• YAKHAK HOEJI
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• v.34 no.3
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• pp.212-214
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• 1990

A new synthetic method for bufexamac, which is a potent anti-inflammatory agent, was described. Friedel-Crafts reaction of butoxybenzene (2) with ethyl ${\alpha}-chloro-{\alpha}-(methylthio)acetate$ (1) gave ethyl 2-methylthio-2-(p-butoxyphenyl) acetate (3). Ethyl 2-(p-butoxyphenyl)acetate (4) was prepared by desulfurization of compound (3) with zinc dust-acetic acid. Bufexamac (5) could be easily synthesized by treatment of compound (4) with hydroxylamine HCl.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1209-1212
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• 2012

In spite of many reports in the literature concerning with oxidation of benzylic alcohols to carbonyl compounds with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in stoichiometric amounts or even more, we surprisingly found that benzylic alcohols are directly oxidized to oximes using a catalytic amount of DDQ in the presence of hydroxylamine hydrochloride under solvent-free conditions. The present tandem catalytic method can be efficiently used for preparation of oximes in the presence of some other functional groups with excellent chemoselectivity.

• Korean Journal of Microbiology
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• v.47 no.1
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• pp.7-13
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• 2011

In general, expression of membrane protein in Escherichia coli is very toxic to the host organism, but the mechanism for the toxicity is not clear yet. Expression of human purinergic receptor $P2X_4$ was found to be extremely toxic to the host E. coli. We examined this toxicity by isolation and analysis of less toxic mutant proteins. We could isolate 30 less toxic mutants of $P2X_4$ after hydroxylamine mutagenesis. Western blot showed that all of them produced proteins smaller than the wild type $P2X_4$. DNA sequencing of two largest mutant proteins showed that they were lost its second transmembrane domain. Localization analysis of these mutant proteins showed that they are not in cytoplasmic membrane, but in inclusion bodies. These data showed that inactive truncated $P2X_4$ is not toxic to E. coli and membrane integration and functionality of $P2X_4$ may be needed to show host toxicity.

• Polymer(Korea)
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• v.27 no.3
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• pp.242-248
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• 2003

PP-g-(AN/Sty) was synthesized by grafting with acrylonitrile (AN) and styrene (Sty) onto PP staple fiber using an electron beam accelerator and followed by amidoximination and phosphorylation. Mole fraction of AN in the graft chain increased with the increase of the AN content in the monomer mixture. The highest AN grafting yield of 45% was obtained at a monomer ratio of 40 vol% AN/60 vol% Sty. Mole fraction of AN in the graft chain decreased with the increase of methanol amount used its solvent. As reaction temperature increased, the grafting yield of copolymer increased and reached equilibrium at 50$^{\circ}C$. Amount of amidoxime group in fibrous ion exchanger was increased as increasing amount of hydroxylamine, and the maximum content of amidoxime group was observed at 5.8 mmol/g with the 9 wt% hydroxylamine concentration. Content of phosphorous group in fibrous ion exchanger increased up to 0.5 N phosphoric acid concentration, and then leveled off. The adsorption ability of the copolymer for uranyl ion by the chelating adsorbents was in the following order : bifunctional PP-g-(AN/sty) > amidoximated PP-g-(AN/Sty) > phosphorylated PP-g-(AN/Sty).

• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.152-155
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• 2000

Cultural Conditions for the Improvement in Gibberellic Acid Productivity by a Mutant of Gibberellafujikuroi ATCC 12616-Gibberella fujikuroi G-36 . Dh, Young-Jun. Department of Food and Biotechnolog}'r Dongshm Umversity, Naju 520-714, Korea - A mutant Gibberella jujih/roi G- 36 was selected by metagenesis of G/bberella fitjikuroi ATCC 12616 with mutagens such as N-methy1-N'~nitro~N"nitrosoguanidine and hydroxylamine for improving productivity of gibberellic acid. The mutant strain produced gibberellic acid (70 mg/l) more than that of wilde type. A fermentation medium containing glucose, $NH_4N0_3$, $MgS0_4$, $KH_2P0_4$ and trace elements was deve]oped for the maximal production of a gibberellic acid by the mutanL The Guctuating cultural temperature that was vaded from 300e to 20DC resulted in higher GA yield than that of fixed cu1tura] temperature at $28^{\circ}C$.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.681-686
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• 1992

In the conversion of D.L-2-amino-$\Delta^2$-thiazoline-4-carboxylic acid(D,L-ATC) to L-cysteine using Pseudomonas sp. CU6. the effects of surfactants on whole cells and the stabilities of cellfree enzyme solution and continuous reactor packed with immobilized whole cells were investigated. The enzymatic reaction was little accomplished by whole cells without adding surfactants, whereas it was well carried out with SDS or Triton X-loo comparable to the case using cell-free enzyme solution. Enzyme activity of the cell-free solution was lost by 50% after 7 hours of storage at $30^{\circ}C$, but not at all under an anaerobic condition by sparging nitrogen gas. On the other hand. effect of nitrogen gas did not appear in a continuous reactor using immobilized whole cells, and hydroxylamine, an inhibitor of L-cysteine desulfhydrase, lowered the enzyme stability.

• Resources Recycling
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• v.10 no.2
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• pp.13-19
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• 2001

Several hydrolyzed extruded PAN's were prepared through reaction of extruded PAN (7.5% methyl acrylate) with NaOH in methanol at various temperatures and times. These were amidoximated with hydroxylamine in MeOH and/or $H_2$O to introduce an excellent adsorption capacity of heavy metal ions. Amidoximated hydrolyzed extruded fAN showed superior swellability to non-hydrolyzed extruded PAM. The amidoximated extruded PAN hydrolyzed for 6h at $60^{\circ}C$ showed the best dimensional stability. Amidoximated hydrolyzed extruded PAN has more adsorption capacity of $Cu^{2+}$ than that of $Ni^{ 2+}$ These PAN derivates also showed an excellent selectivity for adsorption of metal ions.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.49-55
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• 1990

The bioconversion of D, L-20aminothiazoline-4-carboxylic acid (D, L-ATC) to L-cysteine was investigated. After the intracelluar enzyme of a Pseudomonas species was inducibly formed by addition of D, L-ATC in the middle of culture, the cells were isolated and treated with sonication to prepare the crude enzyme solution. The results indicated that the cysteine was produced only in the form of L-isomer from D,L-ATC and its production could be enhanced several tens times by addition of managanese ions which were required as a cofactor in this enzymatic reaction. Bedies, this reaction suffered from the feedback inhibition of L-cysteine. On the other hand, since L-cysteine-decomposing enzyme coexisted in the crude enzyme solution, most of the L-cyseine formed disappeared in the absence of its inhibitor. However, hydroxylamine was found to be a potent inhibitor which could successfully prevent the decomposition of L-cyseine.

• Korean Journal of Microbiology
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• v.33 no.2
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• pp.111-117
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• 1997

Streptomyces virginiae produces a set of autoregulators termed virginiae butanolide A-E(VB-A-E) which trigger virginiamycin production, and possesses a high-affinity virginiae butanolide receptor. To elucidate the functions of VB-C and VB-C receptor, we isolated two mutants from S. virginiae by N-methyl-N'-nitro-N-nitrosoguanidine and hydroxylamine. The characteristics of the mutants showed that the producing time of antibiotics was very delayed due to a slower production of VB-C receptor than that of VB. In S. ostreogriseus(VB', receptor -) and S. graminofaciens(VBU, receptor+), which produce the virginiamycin, the addition of synthetic VB-C repressed the production of antibiotics in S. ostreogriseus but induced tbe production in S. graminofaciens. HPLC analysis of S. graminofaciens suggested that the VB-C might have an ability to induce the production of virginiamycin and other antibiotics. These results imply that the VB-C has an ability to trigger the production of other secondary metabolites as well as virginiamycin under VB-C receptor existence.

• Archives of Pharmacal Research
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• v.15 no.3
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• pp.224-228
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• 1992

Arylhydrazones of diethylacetondicarboxylate 3 was treated with formaldehyde to give 1 aryl-4, 5, 6-trihydropyridaine derivatives 4a-f Cyclization of compound 4a-f by hydroxylamine afforded [3, 4d] 1, 3, 4, 5-tetrahydropyridazine derivatives 5a-f. Also cyclization of compound 4c with semicarbazide gave 1-amidopyrazolo-5-one-1-aryl-3-carboxypyridazine 6. On the other hand compounds 3 reacted with ethylorthoformate to give diethyl-1, 4-dihydro-1-arylpyridazine-4one-2.5 dicarboxylate 7, which on treatment with hydrazine. Semicarbazide and thiosemicarbazide gave pyridazine, amido and thioamido derivatives. The spectral and antimicrobial data of these compounds 1-8 were studied.