Labile Stoffwechselprodukte V. Zur Biogenese Des Formiminoglycins Aus 4(5H)‐Imidazolon

Freter, Kurt; Rabinowitz, Jesse C.; Witkop, Bernhard

doi:10.1002/jlac.19576070121

Cited by 21 publications

(6 citation statements)

References 3 publications

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“…Crude extracts convert 4-aminoimidazole to ammonia and formiminoglycine (404). The reaction is a two-step one, and 4-imidazolone was identified as an intermediate (174). The first enzyme involved in the degradation of 4-aminoimidazole, 4-aminoimidazole aminohydrolase (EC 3.5.4.8), was purified by Rabinowitz and Pricer (404) and requires Fe2+ ions for full activity.…”

Section: Conversion Of Xanthine To Formiminogly-mentioning

confidence: 99%

“…The enzyme was activated and stabilized by the presence of cysteine and various other reducing agents (404). 4-Imidazolone is easily transformed nonenzymatically into formiminoglycine (174) and into glycine under acid and alkaline conditions (404). An enzyme catalyzing the conversion of 4-imidazolone to formiminoglycine was found to be present in C. cylindrosporum (174).…”

Section: Conversion Of Xanthine To Formiminogly-mentioning

confidence: 99%

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Degradation of purines and pyrimidines by microorganisms.

Vogels¹,

Drift²

1976

Bacteriological Reviews

374

192

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Section: Conversion Of Xanthine To Formiminogly-mentioning

confidence: 99%

Section: Conversion Of Xanthine To Formiminogly-mentioning

confidence: 99%

Degradation of purines and pyrimidines by microorganisms.

Vogels¹,

Drift²

1976

Bacteriological Reviews

374

192

View full text Add to dashboard Cite

show abstract

“…The likely candidate for this intermediate was 4-imidazolone. Earlier reports which described the purinedegrading pathway in clostridia implicated 4-imidazolone as an intermediate (15), but this was not experimentally proven until later (5). The chemistry of 4-aminoimidazole conversion to formiminoglycine seemingly dictated the assignment of 4-imidazolone as an intermediate in the earlier experiments.…”

Section: Resultsmentioning

confidence: 99%

“…In microorganisms, both aerobic and anaerobic pathways are known (18). A pathway used by certain clostridia to degrade xanthine to formiminoglycine was first characterized in a series of articles over 35 years ago (5,(11)(12)(13)(14)(15). This pathway is essentially identical to that shown in Fig.…”

mentioning

confidence: 99%

Purine metabolism in Methanococcus vannielii

DeMoll

Auffenberg

1993

J Bacteriol

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Methanococcus vannielii is capable of degrading certain purines to the extent that each of these purines may serve as the sole nitrogen source for growth. Results presented here demonstrate that purine degradation by M. vannielii is accomplished by a route similar to that described for clostridia. Various characteristics of the purine-degrading pathway of M. vannielii are described. Additionally, it is shown that M. vannielii does not extensively degrade exogenously supplied guanine if that compound is present at levels near or lower than those required to supply the cellular guanine requirement. Under those conditions, M. vannielii incorporates the intact guanine molecule into its guanine nucleotide pool. The benefits of a purine-degrading pathway to methanogens are discussed.In the course of determining the metabolic fate of the 8-carbon of GTP in cell extracts ofMethanococcus vannielii, it was discovered that the extracts were catalyzing the degradation of various nucleotides, nucleosides, and purines to xanthine (2, 3). Evidence which showed that xanthine itself is then degraded to the extent that the 2-, 6-, and 8-carbon atoms of xanthine may be recovered as CO2 was presented (3). This degradation allows M. vannielii to be able to utilize some purines as the sole nitrogen sources for growth (2). We show in this communication the route by which M. vannielii degrades purines. Also, we demonstrate that under conditions where the exogenous purine level is below that needed to supply the cellular purine requirement, most of the exogenous purine is not degraded. Instead, the intact molecule is utilized for purine nucleotide synthesis.Purine-degrading pathways in mammals, plants, and various microorganisms have been described. In microorganisms, both aerobic and anaerobic pathways are known (18). A pathway used by certain clostridia to degrade xanthine to formiminoglycine was first characterized in a series of articles over 35 years ago (5,(11)(12)(13)(14)(15). This pathway is essentially identical to that shown in Fig. 5. Experiments which demonstrate how M. vannielii utilizes purines both as direct precursors of nucleotides and as the sources of carbon and nitrogen are presented here.To date, M. vannielii is the only methanogen that is reported to use purines as the sole nitrogen source (8), but Methanococcus voltae has the ability to degrade at least some purines (1). It was found that M. voltae can degrade the hypoxanthine analog, 6-mercaptopurine, at least to the extent that a soluble compound is formed. This would probably mean that M. voltae has enough of a purinedegrading pathway to allow cleavage of the pyrimidine ring of purines. MATERIALS AND METHODSPreparation of cell extracts. For all of these experiments, cell extracts were prepared from frozen (-70°C) cells of M. vannielii as previously described (3). It should be noted that the medium in which the cells were grown did not contain purines. Briefly, cells were thawed in buffer and disrupted by * Corresponding author.sonication. This sonicate was cent...

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“…In the course of a synthetic programme') substantial amounts of 4- imidazolidinone (1 a), as a key intermediate, were required. Previously, compound 1 a had been obtained in small quantities by reductive desulfurization of 1-benzyloxycarbonyl-2-thiohydantoin in an attempt to prepare the labile 3,5-dihydro-4H-imidazol-4-one (2), as described by Witkop and coworkers '). This reaction requires large amounts of the expensive and pyrophoric Raney nickel catalyst.…”

mentioning

confidence: 99%

A short synthesis of 4‐imidazolidinone

Pfeiffer¹,

Riccaboni²,

Erba³

et al. 1988

Liebigs Ann. Chem.

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A gram-scale. convcnient, and simple synthesis or Cimidazoiidinone (1 a) is described. Starting from the readily available glycinamide. 1 a is obtained for the first time in a pure. solid form.In the course of a synthetic programme') substantial amounts of 4-imidazolidinone (1 a), as a key intermediate, were required. Previously, compound 1 a had been obtained in small quantities by reductive desulfurization of 1-benzyloxycarbonyl-2-thiohydantoin in an attempt to prepare the labile 3,5-dihydro-4H-imidazol-4-one (2), as described by Witkop and coworkers'). This reaction requires large amounts of the expensive and pyrophoric Raney nickel catalyst. Moreover, in our hands it appeared low-yielding, scarcely reproducible, and therefore not suitable for medium-scale preparations. Based on the above and on other literature data3), we thought that the reduction of imidazolone 2 could represent a straightforward and easy entry to 1 a. Therefore, the described*) cyclization of N-(iminomethy1)glycine 2-phenylethyl ester was repeated. 'H-NMR analysis of the obtained solution confirmed the presence of 2 and, for the first time, allowed its direct and unequivocal spectroscopic characterization. However, 2 appeared to be an elusive and unstable compound. In the meantime, an apparently cffcient, one-step synthesis of the imidazolone 2 starting from aminoacetonitrile hydrochloride and trimethyl orthoformate was reported4). After careful examination we reached the conclusion, indepcndently supported by other authors ' I, that such a reaction yields actually N-formylaminoacetonitrile as the main product. A by-product identical to that described from the same reaction when catalyzed by formic acid was also isolated. For this product the bicyclic structure 3 was proposed4). However, owing to a very weak stretching IR absorption at 2240 cm-', and to a signal at 116 ppm in the l3C-NMR spectrum due to the presence of a nitrile group, the monocyclic isomeric structure 4 must be considered more appropriate6). Compounds 5a, b were easily cyclized in excellent yields by treatment with formaldehyde to give the imidazolidinones 6a, b, respectively7! Hydrogenolysis of 6 b at 2.5 atm over Pd afforded the monobenzyl derivative 1 b, whereas removal of the amidic benzyl group required, as expectedXJ, conditions not compatible with our preparative purposes. The N-hydroxymethyl substituent could be eliminated from amides by high-pressure hydrogenolysis'~, by mild hydrolysis after oxidation to N-formyl derivatives lo), or by direct hydrolysis "I. However, hydrolytic treatment of the present compound 6 a was completely ineffective or led to concomitant destruction of the ring.We found a very efficient and simple method consisting in the thermal removal of formaldehyde in vacuo from 6a, which afforded in very good yields I-benzyl-4-imida~olidinone (6c). This compound was easily alkylated to give, for instance, 6d, e, thus becoming the precursor of a series of substituted imidazolidinones of potential pharmacological interest 12). Hydrogenolysis of the ...

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Labile Stoffwechselprodukte V. Zur Biogenese Des Formiminoglycins Aus 4(5H)‐Imidazolon

Cited by 21 publications

References 3 publications

Degradation of purines and pyrimidines by microorganisms.

Degradation of purines and pyrimidines by microorganisms.

Purine metabolism in Methanococcus vannielii

A short synthesis of 4‐imidazolidinone

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