• YAKHAK HOEJI
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• v.41 no.4
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• pp.462-472
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• 1997

In this approach, the antimicrobial activities of the compounds were compared with the ${\beta}$-lactam antibiotics against ${\beta}$-lactamase producing strains in vitro. Heteroc yclyl exomethylenepenam derivatives were several numbers of 6-exomethylenepenam sodiums (CH1240, CH1245, CH1250, CH2140, CH2145, CH2150). The inhibitory concentraion assay of six compounds were compared with clavulanic acid, sulbactam, tazobactam. Clavulanic acid, sulbactam and tazobactam are used as inhibitors of a variety of plasmid-mediated beta-lactamases. In vitro ${\beta}$-lactamase inhibitory assay, CH1240 and CH2140 were more active than clavulanic acid, sulbactam and tazobactam against ${\beta}$-lactamases overally. And in vitro comparative antimicrobial susceptibility test of six inhibitors were performed with mixed forms of ampicillin, cefotaxime, amoxicillin, ticarcillin, piperacillin, cefoperazone against ${\beta}$-lactamase producing 31 species strains. Consequently CH2140 and CH1240 among the six compounds enhanced the activity of the ${\beta}$-lactams for 31 ${\beta}$-lactamase producing strains.

• Journal of Yeungnam Medical Science
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• v.27 no.1
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• pp.8-17
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• 2010

It is important to select appropriate antimicrobials for the treatment of infection according to the results of antimicrobial susceptibility tests (ASTs), yet the clinical isolates are sometimes susceptible to antibiotics that are clinically ineffective or this is due to technical error of the ASTs. So, interpretive reading of ASTs is needed and especially for the ${\beta}$-lactams for treating $Enterobacteriacae$. This review describes the interpretive reading of ASTs according to natural antimicrobial resistance and the mechanisms of mechanisms, with giving special attention to the antibiotics phenotypes for $Enterobacteriacae$. Further, as all the diffent tissues have a different antimicrobial concentration for identical antimicrobials, more information is needed on the antimicrobial tissue distribution for the appropriate treatment of infection. (ED note: I hope you send me the paper.)

• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.75-79
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• 1991

A series of compounds, N-(2-substituted-1-carboxy)vinylazetidinones were successfully synthesized in order to test the hypothesis that biological activities of ${\beta}$-lactam antibiotics could be attributed to the smooth flow of electrons after a nucleophilic attack at the carbonyl carbon in the ${\beta}$-lactam ring. After introduction of aminothiazolylacetamido group at 3-position of the azetidinones, their biological activities were evaluated. Their low activities led to the conclusion that the smooth electron flow in ${\beta}$-lactams in not the sufficient source for the biological activities.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.467-472
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• 2003

Optically pure α-mono- and α, α-disubstituted β-amino acids were conveniently prepared in four steps and in 27-40% overall yields from the correspondingly substituted racemic β-hydroxy acids that can be readily obtained from diethyl malonate. In the synthesis, (S)-phenylethylamine has been used as a resolving agent and as a source of the amino group in the β-amino acids.

• Bulletin of the Korean Chemical Society
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• v.23 no.5
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• pp.749-757
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• 2002

Chiral oxazolidin-2-one is easily prepared from D-mannitol and demonstrated to undergo highly diastereoselective alkylation reactions via lithium imide Z-enolates of its N-acyl derivatives to afford ${\alpha}-branched$ products. Evans syn and non-Evans sy n aldol products were also selectively obtained using this new auxiliary in high diastereomeric purity by simply changing the stoichiometry of TiCl4 and the nature of the amine base. Also, this new auxiliary is employed in diastereoselective Staudinger-type ${\beta}-lactam$ syntheses. Using 2-chloro-1-methylpyridinium iodide as the dehydrating agent, the reaction of auxiliary tethered acetic acid with trans imines gave the desired ${\beta}-lactams$ with cis-selectivity.

• Proceedings of the PSK Conference
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• 2003.10a
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• pp.85-87
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• 2003

$\beta$-Lactams are historically and clinically representative antibiotics used for therapeutic purposes. In early days, penicillin (penam antibiotic) and cephalosporin (cephem antibiotic) were found in culture broth of two different filamentous fungi, Penicillium chrysogenum and Acremonium chrysogenum. Since 1970, a variety of $\beta$-lactam structures have been discovered from bacterial cultures including Streptomyces species, which are known as cephamycin, cephabacin (cephem antibiotics), clavulanic acid (oxopenam antibiotic), thienamycin (carbapenem antibiotic), and sulfazecin (monobactam antibiotic). (omitted)

• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3651-3654
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• 2014

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.193-197
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• 1989

The three new Alkylene bisdithionreido $\beta$-lactam derivatives were synthesized and evaluated for antimicrobial activities. Treatment of cefadroxil.2DMF with alkylene diisothiocyanate which was obtained by the reaction of alkylene diamine with carbon disulfide, sodium hydroxide and ethyl chloroformate afforden alkylene bisdithioureido $\beta$ -lactam derivatiives. The antimicrobial activities of the compounds synthesized were ethylene bisdithioureido $\beta$-lactam derivative lost the sensitivity against Escherichia coli but showed potent antimicrobial activity against $\beta$-lactams Escherichia coli, but, tetramethylene bisdithioureido $\beta$-lactam derivative and hexamethylene bisdithioureido $\beta$ -lactam derivative compounds showed diminished or no antimicrobial activities.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.166-172
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• 2006

Metallo-${\beta}$-lactamase (MBL) can hydrolyze all ${\beta}$-lactams except monobactams and frequently coexists with various antibiotic resistance genes such as aminoglycoside resistance, sulfonamide resistance gene, etc. Therefore, the effective antibiotics against infections by these bacteria are markedly limited or can't even be found. We tried to search in-vitro antimicrobial combinations with synergistic effects for a VIM-2 type MBL producing Pseudomonas aeruginosa, isolated from clinical specimen. On the selection of antibiotic combinations with synergistic effects, we performed a one disk synergy test, modified Pestel's method, in agar without aztreonam (AZT). The bacteriostatic synergistic effects of this tests were scored as $S_1$ (by susceptibility pattern in agar without antibiotics), $S_2$ (by the change of susceptibility in agar with or without antibiotics) and $S_3$ ($S_1$ + $S_2$) and was classified into weak (1 point), moderate (2 points) and strong (3 points) by $S_3$ score. Subsequently, we carried out the time-killing curve for the antibiotic combinations with the strong synergistic bacteriostatic effect. One VIM-2 type MBL producing P. aeruginosa confirmed by the PCR showed all resistance against all ${\beta}$-lactams except AZT, aminoglycoside and ciprofloxacin. In the one disk synergy test, this isolate showed a strong bacteriostatic synergistic effect for the antibiotic combination of AZT and piperacillin-tazobactam (PIP-TZP) or AZT and amikacin (AN). On the time-killing curve after six hours of incubation, the colony forming units (CFUs/mL) of this bacteria in the medium broth with both combination antibiotics were decreased to 1/18.7, 1/17.1 of the least CFUs of each single antibiotics. The triple antibiotic combination therapy including AZT, PIP-TZP and AN was shown to be significantly synergistic after 8 hrs of exposure. In a VIM-2 MBL producing P. aeruginosa with susceptibility for AZT, the triple antibiotic combination therapy including AZT, PIP-TZP and AN may be considered as an alternative antibiotics modality against the infection by some MBL type. But the antimicrobial combination therapy for many more MBL producing isolates is essential to know as soon as possible for the selection of effective treatment against the infection by this bacteria.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.2
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• pp.133-139
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• 2014

Veterinary antibiotics (VAs) in animal compost and organic fertilizer can have adverse effect on ecosystem and eventually human health. The main purpose of this research was to evaluate feasibility of Charm II system for monitoring residuals of VAs in animal compost and organic fertilizer. Four different VAs (Tetracyclines: TCs, Sulfonamides: SAs, Macrolides: MLs, and ${\beta}$-lactams: ${\beta}$-LTs) were analyzed and total of 100 samples were monitored. Results reveled that SAs in animal compost showed the highest detection frequency (64%) with exceeded concentration of criteria. However, very low detection frequency (0-12%) for ${\beta}$-LTs was observed in animal compost and organic fertilizer. Depending on physicochemical properties of each VAs, detection frequency of VAs was determined. In conclusion, charm II system can be utilized to screen if residual of VAs is in animal compost and organic fertilizer. Also, more research is necessary to establish standard method for analysis of VAs in complex matrix and to minimize adverse effect of VAs from source to environment.