• Archives of Pharmacal Research
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• v.12 no.2
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• pp.119-124
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• 1989

Cotton xanthate, which was obtained by treating cotton with carbon disulfide in alkaline solution, was treated with the solution of polyvalent metal ions to produce cotton xanthate-metal chelates. This chelation reaction was readily and simply achieved, and antimicrobial agents with suitable structures could subsequently be coupled to the chelate with ease at moderate pH values and in aqueous solution. Metal ions used in present work include Cu(II), Zn(II) and Fe(III). Tetracycline, streptomycin, neomycin and pyrithion were used as antimicrobial/antifungal agents. Antibacterial activities were measured employing ditch plate method against G(+) Staphylococcus aureus, Streptococus faecalis, and G(-) Escherichia coli, Enterobacter aerogenes, and the fungus, Aspergillus niger. All the cotton xanthate-metal-antimicrobial agent chelates exhibited activities whereas the cotton xanthate-metal chelates themselves were inactive. Considering the extensive washing procedures and results from control experiments, possibility of the involvement of physical adsorption for the binding of drugs could be excluded.

• Biomolecules & Therapeutics
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• v.20 no.1
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• pp.19-26
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• 2012

There are many cyclic peptides with diverse biological activities, such as antibacterial activity, immunosuppressive activity, and anti-tumor activity, and so on. Encouraged by natural cyclic peptides with biological activity, efforts have been made to develop cyclic peptides with both genetic and synthetic methods. The genetic methods include phage display, intein-based cyclic peptides, and mRNA display. The synthetic methods involve individual synthesis, parallel synthesis, as well as split-and-pool synthesis. Recent development of cyclic peptide library based on split-and-pool synthesis allows on-bead screening, in-solution screening, and microarray screening of cyclic peptides for biological activity. Cyclic peptides will be useful as receptor agonist/antagonist, RNA binding molecule, enzyme inhibitor and so on, and more cyclic peptides will emerge as therapeutic agents and biochemical tools.

• Journal of the Korean Applied Science and Technology
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• v.16 no.4
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• pp.293-298
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• 1999

Dual-action agents are unique chemical entities comprised of two different types of antibacterial compounds covalently linked together in a single molecule in such a way that both components are able to exert their bactericidal properties. Crosslinked sulfadiazine-sulfacetamide such as antibiotics synthesized by crosslingking reaction such as glutaraldehyde. These structures of the compounds were confirmed by IR, NMR. 4 strains of Gram(+) and Gram(-) revealed effective susceptibility to synthetic crosslinked sulfadiazine-sulfacetamide.

• Fisheries and Aquatic Sciences
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• v.26 no.1
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• pp.1-23
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• 2023

Marine bioactive substances (MBS), such as phlorotannins, collagens, peptides, sterols, and polysaccharides, are increasing attention as therapeutic agents for several diseases due to their pharmacological effects. Previous studies have demonstrated the biological activities of MBS including antibacterial, anticoagulant, antidiabetic, antimicrobial, anti-inflammatory activities. Among numerous human diseases, periodontitis is one of the high-prevalence inflammatory diseases in the world. To treat periodontitis, several surgeries (bone grafting, flap surgery, and soft tissue graft) are usually used. However, the surgery for patients with chronic periodontitis induces several side effects, including additional inflammatory responses at the operated site, chronic wound healing, and secondary surgery. Therefore, this review assessed the most recent trends in MBS using Google Scholar, PubMed, and Web of Science search engines to develop marine-derived therapeutic agents for periodontitis. Further, we summarized the current applications and therapeutic potential of MBS to serve as a reference for developing novel technologies applied to MBS against periodontitis treatment.

• Toxicological Research
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• v.21 no.1
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• pp.39-43
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• 2005

The present study was carried out to investigate the antibacterial activity against Staphylococcus aureus with antibiotic-resistance in vitro and the skin irritation in rabbits with surfactin produced by Bacillus subtilus Complex BC1212. The antibacterial activities of selected antimicrobial agents (surfactin, amoxacillin, colistin, norfloxacin and streptomycin) were evaluated by using the broth microdilution method. As the results, the minimum inhibitory concentration (MIC) of the surfactin was less than 15.6 ㎍/ml. In the skin irritation test, two out of 4 rabbits showed very slight edema at 24 h after the administration of surfactin, and then recovered at 72 h. The change of body weight was normal during the skin irritation test. The primary irritation index in accordance with the Draize evaluation of topical reaction was calculated to be '0.125', which meant not irritating. Based on these results, it could be concluded that the test agent, surfactin, was a non-irritant. We could also think that the surfactin may be useful for the treatment of S. aureus infections such as bovine mastitis.

• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1576-1581
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• 2009

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has led to an urgent need for the discovery and development of new antibacterial agents. As part of an ongoing investigation into the antibacterial properties of natural products, 20-hydroxyecdysone (20E), isolated from the roots of Achyranthes japonica Nakai, was found to be active against MRSA, either alone or in combination with ampicillin (AM) or gentamicin (GM), via checkerboard assay. This study investigated the antibacterial activity of 20E, which exhibited poor antibacterial activity ($MIC=250-500\;{\mu}g/ml$) against MRSA tested. The combined activity of AM or GE plus 20E against MRSA resulted in fractional inhibitory concentractions (FICs) ranging from 4.00 to $0.031\;{\mu}g/ml$, respectively. Meanwhile, the FIC index ranged from 0.16-4.50, indicating a marked synergistic relationship between AM, GE, and 20E against MRSA. Time-kill assays also showed a remarkable decrease between the combination and the more active compound. Therefore, this study demonstrated that AM, GE, and 20E can act synergistically in inhibiting MRSA in vitro.

• Korean Journal of Medicinal Crop Science
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• v.25 no.6
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• pp.375-380
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• 2017

Background: The objective of this study were to determine the antibacterial activity and antibiotic activity-enhancing effect of 70% ethanol extract of the root of Rumex japonicus Houtt. and its fractions when used in combination with gentamicin against aerobic skin flora. Methods and Results: The antibacterial activity and antibiotic (gentamicin) activity enhancing effect against aerobic skin flora were determined using the disc diffusion assay. Chloroform fraction (CF) and ethyl acetate fraction (EF) showed higher activities against Staphylococcus aureus and Staphylococcus epidermidis than those shown by other fractions. Regarding the antibiotic (gentamicin) activity-enhancing effect against aerobic skin flora, the n-hexane fraction (HF) and CF showed strong activity. The combination of HF and CF with gentamicin was evaluated using the broth dilution assay to determine the inhibitory effect on the growth of aerobic skin flora. The combination of CF with gentamicin exhibited the highest inhibitory effect on the growth of S. aureus and S. epdermidis. MTT assay performed to determine the viability of L929 cells revealed that EF treatment resulted in viability of 33.96 - 116.76% at the tested concentration. The combination of 70% ethanol extract and its other fractions with gentamicin showed low cell toxicity. Conclusions: Appropriate use of antimicrobial agents is important prior to the development of new antibiotics. The 70% ethanol extract of the root of R. japonicus Houtt. and its fractions showed significant synergism with gentamicin when used in combination against S. aureus and S. epdermidis. Thus, R. japonicus Houtt. could be used as a functional materials in antimicrobial-related fields.

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.198-205
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• 2021

Objectives: Antibiotics help treat Vaginitis, and prolonged usage of antibiotics can lead to resistance. Methods: This study investigates the antimicrobial activity of two types of lactic acid bacteria using essential oils. After cultivation by adding grapefruit seed extract (GSE), eucalyptus, tea tree, clove bud, cinnamon, lemongrass, thyme, and ginger oils in a specific ratio, pathogenic microorganisms, namely E. coli, C. albicans, and lactic acid bacteria were released. The number of bacteria was measured using a medium suitable for the strains. Results: The essential oils and GSE inhibited pathogenic microorganisms, and the inhibitory concentration of GSE against pathogenic bacteria (E. coli, C. albicans) was confirmed. The non-inhibitory mixing ratio was also confirmed (50 μl of eucalyptus globulus (EG) oil and 50 μl of melaleuca alternifolia oil (tea tree oil, TTO) at 200 ppm GSE (pH 5.0, 5.5, 6.0)). Conclusion: Essential oils can be considered as an alternative to antibiotics because of their antibacterial properties. They are useful as auxiliary antibacterial agents for patients under long-term antibiotic treatment.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1195-1208
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• 2022

Silver nanoparticles (AgNPs) have potential applications in medicine, photocatalysis, agriculture, and cosmetic fields due to their unique physicochemical properties and strong antimicrobial activity. Here, AgNPs were synthesized using actinobacterial SL19 strain, isolated from acidic forest soil in Poland, and confirmed by UV-vis and FTIR spectroscopy, TEM, and zeta potential analysis. The AgNPs were polydispersed, stable, spherical, and small, with an average size of 23 nm. The FTIR study revealed the presence of bonds characteristic of proteins that cover nanoparticles. These proteins were then studied by using liquid chromatography with tandem mass spectrometry (LC-MS/MS) and identified with the highest similarity to hypothetical protein and porin with molecular masses equal to 41 and 38 kDa, respectively. Our AgNPs exhibited remarkable antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. The combined, synergistic action of these synthesized AgNPs with commercial antibiotics (ampicillin, kanamycin, streptomycin, and tetracycline) enabled dose reductions in both components and increased their antimicrobial efficacy, especially in the case of streptomycin and tetracycline. Furthermore, the in vitro activity of the AgNPs on human cancer cell lines (MCF-7, A375, A549, and HepG2) showed cancer-specific sensitivity, while the genotoxic activity was evaluated by Ames assay, which revealed a lack of mutagenicity on the part of nanoparticles in Salmonella Typhimurium TA98 strain. We also studied the impact of the AgNPs on the catalytic and photocatalytic degradation of methyl orange (MO). The decomposition of MO was observed by a decrease in intensity of absorbance within time. The results of our study proved the easy, fast, and efficient synthesis of AgNPs using acidophilic actinomycete SL19 strain and demonstrated the remarkable potential of these AgNPs as anticancer and antibacterial agents. However, the properties and activity of such particles can vary by biosynthesized batch.

• Resources Recycling
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• v.31 no.3
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• pp.16-26
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• 2022

Limestone is the largest mineral resource in South Korea and is used in various industries, particularly as a primary raw material in the cement and iron industries. However, research on the utilization of limestone in fields such as agriculture, powder, and green chemistry is severely lacking. In this review, studies concerning the crop antibacterial industry using unslaked or slaked lime produced from limestone were analyzed. Reports regarding lime bordeaux mixture were also considered. By compiling research results, processing technologies for improving the antibacterial efficiency of lime bordeaux mixture are discussed. In addition, plans for the revitalization of research on crop antibacterial agents through the limestone processing industry were summarized.