scholarly journals The chemistry of flavines and flavoproteins. Photoreduction of flavines by amino acids

1968 ◽  
Vol 109 (2) ◽  
pp. 259-268 ◽  
Author(s):  
G. R. Penzer ◽  
G. K. Radda
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Light Intensity ◽  
Potassium Iodide ◽  
Aromatic Compounds ◽  
Phenylacetic Acid ◽  
Intramolecular Interaction ◽  
Kinetic Scheme ◽  
Dimethyl Sulphoxide ◽  
Triplet States

1. Flavines are photoreduced through their triplet states by amines and amino acids (e.g. EDTA and dl-phenylglycine). The anaerobic photoreduction of FMN and several other flavines with dl-phenylglycine was analysed in terms of a detailed kinetic scheme. 2. The reaction produces equimolar amounts of benzaldehyde, carbon dioxide and reduced flavine. 3. The sensitivity of the rates to substituents in the dl-phenylglycine can be described by a Hammett ρ-value of −1·1. 4. Phenylacetic acid behaves differently from dl-phenylglycine or benzylamine towards a series of flavines. 5. The photoreductions are quenched by several aromatic compounds. From the effects of light-intensity and temperature, and by comparison with potassium iodide quenching, it is concluded that inhibition by the aromatic compounds is not simply a collisional process. 6. FAD reacts more slowly than FMN both in the photoreduction and in dark reduction by NADH. Urea and dimethyl sulphoxide decrease the intramolecular interaction in FAD, but they have no effect on the rate of dark reduction of FAD compared with FMN. In contrast, the photoreduction of FAD is quicker in urea.

METABOLISM OF AROMATIC COMPOUNDS IN HEALTHY AND RUST-INFECTED PRIMARY LEAVES OF WHEAT: II. STUDIES WITH L-PHENYLALANINE-U-14C, L-TYROSINE-U-14C, AND FERULATE-U-14C

1967 ◽  
Vol 45 (11) ◽  
pp. 2137-2153 ◽  
Author(s):  
A. Fuchs ◽  
R. Rohringer ◽  
D. J. Samborski
Keyword(s):  
Amino Acids ◽  
Stem Rust ◽  
Aromatic Compounds ◽  
The Other ◽  
Major Portion ◽  
Insoluble Residue ◽  
Resistant Reaction ◽  
Wheat Leaves

Wheat leaves infected with stem rust, especially those of susceptible plants, contained more phenylalanine and tyrosine than healthy leaves. The utilization of phenylalanine was increased in both the susceptible and resistant reaction, but the utilization of tyrosine was increased only in the susceptible reaction. No evidence of interconversion of these amino acids was obtained.In n-butanol extracts, which contained glycosides, many constituents were labelled after feeding of L-phenylalanine-U-14C. Most of the n-butanol extractives from resistant-reacting leaves contained more label than those from susceptible-reacting leaves or from healthy leaves. However, one of the n-butanol extractives from susceptible-reacting leaves was 5–10 times as active as that isolated from the other tissues.With L-phenylalanine-U-14C and ferulate-U-14C as precursors, more activity was recovered in insoluble than in soluble esters (of ferulate and p-coumarate). With L-tyrosine-U-14C as precursor, the reverse was observed. After infection, the proportion of label in insoluble esters increased more in resistant leaves than it did in susceptible leaves, regardless of the precursor used.A major portion of the activity from these precursors was recovered in the insoluble residue that contained protein and other polymers. In the experiment with L-phenylalanine-U-14C, this residue was fractionated into protein and non-hydrolyzable material. Susceptible-reacting leaves contained equal amounts of activity in these fractions, while resistant-reacting leaves incorporated 2.5 times as much activity into the non-hydrolyzable material as into protein.

Iodination of Aromatic Compounds Using Potassium Iodide and Hydrogen Peroxide

2008 ◽  
Vol 38 (22) ◽  
pp. 3894-3902 ◽  
Author(s):  
K. Suresh Kumar Reddy ◽  
N. Narender ◽  
C. N. Rohitha ◽  
S. J. Kulkarni
Keyword(s):  
Hydrogen Peroxide ◽  
Potassium Iodide ◽  
Aromatic Compounds

Adsorption of carbon dioxide on naturally occurring solid amino acids

2016 ◽  
Vol 4 (3) ◽  
pp. 3170-3176 ◽  
Author(s):  
Sreedipta Chatterjee ◽  
Sadhana Rayalu ◽  
Spas D. Kolev ◽  
Reddithota J. Krupadam
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Naturally Occurring

COMPETITION BETWEEN AMINO ACIDS FOR TRANSPORT INTO EHRLICH ASCITES CARCINOMA CELLS

1961 ◽  
Vol 39 (11) ◽  
pp. 1717-1735 ◽  
Author(s):  
P. G. Scholefield
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Amino Acid ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Transport Systems ◽  
Radioactive Carbon ◽  
Ehrlich Ascites ◽  
Competitive Inhibitors ◽  
Amino Acid Analogues

The cumulative entry of amino acids into Ehrlich ascites carcinoma cells is due to the presence of active transport systems, each with its own specific range of substrates. Several amino acids and amino acid analogues may have an affinity for the same transport system and thus may inhibit transport of other amino acids by acting as competitive inhibitors or competitive substrates. Loss of methionine from ascites cells takes place by a diffusion process which obeys Fick's law. Leucine accumulation by ascites cells is small and is increased on addition of certain other amino acids. The increase is not due to inhibition of leucine oxidation as increase in the rate of production of radioactive carbon dioxide from labeled leucine also occurs. Kinetic aspects of these results are discussed.

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