• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.2
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• pp.97-117
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• 1997

L-Ascorbic acid 및 그 유도체는 항산화 작용과 미백작용 및 섬유아세포의 생장 촉진과 콜라젠 생합성의 증가시키는 효과가 있으므로 화장품에서 오래 전부터 사용되어 왔다. 본 연구에서는 생체에 대한 안전성과 안정성이 우수한 L-Ascorbic acid 유도체를 개발하기 위하여 인지질과 유사하게 L-Ascorbic acid 에 3-Aminopropane phosphoric acid를 결합하여 L-Ascorbic acid-3-aminopropane phosphoric acid diester를 합성하였다. ASA-APPA 는 2-Chlorotetrahydro-2H-1, 3, 2-oxazaphosphorine P-oxide 와 5, 6-isopropylidene L-Ascorbic acid 를 반응 시킨 후 산 사수분해 반응을 통하여 얻을 수 있었다. ASA-APPA는 수용액에서 안정성이 우수하였으며, 독성실험에서 무독성 물질이며, 인체 첩포 실험에서도 무자극 물질임을 확인하였다. 그리고, ASA-APPA 는 L-Ascorbic acid 와 3-APPA 의 혼합물과 거의 유사한 섬유아세포의 증식효과를 나타내었으며, melanoma 에 대한 멜라닌 생성 억제 실험에서 L-Ascorbic acid phosphate magnesium salt 와 유사한 효과를 보였다. 따라서 ASA-APPA 는 멜라닌 생성 억제 효과와 섬유아세포의 증식 효과를 갖는 새로운 화장품 원료로서 사용이 가능할 것으로 생각된다.

• Journal of the Korean Chemical Society
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• v.39 no.1
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• pp.29-34
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• 1995

The rates for the oxidation reaction of l-ascorbic acid by Cu(Ⅱ)-polyamine complexes were measured by Onish's method at the pH 4.6. The oxidation process of l-ascorbic acid is proposed to occur by the inner-sphere mechanism that involves the formation of a Cu(Ⅱ)-ascorbic acid complex and electron transfer at the rate-determining step.

• Archives of Pharmacal Research
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• v.26 no.7
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• pp.575-580
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• 2003

The present study was designed to develop a microencapsulated L-ascorbic acid and iron that could be used to fortify milk and to determine the sensory properties of milk fortified with microencapuslation. Coating material was medium-chain triacylglycerol (MCT), and selected core material was ferric ammonium sulfate and L-ascorbic acid. The highest efficiency of microencapsulation was 95.0% in the ratio of 15:1 as coating to core material. Ascorbic acid release was increased sharply up to 5 d storage as 6.5%. TBA value was the lowest when both capsulated iron and ascorbic acid were added during 12 d storage, compared with other treatments. In sensory analysis, most aspects were not significantly different between control and capsulated ascorbic acid fortified milk at 5 d storage. The present study indicated that the use of microencapsulated ascorbic acid with MCT is effective for fortifying milk. In addition, these results suggest that acceptable milk products can be prepared with microencapsulated ascorbic acid and iron.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1169-1171
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• 2003

A stable derivative of L-ascorbic acid, 2-O-[(3-aminopropyl)phosphinooxy]-L-ascorbic acid (LAAP), was synthesized in moderate yield and its chemical stability and effects on melanin synthesis were investigated. LAscorbic acid was decomposed completely within about 1 hour, while 93% of LAAP remained even after 10 days. Treatment of L-ascorbic acid and LAAP decreased melanin content in normal human melanocytes to 33.8% and 49.1% of control at 2 mM, respectively. Considering chemical instability of L-ascorbic acid, LAAP is a much better whitening agent.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1678-1683
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• 2006

A novel suspension-phase enzyme reaction system for the intermolecular transglycosylation of L-ascorbic acid into 2-O-${\alpha}$-D-glucopyranosyl L-ascorbic acid supplementing extrusion starch as the glycosyl donor was developed using cyclodextrin glucanotransferase from Thermoanaerobacter sp. A high conversion yield compared to the conventional soluble-phase enzyme reaction system using cyclodextrins and soluble starch was achieved. The optimal reaction conditions were 2,000 units of cycIodextrin glucanotransferase, 20 g/l of L-ascorbic acid, and 50 g/l of extrusion starch at $50^{\circ}C$ for 24 h. The new suspension-phase enzyme reaction system also exhibited several distinct advantages other than a high conversion yield, including a lower accumulation of oligosaccharides and easily separable residual extrusion starch by centrifugation or filtration in the reaction mixture, which will facilitate the purification of 2-O-${\alpha}$-D-glucopyranosyl L-ascorbic acid. The new suspension-phase enzyme reaction system seems to be potentially applicable as the industrial process for the production of thermally and oxidatively stable 2-O-${\alpha}$-D-glucopyranosyl L-ascorbic acid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.4
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• pp.954-957
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• 1999

The changes in L ascorbic acid content by processing treatments; gamma irradiation, heating and microwave were investigated using high performance liquid chromatography. The content of L ascorbic acid in standard solutions and citrus fruits decreased from 27.4 to 44.9% and from 6.9 to 21.9%, re spectively, by gamma irradiation doses in the range of 1 to 10 kGy. By heating treatments, L ascorbic acids in standard solutions and citrus fruits were destroyed 22.5 to 36.8% and 4.5 to 18.1%, respectively. By microwave treatment, L ascorbic acid content also decreased from 23.1 to 47.4% and from 6.5 to 22.6%, respectively.

• Analytical Science and Technology
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• v.7 no.2
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• pp.149-153
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• 1994

An amperometric sensor for L-ascorbic acid(AA) in methanol media has been made by immobilizing squash-tissues on a graphite rod disk. A detection limit of the electrode was $2{\times}10^{-6}M$ L-ascorbic acid. In comparison with an isolated enzyme based ascorbate oxidase(AO) electrode, the plant-tissue electrode offered high biocatalytic stability and activity and extremely low cost. The electrode has a useful lifetime of 1 week.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.187-191
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• 2004

For the production of $2-O-{\alpha}-D-glucopyranosyl-L-ascorbic$ acid (ascorbic acid-2-g1ucoside, AA-2G) from ascorbic acid, the usability of spinach seed as the source of ${\alpha}-glucosidase$ having transglucosylation activity was studied. The optimum conditions for the production of AA-2G from ascorbic acid and glucose donor were investigated by using crude extract of Spinachia oleracea L. Woosung, the selected source of enzyme. The production of AA-2G was the highest with 1.053 mM when spinach seeds were grown for 2 days after germination. Maltose was the most effective glucose donor, and the optimum concentration of ascorbic acid and maltose were 175 mM and 225 mM, respectively. The optimum concentration of ${\alpha}-glucosidase$ was 60 units. The most effective buffer was sodium acetate and its optimum concentration was 175 mM. The optimum pH and temperature were 5.0 and $65^{\circ}C$, respectively. Under the optimum condition, 2.14 mM of AA-2G was produced from ascorbic acid after 50 minutes of reaction.

• Korean Journal of Microbiology
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• v.23 no.4
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• pp.302-308
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• 1985

It is shown by means of nuclear magnetic resonance spectroscopy that 3,4,5-trihydroxy-2-keto-L-valeraldehyde (L-xylosone), an ${\alpha}$-ketoaldehyde, is formed during the oxidative catabolism of L-ascorbic acid. It is proposed that this substance serves as a substrate for the glyoxalase system by which it is transformed to L-xylonic acid. As L-xylonic acid is further oxidized to L-erythroascorbic acid, a biochemical pathway is proposed for the action of vitamin C which consists of two further ${\gamma}$-lactones and three different substrates of the glyoxalase system.

• Archives of Pharmacal Research
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• v.11 no.2
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• pp.114-121
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• 1988

To gain insight into possible cellular protective mechanisms against the insult of formaldehyde, we have investigated this molecule's reactivity with both naturally occurring thiol compounds including glutathione and L-ascorbic acid. By UV measurements, for maldehyde was found to rapidly react with glutathione forming an S-hydroxymethyl covalent adduct. The adduct which was confirmed by NMR is transiently stable. Formaldehydissimilar to its reaction with dimedone. The reaction of formaldehyde with glutathione was reduced by 40% in the presence of an excess amount of L-ascorbic acid, due to the trapping of formaldehyde by L-ascorbic acid. The data suggest that L-ascorbic acid may have a possible in vivo role in the metabolism of formaldehyde, thereby protecting cellular glutathione from possible depletion.