• Journal of fish pathology
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• v.28 no.1
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• pp.17-26
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• 2015

The purpose of this study is to explore the possibility of essential oils and flavonoids improving the performance of antibiotics, proving a higher efficacy in the presence of natural substances against Edwardsiella tarda and Streptococcus iniae. Increased efficacy was observed in several cases: both essential oils and flavonoids increased antibacterial efficacy of oxytetracycline and flumequine against E. tarda by 2-fold; essential oils and flavonoids increased antibacterial efficacy of nalidixic acid against E. tarda by 4-fold; flavonoids increased antibacterial efficacy of josamycin against S. iniae by 4-fold. The results obtained in this study suggest that essential oils and flavonoids might be especially useful in increasing the antimicrobial activity of nalidixic acid and josamycin against E. tarda and S. iniae in fish. Natural compounds examined in this study could also be useful to help decrease the overuse of antibiotics in fish.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.109-116
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• 2018

Onion vinegar, which has an undesirable flavor and taste formed through alcohol and acetic acid fermentation, possesses additives that can improve sensory quality. Thus, the objective of this study was to present an optimized blending ratio using response surface methods for an onion vinegar beverage by adding Omija extracts. This study was performed to formulate an Omija-onion vinegar beverage (OOVB) and investigate its antioxidant properties and antimicrobiological effects. The experimental design was conducted using an optimal mixture model of response surface methodology which generated eighteen experimental trials with overall acceptance as the responses. According to the statistical analyses, OOVB demonstrated a ratio containing onion vinegar, water, brown sugar, apple extracts and Omija extracts of 10, 72.3, 4.4, 12.2 and 1.1 (weight ratio), respectively. The OOVB revealed desirable nutrition values (phenolics compounds 19.3 mg/100 g, total flavonoids 3.1 mg/100 g, quercetin 1.9 mg/100). The OOVB displayed antibacterial effects in Gram negative Enterobacter aerogenes, Escherichia coli, Salmonella typhimurium and Gram positive Staphylococcus aureus. The findings revealed that OOVB was 18% in DPPH radical inhibitionand 11% in superoxide dismutase-like activity thus, OOVB has nutritional value and good quality as well as potential biological activities for functional beverages.

• Macromolecular Research
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• v.14 no.5
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• pp.491-498
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• 2006

The thermal degradation of poly(hexamethylene guanidine) phosphate (PHMG) was studied by dynamic thermogravimetric analysis (TGA) and pyrolysis-GC/MS (p-GC). Thermal degradation of PHMG occurs in three different processes, such as dephosphorylation, sublimation/vaporization of amine compounds and decomposition/ recombination of hydrocarbon residues. The kinetic parameters of each stage were calculated from the Kissinger, Friedman and Flynn-Wall-Ozawa methods. The Chang method was also used for comparison study. To investigate the degradation mechanisms of the three different stages, the Coats-Redfern and the Phadnis-Deshpande methods were employed. The probable degradation mechanism for the first stage was a nucleation and growth mechanism, $A_n$ type. However, a power law and a diffusion mechanism, $D_n$ type, were operated for the second degradation stage, whereas a nucleation and growth mechanism, $A_n$ type, were operated again for the third degradation stage of PHMG. The theoretical weight loss against temperature curves, calculated by the estimated kinetic parameters, well fit the experimental data, thereby confirming the validity of the analysis method used in this work. The life-time predicted from the kinetic equation is a valuable guide for the thermal processing of PHMG.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.10a
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• pp.12-12
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• 2010

Nature applied flavanoids, glucosinolates and peptides for a great variety of functions. Flavanoids and glucosinolates are rich source of antioxidants, generally present in colored fruits and vegetables. Quercetin and its glucosides areone of the best examples of flavonol used in daily diet. Whereas peptides can act as antimicrobial, chemical messenger, neurotransmitter etc that regulating various life processes. Aspartame, a dipeptide is used as artificial sweetener and oxytocin for medical purposes, gained importance in everyday life. So, flavanoids, glucosinolates, peptides and their derivatives continue to hold the attention of synthetic chemists, agriculturists and biologists. Apart from a variety of naturally occurring bioactive metabolites, we are aiming to extract, separate and synthesize new analogs of promising natural drug candidates.

• Archives of Pharmacal Research
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• v.19 no.5
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• pp.400-405
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• 1996

In vitro studies were conducted to dertermine the frequency rate of spontaneous resistance to LB20304 and to dertermine whether cross-resistance to other antimicrobial agents develops. In eight strains of bacteria, the frequency of mutation to LB20304 at the concentrations of four and eight times the minimal inhibitory concentration(MIC) ranaged from less than 4.0 ${\times}$ $10^{-10}$ to 2.2 $\{times}$ $10^{-10}$ . These results were similar to those founf for other new fluoroquinolones. THe development of stepwise resistance was determined by repeated subculture in broth in the presence of increasing concentration of the compounds. Exposure of bacteria to increasing concentrations of LB20304 resulted in the selection of organisms with higher MICs. There were 4- to 128-fold increases in the MIC of LB20304 for bacterial strains of Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli and Pseudomonas aeruginosa. However, those strains selected after repeated exposure were well within the susceptibility range for LB20304 except for Pseudomonas aeruginosa. The resistant isolates selected with LB20304 showed cross-resistance when tested against ciprofloxacin and vice versa.

• KSBB Journal
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• v.28 no.2
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• pp.74-79
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• 2013

There are a large number of bioactive sesquiterpene lactones from compositae plants including Hemistepita lyrata Bunge. In the present study, we purified two sesquiterpene lactones, Hemistepsin A and B, from H. lyrata and evaluated their antimicrobial activities against Malassezia obutusa. Chromatographic separation was used for the preparation of Hemistepsin A and B, and the identity of these compounds was confirmed by NMR. Strong inhibition of growth of M. obutusa was obtained with all doses of Hemistepsin A tested. Moreover, antifungal activity of Hemistepsin A occurred in a dose-dependent manner. Hemistepsin B also showed potent antifungal activity at the dose of $800{\mu}m/disc$. From these results, it was suggested that Hemistepsin A and B be beneficial for the preparation of the useful agent for treating scalp diseases occurred by dandruff-causing Malassezia species.

• Biomedical Science Letters
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• v.16 no.2
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• pp.83-90
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• 2010

Hesperidin, a member of the flavanone group of flavonoids, can be isolated in large amounts from the rinds of some citrus species [e.g., Citrus aurantium L. (bitter orange), Citrus sinensis L. (sweet orange) and Citrus unshiu Marcov. (satsuma mandarin)], and has been reported to have anticarcinogenic, antihypotensive and antimicrobial properties. Despite the efficacy of these polyphenolic compounds as immune modulators, the effects of the flavonoids are poorly understood about allergic effect. In this study, we investigated whether hesperidin could influence on Th1 and Th2 balance. Allergic reactions included an increase in the number of eosinophils in bronchoalveolar lavage (BAL) fluid, an increase in inflammatory cell infiltration into the lung tissue around blood vessels and airways, airway luminal narrowing, the development of airway hyper-responsiveness (AHR). The administration of hesperidin before the last airway OVA challenge resulted in a significant inhibition of all asthmatic reactions. Accordingly, this study may provide evidence that hesperidin plays a critical role in the amelioration of the pathogenetic process of asthma in mice. These findings provide new insight into the immunopharmacological role of hesperidin in terms of its effects in a murine model of asthma, and also broaden current perspectives in our understanding of the immunopharmacological functions of hesperidin.

• Mycobiology
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• v.37 no.2
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• pp.141-146
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• 2009

Novel copper(II) complexes have been synthesized from the macrocyclic Schiff bases derived from Knoevenagel condensed ${\beta}$-ketoanilides (obtained by the condensation of acetoacetanilide and substituted benzaldehydes), 4-aminoantipyrine and ophenylene diamine. The structural features have been determined from their analytical and spectral data. All the Cu(II) complexes exhibit square planar geometry. Their high molar conductance values support their 1 : 2 electrolytic nature. The magnetic moment data provide evidence for the monomeric nature of the complexes. The X-band ESR spectra of the |$CuL^1$|$(OAc)_2$ in DMSO solution at 300 and 77 K were recorded and their salient features are reported. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by well diffusion method. A comparative study of inhibition values of the Schiff bases and their complexes indicate that complexes exhibit higher antimicrobial activity than the Schiff bases. Copper ions proved to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.95-100
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• 2013

This study was performed to analyze in vitro and in vivo activities of LCB01-0183, a new oxazolidinone, against clinical isolates of bacteria. In vitro antibacterial activity of LCB01-0183 was tested by the two fold agar dilution method. In vivo activity of LCB01-0183 was determined against systemic infections in mice. LCB01-0183 showed most potent activity among the test compounds against clinical isolates of Gram-positive bacteria. Furthermore, the protective activity of LCB01-0183 was very effective against systemic infections in mice by oral or subcutaneous administration. In time kill study, LCB01-0183 showed a bacteriostatic activity during 24 hours. LCB01-0183 had potent in vitro and in vivo activity against Gram-positive bacteria including drug-resistant strains.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.461-465
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• 2012

Broccoli has a functional substance, sulforaphane that has effects of anticancer, antioxidant, antimicrobial and anti-inflammatory. Sulforaphane, one of the hydrolysis products of glucoraphanin in broccoli, cabbage and kale, was contributed to the role of antioxidant. Broccoli contains a number of bioactive compounds including glucosinolates, S-methyl cysteine sulfoxide and many antioxidants. The ethanol extract (BE), hexane extract (BH), propylene glycol extract (BP) and butylenesglycol extract (BB) of broccoli were used to investigate the antioxidation and anti-inflammatory effects of sulforaphane extracts from broccoli. The high scavenging abilities of DPPH, $O_2{^-}$ were observed. Also sulforaphane extracts from broccoli showed the inhibition effect on NO rate. These results demonstrated that sulforaphane extracts from broccoli could be useful as an antioxidation and anti-inflammatory functional ingredient.