• Korean Journal of Medicinal Crop Science
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• v.17 no.5
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• pp.335-340
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• 2009

To evaluate the availability of Cudrania tricuspidata Bureau as a natural source of antimicrobials, the antimicrobial activity of methanol extracts of harvested parts was investigated using the paper disc diffusion method. The extracts from leaves and root bark had broad antimicrobial activity against various bacteria, including Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Enterobacter aerogenes, Enterococcus faecalis, Salmonella choleraesuis subsp. choleraesuis, Vibrio vulnificus, and Pseudomonas aeruginosa and inhibited Bacillus cereus, Staphylococcus aureus, and Listeria monocytogenes, agents of food poisoning especially well. The extract from ripe fruit had a very high antimicrobial activity against Staphylococcus aureus with a 20.2 mm of clear zone at 50 mg/mL sample concentration. These results indicated that Cudrania tricuspidata could be used as new source for developing natural antimicrobial agents.

• Food Science and Preservation
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• v.19 no.6
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• pp.919-924
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• 2012

This study was conducted to investigate the antimicrobial activities and antioxidant activities of the Korean mistletoe extract and its solvent fractions (e.g. n-hexane, ethyl ether, ethyl acetate, butanol). Ethyl ether fraction against Bacillus cereus showed stronger activities than benzoic acid (2.5 mg/mL). The MIC of korean mistletoe extract and slovent fractions were in the range of 6.25-25 mg/mL. The MIC (6.25 mg/mL) of ethyl acetate fraction onto Staphylocossus aureus was the lowest among them. Ethyl ether fraction which showed the strongest antioxidant activities by DPPH (1,1-diphenyl-2-picryl-hydrazyl) and FRAP (ferric ion reducing antioxidant power) methods had the highest total phenolic contents. It is suggested that Korean mistletoe could be utilized as natural preservative material through the study of the active compounds from ethyl ether fraction.

• Food Science and Preservation
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• v.7 no.2
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• pp.177-183
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• 2000

A supercritical fluid extraction was performed for the extraction of phenolics from grape seeds which up to now have been discarded. The optimum condition for extraction process was predicted through response surface methodology using central composit experimental design. The extraction amount of grape seed phenolics was increased by increasing extraction temperature, pressure, and concentration of co-solvent (ethanol). The optimum extraction conditions were 84.83$^{\circ}$C, 51.50MPa and 1.27% ethanol. The yield of phenolics using SFE was higher with 3 folds than ethanol and 4 folds than hexane but less than 80% methanol. In the respects of food poisoning, the approved solvents were restricted to ethanol and hexane. So, SFE for extraction of phenolics could be powerful alternative method for solvent extraction.

• YAKHAK HOEJI
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• v.46 no.2
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• pp.93-97
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• 2002

Methidathion is one of the organophosphorus pesticides commonly used for stamping out harmful pests in farming areas. This paper presents a fatality due to methidathion intoxication and describes the distribution of methidathion in postmortem blood and tissues obtained at autopsy. Qualitative identification of methidathion was achieved by TLC, GC and GC/MS, and quantitative analysis was performed by GC with thermionic specific detector (TSD). The analytes in postmortem specimens were extracted by liquid-liquid extraction (LLE) with ethylether. After the ethylether layer was evaporated, the residue was partitioned into hexane and acetonitrile, and the acetonitrile layer was used for analysis. Tissue specimens were homogenized with 4% perchloric acid and applied for LLE. After extraction, the extracts were reconstituted 100 $\mu\textrm{g}$ pyraclofos (IS, 100 $\mu\textrm{g}$/ml in methanol) for GC and GC/MS analysis. On analysis of postmortem specimens, methidathion was identified and quantitated. The methidathion concentrations were 2.0 $\mu$l/ml in blood, 24.4 $\mu\textrm{g}$/g in liver, 13.9 $\mu\textrm{g}$/g in lung, 21.8 $\mu\textrm{g}$/g in kidney, respectively.

• Mass Spectrometry Letters
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• v.12 no.3
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• pp.112-117
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• 2021

α-Amanitin and β-amanitin are highly toxic bicyclic octapeptides responsible for the poisoning of poisonous mushrooms such as Amanita, Galerina, and Lepiota by inhibiting RNA polymerase II, DNA transcription, and protein synthesis. A sensitive, simple, and selective liquid chromatography-high resolution mass spectrometric method using parallel reaction monitoring mode was developed and validated for the simultaneous determination of α- and β-amanitin in mouse plasma to evaluate the toxicokinetics of α- and β-amanitin in mice. Protein precipitation of 5 μL mouse plasma sample with methanol as sample clean-up procedure and use of negative electrospray ionization resulted in better sensitivity and less matrix effect. The calibration curves for α- and β-amanitin in mouse plasma were linear over the range of 0.5-500 ng/mL. The intra- and inter-day coefficient of variations and accuracies for α- and β-amanitin at four quality control concentrations were 3.1-14.6% and 92.5-115.0%, respectively. The present method was successfully applied to the toxicokinetic study of α- and β-amanitin after an oral administration of α- and β-amanitin at 1.5 mg/kg dose to male ICR mice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.559-565
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• 2002

The physiological functionalities such as antimicrobial activity, antioxidative activity, angiotensin-I converting enzyme (ACE) inhibitory activity and bile acid binding capacity were measured for the solvent-fractionated methanol extracts of Alaska pollack sik-hae at various time intervals during fermentation. Two temperature schemes of fermentation were studied: constant temperature of 2$0^{\circ}C$ (A) and stepwise change from 2$0^{\circ}C$ (10 days) to 5$^{\circ}C$ (B). The methanol extracts of Alaska pollack sik-hae showed antimicrobial activities against 9 kinds of micro-organisms including pathogenic and food poisoning strains. Among these, gram positive bacteria, in particular Staphylococcus aureus, showed more sensitivity to the extracts than gram negative bacteria and fungi. Antioxidative activity (EDA$_{50}$) increased until 15 days (A, 0.92 mg/$m\ell$) or 16 days of fermentation (B, 0.94 mg/$m\ell$), and then gradually decreased. ACE inhibitory activity was observed in all fermentation time except 0 day, and bile acid binding capacity at 15 days (A) and 16 days (B) only.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.382-390
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• 2020

This study was carried out to evaluate the antimicrobial effect of red ginseng (Panax ginseng C.A. Meyer) against several foodborne pathogens including Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus niger. The antimicrobial effect was determined by agar diffusion method using red ginseng extract, crude saponin and non-water-soluble fractions. Red ginseng extract showed antimicrobial effect against S. aureus, but not C. albicans or A. niger. The extract showed anti-bacterial activity at concentration above 30% against S. aureus, which cause both food poisoning and atophic dermatitis. Crude saponin showed antibacterial activity above 7.5% against the bacterium. However, the ginsenosides purified from crude saponin showed no antimicrobial activities at 100-200 ㎍/mL. To investigate the mode of growth inhibition, red ginseng extract and crude saponin were added to 0.85% NaCl solution containing S. aureus and then incubated at 35℃ for 12 h. The results showed that viable cells were rapidly reduced in above 10% concentration of red ginseng extract and above 2% of crude saponin, respectively. However, the crude saponin and red ginseng extract did not inhibit the bacterial cells completely at those same concentrations. On the other hand, whereas all non-water-soluble fractions showed inhibition zones above 10 mm against S. aureus, they showed no inhibition effects against E. coli, C. albicans or A. niger. The methanol fraction-1 (MF-1) showed the highest antibacterial activity against S. aureus, and the MIC (minimal inhibitory concentration) was 0.625 mg/mL. These results suggest that red ginseng extract, crude saponin and non-water-soluble fractions show selective antibacterial activity against S. aureus, and non-water-soluble fractions might be used as natural antibacterial agents.