• Proceedings of the PSK Conference
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• 2002.10a
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• pp.311.2-311.2
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• 2002

L -ascorbic acid (LAA) was shown to modulate the in vitro growth of leukemic-colony forming cells from patients with acute myelogeneous leukemia (AML). Dendritic cells (DCs) were successfully cultured from the leukemic blasts by us and others. The effects of LAA on the ex vivo cultured leukemic-DC were studied. Plastic adherent cells from the leukemic blasts were cultured with GM-CSF and IL -4 (each 103 U/$m\ell$) with or without LAA (300 ${\mu}$M) for 7 days and harvested. (omitted)

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.418-421
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• 2000

A new direct colorimetric assay of microcystin in water and algal samples is proposed consisting of two procedures as follows: 1) the elimination of phosphorus in the sample and concentration of microcystin using a C(sub)18 cartridge, 2) the detection of the released phosphorus by the ascorbic acid method and determination of protein phosphatase (PP) inhibition by microcystin. The optimum amounts of phosphorylase ${\alpha}$ and PP-1 in 50 ${\mu}$L concentrated sample were 50$\mu\textrm{g}$/50${\mu}$L buffer and 1.0unit/50${\mu}$L buffer, respectively, for the best assay. The pH for the maximum activity of PP-1 was 8. The minimum detectable concentration for this method was about 0.02$\mu\textrm{g}$/L, which is sufficient to meet the proposed guideline level of 1$\mu\textrm{g}$ microcystin/L in drinking water. Consequently, it would seem that the proposed direct colorimetric assay using PP is a rapid, easy, and convenient method for the detection of microcystin in water and algal samples.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2006.11a
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• pp.143-145
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• 2006

• Bulletin of the Korean Chemical Society
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• v.5 no.6
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• pp.264-265
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• 1984

• Horticultural Science & Technology
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• v.18 no.6
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• pp.808-810
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• 2000

The chemical components of xylem sap collected from kiwifruit (Actinidia chinensis Planch cv. Hayward) trees were analyzed and processing of xylem sap drink were accomplished to increase utilization of xylem sap as a drink. Water content, soluble solids, viscosity, and pH of the xylem sap were 99.60%, 0.90%, 1.01, and 6.50, respectively. In the xylem sap, fructose was the highest among free sugars followed by glucose, sucrose, galactose, and mannitol. The major inorganic components in the sap were calcium, potassium, and magnesium, and calcium was the dominant among them. Ten kinds of amino acids in the xylem sap were detected by amino acid analyzer, and the major amino acids were glutamic acid, lysine, and isoleucine. Glutamic acid was the most dominant amino acid in the xylem sap. Major compositions of xylem sap drink were 74.5% xylem sap, 15% kiwifruit puree and 10% high fructose. Nutritional facts in drink (252 mL) processed by using the xylem sap were 21.8 g sugar, 23.1 mg calcium, 14.1 mg potassium, 554.5 mg amino acid, and 15.6 mg ascorbic acid.

• Korean Journal of Microbiology
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• v.26 no.4
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• pp.324-331
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• 1988

Ascorbate oxidizing enzyme from the crude extract of Pleurotus ostreatus was purified by ammonium sulfate precipitation, preparative polyacrylamide gel electrophoresis, DEAE Sepharose CL-6B ion exchange chromatography and Sephadex G-150 gel filtration chromatography. The molecular weight of the enzyme estimated by Sephadex G-150 gel filtration chromatography was 140,000 and that of its subunit by SDS-polyacrylamide gel electrophoresis 66,000. The optimum pH for the maximum activity of the enzyme was 5.2 and the isoelectric point of the enzyme was 6.0 Km values for L-ascorbic acid and D-isoascorbic acid were both 2.2.$\mu$M, which indicates that the enzyme has the asme affinity towards both substrates.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.683-688
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• 1993

The antioxidative effect of the 75% ethanol extracts of preliminary selected Fritillaria ussuriensis Max(Fs), Houttuynia cordata Thunb(Hc), Portulaca oleracea L.(Po) and Perilla frutescene Var javanica Hara cake(Pf) were tested on palm oil and lard by rancimat test. Each solvent fraction of chloroform, ethyl acetate(EtOAc), butanol and water, was also evaluated its antioxidative effect with some synergists, like as ascorbic acid, citric acid and ${\delta}-tocopherol$. Po extract showed higher antioxidative effect on lard and the fraction of all test plants were the most effective on palm oil and lard with ascorbic acid and ${\delta}-tocopherol$. When 200 ppm of EtOAc fraction of Fs, He and Po extract each with 200 ppm of ascorbic acid were added to palm oil, the antioxidative index(AI, induction time of oil containing each extract/induction time of test oil) were 1.60, 1.53 and 1.47 respectively and 200 ppm of EtOAc fraction of Po and Pf extract each with 200 ppm of tocopherol to lard, the AI were 3.19 and 3.63 respectively.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.73-78
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• 2001

This study was carried out to investigated developmental ability of IVM/IVF derived hanwoo embryos after DNA microinjection. Microinjected hanwoo embryos were cultured fur 7 days. The cleavage rates of DNA injected embrys(36.3%) was significantly lower than those of non-injected embryos(67.4%; p<0.05). The percentage of injected embryos reaching to the morulae and blastocyst was significantly lower than those of non-injected embryos(p<0.05). When injected embryo were cultured contaning L-ascorbic acid and $\alpha$-tocopherol for 168 hrs, the morulae and blastocyst rates were significantly higher than control(p<0.05). These results suggested that the addition of L-ascorbic acid and $\alpha$-tocopherol can enhanced development to the morulae and blastocyst of microinjected embryos and improved culture condition increased the transgenic hanwoo embryos.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2213-2218
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• 2012

Efficient synthetic routes were developed to prepare a sizable amount (4-15 grams) of the chiral epoxides 4-6 as versatile intermediates for the synthesis of aspartyl protease inhibitors of therapeutic interest such as HIV protease and ${\beta}$-secretase. Oxidative cleavage of the C(2)-C(3) double bond of L-ascorbic acid followed by functional group manipulation led to the preparation of the epoxide 10, which was opened with an azide to yield a common aziridine intermediate 12. Through opening of the aziridine ring of 12 with either a carbon or a sulfur nucleophile, chiral epoxide precursors 4-6 could be prepared for various HIV protease inhibitors. Except for the final low melting epoxides 5 and 6, all intermediates were obtained as crystalline solids, thus the synthetic pathway can be easily applied to a large-scale synthesis of the chiral epoxides.

• Korean Journal of Medicinal Crop Science
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• v.16 no.4
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• pp.268-272
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• 2008

The effect of elicitor and precursor on salidroside production from Rhodiola sachalinensis A.Bor callus cultures was investigated. Callus cultures were treated with yeast extract, soft-ferrite ceramics powder, methyl jasmonate, ascorbic acid, jasmonic acid and $CuCl_2$/$CdCl_2$ as an elicitor. When callus cultures were treated with $0.2g/\ell$ of yeast extract, salidroside production from callus treated with yeast extract is 3.45 times higher than that of the controlled group. Among of them, callus cultures treated with yeast extract produced the highest salidroside. Callus cultures were treated with L-phenylalanine and L-tyrosine as a precursor for 4 days. The result of salidroside content analysis showed that all feeding of precursors not affected salidroside production from callus cultures. In case of L-tyrosine fed into callus cultures, both callus growth and salidroside production decreased at all concentrations.