• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.971-976
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• 2005

In a 30-1 bioreactor culture, whole differentiation occurred from 48 h, and then proceeded rapidly. As swollen hyphal fragments and arthrospores increased, cephalosporin C (CPC) production increased exponentially to $1.85\;g/1^{-1}$ at 72 h. To explain the morphological changes of Cephalosporium acremonium M25 more quantitatively, specific differentiation rates and fractal analysis were employed. Specific differentiation rates of morphological factors varied greatly during the period of culture time from 48 h to 72 h, when CPC production increased significantly. Changes of fractal dimensions showed a pattern similar to that of the specific rate of arthrospores. Furthermore, it was inversely related to the specific rate of tips. Overall, it was suggested that the fractal dimension had potential for a new morphological parameter of fungal morphology, showing complex differentiation patterns.

• 약학회지
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• 제40권1호
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• pp.102-111
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• 1996

LB10522 is a new parenteral broad spectrum cephalosporin with a catechol moiety at C-7 position of beta-lactam ring. This compound can utilize tonB-dependent iron transp ort system in addition to porin proteins to enter bacterial periplasmic space and access to penicillin-binding proteins (PBPs) which are the lethal targets of ${\beta}$-lactam antibiotics. The chelating activity of LB10522 to metal iron was measured by spectrophotometrically scanning the absorbance from 200 to 900nm. When $FeCl_3$ was added, optical density was increased between 450 and 800nm. LB10522 was more active against gram-negative strains in iron-depleted media than in iron-replete media. This is due to the increased expression of iron transport channels in iron-depleted condition. LB10522 showed a similar activity against E. coli DC2 (permeability mutant) and E. coli DCO (wild type strain) in both iron-depleted and iron-replete media, indicating a minimal permeaility barrier for LB10522 uptake. LB10522 had high affinities to PBP 3 and PBP 1A, 1B of E. coli. By blocking these proteins, LB10522 caused inhibition of cell division and the eventual death of cells. This result was correlated well with the morphological changes in E. coli exposed to LB10522. Although the in vitro MIC of LB10522 against P. aeruginosa 1912E mutant (tonB) was 8-times higher than that of the P. aeruginosa 1912E parent strain, LB10522 showed a similar in vivo protection efficacy against both strains in the mouse systemic infection model. This result suggested that tonB mutant, which requires a high level of iron for normal growth, might have a difficulty in surviving in their host with an iron-limited environment.

• 한국환경농학회지
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• 제20권1호
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• pp.8-14
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• 2001

항생물질 발효산업 부산물인 부산물오니의 농업적 활용성을 검토하기 위하여 98년 5월과 8월 두 차례 열무의 생장량 및 토양 화학성에 미치는 효과를 비교하였다. 오니의 처리수준은 열무의 표준시비량($N-P_2O_5-K_2O=160-59-104$ kg/ha)을 대조구로 하여 오니 및 관행퇴비를 각각 1000 kg/ha 씩 추가 시용 하는 오니 및 퇴비 첨가구 와 오니 및 퇴비 각각에 함유된 질소량의 30%를 질소 시용량에서 공제하는 질소공제 오니 및 퇴비구 등 5개 처리로 비교하였다. 오니 첨가구 및 질소공제 오니구의 열무 발아율과 초기생육은 대조구, 퇴비 첨가구 및 질소공제 퇴비구에 비하여 부진하였다. 이는 미분해된 오니의 토양중 분해과정에서 생성될 수 있는 암모니아가스 피해에 기인된 것으로 생각된다. 그러나 수확기의 열무 수량은 오니 첨가구 및 질소공제 오니구를 포함한 모든 처리구간에 1차 및 2차 시험 모두 유의성 있는 차이가 인정되지 않았다. 이는 오니의 시용에 의한 열무의 생육이 후반기에 빠르게 증진되었다는 것을 시사하고 있다. 식물체의 질소함량과 토양의 무기태 질소 함량은 오니의 시용에 의하여 증가되는 경향이었으나 항생물질 cephalosporin-C는 열무의 지상부나 지하부 그리고 시험 후 토양에서 검출되지 않았다. 따라서 부산물오니는 유기물(750 g/kg)과 전질소(56 g/kg)를 많이 함유하고 유해 중금속 함량이 허용치 이하인 점을 고려할 때 양질의 유기물 자원으로서 농업적 활용가치가 인정되었다.

• Journal of Pharmaceutical Investigation
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• 제32권2호
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• pp.73-80
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• 2002

Cefuroxime axetil is a cephalosporin antibiotic having a high activity against a wide spectrum of Grampositive and Gram-negative microorganisms. It is a cephalosporin antibiotic which exist as 2 diastereoisomers: diastereoisomer A and B. It shows polymorphism of three forms: a crystalline form having a melting point of about $180^{\circ}C$, a substantially amorphous form having a high melting point of about $135^{\circ}C$ and a substantially amorphous form having a low melting point of about 70^{\circ}C$. The crystalline form of cefuroxime axetil is slightly soluble in water because diastereoisomer A has lower solubility than B in water. Substantially amorphous form of which there are no difference in solubility between diastereoisomer A and B has better solubility than crystalline form, but it forms a thicker gel than crystalline form upon contact with an aqueous medium. Based on this reason, cefuroxime axetil is not readily absorbable in the gastrointestinal tract, rendering its bioavailability on oral administration very low. The object of this study was to develop an improved non-crystalline cefuroxime axetil composition having a high physicochemical stability and bioavailability. A non-crystalline cefuroxime axetil solid dispersant showing no peak on a Differential Scanning Calorimetry (DSC) scan is prepared by dissolving cefuroxime axetil and a surfactant in an organic solvent; suspending a water-insoluble inorganic carrier in the resulting solution; and spray drying the resulting suspension to remove the organic solvent, said solid dispersant having an enhanced dissolution and stability of cefuroxime axetil and being useful for the preparation of a pharmaceutical composition for oral administration. Tablet was formulated with this cefuroxime axetil solid dispersant, disintegrants and other ingredients. It disintegrated and dissolved easily and dynamically in dissolution medium, so showed a good dissolution profile.

• Journal of Microbiology
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• 제39권3호
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• pp.229-231
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• 2001

Different DL-amino acids were studied as inducers of D-amino acid oxidase (DAAO) and for their influence on the growth of Trigonopsis variabilis. DL-amino acids with non-polar side groups were found to be the befit inducers of DAAO. Maximum increase in the growth of Trigonopsis variabilis (gram dry weight per liter culfure) was observed with DL-methionine (2.39 g/l) followed by DL-serine (2.22 g/l) and DL-alanine (2.21 g/l).

• 약학회지
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• 제37권2호
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• pp.136-142
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• 1993

To a suspension of 1-cyclopropyl-6,8-difluoro-1,4-dihydro-7-{3,7-diazabicyclo[3.3.0]oct-1(5)-en-3-yl}-4-oxo-3-quinoline carboxylic acid(C1) in sodium hydroxide solution and water is added dropwise with stirring carbon disulfide. [6R-[6$\alpha$, 7$\beta$(Z)]]-7-[[[2-Amino-4-thiazoly)methoxyimino]-acetyl]amino]-3-[[[[7-( 3-carboxy-1-cyclopropyl-6,8-difluoro-1,4-dihydro-4-oxo-7-guinolonyl)-3,7-diazabicyclo[3.3.0]oct-1(5)-en-3-yl]thioxomethyl]thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-2-carboxylic acid (DACD) was synthesized from 1-cyclopropyl-6,8-difluoro-1,4-dihydro-7-[7-(mercapto) thioxomethyl-[3,7-dia zabicyclo[3.3.0]oct-1(5)-en-3-yl}]-4-oxo-3-quinoline carboxylic acid disodium salt(C2) and cefotaxime. The invitro activity of novel dual-action cephalosporin, DACD, was compared with the in vitro activities of CENO(cefotaxime 3'-norfloxacin dithiocarbamate), cefotaxime, and norfloxacin against a variety of bacterial species. In vitro activity of DACD was superior to that of norfloxacin against Streptococcus pyogenes. Against Gram-positive and Gram-negative bacteria, its activity was almost equal to that of CENO.

• Journal of Veterinary Science
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• 제22권2호
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• pp.17.1-17.13
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• 2021

Background: Klebsiella spp. is an important conditional pathogen in humans and animals. However, due to the indiscriminate use of antibiotics, the incidence of antimicrobial resistance has increased. Objectives: The purpose of this study was to investigate antimicrobial resistance in strains of Klebsiella strains and the phylogenetic relatedness of extended-spectrum cephalosporin (ESC)-resistance among Klebsiella strains isolated from clinically ill companion animals. Methods: A total of 336 clinical specimens were collected from animal hospitals. Identification of Klebsiella species, determination of minimum inhibitory concentrations, detection of ESC resistance genes, polymerase chain reaction-based replicon typing of plasmids by conjugation, and multilocus sequence typing were performed. Results: Forty-three Klebsiella strains were isolated and, subsequently, 28 were identified as K. pneumoniae, 11 as K. oxytoca, and 4 as K. aerogenes. Eleven strains were isolated from feces, followed by 10 from ear, 7 from the nasal cavity, 6 from urine, 5 from genitals, and 4 from skin. Klebsiella isolates showed more than 40% resistance to penicillin, cephalosporin, fluoroquinolone, and aminoglycoside. ESCresistance genes, CTX-M groups (CTX-M-3, CTX-M-15, and CTX-M-65), and AmpC (CMY-2 and DHA-1) were most common in the K. pneumoniae strains. Some K. pneumoniae carrying CTX-M or AmpC were transferred via IncFII plasmids. Two sequence types, ST709 and ST307, from K. pneumoniae were most common. Conclusions: In conclusion, this is the first report on the prevalence, ESCresistance genotypes, and sequence types of Klebsiella strains isolated from clinically ill companion animals. The combination of infectious diseases and antimicrobial resistance by Klebsiella in companion animals suggest that, in clinical veterinary, antibiotic selection should be made carefully and in conjunction with the disease diagnosis.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1992년도 제1회 신약개발 연구발표회 초록집
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• pp.15-15
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• 1992

4세대 cephalosporin계 약물로 개발되고 있는 cefpirome, cefepime, SCE-2787과 같은 화합물은 항균 spectrum 및 항균력에서 3세대 약물인 cefotaxime, ceftazidime보다 우수하며 구조적으로 C-3 quarternized기률 함유한 특징을 가지고 있다. 본 연구소에서는 기존에 보고된 화합물보다 개선된 약물을 찾으려는 시도로서 benzimidazole, imidazolopyridine등 기타 유사구조를 가진 C-3 quarternized 화합물 합성을 하여 왔으며, 본 연구에서는 최근에 합성된 9종의 신규 화합물에 대한 합성 및 항균활성을 보고한다. 이중 9 종의 화합물은 시험한 균주에서 일반적으로 cefpirome 보다 우수한 항균 profile을 나타내었으나 실제 신약으로의 개발 가능성 평가를 위하여 자세한 연구가 필요한 것이었다 이 화합물에 대한 확립된 실험실적 합성 공정과 물성자료를 함께 보고한다.

• Bulletin of the Korean Chemical Society
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• 제11권5호
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• pp.383-386
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• 1990

We have synthesized several bicyclic heteroaromatic compounds with bridgehead nitrogen from N-amine salts of heteroaromatic amines. 2-Amino and 2-unsubstituted thiazolo[3,2-b][l,2,4]triazole derivatives 2a-b were prepared by the cyclization reaction from N-amine salts of aminothiazole-5-yl(N-methoxyimino)acetate with cyanogen bromide and formamidine acetic acid salt, respectively. 2-Methylthiazolo[3,2-b][1,2,4]triazole 2c was obtained from N-acetylated N-amine salt of aminothiazole-5-yl(N-methoxyimino)acetate by the cyclization reaction in the presence of polyphosphoric acid (PPA). 2-Substituted and 2-unsubstituted thiazole[3,2-b][1,2,4]triazole derivatives 2a-c were coupled with 7-aminocephalosporanic acid (7-ACA). Coupled cephalosporin derivatives 1a-c did not have good antibacterial activities in vitro.

• 약학회지
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• 제43권3호
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• pp.306-315
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• 1999

To develop new cephalosporin antibiotics with improved antibacterial activities, a series of 7$\beta$-[2-(2-aminothiazol-4-y)-(Z)-2-(1-carboxy-1-methylethoxyimino)acetamido] -3-[5-(heterocycle)thiomethylpy-rrolidin-3-ylthio]methyl-3-cephem-4-carboxylic acid (14~18) having aminothiazol carboxymethylethoxy-imino group on the C-7 position and (heterocycle) thiomethyl pyrrolidinthiomethyl group on the C-3 position of the cephem ring were synthesized. These compounds were tested for antimicrobial activity in vitro against Gram(+) and Gram(-) bacteria. Compounds 15 and 16 showed remarkable antibacterial activity against Salmonella typhimurium TV119 and Alcalienes faecalis KCTC1004, but most of compounds showed lower activity than cefotaxime.