The protective effect of amino acids on the copper(II)-catalyzed autoxidation of ascorbic acid

2020 ◽  
Vol 16 (6) ◽  
Author(s):  
F. Imer ◽  
E. Aldemir ◽  
H. Kiliç ◽  
I. Sonmezoǧlu ◽  
R. Apak
Author(s):  
V. B. Dolgo-Saburov ◽  
N. I. Chalisova ◽  
L. V. Lyanginen ◽  
E. S. Zalomaeva

In an organotypic culture, an investigation was conducted into combined effects of cyclophosphamide DNA as synthesis inhibitor used to model a resorptive action of mustard gas, and cortexin polypeptide or each of 20 encoded amino acids on the development of cell proliferation in cerebral cortex explants of the rat. The combined administration of cyclophosphamide together with cortexin or with each of the 20 encoded amino acids, except glycine, showed suppression of the cytostatic agent inhibitory effect. Thus, cortexin and amino acids have a protective effect on cell proliferation in the tissue culture of the central nervous system under the action of mustardlike substances.


1957 ◽  
Vol 3 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Francis E. Clark

Nodulation responses and certain other characteristics of a mutant soybean line highly recalcitrant to nodulation were compared with those of a nodulating sister line. Roots of the two lines were found to harbor equal numbers of rhizobia. Stem graftings to provide top growths of one line on roots of the other failed to alter the distinctive nodulation responses of rootstocks. Ascorbic acid contents in the two lines were identical, both in the tops and in the roots, although contents in tops greatly exceeded those found in roots. Chromatographic studies on the amino acids in seed hydrolyzates and in alcoholic extracts of seedlings showed no differences between the two lines either in kind or quantities of amino acids. In a survey of stock rhizobia for cultures effective on the nonnodulating line, bacteria were discovered which formed nodules on such soybeans growing in sand and nutrient solution. Isolates from these nodules again yielded effective nodulation on plants in sand culture, but gave no nodulation whatsoever on plants growing in soil. This negative response was confirmed in three different soils. Admixtures of soil and of miscellaneous materials with sand were employed to alter nodulation responses from those shown in sand cultures.


2020 ◽  
Vol 99 (9) ◽  
pp. 1001-1006
Author(s):  
Elvira F. Repina ◽  
Denis O. Karimov ◽  
Samat S. Baygildin ◽  
Gulnara V. Timasheva ◽  
Nadezhda Yu. Khusnutdinova ◽  
...  

Introduction. Among noninfectious diseases, one of the leading places belongs to pathologies caused by the action of industrial toxicants. In this regard, the search for drugs for the prevention and treatment of various intoxications is one of the priority tasks of public health. Treatment of intoxication with drugs with antioxidant and antihypoxic activity is more effective. The aim of this study was to investigate morphological changes in parenchymal organs (liver, kidneys, and pancreas) under acute exposure to high doses of carbon tetrachloride and to evaluate the effectiveness of their correction with a new composition of oxymethyluracil with ascorbic acid. Material and methods. The composition of 5-hydroxy-6-methyluracil with ascorbic acid was first synthesized at the Ufa Institute of Chemistry, Ufa Federal Research Center, RAS. The preventive effect of the new drug was studied in comparison with “Heptor” on the carbon tetrachloride-induced liver injury model. Morphological studies of the liver, pancreas, and kidneys of laboratory animals were carried out. Results. Studies have shown the prophylactic administration of new composition of 5-hydroxy-6-methyluracil with ascorbic acid to have a protective effect on the structure of parenchymal organs in acute carbon tetrachloride intoxication, comparable to the drug “Heptor” (possibly superior). However, reparative properties were observed only in the drug “Heptor”. Conclusion. Comparative estimation of morphological changes in parenchymal organs under acute exposure to high doses of carbon tetrachloride indicates the protective effect of prophylactic administration of the composition of 5-hydroxy-6-methyluracil with ascorbic acid, comparable to the drug “Heptor” (possibly superior).


1962 ◽  
Vol 39 (3) ◽  
pp. 345-352
Author(s):  
H. BARNES

1. The results of some chemical analyses for inorganic and organic constituents of the seminal plasma of Balanus balanus are presented. 2. The inorganic ions show a cation deficit of 178 m-equiv./l., which is probably made up by free amino-acids. 3. Cystine is a prominent amino acid present. 4. Potassium and calcium are present in excess of their quantities in sea water. 5. Reducing sugars, compared with the amount found in sea-urchin spermatozoa, are found in moderate quantities, 1 mg./ml. 6. Phosphorus of all kinds is present in only small quantities (total of o.14 mg./ml.). 7. Some phosphatases are present. 8. There are 21 /µg./ml. of ascorbic acid; the function of this is discussed in relation to its possible contribution to the protective action against the poisoning of -SH groups by thiol-reactive agents.


2020 ◽  
Vol 36 (6) ◽  
pp. 446-453
Author(s):  
Salma Awad Taghyan ◽  
Hend El Messiry ◽  
Medhat Ahmed El Zainy

This study aimed to evaluate the toxic effect of silver nanoparticles (AgNPs) on the parotid glands (PGs) of albino rats histologically and ultrastructurally and assess the possible protective effect of ascorbic acid as an antioxidant. Thirty male albino rats weighing between 150 mg and 200 mg were divided into three groups: the control group (C1) contained 10 rats that received 2 mg/kg (body weight (bw)) of aqueous nitrate buffer by intraperitoneal (IP) injection daily for 28 days; the AgNPs group contained 10 rats that received 2 mg/kg (bw) IP AgNPs daily for 28 days; and the AgNPs-vitamin C group contained 10 albino rats that received 2 mg/kg (bw) AgNPs IP daily for 28 days with oral administration of 100 mg/kg (bw) vitamin C in drinking water daily for 28 days. The PG acinar and ductal cells of the AgNPs group showed signs of toxicity and degeneration characterized as pleomorphic nuclei, binucleation, cytoplasmic vacuolations, and stagnated secretion in the ductal lumen. In addition to degenerated mitochondria, dilated rough endoplasmic reticulum and lysosomes were filled with AgNPs ( p < 0.001). The AgNPs-vitamin C group showed significantly less degenerative changes histologically and ultrastructurally compared to the AgNPs group ( p = 0.002). AgNPs produced significant toxic effects on the PG of albino rats, presumably through the generation of reactive oxygen species and toxic ion release, and administration of vitamin C was shown effective in decreasing these toxic effects.


2002 ◽  
Vol 282 (5) ◽  
pp. G766-G775 ◽  
Author(s):  
Vinzenz Stepan ◽  
Kentaro Sugano ◽  
Tadataka Yamada ◽  
Jung Park ◽  
Chris J. Dickinson

Gastrin requires extensive posttranslational processing for full biological activity. It is presumed that progastrin is cleaved at pairs of basic amino acids by a prohormone convertase to form a glycine-extended intermediate (G-Gly) that serves as a substrate for peptidyl-glycine α-amidating monooxygenase (PAM), resulting in COOH-terminally amidated gastrin. To confirm the nature of progastrin processing in a primary cell line, we performed [35S]methionine-labeled pulse-chase biosynthetic experiments in canine antral G cells. Radiolabeled progastrin reached a peak earlier than observed for G-Gly or amidated gastrin. G-Gly radioactivity accumulated in G cells and preceded the appearance of radioactivity in amidated gastrin. The conversion of G-Gly to amidated gastrin was enhanced by the PAM cofactor ascorbic acid. To determine whether one member of the prohormone convertase family (PC2) was responsible for progastrin cleavage, G cells were incubated with PC2 antisense oligonucleotide probes. Cells treated with antisense probes had reduced PC2 expression, an accumulation of radiolabeled progastrin, and a delay in the formation of amidated gastrin. Progastrin in antral G cells is cleaved via PC2 to form G-Gly that is converted to amidated gastrin via the actions of PAM.


Pancreatology ◽  
2006 ◽  
Vol 6 (5) ◽  
pp. 477-485 ◽  
Author(s):  
Mukaddes Eşrefoğlu ◽  
Mehmet Gül ◽  
Burhan Ateş ◽  
Ismet Yilmaz

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