• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.183-192
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• 2014

For the structure determination of D-(+)-sucrose, which consists of ${\alpha}$-D-(+)-glucose and ${\beta}$-D-(+)-fructose, it was acetylated with acetic anhydride and triethyl amine, pyridine, zinc chloride, and sodium acetate as catalysts. The acetylated D-(+)-sucrose was acid-hydrolyzed using sulfuric acid and sodium chloride in methanolic solution. The structures of the reaction products were determined by $^1H$-NMR and $^{13}C$-NMR spectra. The yield of the acetylation indicated the high value in zinc chloride as 70% in zinc chloride catalyst. The acid-hydrolyzed product of the acetylated D-(+)-sucrose, 2,3,4,6,1',3',4',6'-octa-O-acetyl-D-(+)-sucrose, gave 2,3,4,6-tetra-O-acetyl-${\beta}$-D-(+)-glucose and it suggests that the acetylated D-(+)-sucrose was rearranged through the formation of oxonium ion by mutarotation in the 2,3,4,6-tetra-O-acetyl-${\alpha}$-D-(+)-glucose moiety and through the ring opening in the 1',3',4',6'-tetra-O-acetyl-${\beta}$-D-(+)-fructose moiety.

• Analytical Science and Technology
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• v.11 no.4
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• pp.235-242
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• 1998

Membrane electrode based on chitin(po1y-[$1{\rightarrow}4$]-${\beta}$-N-acetyl-D-glucosamine) was prepared by mixing uniformly grounded of chitin (100 mesh) with PVC and DOS. We investigated the potential response of chitin membrane electrode to metal ions. It was observed that the response slopes for $Cd^{2+}$(34.9 mV/decade) and $Cu^{2+}$(34.0 mV/decade) were larger than those for other ions in pH 4 acetate buffer. The potentiometric response of chitin electrode to varying pH was nearly constant in the pH range of 2~12.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2034-2042
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• 2015

A one-pot process of enzymatic synthesis of deoxythymidine-5'-triphosphate (5'-dTTP) employing whole cells of recombinant Escherichia coli coexpressing thymidylate kinase (TMKase) and acetate kinase (ACKase) was developed. Genes tmk and ack from E. coli were cloned and inserted into pET28a(+), and then transduced into E. coli BL21 (DE3) to form recombinant strain pTA in which TMKase and ACKase were simultaneously overexpressed. It was found that the relative residual specific activities of TMKase and ACKase, in pTA pretreated with 20 mM ethylene diamine tetraacetic acid (EDTA) at 25℃ for 30 min, were 94% and 96%, respectively. The yield of 5'-dTTP reached above 94% from 5 mM deoxythymidine 5'-monophosphate (5'-dTMP) and 15 mM acetyl phosphate catalyzed with intact cells of pTA pretreated with EDTA. The process was so effective that only 0.125 mM adenosine-5'-triphosphate was sufficient to deliver the phosphate group from acetyl phosphate to dTMP and dTDP.

• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.11-14
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• 2000

Transparent conducting ITO thin films have been studied and developed for the solar cell substrate or LCD substrate. ITO thin film has been mostly fabricated by high cost sputtering method. In this research, sol-gel method is applied to fabricate ITO thin film at lower cost. The research is focused on the establishment of process condition and development of precursor. Organic sol was made of indium tri-isopropoxide dissolved in ethylene glycol monoethyl ether. The hydrolysis was controled by addition of acetyl acetone. Tin(IV) chloride was added as dopant. Inorganic sol was made of indium acetate dissolve din normal propanol. Spin coating technique was applied to coat ITO on borosilicate glass. The resistivity of ITO thin film was approximately $0.01\Omega{\cdot}cm$ and the transmittance is higher than $90\%$ in a visible range.

• Research in Plant Disease
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• v.15 no.2
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• pp.120-126
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• 2009

In the course of study on the roles of phytotoxins in the pathogenicity of Botrytis cinerea, we isolated two novel phytotoxins. They were identified as 3-O-acetyl botcinol and 3-O-acetyl botcinolide. In this study, we investigated correlation between the two phytotoxins and the pathogenicity of B. cinerea. In liquid cultures, the two phytotoxins were not produced by three low pathogenic isolates out of 25 B. cinerea isolates. Among strong or moderate pathogenic isolates, some produced the two phytotoxins, but the others did not. On the other hand, the ethyl acetate extracts of fermentation broths of 10 out of 25 isolates showed phytotoxic activity against various plants tested in a whole plant assay. The phytotoxins were detected in all of the 10 phytotoxic ethyl acetate extracts. In planta, the two phytotoxins were detected in all of the plant tissues infected with strong pathogenic isolates. However, there was no correlation between the ability of B. cinerea isolates to produce the two phytotoxins and their pathogenicities. The two phytotoxins began to detect in tomato plant tissues infected with B. cinerea 2-16 at 3 days after inoculation, increased gradually till 4 days after inoculation, and then decreased. The above results suggest that 3-O-acetyl botcinol and 3-O-acetyl botcinolide are one of pathogenicity factors for B. cinerea, but not a primary determinant of its pathogenicity.

• Archives of Pharmacal Research
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• v.23 no.1
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• pp.26-30
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• 2000

The enantiomers of the bronchodilator terbutaline were separated by reversed-phase high performance liquid chromatograhy after derivatization with 2,3,4,6-tetra-O-acetyl-\beta-D-glucopyranosyl isothiocyanate(GITC) reagent. The derivatization proceeded quantitatively within 1 h at room temperature. The corresponding diastereomeric thiourea derivatives were well resolved on an ODS column with acetonitrile-acetate buffer as a mobile phase. Elution orders of the diastereomers were confirmed by derivatization of R-(-)-terbutaline and S-(+)-terbutaline which were collected by semi-preparative chiral HPLC using Sumichiral OA-4700 column. The native fluorescence of terbutaline was quenched by derivatization with GITC. The detection limit was 25ng when monitored at UV 278 nm.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.135-139
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• 1998

Poly(vinyl acetate) (PVAc) from which atactic poly(vinyl alcohol) (PVA) is derived, is always noncrystalline. This was attributed to the irregular steric arrangement of the acetyl groups in PVAc. However, the X-ray diffraction patterns of atactic PVA, a derivative of PVAc, were found to show distinct crystallinity, and to give an identity period of 2,52 ${\AA}$ along the fiber axis, despite the expectation of an irregular arrangement of the hydroxyl groups in atactic PVA, in the same manner as that of the acetyl groups in PVAc.(omitted)

• Bulletin of the Korean Chemical Society
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• v.11 no.6
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• pp.538-542
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• 1990

New aminothiazolyl cephalosporins with alkoxyiminomethyl(2-aminothiazol-4-yl)acetyl substituents at 7-position of cephems were synthesized starting from (2-aminothiazol-4-yl)acetate via one carbon homologation followed by acylation with 7-aminoceph-3-em-4-carboxylic acid derivatives. These new aminothiazolyl cephalosporins exhibit promising in vitro activities against various strains including Gram positive bacteria.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.686-696
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• 2003

Ethyl (coumarin-4-oxy)acetate 1 was prepared through the reaction of 4-hydroxycoumarin with ethyl bromoacetate. Compound 1 was allowed to react with hydrazine hydrate to produce coumarin-4-oxyacetic hydrazide 2. The synthesis of N-(arylidene and alkylidene)-coumarin-4-oxyacetic hydrazones 3-20 was performed. The preparation of 2-substituted-3-[(coumarin-4-oxy) acetamido]thiazolidinones 21-26 and 2-[(coumarin-4-oxy )methyl]-4-acetyl-5-substituted-$\Delta^2$-1,3,4-oxadiazolines 27-33 was performed by the reaction of the hydrazones 3, 4, 7, 9, 12, 14 with mercaptoacetic acid and the hydrazones 3, 4, 5, 7, 12, 15, 16 with acetic anhydride, respectively. The antiviral activities, cytotoxicities and structure-activity relationship (SAR) towards different microorganisms of the prepared compounds were studied.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.54-63
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• 2019

Rubus coreanus Miquel (RCM), also known as Korean blackberry or bokbunja, is used as a South Korean traditional medicine to treat acne and inflammatory skin conditions. The antimicrobial activity of RCM root and its active compounds remain unclear. In this study, we prepared a 50% ethanol fraction, ethyl acetate fraction, and acid-treated ethyl acetate fraction (aglycone fraction) of RCM root, and evaluated antibacterial activities against the skin pathogens Staphylococcus aureus, Pseudomonas acnes, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. In a paper disc assay, all fractions of RCM root showed antimicrobial activities against the five skin pathogens. The ethyl acetate fraction displayed 6-, 12-, and 2-fold higher minimal inhibitory concentration (MIC) than the 50% ethanol fraction against S. aureus, E. coli, and P. acnes, respectively. The aglycone fraction displayed 2-fold higher MIC than methyl paraben against P. acnes, S. aureus, E. coli, and P. aeruginosa. The ethyl acetate fraction displayed a minimal bactericidal concentration (MBC) similar to that of methyl paraben, and the aglycone fraction showed 2- to 4-fold higher MBCs than those of methyl paraben. In particular, the ethyl acetate fraction was not cytotoxic and showed thermal stability after incubation at high temperatures ($60-121^{\circ}C$). Finally, the ethyl acetate fraction was separated and four components were identified: procyanidin C, propelagonidin dimer, ellagic acid, and methyl ellagic acid acetyl pentose. The compounds showed high antibacterial activities. These results suggest that RCM root is potentially applicable as a natural preservative in cosmetics.