• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.168-171
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• 1998

Sesaminol in sesame seed was postulated to have antitumor activity. The present study was performed to characterize the role of crude sesaminol extracted from sesame seed (Sesame Crude Sesaminol; SCS) on inhibiting the in vitro growth of human leukemia HL-60 cells. SCS inhibited the growth of human leukemia HL 60 cells in culture and macromolecular synthesis in a dose and time dependent manner. The cytostatic range of SCS concentration was found to be 60 to 100 $\mu\textrm{g}$/ml. SCS concentration greater than 200 $\mu\textrm{g}$/mlwere cytocidal to HL-60 cells. When SCS concentraction was 6 $\mu\textrm{g}$/mland 50 $\mu\textrm{g}$/ml the synthesis of HL-60 cells was inhibited by 35% for DNA, 6% for RNA and 5% for protein and 83% for DNA, 76% for RNA and 60% for protein. Of specific interest was the irreversible effect of SCS in inhibiting DNA synthesis of HL-60 cells. This was evidenced from the fact that, even after washed with PBS three times, preincubated HL-60 cells still showed the inhibited DNA synthesis.

• Journal of Life Science
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• v.6 no.3
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• pp.165-170
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• 1996

The action of phospholipid on the rhodotorucine A(RH.A) acceptance by heterbasidiomyceteous yeast Rhodosporidium toruloides mating type a cells and the effect of medium composition during sexual differentiation were investigated. Activation of trigger peptidase(TPase)was very sensitive to the originated phospholipid from R. toruloides and was more sensitive to phospholipid liposome made up of phospholipi. Phospholopod present on the membrance of mating type a cells consists of phospatidylglycerol(PG), phosphatidylethanolamine(PE), phospatidylcholine(PC), phospatidylinositol(PI), and phosphatidylserine(PS) of 12.9, suprisingly 45.4, 11.0, and 13.9%, respectively. As the result of using C-1 and N-1 mediums which limited C and N sources capable of inhibiting the synthesis of phospholipid, it resulted inhibiting sexual dlfferentiation and production of Rh.A from mating type Acells.

• Journal of Electrochemical Science and Technology
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• v.6 no.1
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• pp.7-15
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• 2015

3-(4-Iodophenyl)-2-imino-2,3-dihydrobenzo[d]oxazol-5-yl 4-methylbenzenesulfonate (4-IPhOXTs) was synthesized and its inhibiting action on the corrosion of stainless steel 316L (SS) in sulfuric acid was investigated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results of the investigation show that this compound has excellent inhibiting properties for SS corrosion in sulfuric acid. Inhibition efficiency increases with increase in the concentration of the inhibitor. The adsorption of 4-IPhOXTs onto the SS surface followed the Langmuir adsorption model with the free energy of adsorption ΔG⁰_ads of −8.45 kJ mol⁻¹ . Quantum chemical calculations were employed to give further insight into the mechanism of inhibition action of 4-IPhOXTs.

• Mycobiology
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• v.37 no.3
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• pp.203-206
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• 2009

To develop new antidementia nutraceuticals, a potent acetylcholinesterase (AChE)-inhibiting extract was screened from various extracts of nutritional mushrooms and lichens nutritional and its physicochemical properties were investigated. Among the several extracts tested, methanol extracts of Umbilicaria esculenta fruiting body showed the highest AChE inhibitory activity of 22.4%. U. esculenta AChE inhibitor was maximally extracted when fruiting bodies were treated with 80% methanol at $40^{\circ}C$ for 18 h. The methanol extracts contained 18.9% crude lipid, 18.8% crude protein, and 11.6% total sugar. In addition, they contained 444 mg/g glutamic acid, 44 mg/g histidine, and 41 mg/g aspartic acid. The methanol extracts were soluble in a solution of methanol and 20% dimethylsulfoxide, insoluble in n-hexane, chloroform, and water, and were stable at $20{\sim}60^{\circ}C$ and pH $1.0{\sim}5.0$ for 1 h.

• Journal of Plant Biology
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• v.25 no.1
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• pp.21-36
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• 1982

The activity of photosystem II in isolated chloroplast form the leaves of Sedum sarmentosum was measured. The photoreduction rate of DCPIP by photosystem II showed the circadian rhythm with a peak at near midday sample for a continuing fine day and at near afternoon between nidday and sunset sample for a continuing cloudy day in summer. The optimum light intensity of photoreduction by photosystem II in the chloroplast preparation was about 5~9$\times$$10^4$ lux. The saturated light intensity was over 9$\times$$10^1$lux. Photosystem II activity was inhibited by even the lowest concentration of lead. When Pi and ATP of the same concentration as Pb were added to the reaction mixture containing Tris buffer lacking of Pi prior to Pb incubation, photosystem II activity was protected from Pb-inhibiting effect by the pretreament of Pi and ATP. It was assumed that Pb inhibiiton was probably due to one, P-depriving by the precipitates of $Pb_3$ $($Pb_4$)_2$ in the reaction mixture and the other, partially Pb-combing with Pi groups of the active site of photosystem II.

• YAKHAK HOEJI
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• v.45 no.3
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• pp.245-250
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• 2001

Aminoacyl tRNA synthetases of bacteria are known as potential targets for new anti-microbial agents. To isolate new inhibitors of bacterial methionyl-tRNA synthetases from natural sources, a new target-oriented screening system using whole cells which are over-expressing a target enzyme was developed. Approximately 8,000 culture broths of microorganisms from soils were tested by this screening system. Among them, ten culture broths was found to contain inhibitory activity against methionyl -tRNA synthetases of Escherichia coli. For the validation of the screening system, this new method was compared with in vitro enzymatic method. Seven out of 10 culture broths showed inhibitory activity against methionyl-tRNA synthetases of E. coli. This result showed that the new screening system was comparable to the enzyme assay. Thus we believe that our screening system as a new method can be applied for the screening of new antibiotics inhibiting bacterial methionyl-tRNA synthetases from natural products.

• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.154-157
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• 2003

A peptide inhibiting HIV-1 pretense was isolated from the hydrolysate of manila clam (Ruditapes philippinarum) proteins digested with thermolysin. The peptide was purified by using membrane filtration, gel permeation chromatography, ion exchange chromatography, and reverse phase HPLC, The amino acid sequence of the peptide was determined to be Ile-Tyr-Glu-Gly. This tetrapeptide sequence exists in some proteins of Physarum polycephalum and Mycobacterium smegmatis. Chemically synthesized Ile-Tyr-Glu-Gly showed the $IC_{50}$/ value of 22.3 $\mu$M.

• Archives of Pharmacal Research
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• v.24 no.3
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• pp.214-218
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• 2001

The mechanisms responsible for the antidiabetic activity of both the white ginseng radix (Ginseng Radix Alba, GRA) and the rootlet (Cinseng Radix Palva, GRP) were investigated. After a four week oral administration, the fasting blood glucose levels in the GRA- and GRP-treated groups were lower when compared to the control group. To elucidate the hypoglycemic mechanism(s) of the ginseng radices, glucose absorption from the small intestine, hepatic hexokinase and glucose-6-phosphatase activities, in addition to PPAR-${\gamma}$ expression in adipose tissue were examined. The results strongly suggest that GRA can improve hyperglycemia in KKAy mice, possibly by blocking intestinal glucose absorption and inhibiting hepatic glucose-6-phosphatase, and GRP through the upregulation of adipocytic PPAR-$\gamma$ protein expression as well as inhibiting intestinal glucose absorption.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.667-671
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• 2009

Extract of water-soluble polysaccharide (CFWx), showing inhibiting activity on ${\alpha}-glucosidase$, was prepared from the fruiting bodies of Cordyceps militaris by hot-water extraction, and ethanol precipitation. Chemical characteristics of CFWx were as follows: carbohydrate content 30% including 16% of uronic acid; 51% protein content; monosaccharide composition, Man:Glu:Gal (30:43:27); molecular weight $3-5{\times}10^4$. CFWx was further purified by ion-exchange, gel-permeation, and affinity chromatography and $CFWx-AH-{\alpha}$ fraction was isolated. Fundamental structure of $CFWx-AH-{\alpha}$ was deduced as ${\alpha}-(1{\to}4$)-D-glucan with ${\alpha}-(1{\to}3$)- and/or ${\alpha}-(1{\to}6$)-D-glycosidic side chains based on methylation analysis.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.158-165
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• 2004

Up to now, many crack repair techniques have been developed for inhibiting crack growth in structural components. However, the simplest way for inhibiting crack growth is to apply a indentation at the crack tip or at some distance ahead of the expected crack growth path so as to produce residual compressive stresses that can reduce the effective stresses around the crack tip. In spite of its importance to the aerospace industry, little attention has been devoted to evaluation of the indentation residual stress effect on the fatigue crack initiation life quantitatively. Therefore, in the present work, the magnitude and distribution of the indentation residual stresses were investigated in order to estimate the beneficial effect on fatigue crack initiation by using finite element method. Furthermore, to examine the validity of finite element analysis results, residual stress distribution in the indented specimen was measured by using X-ray diffraction technique, and fatigue crack behavior at fastener hole in aluminum alloy 7075-T6 before and after indentation processes was investigated.