The colour reactions of the hydroxyskatoles

Heacock, R. A.; Mahon, M. E.

doi:10.1016/s0021-9673(00)99878-9

Cited by 43 publications

(8 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Both chromatograms were sprayed with );he pdimethylaminobenzaldehyde reagent. 35 No urea was detected in either chromatogram above the limit of detection of 2-5 kg. I t was determined that urea is stable under the acid hydrolysis conditions used.…”

Section: Methodsmentioning

confidence: 90%

Chemical evolution. 31. Mechanism of the condensation of cyanide to hydrogen cyanide oligomers

Ferris¹,

Edelson²

1978

J. Org. Chem.

View full text Add to dashboard Cite

Diamincimaleonitrile undergoes a rapid Ni(I1)-catalyzed or a much slower uncatalyzed decomposition to yield 2 equiv of cyanide. This is not an equilibration between diaminomaleonitrile and the dimer and trimer of HCN as shown by the absence of incorporation of H13CN when incubated with diaminomaleonitrile. The formation of urea and oxalic acid is enhanced and the steady-state concentration of diaminomaleonitrile is decreased when the oligomerization of HCN is performed in the presence of oxygen as compared to a pure nitrogen atmosphere. Small but significant yields of oxalic acid and urea were observed when oxygen was eliminated from the reaction solution. An oligomerization pathway is proposed which is consistent with these data. These findings are not consistent with the proposal that HCN condenses to heteropolypeptides via azacyclopropenylidene imine.Hydrogen cyanide oligomers are believed to have had a significant role in the prebiotic synthesis of purines, pyrimidines, and amino HCN condenses in a stegwise fashion to the dimer 1, trimer 2, and tetramer 3. It was pos-tulated that one or more of these simple HCN derivatives condenses further to yield HCN oligomers, a complex mixture of substances with a molecular weight of 500-1000. Purines, pyrimidines, and amino acids are released on hydrolysis of these oligomers. The oligomerization reaction is dependent only on the pH of the reaction mixture and is independent of added nucleophile.4 Urea and oxalic acid are also products of the oligomerization reaction. An investigation of the me chanism of formation of the oligomers was undertaken because these substances may have had a central role in the formation of biomolecules on the primitive earth. Results and DiscussionThe Proposed Equilibrium between Diaminomaleonitrile (3) and Aminomalononitrile (2). We proposed previously that the monomer, dimer ( l ) , trimer (2), and tetramer (3) of HCN readily equilibrate in aqueous ~o l u t i o n .~ The formation of a precipitate of AgCN when Ag+ is added to an aqueous solution of 3 provided support for this h y p o t h~s i s .~ The observation that diaminomaleonitrile releases cyanide 0022-326317811943-3989$01 .OO/O rapidly when treated with Ni2+ in NH40H solution, a method for the determination of cyanide ion, prompted a reinvestigation of the equilibrium proposed between 1,2, and 3. The catalyzed decomposition of diaminomaleonitrile requires the presence of both Ni2+ and NH3 if it is to proceed a t a rapid rate. Approximately 2 equiv of cyanide are released per mole of diaminomaleonitrile. If diaminomaleonitrile is in equilibrium with HCN, 4 equiv of cyanide would be detected as the Ni(CN)42-complex. The same yield of cyanide is obtained when the hydrolysis proceeds 4 X times slower in the absence of Ni2+. The similar yields of HCN in the catalyzed and uncatalyzed reactions suggest that overall decomposition pathways are the same in both reactions.The mechanisms of both the Ni2+-catalyzed and -uncatalyzed decomposition of diaminomaleonitrile are unclear. Hydrolysis of 3 ...

show abstract

Section: Methodsmentioning

confidence: 90%

Chemical evolution. 31. Mechanism of the condensation of cyanide to hydrogen cyanide oligomers

Ferris¹,

Edelson²

1978

J. Org. Chem.

View full text Add to dashboard Cite

show abstract

“…Fractions containing the p-AB-(Glu)2 were adjusted to pH 3.0, absorbed to a Dowex 50 column (5 by 10 mm), washed with water, eluted with 3 M ammonia, and purified by preparative thin-layer chromatography. The position of migration of the described compound was determined by spraying the plate with Ehrlich reagent (13). The p-AB-(Glu)2 isolated from the halobacteria and converted into the trimethyl ester by reaction for 2 h with 3 M HCl in methanol was identified by mass spectrometry (M+, m/z 437, 2.0% base peak; M+ -32, mlz 405, 9.0% base peak, and base peak at mlz 120).…”

Section: Methodsmentioning

confidence: 99%

Analysis and characterization of the folates in the nonmethanogenic archaebacteria

White

1988

J Bacteriol

View full text Add to dashboard Cite

A detailed analysis of the folate coenzymes in the nonmethanogenic archaebacteria has been performed. By using the Lactobacillus casei microbiological assay for folates, the levels of folates in Sulfolobus solfataricus and Sulfolobus acidocaldarius were found to be 3.7 and 8.3 ng/g (dry weight) of cells, respectively, compared with 88,000 and 28,000 ng/g (dry weight) of cells in Halobacterium halobium and Halobacterium strain GN-1, respectively. The levels of folates found in the Sulfolobus spp. were -100 times less than those found in the typical eubacterium, whereas the levels in the halobacteria were -10 times higher. The folate in Sulfolobus solfataricus was shown to consist of only 5-formyltetrahydropteroylglutamate, and the folate in Halobacterium strain GN-1 was shown to consist of only pteroyldiglutamate. The low folate levels in the Sulfolobus spp. are the same as those found in the methanogenic bacteria, suggesting that another C1 carrier may function in these cells.Folate and its polyglutamates are well-established coenzymes involved in C1 metabolism in both eubacteria and eucaryotes (1), and until recently, they were the only recognized C1 carriers known to function in nature. However, during work on the nature of the coenzymes involved in the reduction of carbon dioxide to methane in the methanogenic archaebacteria, a new pterin-containing coenzyme, methanopterin, was discovered and chemically characterized (22,23). On the basis of its structural similarity to folic acid and on the basis of biochemical evidence that it can serve as a single carbon carrier at the oxidation level of methenyl (6, 24), methylene (7,14), and methyl (8-10), there is little doubt that methanopterin functions in a manner analogous to that of folate in these cells. In addition, existing biosynthetic evidence indicates that methanopterin is the first example of a structurally modified folate (25)(26)(27). It also appears that folates are absent or at very low levels in these bacteria (5,14,17). The occurrence of this unique pterin-containing coenzyme in the methanogenic archaebacteria suggests that other structurally modified folates may be present in the other two groups of archaebacteria, i.e., the extremely thermophilic bacteria and the extremely halophilic bacteria. To address this possibility, the levels and the structures of compounds possessing folate bioactivity in these organisms have been investigated. MATERIALS AND METHODSChemicals and supplies. Nitrobenzoyl chloride was obtained from Aldrich Chemical Co., Inc., Milwaukee, Wis. and Halobacterium strain GN-1, supplied by Barbara J. Javor of the Scripps Institution of Oceanography, La Jolla, Calif., were grown for 3 to 4 days at 39°C on the complex medium described by Javor (16).To determine the effect of the growth medium on the cellular content of folate, cells were grown in 2.8-liter Fernbach flasks containing 1.5 liters of medium, aerated by shaking at 150 rpm. The large quantity of cells needed for the isolation and characterization of folates was grown in 20-...

show abstract

“…Methanobacterium formicicum JF-1, Methanobacterium bryantii MOH, and Methanospirillum hungatei JF were grown in 10-liter batches on a medium modified from Schauer and Ferry (15), consisting of 1.44 g of NH4C1, 1.14 g of K2HPO4, 1.14 g of KH2PO4, 0.5 g of yeast extract (Difco Laboratories, Detroit, Mich.), 0.5 g of tryptone (Difco), 6.0 g of sodium formate, 2.0 g of sodium acetate, 0.01 g of Fe(NH4)SO4, 5.0 g of Na2HCO3, 0.001 g of resazurin, 0.46 g of NaCl, 0.092 g of MgCl2 6H20, 0.26 g of CaCl2 .2H20, 0.25 g of cysteine hydrochloride, and 0.25 g of Na2S 9H20 per liter of water. In addition, vitamin and trace mineral solutions (2) were each added to a final 2% (vol/vol) concentration.…”

Section: Methodsmentioning

confidence: 99%

Structural diversity among methanofurans from different methanogenic bacteria

White

1988

J Bacteriol

View full text Add to dashboard Cite

An examination of the methanofurans isolated from a wide range of methanogenic bacteria and from Archaeoglobus fulgidus has revealed at least five chromatographically distinct methanofurans. Bacteria from each major genus of methanogenic bacteria have been found to contain a chemically different methanofuran. The nature of the differences in the methanofurans appears to lie in the modification of the side chain attached to the basic core structure of 4-[N-(-y-L-glutamyl--y-L-glutamyl)-p-(,-aminoethyl)phenoxymethyl]-2-(aminomethyl)furan. This was supported by the structural elucidation of the methanofuran isolated from Methanobrevibacter smithii, designated methanofuran-c, which was the same as the originally characterized methanofuran except for a hydroxy group at the 2 position of the 4,5-dicarboxyoctanedioic acid moiety of the molecule.Methanofuran (Fig. 1) is a recently characterized cofactor in the conversion of CO2 to methane by methanogenic bacteria (9-11). It is involved in the first step of CO2 reduction, where it serves as a C1 carrier at the formyl level of carbon oxidation (7,10 aminomethyl)furan with different attached side chain molecules. This is supported by the structural analysis of the methanofuran from Methanobrevibacter smithii, which shows it to consist of this basic core structure, peptide bonded, via the terminal glutamyl residue, to the C-1 of 2-hydroxy-4,5-dicarboxyoctanedioic acid (2-hydroxyDCO) (Fig. 1). MATERIALS AND METHODSBacterial strains and growth. Methanobacterium formicicum JF-1, Methanobacterium bryantii MOH, and Methanospirillum hungatei JF were grown in 10-liter batches on a medium modified from Schauer and Ferry (15), consisting of 1.44 g of NH4C1, 1.14 g of K2HPO4, 1.14 g of KH2PO4, 0.5 g of yeast extract (Difco Laboratories, Detroit, Mich.), 0.5 g of tryptone (Difco), 6.0 g of sodium formate, 2.0 g of sodium acetate, 0.01 g of Fe(NH4)SO4, 5.0 g of Na2HCO3, 0.001 g of resazurin, 0.46 g of NaCl, 0.092 g of MgCl2 6H20, 0.26 g of CaCl2 .2H20, 0.25 g of cysteine hydrochloride, and 0.25 g of Na2S 9H20 per liter of water. In addition, vitamin and trace mineral solutions (2) were each added to a final 2% (vol/vol) concentration. Methanobrevibacter smithii PS was grown in 3-liter batches on a medium modified from that of Lovley et al. (13), consisting of 0.45 g of K2HPO4, 0.15 g of KH2PO4, 0.12 g of NH4C1, 0.3 g of NaCl, 0.04 g of CaCl2 2H20, 2.5 g of NaHCO3, 0.14 g of MgCl2 6H20, 2.5 g of sodium acetate, 5.0 g of sodium formate, 2.0 g of yeast extract, 2.0 g of tryptone, 0.0001 g of resazurin, 0.5 g of cysteine hydrochloride, and 0.5 g of Na2S 9H20 per liter of water. Also added were antifoam C, 0.0005% (vol/vol); vitamin and trace mineral solutions (2), 1% each (vol/vol); iosbutyric, 2-methylbutyric, isovaleric, and valeric acids, each to a final concentration of 0.0005% (vol/vol); and Tween 80, 0.002% (vol/vol).Methanococcus maripaludis JJ was provided by William B. Whitman, Department of Microbiology, University of Georgia, Athens. The organism was grown by Whitman on a comple...

show abstract

The colour reactions of the hydroxyskatoles

Cited by 43 publications

References 16 publications

Chemical evolution. 31. Mechanism of the condensation of cyanide to hydrogen cyanide oligomers

Chemical evolution. 31. Mechanism of the condensation of cyanide to hydrogen cyanide oligomers

Analysis and characterization of the folates in the nonmethanogenic archaebacteria

Structural diversity among methanofurans from different methanogenic bacteria

Contact Info

Product

Resources

About