When about 300mg of L-ascorbic acid was given intravenously to the adults saturated with the vitamin, the increased blood level returned to almost the original level in 3 hours. Also the amounts of the vitamin absorbed by the tissue cells and metabolized in the body or excreted into the gastrointestinal tract were found to average 74.1mg in 3 hours. When about 300mg of L-ascorbic acid was given intravenously twice at intervals of 3 hours, an average of 101 mg of the vitamin was absorbed by the tissue cells and metabolized in the body or excreted into the gastrointestinal tract in 6 hours. When the vitamin was given orally to the saturated adults, the absorption rate increased as the test does increased. When large amounts (3.0gm) of the vitamin were given, the absorption rate reached the maximum. The maximum absorption in 6 hours was estimated as 681 mg of the vitamin.
Adult ; Ascorbic Acid/blood/*metabolism ; Human ; *Intestinal Absorption

Vitamin C is an essential vitamin for human beings. It has a huge market in the fields of food and pharmaceuticals. 2-keto-L-gulonic acid is an important precursor to produce vitamin C by microbial fermentation in industrial. In microbial fermentations, the L-sorbose pathway and the D-gluconate pathway have been the focus of research because of high yield. This article aims at stating recent research progress in dehydrogenases related to biosynthesis of vitamin C in the L-sorbose pathway and the D-gluconate pathway. The properties of dehydrogenase in terms of localization, substrate specificity, cofactors, and electron transport carrier are elaborated. And then, the main problems and strategies are reviewed in the L-sorbose pathway and in the D-gluconate pathway. Finally, future research on the dehydrogenases in the biosynthesis of vitamin C through L-sorbose pathway and D-gluconate pathway is discussed.
Ascorbic Acid/biosynthesis* ; Fermentation ; Gluconates ; Oxidoreductases/metabolism* ; Sorbose

Biological synthesis of L-Ascorbyl Palmitate in organic system were studied in this text. The contradiction between conversion of vitamin C and concentration of L-Ascorbyl Palmitate were resolved. High conversion of vitamin C and concentration of L-Ascorbyl Palmitate were obtained by Novo435. A series of solvents(log P from -0.24 to 3.5 )were investigated for the reaction,and acetone was found to be the most suitable from the standpoint of the enzyme activity and solubility of L-ascorbic. And the equilibrium of the reaction was affected by the addition of the molecular sieves and temperature. Reaction carried out at 60 degrees C and with 20% 0.4nm molecular sieves is good for the enzyme to keep its activity and for making the equilibrium go to the product. With 1.094 g palmitic acid, 0.107 g vitamin C and 0.020 g Novo435, rotate rate of 200 r/min, the conversion of ascorbic reached 80% and the concentration of L-ascorbyl palmitate is 20 g/L after 48 h. Furthermore, reaction batch of Novo435 and substrates recycle were observed, the result indicated that Novo435 may used 4-5 times continuously with high conversion. And 6-O-unsaturated acyl L-ascorbates were synthesized through Novo435 condensation of ascorbic acid and various unsaturated fatty acids with high conversion in this text.
Ascorbic Acid ; analogs & derivatives ; biosynthesis ; Catalysis ; Enzymes, Immobilized ; chemistry ; metabolism ; Lipase ; chemistry ; metabolism

OBJECTIVETo study the different and the variety of four organic acids in leaves of Isatis indigotica among different cultivated populations in water stress condition and healthy plant.

METHODFour kinds of organic acids, such as oxalic acid, malic acid, ascorbic acid and citric acid from the leaves, were detected by HPLC.

RESULTSignificant differences of four organic acids in the leaves of Beijing, Mongolia, Hebei and Shanxi cultivated populations. Compared with the healthy plant, the content of oxalic acid, malic acid and citric acid in water stress were increased, while the content of ascorbic acid was decreased.

CONCLUSIONContents of four organic acids can act as the guideline factor in I. indigotica because they were related with the water stress condition.

Ascorbic Acid ; chemistry ; metabolism ; China ; Chromatography, High Pressure Liquid ; Citric Acid ; chemistry ; metabolism ; Dehydration ; Isatis ; chemistry ; metabolism ; Malates ; chemistry ; metabolism ; Oxalic Acid ; chemistry ; metabolism ; Plant Leaves ; chemistry ; metabolism

Antioxidant vitamin supplementation focuses one's attention on the prevention of age-related diseases. This study was conducted to investigate the antioxidant status and lipid profiles and to look into the antioxidant vitamin supplementation that affects lipid metabolism in 20 elderly non-smoking Korean women (placebo group: n = 6, vitC suppl: n = 7, vitE suppl: n = 7). Age, height, weight, muscle, percent of fat and WHR were not significantly different among the groups, however % of fat was above 33% and WHR was above 0.9. And blood pressure of the placebo group was 131.7/81.7 (border line hypertension), that of vitamin C supplement was 141.4/87.1 (hypertension) and that of vitamin E supplement was 151.4/92.9 (hypertension). Although nutrient intakes of all groups were poor, antioxidant status (blood vitamins C, E, A, and beta-carotene) and lipid profile (TG, total-cholesterol, VLDL-cholesterol, LDL-cholesterol, HDL-cholesterol) were normal. For nutritional intervention, the vitamin C supplement group received L-ascorbic acid 1,000 mg, and vitamin E supplement group received d-alpha-tocopherol 400IU for 4 weeks, showing the effects of vitamin E supplementation. Response total cholesterol of HDL-cholesterol (T-Chol/HDL) in vitamin E supplement group was significantly decreased from 4.3 to 3.2. And response LDL-cholesterol of HDL-cholesterol (LDL/HDL) in the vitamin E supplement group was also significantly decreased from 2.6 to 1.7. In addition, after the adjustment for plasma lipids (TG, total cholesterol), plasma vitamin A levels in vitamin E supplement group were significantly increased from 7.89 mg/g to 14.91 mg/g. And systolic blood pressure in vitamin E supplement group was significantly reduced. These results suggested that vitamin E supplementation affects the lipid profiles and blood pressure in elderly non-smoking women. So various nutrition programs must be implemented against age-related diseases and further studies are needed regarding sorts and amounts of antioxidant nutrients and supplementation periods.
Aged* ; Ascorbic Acid ; Blood Pressure ; Cholesterol ; Female ; Humans ; Lipid Metabolism ; Plasma ; Vitamin A ; Vitamin E ; Vitamins

OBJECTIVETo evaluate the 8 main quality characteristic indexes of fruit-using Chaenomeles speciosa and C. sinensis fruits produced in Chongqing and explore the comprehensive assessment for the fresh eating-quality of the samples based on the theory of fuzzy comprehensive.

METHODThe total sugar content, titratable acid content, ascorbic acid content and superoxide dismutase (SOD) activity of fresh samples were determined, and the oleanolic acid, ursolic acid, total flavones and total saponins content of dried sample were determined by HPLC and colorimetry method. The fuzzy probability method was used to comprehensively evaluate their fresh eating-quality of the fruit-using C. speciosa and C. sinensis fruits produced in Chongqing.

RESULTThe mean SOD activity of C. speciosa and C. sinensis fresh fruits separately was 15.99 U x mg(-1) and 27.40 U x mg(-1), respectively. And the fresh fruit titratable acid content, total sugar content, ascorbic acid content separately was 0.357 g x L(-1), 0.854 mg x L(-1), 1.118 mg x L(-1) and 0.252 g x L(-1), 0.845 mg x L(-1), 1.260 mg x L(-1), respectively. The oleanolic acid, ursolic acid, total flavones and total saponins content was 0.320%, 0.461%, 43.90 mg x g(-1), 23.11 mg x g(-1) and 0.255%, 0.176%, 41.24 mg x g(-1), 15.01 mg x g(-1), respectively. The Chaenomeles speciosa and C. sinensis sample quality mean comprehensive evaluation value was 0.599 and 0.367 based on the fuzzy probability method.

CONCLUSIONThe edible quality of fruit-using C. speciosa fruits are better than C. sinensis fruits produced in Chongqing. And the fuzzy probability method could be used to quality comprehensive evaluation of samples containing many trait paramaters.

Ascorbic Acid ; China ; Chromatography, High Pressure Liquid ; Colorimetry ; Fruit ; chemistry ; Rosaceae ; chemistry ; Superoxide Dismutase ; metabolism

The ultimate aim of periodontal treatment is periodontal regeneration, which necessiates the regeneration of bone tissues. This paper investigated the effect of growth factor on bone cells. Platelet-derived growth factor(PDGF) is the one of the polypeptide growth factor that has been reported as a biological mediator which regulates activities of the cell proliferation, migration and metabolism of undifferentiated mesenchymal cells. The purpose of this study is to evaluate the effects of PDGF on bone nodule formation and ALP activity of MC3T3-E1 cells. Cells were seeded at 1x10(5)cells/well in alpha-modified eagle medium containing 10% fetal bovine serum, 10ml beta-glycerophosphate and 50microgram/ml of ascorbic acid. PDGF 0, 0.1, 1, 10ng/ml were added to the cells at a confluent state and cultured for 3, 7, 14, 21, 28 days. We examined bone nodule formation and alkaline phosphatase activity. The results were as follows: There were bone nodule formation at day 21 both in control and all the experimental groups, and at day 28, all the experimental groups showed much more bone nodules than control groups. Compared to control-1 group, ALP activity was increased in PDGF 0.1ng/ml group and was decreased in 1,10ng/ml PDGF treated groups.(P< 0.05, P< 0.01) Compared to control-2, ALP activity was decreased in all the experimental groups except PDGF 0.1ng/ml in 21 day group. In the time-response effect, ALP activity was increased by the day 14 in all the experimental groups and thereafter ALP activity was decreased.(P<0.05, P< 0.01) In the dose-response effect, ALP activity was decreased as the dose of PDGF was increased, and after 21 day ALP activity was lowest in 1ng/ml group, ALP activity was highest in the day 7 in control group and 0.1ng/ml, 14 day experimental group. In conclusion, PDGF is considered more effective in the proliferation than differentiation of osteoblast-like cells, and it may be useful to study the combined effect of PDGF and other growth factors on osteoblast-like cells.
Alkaline Phosphatase ; Ascorbic Acid ; Bone and Bones ; Cell Proliferation ; Eagles ; Intercellular Signaling Peptides and Proteins ; Metabolism ; Regeneration

Animals ; Ascorbic Acid ; metabolism ; Brain Ischemia ; metabolism ; Glutamic Acid ; metabolism ; Hippocampus ; drug effects ; metabolism ; Male ; Propofol ; pharmacology ; Rats ; Rats, Wistar ; Reperfusion Injury ; metabolism

OBJECTIVETo explore arsenic-induced oxidative stress and the protective efficacy of α-lipoic acid and vitamin c.

METHODS50 male SD rats were randomly divided into 5 groups. Ten rats (the control group) were exposed to deionized water for 6 weeks, and the others were alone exposed to sodium arsenite (50 mg/L water) for 6 weeks, at the same time, three group rats were administered intragastrically (i.g.) with α-lipoic acid 10 mg×kg(-1)×d(-1) and vitamin C 25 mg×kg(-1)×d(-1) either alone or in combination. At the end of experiment, blood was drawn from abdominal aorta, and then the blood, brain and liver of rats were used for biochemical assays, including blood glutathione (GSH), δ-aminolevulinic acid dehydratase (δ-ALAD ), reactive oxygen species (ROS) and oxidized glutathione (GSSG) level. At the same time, the super oxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity, catalase (CAT) activity, ATPase activity of brain and liver were determined. The caspase activity of brain were also determined.

RESULTSThere were a significant increase in ROS level (P < 0.05), but a significant decrease in δ-ALAD activity (P < 0.01) in the chronic arsenic toxicity model group compared with the control group. These alterations were marginally restored by co-administration of vitamin C and α-lipoic acid individually, while significant recovery was observed in the animals supplemented with both the antioxidants together with arsenite in rat (P < 0.05). At the same time, there was a significant increase in the ROS and TBARS level of the brain and liver (P < 0.05), and caspase activity of the brain (P < 0.05), while there was a significant decrease in antioxidant enzymes and ATPase activity on arsenite exposure in rats (P < 0.05). These alterations were also marginally restored by co-administration of vitamin C and α-lipoic acid individually, while significant recovery was observed in the animals supplemented with both the antioxidants together with arsenite in rat (P < 0.05).

CONCLUSIONSArsenite-induced oxidative stress can be significantly protected by co-administration of α-lipoic acid and vitamin C individually, but the best effects could be observed with combined administration of two antioxidants during arsenite exposure in animals. The dietary intervention of or supplementation with natural dietary nutrients is possible to prevent the effects of arsenic in populations of risk.

Animals ; Arsenic Poisoning ; metabolism ; Ascorbic Acid ; pharmacology ; Male ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley ; Thioctic Acid ; pharmacology

AIMTo establish a method for screening active substance with scavenging effects on superoxide anion in vitro by designed superoxide dismutase biosensor.

METHODSThe enzyme sensor was built by connecting the immobilized CuZnSOD with optical oxygen sensor through a special way. Superoxide anions were generated by auto-oxidation of pyrogallol. The auto-oxidation speed was examined before and after adding samples into the system, and the Vit C having the scavenging radical activities was served as a positive control.

RESULTSThe limit of biosensor detection was 7.0 U in activity, and lifetime of the immobilized enzyme in the reaction-cell was above 2 weeks. The scavenging effects on superoxide radicals of fifteen active substance were studied in vitro by the sensor, and some of them presented scavenging activities.

CONCLUSIONThe signal from biosensor is stable, easy to be determined, and the kinetic information on scavenging superoxide radicals could be obtained directly. The biosensor system can be used for screening drugs simply and rapidly.

Ascorbic Acid ; metabolism ; Benzaldehydes ; metabolism ; Biosensing Techniques ; Caffeic Acids ; metabolism ; Enzymes, Immobilized ; metabolism ; Free Radical Scavengers ; metabolism ; Pyrogallol ; metabolism ; Superoxide Dismutase ; metabolism