Letters to the Editor

PEDIATRICS ◽  
1968 ◽  
Vol 41 (3) ◽  
pp. 690-691
Author(s):  
Grant Morrow ◽  
Lewis A. Barness
Keyword(s):  
Amino Acids ◽  
Quantitative Analysis ◽  
Carboxylic Acid ◽  
Urea Cycle ◽  
Moderate Increase ◽  
Keto Acid ◽  
Letters To The Editor ◽  
Keto Acids

We would like to thank Doctor Kekomäki for his letter letter concerning our patient with citrullinemia. Doctor Kekomäki's investigations are certainly quite interesting and may explain why we were unable to pick up equi-molar amounts of the urea cycle amino acids. Semi-quantitative analysis of the urine for α-keto acids revealed a moderate increase in α-keto glutarate and pyruvate following the arginine load but no unusual α-keto acid was noted. The urine was not tested for Δ-pyrroline-5-carboxylic acid.

Transamination of branched-chain keto acids by isolated perfused rat kidney.

1978 ◽  
Vol 235 (1) ◽  
pp. E47
Author(s):  
W E Mitch ◽  
W Chan
Keyword(s):  
Amino Acids ◽  
Rat Kidney ◽  
Branched Chain Amino Acids ◽  
Keto Acid ◽  
Branched Chain Amino Acid ◽  
Keto Acids ◽  
Perfused Rat Kidney ◽  
Branched Chain ◽  
Branched Chain Keto Acids ◽  
Isolated Rat

Isolated rat kidney perfused without substrate released serine, glycine, and taurine, and substantially smaller amounts of other amino acids. When branched-chain keto acids were added, the corresponding amino acids were released at rates amounting to 15-25% of keto acid disappearance. Perfusion with 2 mM alpha-keto-isovalerate or alpha-keto-beta-methylvalerate caused an increased glucose release amounting to 18-23% of keto acid disappearance. The activity of branched-chain amino acid transferase (BATase) was significantly stimulated by perfusion with the analogue of leucine, but not by perfusion with alpha-ketoglutarate, the analogues of valine or isoleucine, or with leucine itself. These findings document that the kidney converts branched-chain keto acids in part to the corresponding amino acids and suggest that the keto analogue of leucine may be involved in the control of renal BATase activity, thereby indirectly regulating the metabolism of branched-chain amino acids.

BLOOD BRANCHED-CHAIN AMINO AND α-KETO ACID CONCENTRATIONS AND NET EXCHANGE ACROSS THE PORTAL-DRAINED VISCERA AND HINDLIMB OF FED AND FASTED RUMINANTS

1987 ◽  
Vol 67 (4) ◽  
pp. 1011-1020 ◽  
Author(s):  
RICHARD J. EARLY ◽  
JAMES R. THOMPSON ◽  
ROBERT J. CHRISTOPHERSON ◽  
GARY W. SEDGWICK
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Hind Limb ◽  
Venous Blood ◽  
Branched Chain Amino Acids ◽  
Keto Acid ◽  
Branched Chain Amino Acid ◽  
Keto Acids ◽  
Branched Chain ◽  
Cattle And Sheep

In the first of two experiments, whole blood branched-chain amino acid (BCAA) and plasma branched-chain α-keto acid (BCKA) concentrations in jugular venous blood were determined in cattle and sheep before and during a 6-d fast. In cattle, concentrations of valine, isoleucine, α-ketoisovalerate (KIV) and α-ketomethylvalerate (KMV) remained unchanged whereas leucine and α-ketoisocaproate (KTC) increased (P < 0.05) during fasting. In sheep, only KIV and KMV remained unchanged whereas BCAA and KIC increased (P < 0.05) during fasting. In a second experiment on cattle chronically catheterized to measure BCAA and BCKA exchange across the portal-drained viscera (PDV) and hindlimb (HL), the PDV added and the HL removed BCAA from the blood of fed cattle. The opposite exchange occurred after a 6-d fast. Releases of BCKA from the PDV and HL in both fed and fasted states were small compared to BCAA exchanges. The data suggest that blood BCAA but not BCKA concentrations may respond differently to starvation in sheep versus cattle and that in cattle the PDV and HL do not release appreciable amounts of BCKA relative to the net movements of the BCAA. Key words: Portal-drained viscera, hind limb, branched-chain amino acids, branched-chain α-keto acids, fasting, ruminants

scholarly journals Ability of Thermophilic Lactic Acid Bacteria To Produce Aroma Compounds from Amino Acids

2004 ◽  
Vol 70 (7) ◽  
pp. 3855-3861 ◽  
Author(s):  
Sandra Helinck ◽  
Dominique Le Bars ◽  
Daniel Moreau ◽  
Mireille Yvon
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Amino Acid ◽  
Bacterial Species ◽  
Aroma Compounds ◽  
Lactobacillus Delbrueckii ◽  
Keto Acid ◽  
Amino Acid Catabolism ◽  
Catabolic Pathways ◽  
Keto Acids

ABSTRACT Although a large number of key odorants of Swiss-type cheese result from amino acid catabolism, the amino acid catabolic pathways in the bacteria present in these cheeses are not well known. In this study, we compared the in vitro abilities of Lactobacillus delbrueckii subsp. lactis, Lactobacillus helveticus, and Streptococcus thermophilus to produce aroma compounds from three amino acids, leucine, phenylalanine, and methionine, under mid-pH conditions of cheese ripening (pH 5.5), and we investigated the catabolic pathways used by these bacteria. In the three lactic acid bacterial species, amino acid catabolism was initiated by a transamination step, which requires the presence of an α-keto acid such as α-ketoglutarate (α-KG) as the amino group acceptor, and produced α-keto acids. Only S. thermophilus exhibited glutamate dehydrogenase activity, which produces α-KG from glutamate, and consequently only S. thermophilus was capable of catabolizing amino acids in the reaction medium without α-KG addition. In the presence of α-KG, lactobacilli produced much more varied aroma compounds such as acids, aldehydes, and alcohols than S. thermophilus, which mainly produced α-keto acids and a small amount of hydroxy acids and acids. L. helveticus mainly produced acids from phenylalanine and leucine, while L. delbrueckii subsp. lactis produced larger amounts of alcohols and/or aldehydes. Formation of aldehydes, alcohols, and acids from α-keto acids by L. delbrueckii subsp. lactis mainly results from the action of an α-keto acid decarboxylase, which produces aldehydes that are then oxidized or reduced to acids or alcohols. In contrast, the enzyme involved in the α-keto acid conversion to acids in L. helveticus and S. thermophilus is an α-keto acid dehydrogenase that produces acyl coenzymes A.

BIOSYNTHESIS OF RIBOFLAVIN BY EREMOTHECIUM ASHBYII: VIII. THE AMINO ACID AND KETO ACID POOLS OF THE MYCELIAL CELL-FREE EXTRACTS AND THEIR RELATION TO TRANSAMINASE ACTIVITIES AT DIFFERENT STAGES OF GROWTH

1965 ◽  
Vol 11 (4) ◽  
pp. 619-624 ◽  
Author(s):  
H. G. Osman ◽  
M. S. Chenouda
Keyword(s):  
Amino Acids ◽  
Chromatographic Analysis ◽  
Culture Medium ◽  
Qualitative Change ◽  
Keto Acid ◽  
Stages Of Growth ◽  
Cell Pool ◽  
Mycelial Extract ◽  
Keto Acids ◽  
Mycelial Cell

The chromatographic analysis of the mycelial extract revealed the presence of the following amino acids: cystine, lysine, arginine, histidine, serine, glycine, aspartic, glutamic, threonine, α-alanine, proline, α-aminobutyric, tyrosine, valine, and leucine. Of these, glutamic, aspartic, alanine, valine, leucine, glycine, and serine were the major components. No qualitative change was noticed in the types of the amino acids of 2-, 4-, 6-, and 8-day-old cultures. With the increasing age of the culture, glutamic and alanine decreased while serine and glycine increased. Aspartic and threonine did not show noticeable variations in quantity. Pyruvic and α-ketoglutaric acids were the only detectable keto acids either in the cell pool or in the culture medium. The mycelial cell-free extracts exhibited glutamic–oxalacetic transaminase and glutamic–pyruvic transaminase activities.

KETO ACIDS PRODUCED BY CHLAMYDOMONAS REINHARDTI

1967 ◽  
Vol 13 (8) ◽  
pp. 995-999 ◽  
Author(s):  
R. P. Collins ◽  
K. Kalnins
Keyword(s):  
Amino Acids ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Keto Acid ◽  
Culture Filtrates ◽  
Keto Acids ◽  
Layer Chromatography

It has been shown that a strain of Chlamydomonas reinhardti produces the following α-keto acids: α-ketosuccinic, α-ketoglutaric, pyruvic, α-ketobutyric, and α-ketoisovaleric. The α-keto acids obtained from cells and culture filtrates were identified as their 2,4-diaitrophenylhydrazones by thin-layer chromatography. Identification was confirmed by reduction of the keto acid hydrazones to amino acids, which were analyzed by thin-layer chromatography.

scholarly journals Electrochemical Molecular Conversion of α-Keto Acid to Amino Acid at a Low Overpotential Using a Nanoporous Gold Catalyst

2021 ◽  
Vol 22 (17) ◽  
pp. 9442
Author(s):  
Yasuhiro Mie ◽  
Shizuka Katagai ◽  
Chitose Mikami
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gold Electrode ◽  
Reductive Amination ◽  
Gold Catalyst ◽  
Nanoporous Gold ◽  
Keto Acid ◽  
Applied Potential ◽  
Keto Acids ◽  
Optimized Conditions

A nanoporous gold (NPG) electrode prepared through a facile anodization technique was employed in the electrochemical reductive amination of biomass-derivable α-keto acids in the presence of a nitrogen source to produce the corresponding amino acids. NPG showed a clear reductive current in the presence of α-keto acid and NH2OH, and the electrolysis experiments confirmed the production of L-amino acid. A reductive voltammetric signal at the NPG electrode appeared at a more positive potential by 0.18–0.79 V, compared with those at the planar-gold electrode without anodization and other previously reported electrode systems, indicating the high activity of the prepared nanostructure for the electrochemical reaction. Maximum Faradaic efficiencies (FEs) of 74–93% in the reductive molecular conversion to amino acids of Ala, Asp, Glu, Gly, and Leu were obtained under the optimized conditions. The FE values were strongly dependent on the applied potential in the electrolysis, suggesting that the hydrogen evolution reaction at the electrode surface was more significant as the applied potential became more negative. The effect of potential at the NPG was lower than that at the planar-gold electrode. These results indicate that nanostructurization decreases the overpotential for the electrochemical reductive amination, resulting in high FE.

Direct quantitative analysis of the natural moisturizing factor (NMF) in the stratum corneum by direct analysis in real time mass spectrometry (DART-MS)

2017 ◽  
Vol 9 (33) ◽  
pp. 4851-4857 ◽  
Author(s):  
Katsuyuki Maeno ◽  
Yasuo Shida ◽  
Haruo Shimada
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Quantitative Analysis ◽  
Carboxylic Acid ◽  
Stratum Corneum ◽  
Real Time ◽  
Direct Analysis ◽  
Urocanic Acid ◽  
Pyrrolidone Carboxylic Acid

Analyzing the natural moisturizing factor (NMF) in the stratum corneum (SC), such as amino acids, pyrrolidone carboxylic acid, and urocanic acid, is important in dermatology research.

Synthesis and Antibacterial Potency of 4-Methyl-2,7-dioxo-1,2,3,4,7,10- hexahydropyrido[2,3-ƒ]quinoxaline-8-carboxylic acid, Selected [a]-Fused Heterocyles and Acyclic Precursors

2007 ◽  
Vol 62 (11) ◽  
pp. 1453-1458 ◽  
Author(s):  
Yusuf M. Al-Hiari ◽  
Ali M. Qaisia ◽  
Mohammad Y.Abu Shuheil ◽  
Mustafa M. El-Abadelah ◽  
Wolfgang Voelter
Keyword(s):  
Amino Acids ◽  
Carboxylic Acid ◽  
Antibacterial Activities ◽  
Sodium Dithionite ◽  
E Coli ◽  
Pipecolinic Acid

The reaction of 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (7) with each of sarcosine and (±)-pipecolinic acid afforded the corresponding N-(4- oxoquinolin-7-yl)-α-amino acids 8 and 9. Reductive lactamization of the latter with sodium dithionite gave hexahydropyrido[2,3- f ]quinoxaline (10) and octahydrodipyrido[1,2-a : 2,3- f ]quinoxaline (11) derivatives, respectively. Compounds 8 - 11 and their homologs 1 - 6, accessible from (S)-proline, (2S, 4R)-4-hydroxyproline and (S)-tetrahydroisoquinoline-3-carboxylic acid exhibit good to excellent antibacterial activities against E. coli and S. aureus.

scholarly journals QUANTITATIVE ANALYSIS OF BIOACTIVE COMPOUNDS OF ARTEMISIA NILAGIRICA (CLARKE) PAMP. LEAF EXTRACT

2016 ◽  
pp. 183
Author(s):  
Parameswari P ◽  
Devika Rengaswamy
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Quantitative Analysis ◽  
Secondary Metabolites ◽  
Bioactive Compounds ◽  
Leaf Extract ◽  
Metabolic Reaction ◽  
Quantitative Investigation ◽  
Artemisia Nilagirica ◽  
Quantitative Examination

<p>ABSTRACT<br />Objective: The points of this exploration work were to decide the quantitative examination of bioactive mixes. Customarily, cutting edge meds rely<br />on the phytochemicals got from the plant source in bigger extents. Numerous bioactive auxiliary metabolites have a positive metabolic reaction on<br />different human diseases.<br />Methods: In the present examination, Artemisia nilagirica, leaves were gathered, dried, powdered and put away in hermetically sealed compartments<br />for quantitative investigation of phytochemicals according to standard strategies.<br />Results: The methanolic leaf concentrate of enrolled 4.33 mg of alkaloids, 1.22 mg of saponins, 12.4 mg of tannins, 24.3 mg of glycosides, 10.2 mg<br />terpenoids, 1.33 mg of coumarin, 59.4 mg of amino acids, 12.2 mg of fatty acids, 17.2 mg of flavonoids, 10.2 mg of phenols, and steroids in follows<br />separately.<br />Conclusion: The plant has a high helpful quality as far as an assortment of phytochemicals from leaf remove and had let to a sure level toward<br />extraction and refinement of specific bioactive mixes for human nourishment.<br />Keywords: Artemisia nilagirica, Secondary metabolites, Quantitative analysis, Leaf extract, Flavonoids.</p>

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