitoring 13C incorporations at individual carbon atoms in the corresponding octulose phosphates during photosynthesis experiments with 13CO2.