scholarly journals Actual state of research concerning vitamin C as reflected in the literature (Review article)

2004 ◽  
Vol 10 (1) ◽  
Author(s):  
É. Domokos-Szabolcsy ◽  
I. J. Holb ◽  
Zs. Veres ◽  
Gy. D. Bisztray ◽  
M. G. Fári
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Scientific Literature ◽  
Higher Plants ◽  
Review Article ◽  
Actual State ◽  
Physiological Effects ◽  
Anti Oxidant ◽  
State Of Research ◽  
Living Organisms

Vitamin C (L-ascorbic acid) being essential for many living organisms, including man, became once more into the focus of interests because of its numerous physiological effects. Its anti-scurvy and anti-oxidant properties have already been recognised since long in the human body, but it turned out gradually that it has many other functions. In plants, its primary importance is defense against the photo-oxidative stress. The present review is intended to reveal some details of the artificial synthesis of vitamin C. Emphasis is put on the metabolism of L-ascorbic acid in higher plants. Biosynthetic processes, translocation and accumulation are discussed in detail on the basis of recent results published in the scientific literature.

scholarly journals Vitamin C—Sources, Physiological Role, Kinetics, Deficiency, Use, Toxicity, and Determination

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 615
Author(s):  
Martin Doseděl ◽  
Eduard Jirkovský ◽  
Kateřina Macáková ◽  
Lenka Krčmová ◽  
Lenka Javorská ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Iron Absorption ◽  
Plasma Concentrations ◽  
Physiological Role ◽  
Renal Stones ◽  
Anti Oxidant ◽  
High Doses ◽  
Epigenetic Processes

Vitamin C (L-ascorbic acid) has been known as an antioxidant for most people. However, its physiological role is much larger and encompasses very different processes ranging from facilitation of iron absorption through involvement in hormones and carnitine synthesis for important roles in epigenetic processes. Contrarily, high doses act as a pro-oxidant than an anti-oxidant. This may also be the reason why plasma levels are meticulously regulated on the level of absorption and excretion in the kidney. Interestingly, most cells contain vitamin C in millimolar concentrations, which is much higher than its plasma concentrations, and compared to other vitamins. The role of vitamin C is well demonstrated by miscellaneous symptoms of its absence—scurvy. The only clinically well-documented indication for vitamin C is scurvy. The effects of vitamin C administration on cancer, cardiovascular diseases, and infections are rather minor or even debatable in the general population. Vitamin C is relatively safe, but caution should be given to the administration of high doses, which can cause overt side effects in some susceptible patients (e.g., oxalate renal stones). Lastly, analytical methods for its determination with advantages and pitfalls are also discussed in this review.

Seasonal and Climatic Variation in Cholesterol and Vitamin C: Effect of Vitamin C Supplementation

1992 ◽  
Vol 37 (2) ◽  
pp. 49-52 ◽  
Author(s):  
S.M. MacRury ◽  
M. Muir ◽  
R. Hume
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Vascular Disease ◽  
Serum Cholesterol ◽  
Free Radical Damage ◽  
Cholesterol Levels ◽  
Vitamin C Supplementation ◽  
Healthy Control ◽  
Anti Oxidant ◽  
Radical Damage

Vitamin C (ascorbic acid) is an important anti-oxidant which may help to reduce free radical damage and atheroma formation in blood vessels. In a study in which a group of healthy volunteer subjects were followed up for 12 months and a group of patients with vascular disease taking Vitamin C supplements were followed for 23 months, we confirmed previous findings of seasonal variations in ascorbic acid and cholesterol and have shown an inverse relationship between leucocyte ascorbic acid and serum cholesterol levels. In healthy control subjects the increase in ascorbate and fall in cholesterol during the summer months was reversed when the weather changed to a more winter pattern, presumably due to dietary alterations. We found that ascorbic acid levels were lower in patients with peripheral vascular disease and that although normal ascorbic acid levels were achieved with Vitamin C supplementation, when supplements were stopped at the height of a normal summer, there was a fall in ascorbic acid and a rise in serum cholesterol to winter levels. Given these findings we suggest that patients with vascular disease should have Vitamin C supplements throughout the year.

scholarly journals Review Article: Vitamin C Progress Apoptosis in Breast Cancer

2021 ◽  
Vol 8 (6) ◽  
pp. 84-89
Author(s):  
Alaa A. Abdulrazzaq
Keyword(s):  
Breast Cancer ◽  
Cancer Therapy ◽  
Vitamin C ◽  
Death Rate ◽  
Review Article ◽  
Main Function ◽  
Anti Oxidant ◽  
Type C ◽  
Cancer Suppression

The cancer of breast is virulence in female and is curable in ~70–80% of patients. The vitamin type C is an essential vitamin and consider as an anti-oxidant, so this vitamin could recover the supply for oxygen, stopping the destroy of DNA and other impact necessary in cancer processing. The vitamin C indicate as an active anticancer as the concentricity were monitor in this cancer therapy. The concentricity of this vitamin has a main function in cancer-rising or cancer suppression. These studies have shown a relationship   between the vitamin and increase death-rate of breast cancer, so it’s important to detect the anticancer prospective of vitamin C to detect the different among its effect in healthy and damage cells, especially these studies conducted that this difference could depend on the vitamin c concentration. These studies indicate that large doses of vitamin c could decrease the effect of some cancer therapy such as radiation and chemotherapy.

Amperometric assay of vitamin C using an ascorbate oxidase enzyme electrode

1979 ◽  
Vol 44 (11) ◽  
pp. 3395-3404 ◽  
Author(s):  
Pavel Posádka ◽  
Lumír Macholán
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Oxygen Electrode ◽  
Ascorbate Oxidase ◽  
Current Response ◽  
Reaction Conditions ◽  
Long Term Storage ◽  
Oxidase Enzyme ◽  
Optimal Reaction

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.

scholarly journals Degradation Kinetic Modelling of Ascorbic Acid from Orange Juice

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 55
Author(s):  
Alina Soceanu ◽  
Nicoleta Matei ◽  
Simona Dobrinas ◽  
Viorica Popescu
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Orange Juice ◽  
Storage Temperature ◽  
Kinetic Modelling ◽  
Activation Parameters ◽  
Graphical Analysis ◽  
State Theory ◽  
Activation Process ◽  
Degradation Kinetic

Vitamin C or ascorbic acid is a basic nutrient, a highly effective antioxidant, widely used as food additive. Therefore, quality control in food industry demands ascorbic acid determination methods. The purpose of this study was to determine vitamin C in natural orange juices by spectrometric and voltammetric methods. Another goal was to determine the kinetic and thermodynamics activation parameters for ascorbic acid degradation in orange juices over time and at different temperatures. It was observed that during storage, ascorbic acid concentrations in orange juices were gradually decreased with time at a rate depending on storage temperature and type of orange juice. The reaction order was determined through integrated graphical analysis where the dependences of ln ct/c0 as a function of time reveals the high values for R2, indicating that the kinetics of the degradation of AA follows first order reaction at both studied temperatures. For studied samples the loss of ascorbic acid was varied between 4.33% and 9.13%. Enthalpy variation (ΔH) and entropy variation (ΔS) of activation process were obtained from the Eyring–Polany model based on transition state theory. The values of activation energy ranged between 7289.24 kJmol−1 and 15689.54 kJmol−1.

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