• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.119-124
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• 2011

Currently, people are exposed to many harmful diseases. Therefore, there are many schemes, such as automation of productive facilities, development of information and communication technology, enhanced the quality of human life and wealth. However, these processes lead to weakened immune system. Thus, people are more vulnerable to infections from pathogens and environmental stress. Misuse and abuse of drugs resulted in the rapid emergence of multidrug-resistant microbes and tumors, therefore, to find new antibiotics are urgently needed. One of them is a peptide-antibiotic, that is not or less occurred a drug-resistance, comparing to conventional drugs. Peptides with various antibiotic activities have been identified from life organisms. The present review provides an overview of activities and application of peptide antibiotics.

• Journal of Microbiology
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• v.34 no.3
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• pp.274-278
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• 1996

Two peptides, MA-inv AND MA-ME, with the sequence 10-17 of maganin 2 at their-N-termini were designed and synthesized. The peptides had higher antifungal activities against Aspergilus fumigatus without hemolytic activities. The minimal inhibition concentratory (MIC) values of both peptides against A. fumigatus were 5 .mu.g/ml, whereas those of the native peptides, magainin 2 and melittin, were 10.mu.g/ml. At 3 .mu.g/ml, MA-inv and MA-ME inhibited the mycelium growth of A. fumigatus by 94.6% and 97.3% respectively, whereas magainin 2 and melittin inhibited by 62.2% and 32.4, respectively. MA-inv showed up to 80% inhibition of (1, 3)-.betha.-D-glucan synthase activity of A. fumigatus. The peptides also showed up to 80% inhibition of (1, 3)-.betha.-D glucan synthase activity of A. fumigatus. The peptides also showed antifungal activities for other fungi of Aspergillus sp. However, the antibiotic activities of MA-ME against Escherichia coli, Bacillus subtilis and Fusarium oxysporum were more effective than those of MA-inv, suggesting that the C-terminal sequences of MA-inv and MA-ME may also influence their antibiotic activities. These results suggest that the N-terminal sequence of the designed peptides, KKFGKAFV, is important for their antifungal activities against A. fumigatus and their C- terminal sequences are related to the organism selectivity.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.329-336
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• 1995

For the development of new antitumor antibiotics produced by microorganisms, Streptomyces sp. YBE-316 was isolated from soil. The productivity of the antitumor antibiotic from Streptomyces sp. YBE-316 gradually increased after 60 hours, and was maximum after 100 hours after inoculation in growth medium (2.0% sucrose, 1.0% soybean meal, 0.1% K$_{2}$HPO$_{4}$, pH 7.0) at 30$\circ$C, 150 rpm, 5 NL/min by 30 l jar fermentor. This antitumor antibiotic was present only in mycelium, and stable in pH 5.0-10.0 for 20 minutes at 100$\circ$C. Antitumor and antibiotic activities were maintained at neutral pH, and heat stability was low. This antitumor antibiotic was soluble in methanol and ethanol, and insoluble in water, ethyl acetate, chloroform, and n-hexane. This antitumor antibiotic was sequentially purified by acetone extraction from mycelium, butanol extraction, and silica gel column chromatography. Antitumor activity was low against most tested cell lines, but antibiotic activity was high and low against yeasts and bacteria, respectivelv. The visualization test showed that this antitumor antibiotic had higher hydroxyl, ketone, amino, carboxyl groups, and sugar(s) in its structure. Instrumental analyses showed that this antitumor antibiotic was a pentaene in polyene class antibiotics. In pentaene class antibiotics, this was considered as an eurocidin or capacidin type antibiotics. The molecular weight of this antitumor antibiotic was higher than 683.0 daltons, and this antitumor antibiotic might be glycosylated by other sugar(s), instead of mycosamine or perosamine, an amino sugar.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.30 no.2
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• pp.100-111
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• 2017

Objectives : The purpose of this study was to research the antibiotic, antioxidant and whitening effects of Jwa Kum-Whan(JKW) and Soo Ryeon-Whan(SRW). Both Jwa Kum-Whan and Soo Ryeon-Whan are composed of Coptidis rhizoma and Evodiae fructus, but the ratios of the two species are different. JKW is composed of Coptidis rhizoma and Evodiae fructus by ratio of 6:1 and SRW's ratio is 1:1. Methods : Antibiotic activities of JKW and SRW's water extracts were studied by paper disc diffusion method. Four kinds of bacteria were applied in paper disc, and each extract was dropped, individually. The diameter of inhibition zone was measured. DPPH assay was used for studying free radical scavenging activity. DPPH is quantitatively decolorized from purple color by antioxidant material. Change of color was measured by spectrophotometer. Whitening activity was analyzed by tyrosinase inhibition assay. Tyrosinase is major enzyme for control process of making eumelanin. Optical Density was measured by spectrophotometer. Results : Candida albicans and Staphylococcus aureus's inhibition zone were made large available by Both prescriptions. Inhibition zone's diameter of JKW was preferable to SRW's. Radical scavenging activity was better at SRW, but JKW's activity was available, too. Tyrosinase inhibition activity was found out available only for JKW, not for SRW. Conclusions : JKW had antibiotic effects for Candida albicans, Staphylococcus aureus. And had antioxidant, whitening effects. SRW had antibiotic, antioxidant activities but not whitening effect.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.169-176
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• 2023

The emergence and spread of antibiotic-resistant bacteria have been increasing with anthropogenic contamination. Understanding the prevalence and distribution of these resistant bacteria in environments is crucial for effectively managing anthropogenic pollutants. Lake Gyeongpo in the Gangwon Province of South Korea is known for its diverse ecological features and human interactions. The lake is exposed to pollutants from nonpoint sources, including urban areas, agricultural practices, and recreational activities, which can introduce antibiotics and foster antibiotic resistance in bacteria. The present study investigates Lake Gyeongpo as a potential reservoir for antibiotic-resistant bacteria in a natural ecosystem. A total of 203 bacterial isolates were collected from six sampling locations in Lake Gyeongpo during May, July, and November 2022. Most isolates were taxonomically identified as Pseudoalteromonas, Bacillus, Shewanella, and Vibrio spp.; their abundance showed a spatiotemporal distribution. An antibiotic susceptibility test was conducted on 75 isolates using the disk diffusion method with six drugs according to the CLSI guideline; 42 isolates were resistant to one or more antibiotics. Among these, 15 isolates were identified as multidrug resistant bacteria. This finding suggests the potential anthropogenic impact on Lake Gyeongpo and provides valuable insights into the dissemination of antibiotic resistance caused by anthropogenic pollutants.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.2
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• pp.103-108
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• 1995

Antibiotic and physico-chemical properties of an active compound from actinomycetes isolate G-37, of which the culture filtrate had an inhibitory effect against tobacco mosaic virus(W) infection, were examined. The active compound, which was purified by ethylacetate extraction, silica gel column chromatography, preparative thin layer chromatography, and high performance liquid chromatography, showed strong antibacterial activities especially against Gram-positive bacteria including Bacillus subtillis, Sarcina lutea and Staphylococcus aureus. From the IH-NMR, FAB/RfS, UV spectral data, and physicochemical properties, the active compound of G-37 appears to belong to a peptide antibiotic group. Among the known peptide antibiotics in the antibiotic group, No. 280, A-30912, and Taitomycin showed molecular weights and ultra violet spectrum similar to those of the active compound from G-37, but was not identical to the compound, which suggests that it may be a new peptide antibiotics.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.765-769
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• 2005

The essential oil fraction of Ostericum koreanum was analyzed by GC-MS. Inhibiting activities of this oil and its main components were tested by the broth dilution assay and disk diffusion test against one antibiotic-susceptible and two resistant strains of Salmonella enteritidis and S. typhimurium, respectively. The GC-MS analysis revealed thirty-four compounds; the main components were $\alpha$-pinene (41.12%), $\rho$-cresol (17.99%) and 4-methylacetophenone (7.90%). The essential oil of O. koreanum and its main components were significantly effective against the tested antibiotic-susceptible strains as well as against the resistant strains of the two Salmonella species, with MICs (minimum inhibitory concentrations) ranging from 2 mg/mL to 16 mg/mL. The anti-Salmonella effects of the oils were dose-dependent on $M\"{u}ller-Hinton$ agar plates in this experiment. Additionally, checkerboard titer test results demonstrated significant combined effects of streptomycin and O. koreanum oil or cresol, one of the main components of this oil, against the two streptomycin resistant strains of S. typhimurium, with FICIs ranging from 0.12 to 0.37.

• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.80-84
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• 2009

The in vitro antibacterial activities of anti-acne agents prepared from the extracts of natural sources were investigated against several bacteria including antibiotic-susceptible and -resistant Propionibacterium acnes. SD-1 and SD-2 were prepared with different formulations and they showed strong antibacterial activities. The anti-acne agents completely inhibited the growth of the tested strains at the concentration of 0.5%. There was no difference in antibacterial activity between antibiotic-susceptible and -resistant P. acnes. The inhibitory activities of two agents showed time-dependent manner. In S. aureus, time-kill curve demonstrated 2.8- and 3.4-$log_{10}$-unit killing after 8 h with SD-1 and SD-2, respectively. In P. acnes, time-killing curve demonstrated 5.1- and 6.1-$log_{10}$-unit killing after 24 h with SD-1 and SD-2, respectively. SD-2 showed stronger antimicrobial activity than SD-1. From these results, we expect that SD-1 and SD-2 have strong antibacterial activities and have advantages for treating acne.

• Natural Product Sciences
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• v.19 no.4
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• pp.297-302
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• 2013

The current study was conducted to evaluate the antibacterial and antioxidant activities of the essential oil fraction from the roots of Angelica tenuissima Nakai and its main components. We extracted the essential oil fraction from the roots of A. tenuissima using steam distillation and isolated its main components. Their antibacterial activities were determined by broth dilution test against food-borne pathogenic bacteria. Antioxidant activities were evaluated by DPPH-scavenging assay and reducing-power test. Also tested was their ability to inhibit the growth of two gastrointestinal cancer cell lines, Caco-2 and MKN-45. The A. tenuissima oil fraction and its main components, ligustilide and butylidene phthalide exhibited marked inhibitory effects against most of the tested antibiotic-susceptible and antibiotic-resistant bacterial strains with minimum inhibiting concentrations (MICs) from $0.21{\pm}0.08$ to $3.60{\pm}0.89mg/ml$. They also showed growth-inhibiting activity against Caco-2 and MKN-45 cells. The oil fraction showed significant antioxidant activities in DPPH radical scavenging assay and reducing-power test. Taken together, A. tenuissima essential oil could be used as a safe additive for preventing food contamination by pathogenic bacteria. Additionally, its antioxidative activity and the ability to inhibit gastrointestinal carcinoma cell lines could increase its value for functional foods and prevention of cancer.

• Bulletin of the Korean Chemical Society
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• v.21 no.12
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• pp.1199-1201
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• 2000

31-Hydroxycarbowyacetylquercinic acid, a lanostenoid hydroxyl acid has been isolated from D. dickinsii by solbent extraction, silica gel column chromatography and recrystallization. The structure of this compound has been determined to be 31-hydroxycarboxyacetylquercinic acid by a combinationof spectral data and by HM-BC. This compound showed antimicrobial activities against human pathogenic fungi and bacteria.