• YAKHAK HOEJI
• /
• v.30 no.6
• /
• pp.294-300
• /
• 1986

New antibiotics having moieties of penicillanic acid, cephalosporanic acid and ampicillin on both ends of the central polyalkylene were synthesized by reacting 6-aminopenicillanic acid (6-APAl), 7-amino cephalosporanic acid (7-ACA) and ampicillin with hexamethylene diisocyanate and sebacoyl chloride, respecetively. Antibiacterial activities of the compounds were also investigated.

• YAKHAK HOEJI
• /
• v.35 no.4
• /
• pp.348-351
• /
• 1991

A new agar-disk method was developed from the fast selection and characterization of antibiotic producing organisms.

• Journal of Microbiology and Biotechnology
• /
• v.4 no.4
• /
• pp.354-359
• /
• 1994

An isolate, 90-GT-302, was found to produce antibiotics inducing typical mycelial swelling in Magnaporthe grisea and Fusarium solani. This isolate formed yellow substrate and white rectiflexbiles aerial mycelia in the early stages of growth. The aerial mycelium gradually changed its color to white and finally formed a gray spore mass. Analysis of the cell wall acid hydrolysate revealed the presence of LL- and meso-diaminopimelic acids, glycine, and galactose, which indicated cell wall type X. This result placed our isolate in genus Kitasatosporia. A comparison of isolate 9O-GT-302 with reference strains of Kitasatosporia spp., which not only demonstrated several differences in their physiological properties but also novelty of the active compounds produced by this isolate, led us to designate the isolate as Kitasatosporia kimorexae.

• Korean Journal of Microbiology
• /
• v.19 no.3
• /
• pp.108-114
• /
• 1981

In order to isolate microorganisms which produce antibiotics aganist wheat black rust, some bacteria, molds, and actinomycetes were isolated from soils and screened for the production of antibiptics against wheat black rust. Beacuse wheat black rust-puccinia graminis--is a complete parsitic mold which can't grow in artifical medium, new method for the screening of antibiotic producing microorgsnisms against wheat black rust developed by using live leaves of wheat. With new method, a strain No. $480HS_{20}$ which produces a substnace having strong and Puccinia graminis activity and very narrow antimicrobial spectrum was isolated. the substance produced by the strain No.$480HS_{20}$ had better anti Puccinia graminis activity than any other known antifungal antibotics such as kasurgamycin, balasticidins, actidione, antimycin, ologomycin. And the substance was observed to be very stable at heat and ultraviolet light. The strain was indentified as Bacillus subtilis.

• Biomolecules & Therapeutics
• /
• v.7 no.1
• /
• pp.97-104
• /
• 1999

A new antibiotic bead, CJ-40003 is a combination of three antibiotics, tobramycin, vancomycin and cefazolin embedded in bone cement, for the treatment of osteomyelitis. To evaluate the general pharmacological properties of CJ-40003, the effects of its active ingredients were investigated in mice, rats, dogs and isolated guinea pig ileum. The combination of three antibiotics (CA) did not affect general behavior, central nervous system, smooth muscles, gastrointestinal system, cardiovascular and respiratory system and water and electrolytes excretion when administered intravenously at the doses of 0.3, 1 and 3 mg/kg, respectively, into experimental animals. The CA had no effect on the contractile response of the isolated guinea pig ileum to various spasmogen at concentrations of 1, 3 and 10 $\mu\textrm{g}$/ml, respectively. In conclusion, the active ingredients of CJ-40003 showed no pharmacological effect in these studies.

• Korean Journal of Pharmacognosy
• /
• v.54 no.2
• /
• pp.72-79
• /
• 2023

MRSA is Staphylococcus aureus resistant to β-lactam antibiotics, and is a worldwide infectious disease. Even with the discovery of new antibiotics, resistance develops rapidly, so new alternatives are needed. Jakyakgamcho-tang (JGT) is a combination of Jakyak and Gamcho, and has been mainly used as an antispasmodic and analgesic in oriental medicine. This study was conducted to find out whether there is an effect on MRSA in relation to the anti-inflammatory effect of JGT and the antibacterial effect of Jakyak and Gamcho found in previous studies. In this study, in order to investigate the antibacterial activity of JGT and the combined effect of existing antibiotics, after extracting JGT with 70% EtoH, the disc diffusion method, minimum inhibitory concentration (MIC), drug combination effect (FICI), and time-kill analysis (Time-kill assay), metabolic inhibition, Western blot and qRT-PCR analysis were used to confirm the antibacterial activity mechanism of MRSA of JGT. As a result of the experiment, all of MRSA showed antibacterial activity in JGT's disc diffusion method, and the MIC was 250-1000 ㎍/mL. When existing antibiotics and JGT were combined with drugs, most had synergy or partial synergy. In addition, it was confirmed that the degree of bacterial growth was suppressed over time when simultaneous administration for 24 hours. JGT showed a synergistic effect when administered together with the ATPase-inhibitor DCCD, suggesting that it affected the inhibition of ATPase. As a result of observing the expression of PBP2a, and hla protein in the JGT-treated group and the untreated control group through wstern blot, it was confirmed that the protein expression of the JGT-treated group was significantly suppressed, and the expression levels of mecA, mecR1 and hla genes were also suppressed during JGT treatment. was observed by qRT-PCR. Combining the results of the experiment, it can be seen that JGT has antibacterial activity in MRSA, and when combined with existing antibiotics, the effect was increased compared to treatment with the drug alone. This suggests that JGT can be an alternative to treatment for antibiotic resistance of MRSA.

• YAKHAK HOEJI
• /
• v.47 no.3
• /
• pp.184-189
• /
• 2003

Peptide deformylase (PDF) is essential and unique to bacteria, thus making it an attractive target for the discovery of novel antibacterial drugs. PDF deformylates the N-formylmethionine of newly synthesized polypeptides in prokaryotes. In this study, a pdf gene from Staphylococcus aureus 6538p was cloned in pET-14b vector and PDF protein was over-produced in Escherichia coli BL21 (DE3). NH$_2$-terminal His-tagged PDF protein was purified by nickel-nitrilotriacetic acid (Ni-NTA) metal-affinity chromatography. Enzymatic activity of purified 6xHis-tagged PDF was tested on the substrate (formyl-Methionine-Alanine-Serine) by formate dehydrogenase-coupled spectrometric assay of peptide deformylase. For the discovery of new PDF inhibitors from chemical libraries and culture broths of soil bacteria, a target-oriented screening system using a 96-well plate was developed. About 3,000 commercial chemical libraries were tested in this screening system, and 2 chemicals (0.07％) among them showed an inhibitory activity against PDF enzyme. This result showed that a new screening system can be used for the discovery of new PDF inhibitors.

• Proceedings of the PSK Conference
• /
• 2000.10a
• /
• pp.211.1-211.1
• /
• 2000

• Archives of Pharmacal Research
• /
• v.19 no.2
• /
• pp.153-159
• /
• 1996

A new streptothricin family antibiotic producing Streptomyces spp. SNUS 8810-111 was isolated from a soil sample. Study of its morphological and physiological characters indicated that the antibiotic producing organism was a Streptomyces spp. Taxonomical studies suggested that the organism might belong to the genus streptomyces gougeroti. The organism produced antibiotics most in calcium carbonate-tryptic soy broth. The active principles were recovered from the broth with a cation exchange resin and eluted from the resin with HCI. Cellulose column chromatography gave two active principles.$^1H-^1H$ Homo-COSY study on the first compound revealed four structural components. Total hydrolysis of the antibiotic with HCI allowed isolation of $\beta-lysine$. From these data the antibiotic was found to be streptothricin D. The other compound showed one additional signal in the .$^1H$NMR and the $^{13}C$ NMR spectra. The signal was from a methyl group attached to a nitrogen atom. Comparison of the NMR signals with those of streptothricin D suggested that the compound was N-methyl-streptothricin D which was a new compound in the family of streptothricin antibiotics.

• The Journal of the Korean Society for Microbiology
• /
• v.16 no.1
• /
• pp.1-5
• /
• 1981

Shigella is one of the most prevalent pathogens for the diarrhoeal diseases in the developing countries. One hundered and six strains of shigella were isolated from January 1980 to August 1981 at the dept. of clinical pathology, Han Yang Medical Center. Subgroups of these strains were identified as one strain of S. dysenteriae, 98 strains of S. flexneri and 7 strains of S. sonnei. None of S. boydii was observed. Sex ratio, male to female was 48 to 58. Age distribution disclosed 6 cases under one year, 11 cases one to under 2 years and 21 cases(19.8%) two to under 3 years. Subtotal of 0 to 9 years showed 64 cases(60.4%). Susceptibility for antibiotics of these strains revealed dibekacin 100%, sisomicin 100%, amikacin 98.1%, cefazolin 97.2%, tobramycin 97.1%, gentamicin 95.2%, colistin 93.0%, minocycline 89.6%, kanamycin 83.0%, carbenicillin 18.9%, streptomycin 18.9%, tmp-smz 8.6%, ampicillin 2.8% and chloramphenicol 1.9%. Patterns of resistance to sulfa, streptomycin, chloramphenical and tetracycline have already started at the early part of 1960 decade. Although ampicillin was highly sensitive to shigella at the end of 1960 to the early part of 1970 decade, this study has disclosed high resistance to the strains. New antibiotics such as amikacin, cefazolin, dibekacin, gentamicin, and tobramycin have revealed highly sensitive to these strains, however, multiresistance for those antibiotics will be shown to be prevalent in this country within several years, where it is probably related to the unrestricted sale and use of antibiotics in man.