Nuclear magnetic resonance spectroscopy

Rabenstein, Dallas L.; Guo, Wei

doi:10.1021/ac00163a001

Cited by 27 publications

(6 citation statements)

References 622 publications

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“…Liquid secondary ion mass spectral analysis (Kratos MS50 mass spectrometer) of 2U9 gave a molecular ion of 497. (26) indicated that the ␣-carboxyl group of glutamate was present but that of glycine was absent. On this basis the structure of the thiol was assigned as ␥-L-glutamyl-L-cysteinylglycine amide (GASH) (Fig.…”

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confidence: 99%

Glutathione amide and its perthiol in anaerobic sulfur bacteria

et al. 1996

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Chromatium species produced the novel biological thiol glutathione amide, ␥-L-glutamyl-L-cysteinylglycine amide (GASH), when grown photoheterotrophically. GASH was largely converted to the corresponding perthiol during photoautotrophic growth on sulfide, suggesting that GASH may have a function in anaerobic sulfide metabolism. This unprecedented form of glutathione metabolism was probably present in anaerobic ancestors of modern cyanobacteria and purple bacteria.Interest in glutathione (GSH) metabolism has undergone explosive growth during the past two decades as evidence has accumulated documenting its important role in protecting animal cells against the toxicity of oxygen and its by-products (5,8,12,17,18,23,27,29). Among prokaryotes, GSH production is restricted almost entirely to the cyanobacteria and the purple bacteria (9, 20), the former being oxygenic phototrophs and the latter including bacteria responsible for the evolution of pathways involved in mitochondrial oxidative phosphorylation (6,13). GSH metabolism appears to have been introduced into eukaryotes during the endosymbiotic processes that gave rise to mitochondria and chloroplasts (11,21,24). The association between the evolution of GSH metabolism and that of oxygenic photosynthesis and oxygen-dependent respiratory metabolism is consistent with GSH's role as a protective antioxidant. However, it is difficult to understand how GSH production could have evolved and become uniformly distributed among cyanobacteria and purple bacteria after the appearance of oxygenic photosynthesis; a more likely scenario is that GSH metabolism was present in an anaerobic ancestor of the cyanobacteria and purple bacteria, in which it served a different function (12). The report of GSH production by the anaerobic sulfur phototroph Chromatium vinosum (9) and of the presence of a GSH reductase in this organism (7) suggested that Chromatium spp. might be suitable organisms in which to search for an anaerobic function for GSH. We show here that Chromatium spp. do not, in fact, produce GSH but instead produces two novel GSH derivatives whose structure and variation in content with growth conditions indicate that these GSH derivatives may be involved in anaerobic sulfide metabolism.C. gracile (DSM 1712) was grown photoheterotrophically on the medium of Arnon et al. (2) supplemented with NaCl (20 g/liter). Cells were extracted in 50% acetonitrile-water at 60ЊC in the presence of monobromobimane (mBBr) to produce fluorescent bimane derivatives (RSmB) which were analyzed by high-performance liquid chromatography (HPLC; Fig. 1A) as detailed elsewhere (10). No GSH derivative (GSmB) was detected, showing that GSH is not produced in significant amounts, but two unknown thiol derivatives, 2U9 and 2U13 (for HPLC method 2, Unknown, x-min retention time), were observed which could not be assigned to any of the common biological thiols used as standards (10). A full description of HPLC methods 1 and 2 and the elution times for the mBBr derivatives of common thiols has been published ...

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confidence: 99%

Glutathione amide and its perthiol in anaerobic sulfur bacteria

et al. 1996

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“…The solid state 31 P NMR spectrum of PCTHB microspheres showed two resonance signals at 19.8 and at À1.9 ppm, indicating the presence of -NQP(-Cl) 2 and -PQ(-OPh)(-Cl), respectively, which is comparable with the literature. 33,34 The ratio of the integral values of the two resonances indicates that about one-third of the phosphorus atoms exist as -NQP(-OPh)(-Cl) 2 in the cross-linked solid PCTHB microsphere particles represented in Fig. 6.…”

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confidence: 99%

A facile synthesis, structural morphology and fluorescent properties of cross-linked poly(cyclotriphosphazene-co-1,3,5-tri(4-hydroxyphenyl)benzene) hybrid copolymer microspheres

et al. 2016

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“…13C-NMR spectra of the extracts and some authentic specimens were measured on a JEOL FX-90Q FT-NMR spectrometer at 50°C with an external standard method, using a sealed tube containing 3-(trimethylsilyl)-propionic acid-d 4 sodium salt (TSP-d 4 ) in '0 2°( 22.5 MHz; 10 mm cell; spectral width, 5000 Hz; 45°C pulse; pulse repetition time, 1 sec).…”

Section: Methodsmentioning

confidence: 99%