• Bulletin of the Korean Chemical Society
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• v.4 no.2
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• pp.72-76
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• 1983

Cephaloglycin was synthesized directly from D-${\alpha}$ -phenylglycine methyl ester and 7-aminocephalosporanic acid using whole cell enzyme of Xanthomonas citri (IFO 3835). Some optimal conditions for cephaloglycin synthesis were investigated, and yield improvements for its production by several methods were attempted. Using the whole cell enzyme system, the reaction kinetic model for cephaloglycin synthesis is proposed, and the kinetic constants for D-${\alpha}$ -phenylglycine methyl ester hydrolysis, cephaloglycin synthesis, and cephaloglycin hydrolysis were determined. The $K_m$ values of D-${\alpha}$-phenylglycine methyl ester, 7-aminocephalosporanic acid, and cephaloglycin were 11 mM, 24 mM, and 167 mM, and $K_i$ value of D-${\alpha}$-phenylglycine was 15 mM, respectively. The pattern of product inhibition was found to be competitive one.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2296-2302
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• 2018

Internally plasticized PVC was prepared via chemical reaction of azide PVC and alkynyl group containing castor oil methyl ester. The chemical structure of alkynyl group containing castor oil methyl ester and internally plasticized PVC was characterized with FT-IR and $^1H$ NMR. Properties of internally plasticized PVC, including thermal stability, tensile tests and resistance to extraction in different solvents, was investigated. The results showed that alkynyl group containing castor oil methyl ester, as internal plasticizer of PVC, not only decreased the $T_g$ of PVC from $84.6^{\circ}C$ to $41.6^{\circ}C$ efficiently, but also presented no plasticizer loss in five different solvents. The tensile tests showed that elongation at break and tensile strength of internally plasticized PVC was 353.8% and 18.1 MPa. The internally plasticized PVC has potential application in replacing the traditional PVC material in PVC products with high durability.

• Journal of the Korean Chemical Society
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• v.44 no.3
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• pp.290-293
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• 2000

• Bulletin of the Korean Chemical Society
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• v.22 no.11
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• pp.1173-1174
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• 2001

• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.385-393
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• 2004

2-Ethoxycarbonyl-3-methylquinoxaline 1,4-dioxide (8) was synthesized from benzofuroxan and ethyl acetoacetate. The reaction of compound 8 with hydrazine hydrate or selenium dioxide gave 2-hydrazinocarbonyl-3-methylquinoxaline 1,4-dioxide (9) or 2-ethoxycarbonyl-3-formylquinoxaline 1,4-dioxide (10), respectively. The reaction of compound 9 with alkanoyl chlorides, benzoyl chlorides, heteroacyl chlorides, and benzenesulfonyl chlorides afforded 3-methyl-2-(substituted hydrazinocarbonyl)quinoxaline 1,4-dioxides (11-14), respectively. The reaction of compound 9 with sodium azide gave 2-azidocarbonyl-3-methylquinoxaline 1,4-dioxide (15), and then its refluxing in dioxane/alcohols resulted in the Curtius rearrangement to give N-(3-methyl-1,4-dioxoquinoxalin-2-yl)-alkyl carbamates (16). The reaction of compound 15 with substituted anilines afforded 2-(3-substituted phenylureido)-3-methylquinoxaline 1,4-dioxides (17). The reaction of compound 10 with benzoic hydrazide or substituted anilines provided quinoxaline 1,4-di-oxides (18, 19), respectively. The herbicidal and fungicidal activities of the synthesized compounds were investigated.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.679-682
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• 1994

The volatile sulfur compounds in raw and dried garlic (Allium sativum L.) under various temperatures (50, 60, 70 and $80^{\circ}C$ ) were separated, identified by GC and GC/MS. In hexane extracts of raw garlic, 8 volatile sulfur compounds were identified and 11 compounds were identified in steam distillation extracts. The volatile sulfur compounds of raw and dried garlic were mostly composed of diallyl disulfide, diallyl trisulfide, allyl methyl trisulfide. According to the increase of drying temperature total amounts of volatile sulfur compounds in the hexane extracts decreased to $40{\sim}75$$, and in the steam distillation extracts decreased to $10{\sim}20%$. The amounts of diallyl disulfide, allyl methyl trisulfide decreased more than other volatile sulfur compounds, but diallyl trisulfide comparatively decreased lower.

• Journal of Environmental Science International
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• v.6 no.1
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• pp.45-52
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• 1997

Methyl methanesulfonate (MMS) was fed to Drosophila melnogaster in order to investigate its toxic capability at developmental and adult stages, and the hereditary effect of toxicity and the potency for induction of sex-linked lethal mutation during the slyer-matogenesis by the means of an attached-X method. In the control group, the egg to adult viability of D. melnogaster was 95.2%, while 3. 5mM and 5.0mM treated groups were 90.0% and 84.1%, respectively. In the case of their progenies (Fl), the viability was 96.9% in the control group, while 3.5mM and 5.0mM treated groups were 54.5% and 1.6%, respectively. Therefore, these differences between two generations show significant physiological toxic effects in the next generation. In the parental generation, the developmental time was calculated 11.05 days in the control group, 12.43 days In 3.5%mM treated group, and 13.23 days in 5.0mM. In the case of Fl it was estimated 10.35 days in the control group, and 11.43 days In 3.5mM treated group. Compared with the control groups In two generations, the developmental time generally delayed as the dose of MMS increased. As to the sex-ratio, there was no differences between the control and MMS treated groups. The toxic values of adult stage showed which increased the frequency of mortality with MMS concentrations. The mortality at 120hr In the control group was 1.67% and it in 0.5mM MMS treated group 3.33%. In 2.5mM MMS treated group, it was 33.3% at 72hr, and it 95% at 120hr The increase of the morality was shown from 72hr in 4.0mM treated group which was 100% at 96hr. There was the concentration-dependent induction of sex-linked lethal mutation during the spermatogenesis by means of an attached-X method, MMS had more pronounced effect in sperm and spermaid stages in D. melnogaster.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.228-233
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• 2010

Mn-doped $Zn_2SiO_4$ phosphor particles having submicrometer sizes were synthesized by a solid-state reaction method using methyl hydrogen polysiloxane-treated ZnO, fumed $SiO_2$ and various Mn sources. The crystallization and photoluminescent properties of the phosphor particles were investigated by X-ray diffraction(XRD), scanning electron microscope(SEM), and by their photoluminescence(PL) spectra. Due to the effect of the dispersion and coherence of the methyl hydrogen polysiloxane-treated ZnO, the Mn-doped $Zn_2SiO_4$ particles were successfully obtained by a solid state method at $1000^{\circ}C$, and the maximum PL intensity of the prepared particles under vacuum ultra violet(VUV) excitation occurred at a Mn concentration of 0.02mol and a sintering temperature of $1000^{\circ}C$.

• Food Science and Preservation
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• v.12 no.1
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• pp.68-74
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• 2005

This study was carried out to analyze to the flavor components of Lindera obtusiloba BL leaf teas by different processing methods. 81 kinds of flavor components in the masted tea, 78 in the roasted tea after steaming, 88 in the withered tea, 86 in the fermented tea, 72 in the steamed tea, and 89 in the air dried tea ware by GC/MS. Hydrocarbones in Lindera obtusiloba BL leaf teas were 45 kinds of $\beta-piepne$, and 16 kinds of alcohols such as Linalool, n-octanoal, phenyl acetaldehyde, $(-)-\alpha-terpineol$, elemol, and cholest-5-en-3-ol. 11 kinds of ketones sachas 2-ethyl-2- propyl-cyclohexanone, and 8 kinds of aldehydes sach as phenyl acetaldehyde, tetradecanal, 10-undecanal, 4-Bromo-2-methylbutanal were found. Esters were methyl 9,12,15-octadecatrienate, didodecyl phthalace, 1,2-benzenediccarbaboxy acid-bis (2-ethylhexyl)ester and phenols was 2,6-bis(1,1-dimethylethyl)-4-methyl-phenol.

• Journal of the Korean Chemical Society
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• v.46 no.4
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• pp.330-336
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• 2002

For the purpose of development of new agrochemical fungicide of ${\alpha},{\beta}-unsaturated$ carboxanilide series a synthesis of 4-acetyl-3-methyl-N-phenyl-1,4-thiazine-2-carboxamide (6) is described. Pummerer reaction of sulfoxide 7 obtained by sulfoxidation of dihydro-1,4-thiazine methyl ester 11 gave ${\alpha}-acetoxy$ dihydro-1,4-thiazine 10a. Under the same reaction conditions, dihydro-1,4-thiazine carboxanilide sulfoxide 14 was converted to acetoxymethyl dihydro-1,4-thiazine 18 through vinylogous Pummerer reaction involving carboxanilide of sulfonium ion through intermediate 15.1,4-Thiazine carboxanilide 6 was synthesized from the treatment of ${\alpha}-acetoxy$ dihydro-1,4-thiazine 10a with acid cat-alyst followed by hydrolysis and then the reaction with aniline.