Pterins. III. Methylation of 6-Methyl-5,6,7,8-tetrahydropterin, N-5-Demethylation of 1,3,5,6-Tetramethyl-5,6,7,8-tetrahydropterinium chloride hydrochloride and exchange of the 5-Methyl group in 5,6-Dimethyl-5,6,7,8-tetrahydropterin

1978 ◽  
Vol 31 (5) ◽  
pp. 1081 ◽  
Author(s):  
WLF Armarego ◽  
H Schou
Keyword(s):  
Sodium Hydroxide ◽  
Aqueous Ammonia ◽  
Methyl Group ◽  
Aerial Oxidation ◽  
Tetrahydrofolic Acid

Methylation of 6-methyl-5,6,7,8-tetrahydropterin (1) in the presence of sodium hydroxide furnishes 1,3,6-trimethyl-5,6,7,8-tetrahydropterinium chloride (3) which can be methylated further to yield 1,3,5,6- tetramethyl-5,6,7,8-tetrahydropterinium chloride (4). Demethylation of the latter salt occurred on a Dowex 50W/3 N-aqueous ammonia column with loss of the 5-methyl group to give the salt (3). The structures of these salts were deduced by a study of similar alkylations of authentic 1,6-dimethyl-,3,6-dimethyl- (6), 5,6-dimethyl-(15), 6,8-dimethyl-, 1,5,6-trimethyl-, and 3,5,6-trimethyl-5,6,7,8-tetrahydropterin (7), and of 6-methyl-2-methylamino-5,6,7,8-tetrahydropteridin- 4(3H)-one (10). Methylation of 5,6-dimethyl-5,6,7,8-tetrahydropterin (15), with trideuteromethyl iodide in the presence of alkali, was shown to give the tetramethylpterinium salt (4) in which considerable exchange of the 5-methyl group by a trideuteromethyl group had taken place. ��� The pterinium salts (3) and (4) were considerably more stable to aerial oxidation than 6-methyl-, 1,6-, 3,6-, 5,6-, 6,7-, 6,8-dimethyl-, and 1,5,6-trimethyl-5,6,7,8-tetrahydropterin. Loss of the 5-methyl group from the salt (4), and exchange of the 5-methyl group in the 5,6- dimethylpterin (15), allowed a mechanism for the enzymic transfer of the 5-methyl group in 5-methyl-5,6,7,8-tetrahydrofolic acid in biological methylations to be proposed.

Urea treatment as a means of preserving/processing moist wheat for intensively finished cattle

1999 ◽  
Vol 1999 ◽  
pp. 54-54 ◽  
Author(s):  
M. Lewis ◽  
B.G. Lowman ◽  
M. Ford
Keyword(s):  
Sodium Hydroxide ◽  
Dry Matter ◽  
Aqueous Ammonia ◽  
Wheat Variety ◽  
Urea Solution ◽  
Processing Methods ◽  
Urea Treatment

Wheat requires processing for feeding to cattle otherwise large amount remain undigested. Processing methods can be mechanical or chemical (sodium hydroxide or aqueous ammonia) but these require specialised equipment and/or the use of contractors. The objective of this trial was to evaluate moist wheat fed whole, but treated with urea at harvest as a means of generating ammonia in situ, in diets for intensively finished cattle.Eighty tonnes of wheat (variety Riband) was harvested on 21-22 August 1997 at a dry matter (DM) of 750 g/kg and treated immediately with 53 l/tonne of a urea solution (430 g urea/litre) to supply 30 g urea/kg wheat DM. Treatment was achieved by applying the urea to the wheat as it was augered into the storage silo, which was then sealed with polythene.

scholarly journals Synthesis of the anhydrides of α-aminoacyl glucosamines

1913 ◽  
Vol 88 (605) ◽  
pp. 455-461 ◽  
Keyword(s):  
Amino Acids ◽  
Sodium Hydroxide ◽  
Aqueous Ammonia ◽  
Degradation Products ◽  
Amino Sugars ◽  
Amino Group ◽  
Glucosamine Hydrochloride ◽  
Aliphatic Acids ◽  
Condensation Products

The behaviour of the albumin glucosides and the mucus bodies known as mucins, mucinogens, mucoids , and hyalogens , on hydrolysis suggests the probability that these complex proteins would bear the same relation to the condensation products of the sugars or the amino-sugars with the amino-acids as the simpler proteins bear to the polypeptides. Consequently, the authors decided two years ago to make a start in the synthesis of the glucoproteins by preparing the condensation products of glucosamine with the amino-aliphatic acids, in order that their properties and behaviour towards ferments could be ascertained and compared with those of the degradation products of the glucoproteins and thereby throw some light on the constitution of these complex and important organic bodies. After many failures, the method of synthesis which we eventually adopted for the condensation of glucosamine with amino-aliphatic acids was somewhat similar to one of the methods employed by Emil Fischer and his co-workers in the synthesis of the polypeptides. In brief, the method consists in condensing α -bromoacyl haloids with glucosamine hydrochloride in the presence of sodium hydroxide, and then displacing the halogen in the resulting α -bromoacyl glucosamines by an amino-group through the action of cold aqueous ammonia, viz:- α -Bromoacyl Haloid + Glucosamine Hydrochloride. sodium ↓ hydroxide. α -Bromoacyl Glucosamine. aqueous ↓ ammonia. Anhydride of α -Aminoacyl Glucosamine.

scholarly journals Two-Step Delignification of Miscanthus To Enhance Enzymatic Hydrolysis: Aqueous Ammonia Followed by Sodium Hydroxide and Oxidants

2014 ◽  
Vol 28 (1) ◽  
pp. 542-548 ◽  
Author(s):  
Zhongguo Liu ◽  
Sasisanker Padmanabhan ◽  
Kun Cheng ◽  
Hongxue Xie ◽  
Amit Gokhale ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sodium Hydroxide ◽  
Aqueous Ammonia

Methanol and methyl group conversion in acetogenic bacteria: Biochemistry, physiology and application

2020 ◽  
Author(s):  
Florian Kremp ◽  
Volker Müller
Keyword(s):  
Low Cost ◽  
Methanol Conversion ◽  
Methyl Group ◽  
Bulk Chemicals ◽  
Acetogenic Bacteria ◽  
Bulk Chemical ◽  
Tetrahydrofolic Acid ◽  
Alternative Sources ◽  
Biochemical Production ◽  
Emission Of Greenhouse Gases

Abstract The production of bulk chemicals mostly depends on exhausting petroleum sources and leads to emission of greenhouse gases. Within the last decades the urgent need for alternative sources has increased and the development of bio-based processes received new attention. To avoid the competition between the use of sugars as food or fuel, other feedstocks with high availability and low cost are needed, which brought acetogenic bacteria into focus. This group of anaerobic organisms uses mixtures of CO2, CO and H2 for the production of mostly acetate and ethanol. Also methanol, a cheap and abundant bulk chemical produced from methane, is a suitable substrate for acetogenic bacteria. The microorganisms with the ability to convert methanol (or methyl groups from other sources) are summarized in the group of methylotrophs that includes aerobic as well as anaerobic organisms like acetogens. In methylotrophic acetogens the methyl group is transferred to the Wood-Ljungdahl pathway, a pathway to reduce CO2 to acetate via a series of C1-intermediates bound to tetrahydrofolic acid. Here we describe the biochemistry and bioenergetics of methanol conversion in the biotechnologically interesting group of anaerobic, acetogenic bacteria. Further, the bioenergetics of biochemical production from methanol is discussed.

The Mechanism of Gelation of Latexes

1952 ◽  
Vol 25 (3) ◽  
pp. 596-608
Author(s):  
R. M. Panich ◽  
K. A. Kalyanova ◽  
S. S. Voyutskiĭ
Keyword(s):  
Zinc Oxide ◽  
Sodium Hydroxide ◽  
Strong Influence ◽  
Aqueous Ammonia ◽  
Ammonium Hydroxide ◽  
Ammonium Ion ◽  
Ammonium Ions ◽  
Alkali Solutions ◽  
Hydroxyl Ion ◽  
High Alkalinity

Abstract 1. The solubility of zinc oxide in ammonia and sodium hydroxide solutions was studied. In this case the presence of an ammonium salt in the system has a strong influence, and increases the solubility of zinc oxide, because the ammonium ion inhibits dissociation of ammonium hydroxide into NH4+ and OH− ions, and thus aids the formation of complex zinc-ammonium ions. We established that, in the 0–60° range, the temperature has little effect on the solubility of zinc oxide in aqueous ammonia. 2. The action of the zinc-ammonium ion on solutions of stabilizers of the soap type is explained, and it is shown that, at sufficiently high alkalinity, zinc-ammonium soaps do not precipitate from solution, but remain in a colloid state, stabilized by the alkaline soap or hydroxyl ion. 3. It is established that, in the absence of the ammonium ion, zinc oxide does not cause gelation of latexes stabilized by soaps. 4. The effect of formaldehyde on the gelation of latexes stabilized with soaps has been studied. 5. The reactions which can take place when zinc oxide is added to ammonia and alkali solutions, to ammonium and alkaline soap solutions, and to ammoniated and non-ammoniated latexes are discussed. A scheme of successive reactions which must take place during the gelation of latexes stabilized with soaps is presented.

A complex of gallium with a Schiff base - bis(orthoquinone) ligand

1999 ◽  
Vol 77 (4) ◽  
pp. 502-510 ◽  
Author(s):  
Martyn A Brown ◽  
Jesus A Castro ◽  
Bruce R McGarvey ◽  
Dennis G Tuck
Keyword(s):  
Schiff Base ◽  
Liquid Ammonia ◽  
Aqueous Ammonia ◽  
Tridentate Ligand ◽  
Triclinic Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Spin Resonance ◽  
Aerial Oxidation ◽  
A Cell

The electrochemical oxidation of gallium in a cell containing a solution of 3,5-di-tert-butylcatechol (H2dbc) in a mixture of liquid ammonia and diethyl ether gives rise to the complex Ga(dbqdi)2, where dbqdi is a tridentate ligand formed by the condensation of two molecules of H2dbc and ammonia. The same paramagnetic molecule can be prepared by treating GaCl3 with H2dbc in ethanol with concentrated aqueous ammonia, with subsequent aerial oxidation. The crystal parameters are triclinic, space group P[Formula: see text], a = 11.6140(8), b = 12.3415(9), c = 20.765(1) Å, α = 89.491(1)°, β = 74.287(1)°, γ = 75.748(1)°, Z = 2, and R = 0.0542 for 7578 unique reflections. The structure, which is based on a GaO4N2 kernel, is discussed on the basis of crystallographic and ESR results.Key words: gallium, electrochemical synthesis, electron spin resonance, X-ray crystallography.

The metabolism of some folates in the rat

1975 ◽  
Vol 33 (3) ◽  
pp. 299-308 ◽  
Author(s):  
J. R. G. Beavon ◽  
J. A. Blair
Keyword(s):  
Body Weight ◽  
Oral Administration ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Small Extent ◽  
Methyl Group ◽  
Tetrahydrofolic Acid ◽  
Layer Chromatography

1. A number of folates labelled with 14C were administered orally to rats, at various doses, and urinary, faecal and hepatic folates examined.2. 10-Formylpteroylmonoglutamic acid (10CHO—PGA) entered the folate pool very slowly, and is thought to be relatively ineffective in nutrition.3. 10-Formyl[2-14C]tetrahydrofolic acid (10CHO—[2-14C]THF) entered the folate pool very rapidly. 5-Methyl[2-14C]tetrahydrofolate (5CH3—[2-14C]THF) was the major urinary folate.4. 5-Formyl[2-14C]tetrahydrofolic acid (5CHO—[2-14C]THF) entered the folate pool only to a small extent. 5CHO—[2-14C]THF, given intravenously, produced no urinary 5CH3—[2-14C]THF in the first 6 h.5. 10-Methylidyne[2-14C]tetrahydrofolic acid was metabolized to an extent which was dependant on the dose. At doses of 3 and 30 μg/kg body-weight, 5CH3—[2-14C]THF represented 5·4 and 20% respectively of urinary folates and for 10CHO—[2-14]PGA, the values were 16% of total urinary folates after the higher dose, and 78·5% after the lower dose.6. Results obtained for the metabolism of 5CH3—THF varied depending on the position of the labelling: 514CH3–THF gave no labelled urinary folate, the methyl group being lost rapidly. When 5CH3—[2-14C]THF was given, it appeared as the major urinary folate.7. Folates found in the liver after oral administration of labelled folates were identified by thin-layer chromatography; only folate monoglutamates were identified.

Aflatoxin Destruction in Corn Using Sodium Bisulfite, Sodium Hydroxide and Aqueous Ammonia

1980 ◽  
Vol 43 (7) ◽  
pp. 571-574 ◽  
Author(s):  
KURT E. MOERCK ◽  
PAUL McELFRESH ◽  
ALAN WOHLMAN ◽  
BARNEY W. HILTON
Keyword(s):  
Moisture Content ◽  
Ambient Temperature ◽  
Sodium Hydroxide ◽  
Aflatoxin B1 ◽  
Aqueous Ammonia ◽  
Sodium Bisulfite ◽  
Total Aflatoxin ◽  
Yellow Corn ◽  
Dent Corn ◽  
Aflatoxin B2

Naturally contaminated yellow dent corn containing 235 ppb of aflatoxin B1 and B2 was adjusted to a moisture content of 20% and then treated for 24 h at ambient temperature with NaHS03, NaOH or aqueous NH3 at 0.5%, 1.0%, or 2.0% concentrations. All treatments were effective in reducing aflatoxin B1 and B2 levels. Sodium bisulfite was more effective in destroying aflatoxins than were NaOH or aqueous NH3 at 0.5% and 1.0% concentrations, while NaOH and aqueous NH3 were more effective than bisulfite at 2.0% concentration. Subjecting yellow corn samples to either NaHSO3, NaOH or aqueous NH3 at 2.0% concentrations reduced aflatoxin B1 and B2 levels to below the FDA guideline of 20 ppb total aflatoxin. Sodium bisulfite was also effective in reducing the levels of aflatoxins in a white dent corn sample containing 81 ppb of aflatoxin B1 and 12 ppb of aflatoxin B2. Results suggest that NaHSO3, NaOH or aqueous NH3 can be used to effectively destroy aflatoxins in corn and possibly other agricultural commodities.

scholarly journals Effect of Vitamin B12 deficiency on phosphatidylethanolamine methylation in rat liver

1978 ◽  
Vol 40 (3) ◽  
pp. 521-527 ◽  
Author(s):  
B. Åkesson ◽  
C. Fehling ◽  
Margaretha JÄGerstad
Keyword(s):  
Chemical Analysis ◽  
Vitamin B12 ◽  
Phospholipid Composition ◽  
Vitamin B12 Deficiency ◽  
Lower Proportion ◽  
Vitamin B ◽  
Methyl Group ◽  
B12 Deficiency ◽  
Tetrahydrofolic Acid ◽  
Phosphatidylcholine Synthesis

1. In vitamin B12 deficiency the activity of tetrahydropteroylglutamate methyltransferase (EC 2.1.1.13) is depressed and the synthesis of methionine is reduced. Because the methyl group of methionine is largely utilized for the methylation of phosphatidylethanolamine, we investigated the effects of vitamin B12 deficiency on phosphatidylcholine synthesis.2. The incorporation of injected [14Clformaldehyde into liver phosphatidylcholine was reduced by approximately 50% in vitamin B12-deficient rats. Also the corresponding incorporation of 5-[14C]methyl-tetrahydrofolic acid tended to decrease. The findings are consistent with a lower conversion of these precursors to methionine.3. The effect of the deficient methyl-group supply on phosphatidylcholine synthesis was also investigated by the injection of [14C]ethanolamine. The amount (%) of lipid-14C recovered in phosphatidylcholine was significantly reduced in vitamin B12 deficiency.4. Chemical analysis of liver phospholipids showed that the vitamin B12-deficient rats had a higher proportion of phosphatidylethanolamine and a lower proportion of phosphatidylcholine, indicating that the impaired synthesis of phosphatidylcholine by methylation leads to changes in membrane phospholipid composition.

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