• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.96-100
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• 1998

Pseudomonas sp. S-47 degraded 4-chlorobenzoate (4CBA) to 4-chlorocatechol (4CC) that was subsequently ring-cleaved to form 5-chloro-2-hydroxymuconic semialdehyde. These intermediate compounds were identified by GC-mass spectrometry and UV-visible spectrophotometry. 5-chloro-2-hydroxymuconic acid converted from 5-chloro-2- hydroxymuconic semialdehyde (5C-2HMS) was dechlorinated to produce 2-hydroxypenta-2,4-dienoic acid (2HP-2,4DA) by the strain. These results indicate that Pseudomonas sp. S-47 degrades 4CBA to 2HP-2,4DA via a novel pathway including the meta-cleavage of 4CC and dechlorination of 5C-2HMS.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.8-14
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• 2002

Pseudomonas sp. S-47 is capable of degrading 4-chlorobenzoate to produce 5-chloro-2-hydroxymuconic semialdehyde (5C-2HMS) by the enzymes encoding by xylXYZLTE cluster. In this study, the resulting 5C-2HMS was confirmed to be transformed to 5-chloro-2-hydroxymuconic acid (5C-2HMA) by 5C-2HMS dehydrogenase. The xylG gene encoding 5C-2HMS dehydrogenase was cloned from the chromosomal DNA of strain S-47. The nucleotide sequence of xylG showed to be composed of 1,600 base pairs with ATG initiation and TGA termination codons. A deduced amino acid sequence of the 5C-2HMS dehydrogenase (XylG) exhibited 98％, 93％, and 89％ identity with those of the dehydrogenases from P. putida mt-2, P. putida G7, and Pseudomonas sp. CF600, respectively.

• Applied Biological Chemistry
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• v.35 no.5
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• pp.382-388
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• 1992

Mycelial growth inhibition activity of forty-one N-substituted phenyl 5-chloro-1,3-dimethylpyrazole-4-carboxamides against Rhizoctonia solani was analysed quantitatively by multiple regression analysis using physicochemical parameters of substituents as independent variables and $pEC_{50}$ as dependent variable. As a result, a quantitative structure-activity relationship was formulated using eight physicochemical parameters, which explains 83% of variance of the fungicidal activity. The most important parameter for the biological activity was log k', as related to the penetration and transport processes in the biological system. The activity also correlated with other hydrophobic parameters$({\pi}_2,\;{\pi}_3)$, an electronic parameter$({\Sigma}{\sigma})$, and steric parameters$(STERIMOL\;parameters\;L_3,\;L_4)$.

• The Korean Journal of Pesticide Science
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• v.8 no.2
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• pp.129-136
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• 2004

In order to determine the amounts of impurities and to identify the chemical structures of the impurities in the technical product of the plant growth regulator Atonic, the extracts of diethyl ether and dichloromethane were analyzed with GC-FID and GC-MSD. resulting in detection of five impurities and identification of their chemical structures. The amount of the active ingredient atonic in the technical product was about 84% and those of the impurities ranged from 0.24 to 10.74%. The identified impurities in this technical product are 2-methoxyphenol (guaiacol, m/z 124), 2-chloro-6-methoxyphenol and/or 4-chloro-6-methoxyphenol (m/z 158), 1,2-dimethoxy-4-nitrobenzene (m/z 183), and 2,6-bis(1,1-dimethylethyl)-4-methylphenol (m/z 220), suggesting that they are not hazardous impurities.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.1047-1051
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• 2012

The nucleophilic substitution reactions of (2R,4R,5S)-(+)-2-chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 2-sulfide with X-pyridines are investigated kinetically in acetonitrile at $5.0^{\circ}C$. The free energy relationships for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a break point at X = 3-Ac. Unusual positive $\rho_X$ (= +4.73) and negative ${\beta}_X$ (= -0.75) values are obtained with the weakly basic pyridines, and rationalized by the isokinetic relationship with isokinetic temperature at $t_{ISOKINETIC}=39.3^{\circ}C$. A concerted mechanism involving a change of nucleophilic attacking direction from a frontside attack with the strongly basic pyridines to a backside attack with the weakly basic pyridines is proposed on the basis of greater magnitudes of selectivity parameters ($\rho_X$ = -6.15 and ${\beta}_X$ = 1.11) with the strongly basic pyridines compared to those ($\rho_X$ = 4.73 and ${\beta}_X$ = -0.75) with the weakly basic pyridines.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.265-268
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• 1992

Ruthenium(III) unsymmetrical Schiff base complexes, $[Ru(CHBPH-TP)Cl_2]$ and $K[Ru(CHBPH-HB)Cl_2]$ were synthesized, where CHBPH-TP and CHBPH-HB are 5-chloro-2-hydroxybenzophenonethiophencarba aldehydephenylenediimine and 5-chloro-2-hydroxybenzophenonehydroxybenzophe nonephenylenediimine. These Schiff bases were obtained from the reactions of 5-chloro-2-hydroxybenzophenone (CHB) and 2-thiophenecarbaldehyde (TP) or hyroxybenzophenone (HB) and 1,2-diaminobenzene. Elemental analysis, conductivity and infrared studies of the complexes suggest an octahedral geometry around ruthenium. Magnetic moments of the complexes indicate a single unpaired electron in alow spin $d^5$ configuration. The complexes are capable of catalyzing the oxidation of styrene with sodium hypochlorite in the presence of phase transfer agent. Oxidative cleavage of C=C bond is the major reaction pathway to form benzaldehyde for styrene oxidation.

• Analytical Science and Technology
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• v.29 no.1
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• pp.29-34
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• 2016

This study explores the means by which MX can be effectively extracted from chlorinated water 3-Chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a potent mutagen commonly found in chlorinated drinking water at concentrations of up to a few hundred ng/L, was quantitatively determined using sample enrichment followed by liquid-liquid extraction (LLE), derivatization to methylated form, and analysis with GC-MS. A 4-L water sample was enriched to a concentration of 0.4 L using a vacuum rotary evaporator at 30 ℃. MX in the water was extracted using ethyl acetate (100 mL × 2) as a solvent and MX in the extract was methylated with 10 % H₂SO₄ in methanol. MX was recovered at a rate of 73.8 %, which was higher than that (38.1 %) for the resin adsorption method. The limit of quantification and repeatability (as relative standard deviation) were estimated to be 10 ng/L and 2.2 %, respectively. This result suggested that LLE can be used for the determination of MX in chlorinated water as an alternative to more time-consuming resin adsorption method.

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.183-190
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• 2010

To search the new potent herbicidal agents by receptor-based approach, the interactions between receptor and substrate molecules from molecular docking to acetyl-CoA carboxylase(PDB code: 3K8X) of 2-(4-(6-chloro-2-benzoxazolyl)oxy)phenoxy-N-phenylpropionamide analogues (1-38) as substrate molecules were performed and discussed quantitatively. The most of the substrate molecules were formated 2 H-bonds between carbonyl oxygen atom of the substrate molecules and the amino acid residues (Ala1627 and Ile1735) in binding site of acetyl-CoA carboxylase (ACCase). But, the substrate molecules such as $R_l$=Acetyl substituents (6 & P9) were formated 3 H-bonds between H-bond acceptors in the substrate molecules and the H-bond donors in three amino acid residues including the rest residue (Gly 1998). Therefore, the inhibitory activity factors of the substrate molecules against ACCase are due to the H-bonding characters that will be able to apply to the optimization of herbicidal agents.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.21-28
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• 2000

A new fourty six 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-phenylpro- pionamide derivatives were synthesized and the herbicidal activities against rice plant and barnyard grass with pre-emergence in down land were measured. The structure activity relationships (SAR) between the activities and physicochemical parameters of the substituted(X) N-phenyl group in substrates were analyzed and discussed by Free- Wilson and Hansch method from the basis on the former study (Sung. et. al., 1999). The conditions of selective herbicide activity both the barnyard grass and rice plant are shown that the optimal hydrophobicity, $({\pi})_{opt.}=1.34$ and electron donating with field effect (F<0) of meta and ortho, para-substituted mono or disubstituent on the N-phenyl ring were found to contribute significantly. The herbicidal activities against barnyard grass are roughly the same as the results in up land whereas damage to rice plant in down land more increase than that of up land. Degradation products in water are 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)propionic acid ((A)) (obs. pKa=4.35 & obs. logP=4.77) and 6-chloro-2-benzoxazolone (B) (obs. pKa=8.40 & obs. logP=2.90). These results were supposing that the hydrolysis product of substrates, (A) is comparatively absorbed in rice plant but not in barnyard grass. And it is assumed from the SAR equations that the 2,6-dimethyl-4-methoxymethyl group substituent ($pI_{50}=5.41$, 3g/ha) is selected as the most highest herbicidal activity against barnyard grass in green house.

• YAKHAK HOEJI
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• v.50 no.1
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• pp.52-57
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• 2006

The activation of cyclin dependent kinase 4 (CDK4) is found in more than half of all human cancers. Therefore CDK4 is an attractive target for the development of a novel anticancer agent. For mass screening of CDK4 inhibitor, we set up in vitro kinase assay for CDK4 activity using a cyclin D1-CDK4 fusion protein, which is constitutively active and exhibits enhanced stability. From the screening of representative compound library of Korea Chemical Bank, we found that 7-chloro-4-nitro-benzo[1,2,5]oxadiazole 1-oxide (FBP-1248) selectively inhibited CDK4 activity in vitro by ATP competitive manner. This compound prevented the phosphorylation of retinoblatsoma tumor suppressor protein, Rb, and inhibited cell growth through cell cycle arrest. In summary, we developed an efficient assay system for CDK4 activity in vitro and identified the CDK4 inhibitory compound, FBP-1248.