scholarly journals HISTOCHEMICAL DIFFERENTIATION BETWEEN TYROSINE AND CHLOROGENIC ACID IN PLANT TISSUES I. NITROUS ACID REACTIONS AND METAL CHELATION OF NITROSOTYROSINE

1968 ◽  
Vol 16 (3) ◽  
pp. 191-198 ◽  
Author(s):  
R. M. REEVE
Keyword(s):  
Amino Acids ◽  
Chlorogenic Acid ◽  
Nitrous Acid ◽  
Metal Chelate ◽  
Ultrastructural Localization ◽  
Plant Tissues ◽  
Metal Chelation ◽  
Copper Chelation ◽  
Acid Reaction ◽  
Color Reactions

Copper chelation of nitrosotyrosine has been found useful for histochemical localization for tyrosine in thick, fresh sections of large celled plant tissues. The nitrous acid reaction for ortho-dihydroxyphenolics also has been found useful for localization of chlorogenic acid, caffeic acid and dihydroxyphenylalanine in plant tissues. Application of these tests separately to serially adjacent sections demonstrated the distribution of tyrosine and chlorogenic acid in different plant tissues. Tests tube reactions on known substances verified specificity and also demonstrated that the presence of other amino acids and phenolics did not interfere with the positive test for tyrosine. The color reactions are sufficiently intense for stereoscopic microscopy and tested sections may be measured photometrically. Further adaptability of the nitrosotyrosine-metal chelate reaction to procedures for ultrastructural localization is suggested.

scholarly journals Localization of D-amino acid oxidase on the cell surface of human polymorphonuclear leukocytes

1978 ◽  
Vol 77 (1) ◽  
pp. 59-71 ◽  
Author(s):  
JM Robinson ◽  
RT Briggs ◽  
MJ Karnovsky
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cell Surface ◽  
Polymorphonuclear Leukocytes ◽  
Ultrastructural Localization ◽  
H2o2 Production ◽  
Acid Oxidase ◽  
Resting Cells ◽  
Amino Acid Oxidase ◽  
Human Polymorphonuclear Leukocytes

The ultrastructural localization of D-amino acid oxidase (DAO) was studied cytochemically by detecting sites of hydrogen peroxide production in human polymorphonuclear leukocytes (PMNs). Reaction product, which forms when cerous ions react with H2O2 to form an electron-dense precipitate, was demonstrated on the cell surface and within the phagosomes of phagocytically stimulated cells when D-amino acids were provided as substrate. Resting cells showed only slight activity. The competitive inhibitor D,L-2-hydroxybutyrate greatly reduced the D-amino acid-stimulated reaction while KCN did not. The cell surface reaction was abolished by nonpenetrating inhibitors of enzyme activity while that within the phagosome was not eliminated. Dense accumulations of reaction product were formed in cells which phagocytosed Staphylococcus aureus in the absence of exogenous substrate. No reaction product formed with Proteus vulgaris while an intermediate amount formed when Escherichia coli were phagocytosed. Variation in the amount of reaction product with the different bacteria correlated with the levels of D-amino acids in the bacterial cell walls which are available for the DAO of PMNs. An alternative approach utilizing ferricyanide as an electron acceptor was also used. This technique verified the results obtained with the cerium reaction, i.e., the DAO is located in the cell surface and is internalized during phagocytosis and is capable of H2O2 production within the phagosome. The present finding that DAO is localized on the cell surface further supports the concept that the plasma membrane is involved in peroxide formation in PMNs.

γ-Amino-Butyric Acid and β-Alanine in Plant Tissues: Amino-Acids of the Apple Fruit

Nature ◽  
1950 ◽  
Vol 165 (4201) ◽  
pp. 716-717 ◽  
Author(s):  
A. C. HULME ◽  
W. ARTHINGTON
Keyword(s):  
Amino Acids ◽  
Butyric Acid ◽  
Apple Fruit ◽  
Plant Tissues ◽  
Amino Butyric Acid

THE WEIGHT-DEPRESSING ACTION OF α-METHYL-DL-TRYPTOPHAN IN THE RAT

1962 ◽  
Vol 40 (1) ◽  
pp. 739-747 ◽  
Author(s):  
I. Sankoff ◽  
T. L. Sourkes
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Glyoxylic Acid ◽  
Essential Amino Acids ◽  
Enzymic Activity ◽  
B Vitamins ◽  
Metabolic Studies ◽  
Comparable Effect ◽  
Acid Reaction ◽  
Tryptophan Pyrrolase

α-Methyl-DL-tryptophan, injected intraperitoneally into rats, has a weight-depressing action lasting up to 72 hours. Dosages in the range 0.015–2.0 millimoles/kg body weight (3.3–436 mg/kg) are effective. Attempts to antagonize the weight-depressing action by giving essential amino acids and B vitamins were unsuccessful. Metabolic studies have shown that about half the injected dose of the compound (or its derivatives), as measured by the Hopkins–Cole glyoxylic acid reaction, is excreted in the urine in 24 hours; most of this appears during the first 4 hours after the injection. Ina search for an explanation for the weight-depressing action of α-methyltryptophan, tryptophan pyrrolase activity in the liver was estimated. This enzymic activity increases for 8 hours after the injection of α-methyltryptophan, and thereafter remains high for 72 hours. Tryptophan-injected animals showed increases in tryptophan pyrrolase level for 1.5 hours, and a return to normal concentrations within 24 hours. Other α-methyl amino acids which were tested had no comparable effect on body weight.

USE OF KANAMYCIN FOR THE ISOLATION OF AUXOTROPHIC MUTANTS OF ACTINOBACILLUS MALLEI

1966 ◽  
Vol 12 (4) ◽  
pp. 641-652 ◽  
Author(s):  
D. H. Evans
Keyword(s):  
Amino Acids ◽  
Nitrous Acid ◽  
Minimal Medium ◽  
Inhibitory Concentration ◽  
Bactericidal Effect ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Auxotrophic Mutants ◽  
Viable Cells ◽  
Minimal Media

Growth of Actinobacillus mallei was inhibited by kanamycin; the minimal inhibitory concentration in a complex medium was 1.25 μg/ml and in a chemically defined medium 5 μg/ml. Higher concentrations of kanamycin had a pronounced bactericidal effect. When a suspension of cells containing 5 × 107 viable cells/ml was incubated in the presence of 20 μg/ml of kanamycin in a chemically defined medium, complete sterilization resulted after 6 hours. Cells irradiated with ultraviolet light were grown in complex or supplemental minimal media, washed, and exposed to 20 μg/ml of kanamycin in minimal medium for 4 hours. Auxotrophic mutants with requirements for tryptophane, phenylalanine, proline, and uracil were detected among the survivors of kanamycin treatment. After treatment with 0.01 M nitrous acid and growth in minimal medium supplemented with amino acids, cells were washed and then exposed to kanamycin in minimal medium. The proportion of autotrophs among the survivors varied from 1.3 to 75%. Mutants with requirements for each of the following amino acids were identified: methionine, methionine or cystine, arginine, leucine, tryptophane, histidme, and proline, with methionine-requiring mutants predominating. Exposure of mixtures of prototrophs and uracil-dependent and methionine-dependent auxotrophs to 20 μg/ml of kanamycin for 4 hours resulted in approximately 700- and 300-fold increases, respectively, in the ratio of auxotrophs to prototrophs.

Effect of inclusion complex on nitrous acid reaction with flavonoids

2011 ◽  
Vol 81 (1) ◽  
pp. 661-665 ◽  
Author(s):  
Lida Khalafi ◽  
Mohammad Rafiee ◽  
Sajjad Sedaghat
Keyword(s):  
Inclusion Complex ◽  
Nitrous Acid ◽  
Acid Reaction

ChemInform Abstract: Kinetic Study of the Phenylurea-Nitrous Acid Reaction: Evidence for an O-Nitrosation Initial Step.

ChemInform ◽  
1988 ◽  
Vol 19 (14) ◽  
Author(s):  
F. MEIJIDE ◽  
J. VAZQUEZ TATO ◽  
J. CASADO ◽  
A. CASTRO ◽  
M. MOSQUERA
Keyword(s):  
Kinetic Study ◽  
Nitrous Acid ◽  
Initial Step ◽  
Acid Reaction
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