• 한국응용과학기술학회지
• /
• 제18권3호
• /
• pp.180-185
• /
• 2001

Antibiotics polymer prepared by chemical bonding and simple blending of antibacterial into polymers have attracted much interest because of their long-lasting and antibacterial activity. Antibiotics polymer can significantly reduce losses associated with dissolution, photolytic decomposition and volatillization. Further more, increased efficiency safety and selectivity are additional benefits which may be realized. In this study, Antibiotics polymer was synthesized by chemical reaction of polyacrylic acid with sulfamethazine by N,N'-dicyclohexylcarbodiimide(DCC) method. Antibacterial susceptibility was determined against Streptococcus pyrogenes[gram(+)] and Esherichia coli.[gram(-)] using a standardized disc test. As a result, the synthetic antibiotics polymer exhibited the broad susceptibilty against Streptococcus pyrogenes and Esherichia coli. Especially, the antibiotic effect of antibacterial polymer against Gram negative(Esherichia coli) was much stronger than that against Gram positive(Streptococcus pyrogenes).

• Archives of Pharmacal Research
• /
• 제20권1호
• /
• pp.80-84
• /
• 1997

Substituted cinnamoyl-tyramine derivatives were synthesized by DCC-coupling of substituted cinnamic acid with tyramine or tyramine methyl-1-ether to evaluate PAF-receptor binding antagonistic activities and inhibitory activities on PAF-induced platelet aggregation with interest on structure-activity relations. The results show that 3,4-dimethoxy-cinnamoyl tyramine-amide or its methyl ether have significant PAF-receptor binding antagonistic activity and platelet anti-aggregatory activities.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2013년도 전력전자학술대회 논문집
• /
• pp.224-225
• /
• 2013

This paper describes the four switch three-phase Z-source active power filter. This novel configuration has many advantages like reduction of cost, switching loss and smaller drive circuit. The paper presents an application of direct current control(DCC) method in a three-phase parallel Z-source active power filter to reduce the harmonics generated by the nonlinear load. The compensation principles and dynamics of the system are discussed in detail. The results show that the proposed control strategy is feasible and efficient.

• Bulletin of the Korean Chemical Society
• /
• 제33권6호
• /
• pp.1939-1944
• /
• 2012

Benzoyloxy benzophenone derivatives were prepared in 3 steps including DCC coupling, Fries rearrangement and esterification from benzoic acids in 24-89% total yields. Among the prepared 12 benzophenone analogues 1a-1l, the compound 1b having three chloro groups at the para position showed maximum inhibitory effects of ICAM-1 expression but, 1a which have no substituents at all showed no inhibitory activity. This study provides the evidences that benzoyloxy benzophenone derivative, 1b may exert its anti-inflammatory activity by suppressing IFN-${\gamma}$-induced ICAM-1 expression.

• Bulletin of the Korean Chemical Society
• /
• 제22권6호
• /
• pp.587-592
• /
• 2001

The potential anticancer agents new anthracycline derivatives (2~9) have been synthesized from daunomycin (1a) and doxorubicin (1b) ad starting materials. Compounds 2 and 6 were prepared by the nucleophilic displacement type esterification of a 14-bromodaunomycin (1c) with a acetylsalicylic and palmitic acid in triethylamine, respectively. Compound 3 and 7 were obtained from daunomycin (1a) by direct amidation with the corresponding acids in the presence of EDCI and PP as esterification regents. Whereas 4 and 8 were prepared by reaction of doxorubicin (1b) with one equivalent of acetylsalicylic and palmitic acid using DCC/DMAP, respectively, 5 and 9 were obtained from 1b by acylation with two equivalents of the corresponding acids using EDCI/PP reagents.

• Bulletin of the Korean Chemical Society
• /
• 제26권12호
• /
• pp.2021-2026
• /
• 2005

The oxidation of cytidine 1 and inosine 5 by sodium metaperiodate followed by the reaction of the product with $CH_3I$ in NaOH afforded 2',4'-dihydroxyhexopyranosyl derivatives 2 and 14 respectively. The reaction of thiophene-2-carboxylic acid or furfural with cytidine were taken place via cycloaddition afforded adducts 3 and 4 respectivily. The bromination of inosine 5 or its 2',3'-O-isopropylidine inosine 6 led to the formation of 8-bromoanalogue 7 and 8, respectively. The reaction of 8-bromo-2',3'-O-isopropylidine inosine (8) with ethylglycinate hydrochloride afforded 8-ethoxycarbonylmethylaminoinosine 9. The alkylation of the compound 6 with urea led to the formation of 3-carbonylaminoinosine 10. The oxidation of 6 with DCC afforded 4'-formyl derivative 11, which on reaction with ethyl glycinate hydrochloride followed by reaction with sodium cyanoborohydride afforded 12, while the treatment of dialdehyde inosine 13 with ethyl cyanoacetate in the presence of 0.5 N NaOH afforded compound 15.

• 약학회지
• /
• 제42권1호
• /
• pp.12-24
• /
• 1998

For the development of new cephalosporin antibiotics with aminothiazolcarboxymethylethoxyimino moiety on the C-7 position and tetrazolymethyl moiety on the C-3 position of cephe m ring, 7${\beta}$-[(Z)-2-(2-aminothiazol-4-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[5-(substituted)tetrazol-2-yl]methyl-3-cephem-4-carboxylic acids(28-35) were synthesized. These compounds were tested for antimicrobial activity in vitro against Gram(+) and Gram(-) bacteria. They showed remarkable antibacterial activity against Escherichia coli AB 1157, Escherichia coli AB 0111, Escherichia coli BE 1186, Micrococcus luteus ATCC 9341, Salmonella typhimurium TV 119, Salmonella typhimurium SL 1102, Staphylococcus aureus IFO 12732, Staphylococcus aureus R-209, but these compounds were not active against Pseudomonas aeruginosa N-10.

• 공업화학
• /
• 제9권5호
• /
• pp.704-709
• /
• 1998

${\alpha}$-Methyl styrene과 maleic anhydride를 공단량체로 사용하여 유리전이온도가 높고 내열성이 우수한 poly (${\alpha}$-methylstyrene-co-maleic anhydride) (MSMA) 기재 고분자 (substrate polymer)를 합성하고 여기에 니트로기를 가진 발색단을 고분자반응을 이용하여 도입하는 반응 및 생성된 비선형 광학 고분자의 전기 광학 특성에 대해 조사하였다. MSMA 기재 고분자에 hydroxyl기를 가지는 azo계 발색단 (chromophore) 2-[4-(4-nitrophenylazo)-N-ethylphenylamino]ethanol (DR1)을 고분자 반응 (polymer reaction)으로 maleic anhydride에 ester 결합으로 도입할 때 4-dimethylaminopyridine (DMAP) 촉매만을 쓴 것 (MSMA-D)보다 DMAP와 3-dicyclohexyl carbodiimid (DCC)를 동시에 사용한 경우 (MSMA-DC)가 DR1 발색단의 도입율이 높게 나타났다. 비선형 광학 고분자 (MSMA-DC)의 전기광학계수 ($r_{33}$)는 파장이 632.8 nm인 광원에서 18 pm/V의 값을 나타냈으며 열적 안정성도 유리전이 온도 ($T_g$)가 $175^{\circ}C$ 이상으로 우수하게 나타났다.

• Journal of Pharmaceutical Investigation
• /
• 제25권2호
• /
• pp.101-108
• /
• 1995

The surface of albumin microspheres could be modified with methotrexate (MTX) by using 1,3-dicyclohexylcarbodiimide (DCC). Surface-modified albumin microspheres entrapping no MTX (SAMS), free MTX (SAMSF) and MTX-bovine serum albumin (BSA) conjugates (SAMSC) were prepared. respectively, and their release characteristics were investigated in the presence of trypsin using a dissolution tester. The mean diameters of all the microspheres were $5{\sim}8\;{\mu}m$, and their shapes was small and uniform. MTX bound tn their surfaces was released slower than the entrapped free MTX, and laster than the entrapped MTX-BSA conjugates. Also, surface-modified MTX was scarcely released in the absence of a proteolytic enzyme. Therefore, the surface-modified MTX may be released rapidly from SAMSC at the target site, and thereafter MTX may be released slowly from the encapsulated MTX-BSA conjugates in SAMSC for a long period.

• 재무관리연구
• /
• 제26권3호
• /
• pp.199-226
• /
• 2009

본 논문은 우리나라 주식시장과 외환시장의 기대 수익률과 조건부 변동성간의 시계열적 관계를 2요인 자본자산가격결정모형(two-factor ICAPM)을 이용하여 실증 분석하였다. 주가와 환율의 조건부 분산은 GARCH 모형과 비대칭성을 반영한 GJR(1993) 모형으로 추정하였으며, 주가와 환율과의 조건부 공분산은 Bollerslev(1990)의 일정 상관관계(CCC) 모형과 Engle(2002)의 동태적 조건부상관관계(DCC) 모형을 이용하여 추정하였다. 실증 분석모형은 MGARCH-M 모형을 사용하였으며, 추정방법은 준최우추정법(QMLE)을 사용하였다. 실증 분석결과 외환위기 이후에 주식시장의 기대 수익률은 주가의 분산에 대해, 그리고 환율과의 공분산에 대해 유의한 음(-)의 관계를 갖는 것으로 나타났다. 그러나 외환시장에서 기대 수익률은 조건부 분산과 조건부 공분산에 대해 유의하지 않은 것으로 나타났다. 조건부 분산의 추정에서는 GJR 모형이 GARCH 모형에 비해 더 적합한 것으로 나타났다. 그리고 DCC 모형이 CCC 모형에 비해 설명력이 더 높은 것으로 나타났다. 본 논문의 분석결과는 주식시장에서 환율 변동이 위험 요인으로 작용하고 있기 때문에 포트폴리오 구성이나 위험 관리 등에서 환율 변동을 고려할 필요가 있고, 변수들간의 상관관계는 시변하는 모형을 사용할 필요가 있음을 시사한다.