• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.44-47
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• 2014

A biotransformation approach using microbes as biocatalysts can be an efficient tool for the targeted modification of existing antibiotic chemical scaffolds to create previously uncharacterized therapeutic agents. By employing a recombinant Streptomyces venezuelae strain as a microbial catalyst, a reduced macrolide, 10,11-dihydrorosamicin, was created from rosamicin macrolide. Its chemical structure was spectroscopically elucidated, and the new rosamicin analog showed 2-4-fold higher antibacterial activity against two strains of methicillin-resistant Staphylococcus aureus compared with its parent rosamicin. This kind of biocatalytic approach is able to expand existing antibiotic entities and can also provide more diverse therapeutic resources.

• Archives of Pharmacal Research
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• v.21 no.5
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• pp.527-530
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• 1998

The antibacterial activity of novel ${\beta}$-lactamase inhibitors, 6-exomethylene penamsulfones (CH1240, CH2140), has been compared in vivo with that of sulbactam and clavulanic acid against b-lactamase producing strains. In vivo microbiological assessment was used as experimental mouse infection model by gram negative strains. Against Pseudomonas aeruginosa F0013, cefoperazone/CH 1240 was slightly less active than sulbactam. ampicillin/CH 2140 was less effective than sulbactam against escheriachia coli 3457. Especially against Citrobacter diversus 2046E, amoxicillin/CH 2140 was the most potent and amoxicillin/CH 1240 was slightly more active than clavulanic acid. consequently the difference in efficacy between the drug combinations appers to be related to the degree of protection afforded the animals by the b-lactamasse inhibitors. CH1240 and CH2140 are promising new agents and should undergo further investigations.

• International Journal of Oral Biology
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• v.44 no.1
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• pp.27-29
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• 2019

Halitosis is a very common disease that affects the majority of the population and is characterized by unpleasant odor during expiration. Anaerobic bacteria produce a range of malodorous substances including volatile sulfur compounds. To reduce oral malodor, the amount of oral microorganisms should be managed through brushing, scraping, and use of antibacterial agents. In this study, a mouthwash containing 0.05% cetylpyridinium chloride was tested on 22 candidates with oral malodor for two weeks to confirm oral malodor reduction through the use of antibacterial mouthwashes. Volatile sulfur compound measurements were significantly lower after using the mouthwash than before using it; thus, the mouthwash effectively reduced oral malodor.

• Journal of Sensor Science and Technology
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• v.32 no.4
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• pp.213-218
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• 2023

Triboelectric nanogenerators (TENGs) have emerged as a highly promising energy harvesting technology capable of harnessing mechanical energy from various environmental vibrations. Their versatility in material selection and efficient conversion of mechanical energy into electric energy make them particularly attractive. TENGs can serve as a valuable technology for self-powered sensor operation in preparation for the IoT era. Additionally, they demonstrate potential for diverse applications, including energy sources for implanted medical devices (IMDs), neural therapy, and wound healing. In this review, we summarize the potential use of this universally applicable triboelectric energy harvesting technology in the disinfection and blocking of pathogens. By integrating triboelectric energy harvesting technology into human clothing, masks, and other accessories, we propose the possibility of blocking pathogens, along with technologies for removing airborne or waterborne infectious agents. Through this, we suggest that triboelectric energy harvesting technology could be an efficient alternative to existing pathogen removal technologies in the future.

• Journal of the Korean Chemical Society
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• v.68 no.4
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• pp.199-204
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• 2024

Chamaecyparis obtusa (Siebold & Zucc.) Endl. is an evergreen tree of the family Cupressaceae well known for its unique scents. The seed extract of this cypress tree was phytochemically investigated to isolate a novel abietane-diterpene compound (1) along with fifteen known terpenoids (2-16). All of the isolated compounds were subjected to the screening of antimicrobial activities against Cutibacterium acnes and Staphylococcus epidermidis including erythromycin resistant strains. Among the isolates, 1α-hydroxy-hinokione (1), hinokione (3), 1,2-dehydrohinokione (4) and ferruginol (9) showed significant antibacterial activities against both acne-causing strains. This study demonstrated that abietane-type diterpenoids are the main antibacterial components in C. obtusa seed extract, and some isolated compounds can be further developed as potential acne-treatment agents.

• Journal of Food Hygiene and Safety
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• v.8 no.1
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• pp.9-15
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• 1993

In an attempt to quantitate and qualitate residual antibiotics and antibacterial agents in meat simultaneously, we studied a gas chromatography-mass spectrometry(GC/M8) analysis. For a simultaneous analysis of penicillin G, chloramphenicol and thiamphenicol in meat, a simple and rapid clean-up procedure including extraction with 0.01 M EDTA-2Na Mcilvaine buffer (pH 4.0), defatting with n-hexane, and elution with 0.01M-methanolic oxalic acid from Bond Elute $C_{18}$ cartridge, and quantitation by selected ion monitoring (SIM) mode after derivatization was performed. The recoveries (%) of penicillin G, chloramphenicol and thiamphenicol (CV, %) at 1 ppm fortification level were 63.5 (7.6), 76.3 (8.1) and 84.7 (2.0), and the detection limits of those were 0.6, 0.085 and $0.084\;\mu\textrm{g}$ beef, respectively. This method using 81M mode allows excellent detection and quantitation of residual antibiotics and antibacterial agents in meat. Moreover, confirmation by a full scan electron impact mass spectrum is possible if residual level in the sample in above 1 ppm.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.569-576
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• 2007

Four hundred and fifty tilapias ($6.77{\pm}0.23$ g) were assigned randomly to six groups to evaluate the feasibility of the tested antibacterial peptides (ABPs) and oligosaccharides as substitutes for antibiotics. The control group was fed with a commercial tilapia diet; other five groups were fed with the same commercial diet supplemented with konjac glucomannan (KGLM), cluster bean galactomannan (CBGAM), and three animal intestinal ABPs derived from chicken, pig and rabbit at 100 mg/kg respectively. After 21 days of feeding, growth, disease resistance, and in vivo anti-adherence were determined. Furthermore, the inhibitory effect of tested agents on adhesion of Aeromonas veronii biovar sobria (A.vbs) strain BJCP-5 to tilapia enteric epithelia in vitro was assessed by cell-ELISA system. As a result, the tested agents supplemented at 100 mg/kg show significant benefit to tilapia growth and disease resistance (p<0.05), and the benefit may be correlated with their interfering in the contact of bacteria with host mucosal surface. Although none of the tested agents did inhibit the growth of BJCP-5 in tryptic soy broth at $100{\mu}g/ml$, all of them did inhibit the adhesion of A.vbs to tilapia enteric epithelia in vivo and in vitro. In vitro mimic assays show that three ABPs at low concentrations of $25{\mu}g/ml$ and $2.5{\mu}g/ml$ have the reciprocal dose-dependent anti-adherence effect. The inhibition of ABPs may be correlated with a cation bridging and/or receptor-ligand binding, but not with hydrophobicity. The KGLM and CBGAM inhibited the adherence of BJCP-5 to tilapia enteric epithelia with dose-dependent manner in vitro, and this may be through altering bacterial hydrophobicity and interfering with receptor-ligand binding. Our results indicate that the anti-adherence of the tested ABPs and oligosaccharides may be one of the mechanisms in promoting tilapia growth and resistance to A.vbs.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2004.06a
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• pp.172-173
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• 2004

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.221-221
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• 1994

The cross-coupling reaction of organo tin reagents with a variety of organic halides, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. We use this method for antibacterial agents, and synthesis of new quinolone derivatives which have carbon-carbon bond at C-7 position of general quinolone moieties. Aryl tin, quinolone moieties, and palladium catalyst were refluxed in DMF to afford new quinolone derivatives. This palladium catalyzed coupling reactions have capacity for further synthetic elaboration.

• YAKHAK HOEJI
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• v.15 no.3_4
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• pp.93-97
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• 1971

Seventeen novel compounds of thiosemicarbazone derivatives were synthesized and evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H$_{37}$Rv and antibacterial activity against Staphylococcus aureus, Escherichia coli. It was found that 4-($\alpha$-naphthyl)-1-(2-furfuraldehyde)-3-thiosemicarbazone was active at 0.01$\mu$g/ml and 1, 1'-(p-phenylene)-4, 4'-bis(phenyl)-2, 2'-dithiosemicarbazide, at 0.01$\mu$g/ml against E. coli, respectively.