• Korean Journal of Weed Science
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• v.17 no.3
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• pp.325-333
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• 1997

Selection of pepper (Capsicum sp.) cultivars tolerant to acetolactate synthase (ALS)-inhibiting herbicides {imazethapyr, 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3=pyridine-carboxylic acid, and primisulfuron methyl 2-[[[[[4,6-bis(difluoromethoxy)-2-pyrimidinyl]amino] carbonyl]amino]sulfonyl]benzoate} was investigated. Pepper cultivars such as Red Top, Happy Dry, Golden Tower, and Hagyeorae showed relatively tolerant response to imazethapyr, while cultivars; Korea, Cheongyang, Oriental Glory, and Hanam were susceptible. Red Horn, Jopoong, Kwangbok, and Wangcho cultivars were tolerant to primisulfuron whereas Korea, Dahhong, Chamjoah, and Poongchon cultivars were susceptible. Determination of growth inhibition by ALS-inhibiting herbicides showed that the $I_{50}$ estimates of growth from the susceptible- and tolerant-cultivars were 0.075 and 0.20kg ai/ha for imazethapyr; 0.06 and 0.16kg ai/ha for primisulfuron, respectively. Furthermore, the $GR_{50}$ estimates of growth from the susceptible and tolerant cultivars were 0.05 and 0.20kg ai/ha for imazethapyr; 0.07 and 0.16kg ai/ha for primisulfuron, respectively. This result, based on the $GR_{50}$ and $I_{50}$ values, indicates that responses of pepper to ALS-inhibiting herbicides between tolerant- and susceptible-cultivars were different about 3- to 4-fold to imazethapyr, and 2- to 3-fold to primisulfuron.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.105-112
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• 2005

Stabilizing and rousing sludge water generated from washing truck mixer and batcher plant can resolve inconsistency in quality and improve strength, therefore it is essential to review how to utilize it. This research conducted experiments and studied on solids of sludge water to find out the types of stabilizing agents available in conditions of producing ready mixed concretes in Korea. The result showed that oxy carboxylic acid retarder dedicated for stabilizing sludge water was most effective in decreasing solid. However, the setting time of cement paste was retarded due to surplus reactants, but it did not impede application of ready mixed concretes. When we left the sludge water mixed with stabilizing agent, it has been noted that initial retard effect recovered to the level using just service water in 7${\~}$8 days and that it is effective to use stabilized sludge water in 2${\~}$3 days. On the other hand, saccharic type super retarding agent was also outstanding in applicability by showing similar effect. The sludge water stabilizing agents currently marketed depend on imports, therefore it is necessary to locally manufacture usable stabilizing agents and to review its usability with multi-dimensional view.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.191-196
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• 2001

${\alpha},{\beta}$-Unsaturated carboxanilides 5 with trifluromethylated dihydro-1,4-oxathiins were synthesized for the development of new agrochemical fungicide. Chlorination of trifluoromethylated ${\beta}-keto$ ester 6 followed by the reaction with 1,2-mercaptoethanol gave intermediate 1,4-oxathiane 11. Without purification of 11, substitution of hydroxy group by chlorine, followed by dehydrochlorination of 10 in the presence of triethylamine afforded trifluoromethylated dihydro-1,4-oxathiin ethyl ester 9. Acylation of the hydroxy group of the carboxylic acid 12 followed by treatment of various amines gave the corresponding trifluoromethylated dihydro-1,4-oxathiin carboxamides 5. Antifungal screening (in vivo) of the synthesized compounds against typical plant diseases, which include rice blast, rice sheath blight, cucumber gray mold, tomato late blight, wheat leaf rust, and barley powdery mildew, was carried out. Where meta position of the phenyl group was substituted with isopropoxy or isopropyl group, excellent antifungal activities against rice sheath blight and wheat leaf rust were detected.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.4
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• pp.273-279
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• 2009

The accumulation of ${\beta}$-amyloid (A${\beta}$) aggregates is a characteristic of Alzheimer's disease (AD). Furthermore, these aggregates have neurotoxic effects on cells, and thus, molecules that inhibit A${\beta}$ aggregate formation could be valuable therapeutics for AD. It is well known that aggregation of A${\beta}$ depends on its hydrophobicity, and thus, in order to increase the hydrophilicity of A${\beta}$, we considered using citrate, an anionic surfactant with three carboxylic acid groups. We hypothesized that citrate could reduce hydrophobicity and increase hydrophilicity of A${\beta}_{1-40}$ molecules via hydrophilic/electrostatic interactions. We found that citrate significantly inhibited A${\beta}_{1-40}$ aggregation and significantly protected SH-SY5Y cell line against A${\beta}_{1-40}$ aggregates-induced neurotoxicity. In details, we examined the effects of citrate on A${\beta}_{1-40}$ aggregation and on A${\beta}_{1-40}$ aggregates-induced cytotoxicity, cell viability, and apoptosis. Th-T assays showed that citrate significantly inhibited A${\beta}_{1-40}$ aggregation in a concentration-dependent manner (Th-T intensity: from 91.3% in 0.01 mM citrate to 82.1% in 1.0 mM citrate vs. 100.0% in A${\beta}_{1-40}$ alone). In cytotoxicity and viability assays, citrate reduced the toxicity of A${\beta}_{1-40}$ in a concentration-dependent manner, in which the cytotoxicity decreased from 107.5 to 102.3% as compared with A${\beta}_{1-40}$ aggregates alone treated cells (127.3%) and the cell viability increased from 84.6 to 93.8% as compared with the A${\beta}_{1-40}$ aggregates alone treated cells (65.3%). Furthermore, Hoechst 33342 staining showed that citrate (1.0 mM) suppressed A${\beta}_{1-40}$ aggregates-induced apoptosis in the cells. This study suggests that citrate can inhibit A${\beta}_{1-40}$ aggregation and protect neurons from the apoptotic effects of A${\beta}_{1-40}$ aggregates. Accordingly, our findings suggest that citrate administration should be viewed as a novel neuroprotective strategy for AD.

• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.87-93
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• 2014

We investigated the effects of an ethanol extract from Perilla frutescens sprouts (PFSE) as an antioxidant, and its effects on edema and inflammation in RAW 264.7 cells and HMC-1 cells. The antioxidant activities (DPPH and ABTS radical scavenging) of PFSE were similar to those of butylated hydroxytoluene (BHT) and (${\pm}$)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox). We also investigated the anti-inflammatory effects of PFSE on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and HMC-1 cells stimulated with phorbol 12-myristate 13-acetate (PMA) with the calcium ionophore A23187. TNF-${\alpha}$ and IL-$1{\beta}$ production, which had been increased by treatment with LPS or PMA plus A23187, were significantly inhibited by PFSE in a dose-dependent manner. Furthermore, PFSE significantly reduced the xylene-induced ear edema and the carrageenan-induced paw edema of ICR mice in a dose-dependent manner. The effects of PFSE (200 mg/kg) in reducing ear and paw edema were similar to those of aspirin (50 mg/kg). These results suggest that PFSE can be potentially used as a medicine for treating oxidative stress, an edematous and inflammatory disease.

• YAKHAK HOEJI
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• v.40 no.4
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• pp.428-437
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• 1996

The in vitro and in vivo antibacterial activities of a new fluoroquinolone, DWP20364(1-cyclopropyl-5-amino-6,8-difluoro-7-(2,7-diazabicyclo[3.3.0]oto-4-ene-7-yl)-1 ,4-di-hydro-4-oxoquinoline-3-carboxylic acid) were evaluated in comparison with those of ciprofloxacin(CPFX), sparfloxacin(SPFX) and ofloxacin(OFLX). DWP20364 was more potent than CPFX and OFLX against Staphylococcus spp., Streptococcus spp. and Enterococcus faecium MD8b and it was similarly or slightly less active than CPFX against Escherichia spp. and Pseudomonas spp.. For MRSA and OFLX resistant strains (Staphylococcus spp.(14),Enterococcus spp.(4), Acinetobacter spp.(2), Pseudomonas spp.(9), Klebsiella spp.(2) and Serratia spp.(6)),DWP20364(MICs for 90% of strains,0.025 and 12.5${\mu}$g/ml, respectively) was 4 to 32 folds more potent than SPFX and CPFX. The activity of DWP20364 decreased moderately in the presence of 5mM $Mg^{2+}$. However, various pHs and the concentrations of various serum had no effect on the activity of DWP20364. DWP20364 possessed a bacteriocidal effect at the 1MIC against gram positive and gram negative strains. The protective effect of DWP20364 against systemic infections in mice caused by S. aureus Smith or S. aureus L2379 was superior to that of CPFX and SPFX but it was less active than that of CPFX against infection by P. aeruginosa E-2.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.66-70
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• 1997

LGC-40863(proposed common name ; pyribenzoxim), (benzophenone O-[2,6-bis[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzoyl]oxime) is a new rice herbicide being developed by LG Chemical Ltd. The herbicide is highly selective between rice(Oryza sativa L.) and weeds including barnyardgrass (Echinochloa crus-galli(L.) P. Beauv.), and assumed to inhibit acetolactate synthase(ALS ; EC 4.1.3.18) because other structurally related herbicides inhibit the enzyme. To know inhibitory activity and the mode of inhibition of LGC-40863, $I_{50}$(concentration inhibiting ALS activity by 50%) and inhibition kinetics were investigated using ALS extracted from rice and barnyardgrass. $I_{50}$ values of LGC-40863 were 14 and 16mM in rice and barnyardgrass, respectively. In contrast to imazapyr(2-[4,5-dihydro-4-mythyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-pyridine-carboxylic acid) which showed an uncompetitive inhibition pattern, LGC-40863 was a noncompetitive inhibitor to ALS with respect to pyruvate similar to chlorsulfuron(2-chloro-N-((4-methoxy-6-methyl-l,3,5-triazin-2-yl) aminocarbonyl)benz-enesulfonamide) in both plants.

• Journal of Life Science
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• v.22 no.1
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• pp.87-91
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• 2012

Phorbol 12-myristate 13-acetate (PMA), a known tumor-promoting phorbol ester, activates the signal transduction enzyme protein kinase C (PKC) in animal cells. We investigated the effect of PMA on the regulation of gravitropism via ethylene production in primary roots of maize. PMA stimulated root growth and the gravitropic response in a concentration-dependent manner at $10^{-6}$ M and $10^{-4}$ M over 8 hrs. These effects were prevented by treatment with staurosporine (STA), a potent inhibitor of PKC. These results support the possibility that the gravitropic response might be regulated through protein kinases that are involved in the signal transduction system. Ethylene is known to play a role in the regulation of root growth and gravitropism. Ethylene production was increased by about 26% and 37% of the control rate in response to $10^{-6}$ M and $10^{-4}$ M PMA, respectively. PMA also stimulated the activity of ACC synthase (ACS), which converts the S-adenosyl-L-methionine (AdoMet) to 1-aminocyclopropane-1-carboxylic acid (ACC) in the ethylene production pathway. These effects on ethylene production were also prevented by STA treatment. These results suggest that the root gravitropic response in maize is regulated through protein kinases via ethylene production.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.510-518
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• 2016

Ethyl cellulose-g-poly(ethylene glycol) (EP) was synthesized by esterification of carboxylic acid functionalized methoxy polyethylene glycol (MPEG-COOH) with ethyl cellulose (EC) in order to develop a hydrophilic substrate for thin-film composite (TFC) membrane in a forward osmosis (FO) system. A porous EP substrate, fabricated by a non-solvent induced phase separation method, was found to be more hydrophilic than the EC substrate due to the presence of polyethylene glycol (PEG) side chains in the EP. Since the EP substrate exhibits smaller water contact angles and higher porosity, the structural parameter (S) of TFC-EP is smaller than that of TFC-EC, indicating that internal concentration polarization (ICP) within porous substrates can occur less when TFC-EP is used as a membrane. For example, the water flux value of the TFC-EP is 15.7 LMH, whereas the water flux value of the TFC-EC is only 6.6 LMH. Therefore, we strongly believe that the TFC-EP could be a promising candidate with good FO performances.

• Korean Journal of Environmental Agriculture
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• v.13 no.1
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• pp.60-65
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• 1994

Absorption and translocation of bensulfuron-methyl {methyl 2[[[[[(4,6-dimethoxy-2-pyrimidinyl) amino]carbonyl]amino]sulfonyl]methyl]benzoate} in rice (Oryza sativa L.) as affected by mineral nutrients and mixed herbicides were determined using the $^{14}C-labeled$ herbicide in culture solution. Absorption of $^{14}C-bensulfuron-methyl$ by the root decreased with increasing concentration of bensulfuron-methyl. However, increase in the application concentration did not affect movement of the $^{14}C$ to the shoot. There was no difference in total amount of $^{14}C-bensulfuron-methyl$ taken up between absorption periods of 12 and 48 hours, whereas $^{14}C-bensulfuron-methyl$ translocated to the shoot increased with increasing the absorption period. When bensulfuron-methyl mixtures were applied, butachlor [N-(butoxymethyl)-2-chloro-N-(2',6'-diethylphenyl)acetamide] did not affect absorption and translocation of $^{14}C-bensulfuron-methyl$. However, quinclorac (3,7-dichloro-8-quinoline carboxylic acid) mixed at a high concentration resulted in decrease in absorption and translocation of $^{14}C-bensulfuron-methyl$. Nutritional disorder such as deficient or excess supply of mineral nutrients caused to inhibit absorption of $^{14}C-bensulfuron-methyl$. The greatest decrease and delay of $^{14}C-bensulfuron-methyl$ absorption and/or translocation occurred in N-deficient and S-excess supply conditions.