• Membrane and Water Treatment
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• 제7권2호
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• pp.143-154
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• 2016

Acetic acid can be removed from wastewater by esterification in a membrane reactor. Pervaporation membrane reactor (PVMR) is an alternative process to conventional separation processes. It is an environmentally friendly process. The main advantages of the PVMR are simultaneous water removal and production of an ester economically. In this study, the synthetic wastewater has been used. Esterification reaction of acetic acid with isopropanol has been studied in the presence of tungstosilicic acid hydrate as a catalyst in a batch reactor and in a PVMR. The effects of important operating parameters such as reaction temperature, initial molar ratio of isopropanol to acetic acid and catalyst concentration has been examined. Removal of acetic acid (conversion of acetic acid) was obtained as 85% using a PVMR by removal of water from the reaction mixture.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.329-329
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• 2006

Various new active ester monomers based on (meth)acrylates and 4-vinylbenzoic acid have been prepared. Investigation of the controlled radical polymerization behavior of the respective monomers resulted in excellent polymerization control, thus, opening synthetic routes to reactive block copolymers. Polymer analogous reactions with amines yielded functional polymers. In the case of the copolymer poly(N-isopropylacrylamide-co-acetone oxime acrylate) a lower critical solution temperature could be measured at $52^{\circ}C$. Thus, the reactive copolymer features two characters: reactive AND stimuliresponsive behavior.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.171-174
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• 2006

In this work, we report the synthesis and characterization of azomethine-ester polymers that consist of banana-shaped mesogen in their backbone. Two parts of the key structure of five-ring bent-core mesogen were modified by connecting different angle of central unit (Ar), and introducing lateral substituent into the outer ring (X). The synthetic details includes (1) placing the dioxydodecamethylene unit as a flexible spacer, (2) possessing 2,3- or 2,7-naphthylene, or 1,2-phenylene connection on the central unit, and (3) introducing fluorine or chlorine substituent (X = F or Cl) into the outer phenylene unit.

• Archives of Pharmacal Research
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• 제17권5호
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• pp.354-359
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• 1994

The activity of SD-framesylcysteine O-methyltransferase was assayed by incubating the enzyrne with a synthetic in vitro substrate, [N-acetyl-S-trans, trns-famesyl-L-cysteine (AFC)], together with S-adenosyl-L-[emthyl-$_{14}$C)ester(AFCME)], was then analyzed either directly on HPLC or by converting the AFC[$methyl^{14}C$]ME to [$methyl^{14}C$] aclcohol by basehydrolysis. Employing these two analytical methods, it was established that a peptide purifed from rat liver cytosol fraction [Int. J. Biochem., 25, 1157 919930] strongly inhibited the above enzyme activity with $IC_{50}\; of\; 7.1\times 10^{-8}$ M. Also, the S-famesylcysteine O-methyltransferase from several human colon cancer cells was equally inhibited by the peptide.

• 한국균학회지
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• 제8권1호
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• pp.69-71
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• 1980

To establish a competent method of microbiological assay for bacampicillin, one of new semi-synthetic derivatives of ${\beta}-lactam$ antibiotics, a comparison was carried out between different conditions for hydrolysis of bacampicillin into ampicillin which was then subjected to cylinder plate method. The results showed that the use of carboxylic ester hydrolase in vitro as a pretreatment of it in either pH value 6 or 8 was feasible and that the cylinder plate method with Sarcina lutea was adequate for potency estimation.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2953-2958
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• 2013

A noble phenylsulfonyl reagent 8 having ${\alpha}$-oxo (cyanomethylene)triphenylphosphorane ylide subunit readily condensed with various alkyl halides under basic conditions to afford ${\beta}$-alkyl-${\alpha}$-oxo-${\beta}$-phenylsulfonyl (cyanomethylene)triphenylphosphorane ylides 9 in excellent yields. These sulfonyl ylides 9 were then reductively desulfonylated with $Na(Hg)/Na_2HPO_4$ in the presence of methanol to provide ${\alpha}$-keto (cyanomethylene)-triphenylphosphorane ylides 2' in good to excellent yields. Our new synthetic approach offers an expeditious access to various ${\alpha}$-keto (cyanomethylene)triphenylphosphorane ylides from alkyl halides utilizing a new phenylsulfonyl reagent as the key reagent under mild reaction conditions in good overall yields.

• Bulletin of the Korean Chemical Society
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• 제8권1호
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• pp.15-19
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• 1987

Preparation of optically pure (3R, 4R)-4-acetoxy-3-[(1R)-1-hydroxyethyl]azetidin-2-o ne derivatives, which can be employed as starting materials for synthesis of carbapenem and penem antibiotics, was established in high efficiency from 6-amino-penicillanic acid (6-APA). 6-APA was diazotized and brominated to give 6, 6-dibromopenicillanic acid and its methyl ester was metalated with methylmagnesium bromide and condensed with acetaldehyde. The product, methyl 6-bromo-6-(1-hydroxyethyl)penicillanate was reduced with Zn-$NH_4Cl-NH_4OH$-acetone efficiently to give methyl 6-(l-hydroxyethyl)-penicillanate, which was protected either with ${\beta},{\beta},{\beta}$ -trichloroethoxycarbonyl group or with t-butyldimethylsilyl group. The thiazolidine rings of these compounds were cleaved by treatment of mercury(II) acetate in acetic acid and permangante in acetone in sequence to afford the desired optically pure final products.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7265-7270
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• 2013

Objective: The present study was designed to investigate the probable mechanisms of synthetic retinoid 4-amino-2-tri-fluoromethyl-phenyl ester (ATPR) inhibition of the proliferation and migration of A549 human lung carcinoma cells. Materials and Methods: After the A549 cells were treated with different concentrations of ATPR or all-trans retinoic acid (ATRA) for 72 h, scratch-wound assays were performed to assess migration. Immunofluorescence was used to determine the distribution of CAV1 and $RXR{\alpha}$, while expression of CAV1, MLCK, MLC, P38, and phosphorylation of MLC and P38 were detected by Western blotting. Results: ATPR could block the migration of A549 cells. The relative migration rate of ML-7 group had significantly decreased compared with control group. In addition, ATPR decreased the expression of a migration related proteins, MLCK, and phosphorylation of MLC and P38. ATPR could also influence the expression of RARs or RXRs. At the same time, CAV1 accumulated at cell membranes, and $RXR{\alpha}$ relocated to the nucleus after ATPR treatment. Conclusions: Caveolae may be implicate in the transport of ATPR to the nucleus. Change in the expression and distribution of $RXR{\alpha}$ may be implicated in ATPR inhibition of A549 cell proliferation. The mechanisms of ATPR reduction in A549 cell migration may be associated with expression of MLCK and phosphorylation of MLC and P38.

• 한국식생활문화학회지
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• 제14권1호
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• pp.43-48
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• 1999

본 연구에서는 탈지참깨박의 기능성을 검토하기 위하여 탈지참깨박으로부터 페놀산을 추출하여 이들 추출물의 항산화 효과를 합성항산화제인 BHA, AP 및 TBHQ의 항산화 효과와 비교하였다. 탈지참깨박 중 페놀산 추출물은 유리형, 에스터형, 불용성 페놀산이 각각 246.8, 109.6, 85.8mg/100g으로 유리형이 가장 높았으며, 유리형 페놀산에는 6종류의 페놀산이 다량 함유되어 있었고 에스터형과 불용성 페놀산에는 각각 3종류의 페놀산이 함유되어 있었다. 탈지참깨박 중의 3가지 형태의 페놀산의 항산화력은 유리형이 가장 컸고 에스터형, 불용성 순으로 나타났는데 이것은 유리형 페놀산 group의 종류와 함량이 가장 많은 것에 기인하는 것으로 생각된다. 탈지참깨박 페놀산 추출물의 항산화 효과는 BHA나 AP(0.02%)보다 강한 것으로 나타났으며, 유리형 페놀산의 경우는 합성 항산화제 중 가장 우수한 것으로 나타난 TBHQ의 항산화력과 거의 유사할 정도로 높았다.

• 한국식품과학회지
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• 제24권5호
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• pp.504-510
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• 1992

고정화 thermolysin에 의한 아스파탐 전구체의 하나인 N-Benzoylaspertame(BzAPM)의 합성을 효율적으로 할 수 있는 수용성 유기용매가 함유된 용매계를 산정하고자 하였다. BzAPM 및 L-phenylalanine(Phe)의 용해도는 methanol 45%가 함유된 용매계에서 각각 1.84 및 1.79%로 가장 높았으며, dimethyl sulfoxlilde(DMSO) 25%와 polyethylene glycol(PEG) 200 20%가 함유된 혼합 용매계도 비교적 높은 용해도를 보였다. BzAPM의 용해도는 ethylene glycol류의 분자량이 커질수록 용해도가 증가하였으나, Phe의 경우에는 이러한 경향을 나타내지 않았다. 고정화 thermolysin에 의한 BzAPM의 합성역가는 methanol 45% 및 DMSO 45%의 난일 유기용매계와 DMSO 25% 및 PEG 200 20%가 함유된 혼합 용매계에서 높게 나타났으며, 초기 합성속도도 빠른 것으로 나타났다. $40^{\circ}C$에서 42일간 고정화 효소를 보관하였을 때, thermolysin은 DMSO 25%와 PEG 200 20%가 함유된 용매계에서 가장 안정하였다. L-phenyalanine methyl ester의 비효소적 가수분해 속도는 methanol함유 용매계에서 가장 낮았고, DMSO 25%와 PEG 200이 함유된 용매계에서는 이들의 중간 정도인 것으로 확인되었다. 그리하여 고정화 thermolysin에 의한 BzAPM의 합성에 적합한 용매계로서 DMSO 25% 및 PEG 200 20%가 함유된 용매계를 선정하였다.