• Applied Biological Chemistry
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• v.43 no.3
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• pp.190-195
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• 2000

Tolaasin is a peptide toxin produced by Pseudomonas tolaasii and causes a brown blotch disease forming brown, slightly sunken spots and blotches on the cultivated mushrooms. It is a lipodepsipeptide consisting of 18 amino acids and its molecular mass is 1,985 Da. It forms a pore in plasma membranes, resulting in the disruption of membranes of fungal, bacterial, plant, and animal cells as well as mushroom tissue. In order to measure the toxicity of tolaasin, erythrocytes of blood were used to evaluate the tolaasin-induced hemolysis. Hemolytic activity of tolaasin was measured by observing the absorbance change either at 420 nm, representing the release of hemoglobins from red blood cells(RBCs), or at 600 nm, representing the density of residual cells. The hemolytic activity of culture-extract of P. tolaasii increased at early-stationary phase of growth and was maximal at late stationary phase. The hemolytic activity of tolaasin appeared high in the RBCs of dog and rat. The RBCs of rabbit and hen were less susceptible to tolaasin. The effects of various cations were also measured. $Cd^{2+}$ and $La^{3+}$. as well as $Zn^{2+}$ appeared inhibitory to the tolaasin-induced hemolysis. The effects of various anions on tolaasin-induced hemolysis were measured and carbonate showed the greatest inhibition to the hemolysis. However, phosphate stimulated the tolaasin-induced hemolysis and no effects were observed by chloride and nitrate.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.84-87
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• 2008

In this research, we screened for glucosyltransferase (GTase) inhibitors that effectively prevent the dental caries from 420 kinds of boiled water extracts of herbs and wild plants and searched for GTase inhibitory activities. Among them, 13 kinds of hot water extracts had high GTase inhibitory activities and especially, we focused on Foeniculum vulgare which showed the highest inhibitory activity on GTase. The boiled water extract of F. vulgare was stable at high temperature and showed as a mixed type of competitive and uncompetitive inhibition kinetic behavior. It did not have antibacterial effect on Streptococcus mutans and had inhibitory activity on GTase. Specially, in the clinical trial, the group treated by boiled water extract of F. vulgare showed more decrease of plague index at 4.8 point than untreated group. These results suggested that boiled water extract of F. vulgare can effectively suppress the plague formation as it inhibits the GTase activity.

• Microbiology and Biotechnology Letters
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• v.12 no.4
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• pp.277-283
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• 1984

In the forward reaction (ADP formation) of the adenylate kinase from baker's yeast, dissociation constants from binary complexes are higher by a factor of about 4 times then those from at ternary complexes. In the reverse reaction, dissociation constants from the binary complexes are 2 times higher then those from the ternary complexes. The enzyme showed activities against various nucleotide triphospate in following orders; ATP 100, UTP 18, ITP 9 and GTP 5, of the necleotide monophosphate. only dAMP showed 33% activity of that AMP as phosphate acceptor. Divalent cations were required in enzyme reaction in following orders; $Mg^{2＋}$ 100, Co$^{2＋}$ 57, Mn$^{2＋}$ 54, $Ca^{2＋}$ 51, Ni$^{2＋}$ 10 and Sn$^{2＋}$ 6. AMP, as a substrate inhibitor, competitively inhibited the adenylate kinase at pH 7.2 or 8.0. Inhibition constants of the enzyme showed greater dependence on the pH of the reaction mixture, which was the lower Ki values under higher pH. Adenosine pentaphospho adenosine was competive inhibitor to the enzyme against all substrate, and it showed the same Ki values, 2.9mM. Further, PEP was competive inhibitor with respect to AMP and non-competive inhibitor with respect to MgATP. Adenylate kinase from bakers yeast was similar to mitochondrial type of animal in the contents of aianine, leucine and asparagine or asparatic acid differing from muscle type enzyme. Based on the results and observation, characteristic of yeast adenylate kinase resembled the adenylate kinase of mitochondrial type from animals. Further, difference of characteristics in adenylate kinasa depending upon the workers might be due to the difference of strain used.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.2
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• pp.1-12
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• 2011

Objectives: The object of this study was to observe the in vitro antibacterial effects of Chungdae-tang aqueous extracts, traditionally used for treating various gynecological diseases including vaginitis in Korea against Gardnerella vaginalis, and combination effects of Chungdae-tang extracts with Clindamycin were also monitored in this study. Methods: Antibacterial activities against Gardnerella vaginalis of Chungdae-tang aqueous extracts were detected using standard agar microdilution methods. In addition, the effects on the bacterial growth curve were also monitored at MIC and MIC${\times}$2 levels. The combination effects of Chungdae-tang aqueous extracts with Clindamycin were observed by Checkerboard microtiter assay, and the effects of bacterial growth curve treated with or Chungdae-tang aqueous extracts MIC+Clindamycin MIC, 1/2MIC and 1/4MIC, respectively. In the present study, Gardnerella vaginalis were incubated under $37^{\circ}C$, 10% $CO_2$; and bacterial growth curves were calculated at 24, 48, 72, 96 and 120hrs after incubations. Results: MIC of Chungdae-tang aqueous extracts against Gardnerella vaginalis were detected as $3.906{\pm}2.344$(0.782~6.250) mg/$m\ell$, respectively. MIC of Clindamycin was detected as $0.010{\pm}0.006$(0.004~0.016) ${\mu}g/m\ell$ at same conditions. In addition, Clindamycin and Chungdae-tang aqueous extracts also showed marked dosage-dependent inhibition of bacterial growth, and more dramatical inhibitions were detected in Clindamycin+Chungdae-tang aqueous extracts MIC treatment as compared with each of single Clindamycin MIC and Chungdae-tang aqueous extracts MIC treatments, respectively. In addition, quite similar inhibitory effects on bacterial growth were detected in Clindamycin 1/4 MIC+Chungdae-tang aqueous extracts MIC treatment as compared with single Clindamycin MIC treatment in the present study. FIC index in combination of Chungdae-tang and Clindamycin were detected as $0.775{\pm}0.285$ (0.500~1.250) at Checkerboard microtiter assay. Conclusions: The results obtained in this study suggest that Chungdae-tang aqueous extracts showed antibacterial effects against Gardnerella vaginalis, and it also showed dosage-dependent inhibitory effects on the bacterial growth. In addition, combination treatment of Chungdae-tang aqueous extract with Clindamycin showed more potent inhibitory effects on the growth of Gardnerella vaginalis with FIC index $0.775{\pm}0.285$(0.500~1.250), respectively. It means, the combination of Chungdae-tang aqueous extract with Clindamycin is partially synergistic effects. It, therefore, is expected that effective dosages of Clindamycin will be reduced to 1/4 or over 1/4 levels as combination with Chungdae-tang extracts, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.40-47
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• 1994

The objective of this research was to examine the effect of ammonium thiosulfate(ATS) on urease activity and on biological and chemical properties of flooded paddy soil especially having high organic matter content by comparing with the effect of sodium thiosulfate(STS). The results obtained are summarized as follows. 1. The hydrolysis of urea was inhibited at 3 and 5 days after treatment of thiosulfate(ATS and STS) +glucose and thiosulfate only, respectively. The inhibitory effect of ATS on urea hydrolysis was slightly lower than that of STS in glusoce-added soils, but when the glucose was not added, the effects of ATS and STS were not different significantly. 2. The soil pH and Eh was lowered by 0.3~0.5 units and 30~120 mV, respectively, when incubated flooded soil with ATS and glucose at $25^{\circ}C$. 3. Soil respiration rate in/flooded soil was increased by 10~70% with the treatment of ATS during the 20 day experimental period. 4. The contents of acetic and butyric acid in thiosulfate treatment soil was below $10{\mu}g/g$, which was lower than that($220.3{\mu}g/g$) of critical growth inhibition of rice.

• Journal of Life Science
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• v.23 no.2
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• pp.249-258
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• 2013

The antioxidative activity and bioactivity of water, ethanol, and methanol extracts from Paecilomyces japonica (PJ), Cordyceps militaris (CM), and cordycepin-enriched C. militaris JLM0636 ($CM{\alpha}$) were tested in in vitro experimental models. The PJ water extract showed the highest extraction yield (42.53%). The highest content of phenolic compounds and flavonoids were found in the water extract of PJ, 2.72% and 1.73%, respectively. The major minerals were K, Mg, and Ca. The water extracts of PJ also showed the highest DPPH free radical scavenging activity and reducing power. Linoleic acid peroxidation and antioxidative activities were strong in $CM{\alpha}$. The methanol extracts of PJ showed the highest inhibition activity against tyrosinase. Fibriolytic activity was higher in $CM{\alpha}$ than in CM. These results may provide basic data to understand the biological activities of bioactive materials derived from $CM{\alpha}$ for the development of functional foods, cosmetics, and antithrombotics.

• Korean Journal of Food Science and Technology
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• v.48 no.1
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• pp.86-91
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• 2016

Oxidative stress caused by reactive oxygen species is ascribed to many neurodegenerative diseases like Alzheimer's disease. Phenolic antioxidants can reduce the oxidative stress. In this study, ripe fruits of Opuntia ficus-indica var. saboten (OFS) were extracted using 80% (v/v) aqueous ethanol. Total phenolic and flavonoid contents of the OFS fruits (100 g) were 409.9 mg gallic acid equivalents and 72.2 mg catechin equivalents, respectively. The OFS fruits had antioxidant capacity at 381.2, 298.2, and 3,219.9 mg vitamin C equivalents/100 g in ABTS, DPPH, and ORAC assays, respectively. The OFS fruits showed protective effects on PC-12 cells against oxidative stress in a dose-dependent manner, partly due to decrease of intracellular oxidative stress. Furthermore, the OFS fruits inhibited both acetylcholinesterase and butyrylcholinesterase. Consequently, these results suggest that the OFS fruits might be served as a source of functional materials to reduce oxidative stress in neuronal cells and to inhibit cholinesterases.

• Korean journal of food and cookery science
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• v.21 no.6 s.90
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• pp.769-775
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• 2005

In this study we isolate substances to serve as dietary resources in order to replace the female hormone. Silkworm (Bombyx mori) is one of the most attractive hosts for large-scale production of eukaryotic proteins which have been proven safe as a dietary resource. We report on the estrogenicity of a mixture of silkworm pupa and herbs (Ginseng,Ulkeum, and Hasuo) using the immature rat uterotrophic assay in vivo. Silkworm pupa aqueousextract (KW) and silkworm oil extract (KO) induced effects on the immature rat uterotrophic assay. KO showed neither positive uterotrophic response nor inhibition on E2 induced effect, while KW and MK (mixture of KW and herbs) showed both of the effects. It is concluded that ethanol extracts from silkworm might be a good, therapeutic, natural product for hormone-deficient diseases.

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.11-11
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• 1999

;It has been reported that suspension-cultured rice cells grown on mixed carbon sources of glucose (GIc) and acetate exhibited diauxic growth in which acetate was the preferred carbon source (Lee and Lee, 1996). Carrot (Daucus carota L.) suspension cells, showing a diauxic growth very similar to that of rice cells, were used to delineate the mechanisms underlying this preferential use of acetate over GIc. Uptakes of both GIc and 3-0-methylglucose (3-0MG), a non-metabolizable GIc analogue, were similarly inhibited when acetate or butylate, weak acids which are capable of transporting protons into the cytosol, were present in the uptake assay mixture containing cells harvested during the GIc-utilizing second growth phase. Inhibition of GIc uptake by these weak acids was similar when equivalent experiments were carried out with isolated plasma membranes. It was further shown that Glc uptake, which requires a proper proton gradient across the plasma membranes, was inhibited during the first growth phase by acetate-mediated alkalization of growth medium and/or simultaneous acidification of cytosol. This study strongly suggests that Glc utilization in plant cells is inhibited by co-presenting carbon source(s) which can alter the proton gradient across the plasma membrane. We further examined diauxic growth in culture containing GIc and malate. Unlike the case in the culture with GIc and acetate, carrot cells used GIc first. Malate was utilized only after Glc is depleted from medium. These results indicate that GIc can be a preferred or less-preferred carbon source depending on the competing carbon source. It was noted that malate was not directly taken up by cells. Instead it was converted extracellularly into fumarate which was subsequently transported into cells. During the malate-growth phase malate uptake was negligible, and fumarate uptake was active and pH-sensitive. It was shown that fumarase released into medium was responsible for the extracellular conversion of malate into fumarate. An immunoblot experiments showed that fumarase antibody raised against Arabidopsis fumarase provided positive signals only in medium in malate culture, not in fumarate or GIc cultures. This study demonstrates the first example in that fumarase, a mitochondria marker enzyme, can be present in places other than mitochondria.ndria.

• Food Science and Preservation
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• v.19 no.6
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• pp.946-950
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• 2012

The antioxidant activity and whitening effect of the distilled water (DW) and ethanol extracts of the Prunus persica flower and calyx were studied. In the oxygen radical absorption capacity (ORAC) assay for antioxidant activity measurement, it was confirmed that the flower extract was stronger than the calyx extract, and that the ethanol extract was relatively stronger than the DW extract. To define the whitening effect, an experiment was conducted involving tyrosinase inhibitory assay and measurement of the melanin content of B16F10. As a result of the use of tyrosinase, the DW extract of calyx showed 53% inhibition as the highest activity. The melanin content inhibitory rates were defined as 57% for the ethanol flower extract and 63% of the ethanol calyx extract, based on a $10{\mu}g/mL$ concentration. Based on these results, mixture with the whitening effect in the extract of P. persica and another compounds should be researched for development as a cosmetic ingredient.