• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2180-2184
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• 2010

We synthesized and tested the anti-HIV activity of the SATE prodrug of a 2'-methyl 5'-norcarbocyclic adenine analogue. The introduction of a methyl group in the 2'-position was performed by the addition of a carbonyl using isopropenyl magnesium bromide. The adenine base was efficiently coupled using the Mitsunobu reaction. The chemical stability study of the bis(SATE) derivative 18 was measured at neutral (pH 7.2) and slightly acid (milli-Q water, pH 5.5) pH, and compounds 16 and 18 were evaluated as potential anti-HIV-1 agents.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.609-614
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• 2015

This study was to investigate the production of combustion toxic gases of pinus rigida specimens treated with pyrophosphoric acid (PP)/4ammonuium ion ($4NH_4{^+}$), methylenepiperazinomethyl-bis-phosphonic acid (PIPEABP) and PIPEABP/$4NH_4{^+}$. Each pinus rigida plates was painted in three times with 15 wt% in the aqueous solution followed by drying the species at room temperature. Emission of combustion toxic gases was examined by the cone calorimeter (ISO 5660-1). First-time to peak mass loss rate (1st-$TMLR_{peak}$) treated with chemicals was delayed upto 66.7~250.0% compared to those of untreated specimens. For test pieces treated with the chemicals, the emission of peak carbon monoxide ($CO_{peak}$) values of 0.0136~0.0178% and peak carbon dioxide ($CO_{2\;peak}$) value of 0.04432~0.3648% were obtained, which were higher than those for the virgin plate. In particular, oxygen emission is much higher than the level of 15% which can be fatal to humans. Therefore, the resulting risk could be eliminated. However it is supposed that the combustion-toxicities were partially increased compared to those of virgin plate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.12
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• pp.71-75
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• 1972

To investigate the effects of C. E. P. A(2-chloroethyl phosphonic acid) on the ripening of tobacco leaf, the effects on the yield and quality of leaf tobacco, this experiments were carried out during the period of from 1970 to 1971 at tobacco experiment station, Sosa, Korea and 3 locations. The results are summarized as follows. 1. The higher the C. E. P. A concentration was, the more the leaf ripening was accelerated. During the period from 3 to 4 days after treatment, the differences of leaf ripening among levels were prominent. 2. Treatment with C. E. P. A only on the upper surface of the tobacco leaf, accelerated the ripening of that particular part treated, but not apparently the other parts of leaf. 3. Distinctive acceleration of leaf ripening was, obserbed in the fully develope1lower leans, however, the upper leaves were indistinctive. 4. The higher C. E. P. A concentration was, the more the effect of ripening acceleration was. But the yield was reduced over 900ppm because of the low of growth of leaves and the reduced yield was 90% at the 3, 000ppm. So the proper concentration was regarded as 900ppm. 5. In the view point of the days of C. E. P. A ripening acceleration, it was shortened one days at 100 ppm, three days at 300ppm, three days at 450ppm, four days at 900ppm, seven days at 3, 000ppm. 6. In the point of curing process, it was possible that the curing time and fuel was reduced 29% and 45% respectively in the C. E. P. A treatment than the check. 7. Therefore, if it is treated the C. E. P. A at 900ppm in the tobacco cultivation, the quality shall be increased 13.5% and the price shall be increased 12% in the 10 Are. In the point of subsidiary affect, it is possible that the C. E. P. A ripening acceleration is shortened about 7 days at 3, 00ppm and curing time is shortened about 24 hours.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.89-92
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• 1998

1. Introduction : Among many azeotropic compounds, pyridine which forms an azeotropic mixture with three moles of water boiling at 92-93$\circ$C is very useful synthetic intermediate in laboratory and industry. With conventional separation method, the dehydration of pyridine aqueous solution is difficult and requires strong drying chemicals. To overcome these difficulties, several researchers have investigated on the separation of pyridine from aqueous solution through polymer membranes. Kujawski reported several ion-exchang membranes containing carboxylic and sulfonic fuctional group for dehydration of aqueous pyridine solution [1]. We have applied the idea of activation of water tranport through ion-dipole interactions between polymer membrane and aclueous feed. Our previous studies reported on the in-situ complex membrane to separate water from aqueous pyridine solution based on simple acid'-base theory [2, 3]. Water transport was enhanced through in-situ complex formation between the , acid moiety in the membrane and the incoming pyridine moiety in the feed.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.39-44
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• 2016

This study was to investigate the characteristics of combustion toxic gases of pinus rigida specimens treated with chemical additives such as pyrophosphoric acid (PP)/ammonuium ion ($NH_4{^+}$), methylenepiperazinomethyl-bis-phosphonic acid (PIPEABP) and $PIPEABP/NH_4{^+}$. Each pinus rigida plates was painted in three times with 15 wt% of each chemical additives in the aqueous solution. After drying these specimens at room temperature, the production of combustion gases and smoke was examined by the cone calorimeter (ISO 5660-1). As a result, the peak mass loss rate time (PMLR time) treated with chemicals was delayed upto 10.5~47.4% compared to that of using untreated specimen. In addition, the peak production of carbon monoxide ($CO\;_{peak}$) of 32.1~71.4% and total smoke release rate (TSRR) of 15.6~43.6% for test pieces treated with the chemical additive were higher than that of using the virgin plate. In particular, for the specimens treated with the chemical additive, the rate of smoke release (RSR) 29.4~41.5% was obtained higher than that of untreated plate except the specimen treated with $PP/4NH_4{^+}$. It can thus be concluded that the treatment using the chemical additive could partially increase the combustion-retardation properties of the species when compared to those of the virgin plate.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.86-87
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• 2013

새로운 알킬렌디아미노알킬-비스-포스포닉산 유도체인 3종을 합성하고, 그들의 연소특성을 측정하였다. 알킬렌디아민 및 알데히드에 아인산을 첨가하여 한 단계로 반응시켜 91.3~97.3%의 수득률을 얻었다. 연소특성은 육송에 화합물을 도포한 후 콘칼로리미터(ISO 5660-1)를 이용하여 측정하였다. Heat flux는 25kW로 고정하였다. 시험결과 착화시간은 육송에 비해 51s~83s 정도 지연되었으며 착화시간이 지연 될수록 최대 열방출율이 증가하는 경향을 나타내었다.

• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1171-1174
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• 2007

We have developed an electrochemical immunosensor that combines the electrocatalytic property of carbon nanotube and the low background current of indium tin oxide (ITO) electrode. A partial monolayer of carboxylated single-walled carbon nanotube (CCNT) is covalently formed on an ITO electrode modified with amine-terminated phosphonic acid. Nonspecifically adsorbed avidin on the hydrophobic sidewalls of CCNT is used to immobilize biotinylated antibody and to reduce the nonspecific binding to CCNT. The biotinylated antimouse IgG bound on avidin and the antimouse IgG conjugated with alkaline phosphatase (ALP) sandwiches a target mouse IgG. ALP catalyzes the conversion of p-aminophenyl phosphate monohydrate into p-aminophenol, which is electrocatalytically oxidized to p-quinone imine on CCNT surface. Moderate electrocatalytic electrode obtained with the combination of CCNT and ITO allows low detection limit (0.1 ng/ mL).

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.158-158
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• 1998

The non-mevalonate pathway is a newly discovered isoprenoid biosynthetic pathway in some bacteria, cyanobacteria, algae and plants. Because isoprenoid metabolites (ubiquinone, menaquinone, undecaprenol) are essential for bacterial growth, this pathway may represent a novel target for antibacterial agents. Antibiotics with a unique mechanism of action are needed to combat the risk of antibiotic resistance that is a current worldwide problem. In order to study this pathway as viable target, it was necessary to verify use of the pathway in our model system, the bacterium Bacillus subtilis. Incubation experiments with [6,6-$^2$H$_2$]-D-glucose and [l-$^2$H$_3$]-deoxy-D-xylulose were conducted to provide labeled menaquinone-7 (MK -7), the most abundant isoprenoid in B. subtilis. $^2$H-NMR analysis of the MK-7 revealed labeling patterns that strongly support utilization of the non-mevalonate pathway. Another approach to study the pathway is by structure activity relationships of proposed inhibitors of the pathway. Fosmidomycin is a phosphonic acid with antibacterial activity known to inhibit isoprenoid biosynthesis in susceptible bacteria and may act by inhibiting the non-mevalonate pathway. Fosmidomycin and an N-methyl analog were synthesized and tested for antibacterial activity. Fosmidomycin was active against Escherichia coli and B. subtilis, while N-formyl-N-methyl-3-amino-propylphosphonic acid was inactive.

• Analytical Science and Technology
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• v.15 no.2
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• pp.127-134
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• 2002

Analytical method to determine rare earth elements which were extracted to organic phase by inductively coupled plasma mass spectrometry(ICP-MS) was investigated. Organic phase which had extracted rare earth elements was directly aspirated into ICP-MS by ultrasonic nebulizer(USN) in order to reduce solvent load to the plasma. Then, the count rate increased when MIBK(methyl isobutyl ketone) was added to EtOH(ethanol) but decreased when 0.03 M HEH(2-ethylhexyl-2-ethylhexyl phosphonic acid, $P_{507}$, PC88A) was added to solvent which mixed MIBK with EtOH. The optimal temperatures of desolvation system were -10 $^{\circ}C$ for the condenser and 150 $^{\circ}C$ for the heating tube. The optimal nebulizer flow rate which gave maximum count rate and minimum reflect power was 0.7 L/min. The optimal pH and extraction time were 4.3 and 10 min for MIBK-0.03 M HEH system. Detection limits which were obtained through calibration curves at the range of 0.2 ${\sim}$ 20 ng/mL were 0.02 ${\sim}$ 0.05 ng/mL under the optimal experimental conditions.

• Food Science and Preservation
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• v.3 no.2
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• pp.155-170
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• 1996

In order to determine the physiolosical characteristics of plum fruits(Oishi wase) during maturation and guilty according to temperature after harvest, (2-chloroethyl) phosphonic acid(ethphon) 390ppm was sprayed on plum tree 11days before commercial matuarity in Suwon area. And also this study was acted to investigate fruits quility(Formosa) influenced by temperature(room, low) and polyethylene films(0.03, 0.06, 0.1mm), 1. Effect of ethphon on the fruits maturation and fruits(Oishi wase) quility according to temperature ofter harvest. Ethephon stimulated fruits ripening but the firmness was reduced rapidly. Soluble solids and titratable acidity was not very different than each treatment. Carbon dioxide and ethylene production were advanced and the production peak were shown earlier by ethephon treatment as compared with control fruit. Anthocyanin development was enhansed rapidly by ethephon treatment but it exerted a bad influence on fruits color after harvest, The soluble sugars in fluits were mainly glucose, sucrose, and fructose. Those content were higher in treated fruit than control. The organic acid was mainly malic acid. The shelf life was less than about 5days at room temperature and about 10 days at low temperature. 2. Fruits(Formosa) quility as affected by polyethylene film bagging. The polyethylene films well maintained the firmness both room and low temperature. Low temperature was more effective in maintaining titratable acidity than room temperature, especially polyethylene films. On the Other hand, soluble solids content was not shown wide differance between room and low temperature. Polyethylene film showed a high resperation rate, the rate was higher at room temperature than low temperature and thicker films revealed higher rate. Otherwise, ethylene production was low in all treatment Polyethylene film inhibited the coloration of fruits, decreased anthocyanin content. Fruits coloration delayed by low temperature in control. The shelf life of plum fruits was about 6 days at room temperature and 13 days at low temperature in control Polyethylene film had no advantage on shelf life both at room and low temperature.