• Korean Journal of Food Science and Technology
• /
• v.32 no.1
• /
• pp.218-224
• /
• 2000

The antimicrobial activities of chitosan oligosaccharide(chitohexaose) and two types of chitosans M.W.(10,000 and M.W. 100,000) were examined against Escherichia coli O157 : H7(ATCC 43894), Staphylococcus aureus(ATCC 144458) and Candida albicans(KFRI 432). Chitosan with molecular weight of 10,000 showed the strongest antimicrobial activities to E. coil O157 : H7 and S. aureus, whereas chitohexaose acted most strongly against C. albicans. The most effective concentration of chitosan was measured to be 0.1 mg/mL for E. coil O157 : H7 and S. aureus, and that of chitohexaose to be 1 mg/mL for C. albicans. Antimicrobial activities of chitosans and chitohexaose were maintained for 60 min after their treatment. They were found to induce leakage of intracellular proteins and nucleic acids from treated microorganisms. The efflux determined by assaying the ${\beta}-galactosidase$ leaked from the lactose-induced E. coli O157 : H7 cells was observed to reach the highest level within 60 min after treatment with the antimicrobial agents and chitosan with 10,000 molecular weight gave the highest ${\beta}-galactosidase$ activity. Therefore, it is supposed that the antimicrobial activity of chitosan with its unique polycationic nature might be caused by its binding to anionic component(s) of the cell envelope and thereby inhibiting the membrane metabolism and/or leaking intracellular materials.

• The Korean Journal of Pesticide Science
• /
• v.5 no.1
• /
• pp.12-18
• /
• 2001

The effects of organophosphorus were examined with inhibition of the cholinesterase activity on tile chicken plasma in vivo and in vitro. The cholinesterase activity in chicken plasma determined by tile Ellman mettled was $23{\mu}mol$/min/g protein. After oral administration with 0.2 and 0.5 times of organophosphorus terbufos $LD_{50}$(1.81 mg/kg), cholinesterase activity were inhibited to 36% and 96% of control after 15min in vivo, respectively. After oral administration with 0.2 and 0.5 times of terbufos $LD_{50}$(1.81 mg/kg), then the recovery of cholinesterase activity followed to 99% and 56% of control after 11hr, respectively. Ki of phosphorodithioate and phosphorothioate with P=S was $74{\sim}322\;mole^{-1}min^{-1}$ in vitro. Ki of phosphate and phosphorothiolate with P=O was $13898{\sim}79610\;mole^{-1}min^{-1}$. Toxicology of organophosphorus with P=S was higher than that of organophosphorus with P=S by oxidation. $pI_{50}$ of phosphorodithioate and phosphorothioate with P=S was $21{\sim}102$ mg/L. $pI_{50}$ of phosphate and phosphorothiolate with P=O was $0.519{\sim}0.071$ mg/L. Enzyme-Inhibition method with cholinesterase was the rapid bioassay method to detect the organohpophorus pesticides in vitro.

• Food Science and Preservation
• /
• v.21 no.5
• /
• pp.718-726
• /
• 2014

The objective of this study was to investigate the physiological activities of Aronia melanocarpa extracts on extraction solvents (through hot water extraction, 50% ethanol extraction, and 50% methanol extraction). The yield of 50% ethanol extract, 84.50%, was higher than that of the hot water extract (84.05%) and of the 50% methanol extract (76.20%). The total sugar content of the extraction solvent, 35.56~37.68 g/100 g, did not significantly differ. The total anthocyanin content of the 50% methanol extract, 395.10 mg/100 g, was higher than of 50% ethanol extract (318.61 mg/100 g) and of the hot water extract (252.82 mg/100 g). The anthocyanin composition of the cyanidin-3-galactoside, 364.65 mg/100 g, was higher than that of the cyanidin-3-arabinoside (163.06 mg/100 g) and of the cyanidin-3-glucoside (35.69 mg/100 g) in the 50% methanol extract. The DPPH radical scavenging activities of the 50% ethanol and the 50% methanol extracts at $100-1,000{\mu}g/mL$ were 7.96-70.01%, and 8.90-69.21%, respectively. The superoxide radical scavenging activities of all the extracts improved with an increase in the treatment concentration. The FRAP of the 50% ethanol extract and the 50% methanol extract at $100-1,000{\mu}g/mL$ were $57.14-817.87{\mu}M$ and $67.32-812.78{\mu}M$, respectively. The tyrosinase inhibitory activity of the 50% ethanol extract, 23.03-33.82% ($100-1,000{\mu}g/mL$), was higher than that of the other extracts. The cancer cell growth inhibition activity of the 50% ethanol extract (76.86% at $1,000{\mu}g/mL$) on HeLa cell line was significantly higher than of the hot water and of the 50% methanol extracts. There results suggest that the 50% ethanol extract from Aronia melanocarpa may be a useful for functional food material in the food industry.

• Journal of Applied Biological Chemistry
• /
• v.53 no.3
• /
• pp.179-183
• /
• 2010

To produce the functional food materials from edible mushrooms, hot-water extracts from 70 kinds of mushroom mycelia were examined for anti-complementary activity and Phellinus linteus showed the highest activity through the complement fIxation test. The maximum production of Phellinus linteus mycelia with anti-complementary activity was observed in culture medium containing soluble starch 3.0%, peptone 0.3%, yeast extract 0.4%, $MgSO_4{\cdot}7H_2O$ 0.1%, $K_2HPO_4$ 0.2% and in the culture conditions controlled at initial pH 7.0, $30^{\circ}C$ and 150 rpm by the rotary shaker. In addition, the maximum production of mycelial dry weight was 15 mg/mL after 18 days under the optimal conditions, and anti-complementary activity was reached to 88% in 5 L-jar fermenter.

• Korean journal of food and cookery science
• /
• v.27 no.4
• /
• pp.17-26
• /
• 2011

This study was performed to analyze the antibacterial activity against food hazardous microorganisms and antimutagenic effects of Sanguisorba officinalis L. ethanol extracts on Salmonella Typhimurium TA100. The antibacterial activity was evaluated by paper disc diffusion assay, minimum inhibition concentration (MIC), and optical density of the culture with the ethanol extract for 24 hr. Antibacterial activity was tested with seven microorganisms including Escherichia coli, Escherichia coli O157:H7, Pseudomonas aeruginosa, Salmonella Typhimurium, Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus. The paper disc diffusion assay showed distinct clear inhibition zones around the discs treated with the extract for five microorganisms, except Escherichia coli and Escherichia coli O157:H7. MIC values were 0.625-2.5 mg/mL for these five strains that showed clear zones. The time-kill assay was consistent with the results from the paper disc diffusion assay and MIC test. Additionally, antimutagenicity of the extract was determined using the Ames test. The ethanol extract at 5 mg/plate inhibited 72.42% and 89.85% of mutagenicity induced by 4-nitroquinoline 1-oxide and sodium azide, respectively. These results demonstrate that the ethanol extract from S. officinalis L. has remarkable antibacterial activity and antimutagenicity.

• Journal of the Korean Chemical Society
• /
• v.66 no.2
• /
• pp.78-85
• /
• 2022

Natural white clay was treated with 6 M of H₂SO₄ and heated at 80℃ for 6 h under mechanical stirring and the resulting acid active clay was used as an adsorbent for the removal of Cs⁺ in water. The physicochemical changes of natural white clay and acid active clay were observed by X-ray Fluorescence Spectrometry (XRF), BET Surface Area Analyser and Energy Dispersive X-line Spectrometer (EDX). While activating natural white clay with acid, the part of Al₂O₃, CaO, MgO, SO₃ and Fe₂O₃ was dissolved firstly from the crystal lattice, which bring about the increase in the specific surface area and the pore volume as well as active sites. The specific surface area and the pore volume of acid active clay were roughly twice as high compared with natural white clay. The adsorption of Cs⁺ on acid active clay was increased rapidly within 1 min and reached equilibrium at 60 min. At 25 mg L^- of Cs⁺ concentration, 96.88% of adsorption capacity was accomplished by acid active clay. The adsorption data of Cs⁺ were fitted to the adsorption isotherm and kinetic models. It was found that Langmuir isotherm was described well to the adsorption behavior of Cs⁺ on acid active clay rather than Freundlich isotherm. For adsorption Cs⁺ on acid active clay, the Langmuir isotherm coefficients, Q, was found to be 10.52 mg g^-1. In acid active clay/water system, the pseudo-second-order kinetic model was more suitable for adsorption of Cs⁺ than the pseudo-first-order kinetic model owing to the higher correlation coefficient R² and the more proximity value of the experimental value q_e,exp and the calculated value q_e,cal. The overall results of study showed that acid active clay could be used as an efficient adsorbent for the removal of Cs⁺ from water.

• Korean Journal of Plant Resources
• /
• v.9 no.3
• /
• pp.203-210
• /
• 1996

The activities of the antioxidative enzymes in the roots of Codonopsis lanceolata have been compared depending on the cultivated environments - wildness, cultivate paddy fields and cultivate dry fields - and the parts of the root. In the Codonopsis lanceolata raised in cultivate paddy fields, the activity of SOD was higher in 2 yrs old than 1 yr old, but the activity in 1 yr old was higher than in 2 yrs old for the plants raised in the cultivate dry fields. The specific activity of SOD in wildness plants 86.069unit/mg protein was the highest among plants studied. The tissue distribution of the SOD activity showed differences depending on the enviroment. The highest activity of SOD was shown in the upper part of the root for the cultivate paddy fields, the loewr parts for the cultivate dry fields and middle parts for the wildness. The specific activity of POD was increased with ages of the plants, and that in the wildness was the highest 68 unit/mg protein among the plants studied. The activity of POD in the parts of the roots was shown as middle>lower>upper. The activity of POD in the middle part of the root, rasied in Soebick province was 85 unit/mg protein. The specific activity of CAT was decreased with ages of the plants. The activities of wildness and cultivate paddy fields was similar, but that in cultivate dry fields was lower than others. The tissue distribution in the parts of the roots was upper>lower>middle. The activity of CAT middle part of rasied in the Sebuck area was 5.359 unit/mg protein. The activities antioxidative in the cells cultured in MSID(Murashige and Skoog +2.4-D 1mg/$\iota$) was followings: 1564 for CAT. 30 for POD and 22200 unit/mg protein for SOD. These figures were lower than that in in vivo.

• Korean Journal of Microbiology
• /
• v.21 no.3
• /
• pp.143-148
• /
• 1983

The occurrence of PZ-peptidase in Streptococcus sanguis and other oral bacteria was investigated utilizing washed whole cells as the enzyme source and PZ-pentapeptide as its substrate. Under the culture conditions employed in the present study. Streptococcus sanguis strains, fresh isolates as well as laboratory strains, produced a broad range of the enzyme activity (0.5-7.9 unit/mg protein). The strains of both Streptococcus mutans and Lactobacilli showed low levels of activity (0-0.5 unit/mg protein for S. mutans). As compared with the enzyme activities of other bacteria, a moderate range of activity was produced by the strains of Strptococcus mitis nad Strptoccus salivarius. Actinomyces strains, like those of S. sanguis, produced a varying amount of activity (0-9.8 unit/ mg protein). A possible involvement of the oral bacterial PZ-peptidase in the metabolism of human saliva proteins is discussed.

• Korean Journal of Food Science and Technology
• /
• v.52 no.5
• /
• pp.476-481
• /
• 2020

This study investigated the antioxidant and hepatoprotective effects of Ainsliaea acerifolia water extract (AAWE) on HepG2 cells. Five types of caffeoylquinic acid (CQA) were detected in AAWE, namely, 4,5-di-O-caffeoylquinic acid (4,5-DCQA; 11.16 mg/g), 3,4-di-O-caffeoylquinic acid (3,4-DCQA; 5.23 mg/g), 5-O-caffeoylquinic acid (5-CQA; 4.88 mg/g), 3,5-di-O-caffeoylquinic acid (3,5-DCQA; 3.51 mg/g), and 4-O-caffeoylquinic acid (4-CQA; 3.31 mg/g). AAWE exerted ABTS⁺ antioxidant effects, evidenced by polyphenol content and 2,2'2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH radical scavenging) activities. AAWE (300 ㎍/mL) treatment significantly decreased the activities of gamma glutamyl transferase (GGT), aspartate transaminase (AST), and lactate dehydrogenase (LDH) as compared to control and exerted protective effects against the increase in liver function index induced by lipopolysaccharide (LPS)/galactosamine (D-GalN) in HepG2 cells. In addition, the secretion of tumor necrosis factor (TNF)-α by HepG2 cells induced by LPS/D-GalN significantly increased in all treatment groups compared to that in the control. However, AAWE (100-300 ㎍/mL) treatment significantly decreased the secretion of TNF-α compared to that in the control. These results suggest that AAWE treatment reduces hepatotoxicity by increasing antioxidant activities, reducing GGT, AST, and LDH activities, and inhibiting TNF-α secretion.

• Journal of the Korean Ceramic Society
• /
• v.41 no.8
• /
• pp.573-577
• /
• 2004

We have synthesized a Eu$^{2＋}$-activated Sr$_3$MgSi$_2$ $O_{8}$ blue phosphor and investigated an attempt to develop blue LEDs by combining it with a InGaN blue LED chip (Len=405 nm). The InGaN-based Sr$_3$MgSi$_2$ $O_{8}$：Eu LED Lamp shows two bands at 405 nm and 460 nm. The 405 nm emission band is due to a radiative recombination from a InGaN active layer. This 405 nm emission was used as an optical transition of the Sr$_3$MgSi$_2$ $O_{8}$：Eu phosphor. The 460 m emission band is ascribed to a radiative recombination of Eu$^{2＋}$ impurity ions in the Sr$_3$MgSi$_2$ $O_{8}$ host matrix. As a consequence of a preparation of W blue LED Lamp using the Sr$_3$MgSi$_2$ $O_{8}$：Eu blue phosphor, the highest luminescence efficiency was obtained at the ration of epoxy/blue phosphor(1/0,202). At this time, the CIE chromaticity was x=0.1417 and y=0.0683.