• Korean Journal of Microbiology
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• v.38 no.4
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• pp.245-245
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• 2002

Catabolic pathways for the degradation of various aromatics by Sphingomonas yanoikuyae Bl are intertwined, joining at the level of substituted benzoates, which are further degraded vita ring cleavage reactions. The mutant strain EK497, which was constructed by deleting a large DNA region containing most of the genes for biphenyl, naphthalene, m-xylene, and m-toluate degradation, was unable to grow on all of the aromatics tested except for benzoate as the sole source of carbon and energy.S. yanoikuyae EK497 was found to possess only catechol ortho-ring cleavage activity due to deletion of the genes for the meta-cleavage pathway. Wild-type S. yanoikuyae Bl grown on benzoate has both catechol orthoand meta-cleavage activity. However, m-xylene and m-toluate, which are metabolized through methylbenzoate, and biphenyl, which is metabolized through benzoate, induce only the meta-cleavage pathway, suggesting the presence of a substrate-dependent induction mechanism.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.481-485
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• 1993

Dialkyl 1-bromobenzene-2,6-diacetates were easily prepared by the carbonylation of the moiety of benzylic bromide in 1-bromo-2,6-bis(bromomethyl)benzene with alcohol in the presence of NaOAc< TEX>${\cdot}$3H$_2$O and a catalytic amount of Co$_2$(CO)$_8$under the atmospheric pressure of carbon monoxide at room temperature in excellent yield. Alkyl 2,6-bis(alkoxymethyl)benzoates were obtained by the carbonylation of the moiety of aryl bromide in 1-bromo-2,6-bis(alkoxymethyl)-benzene, which derived from 1-bromo-2,6-bis(bromomethyl)benzene, alcohol, NaOR, and CH$_3$I under the same conditions. Alkyl 2,6-bis(carboxymethyl)benzoate was also obtained in a trace amount for 24 hrs at room temperature.

• Bulletin of the Korean Chemical Society
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• v.16 no.12
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• pp.1203-1208
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• 1995

Theoretical studies of the effect of the nonleaving group (RY) on the breakdown mechanism of the tetrahedral anionic intermediate, T-, formed by the addition of a less basic phenoxide nucleophile (X) to phenyl benzoates with a more basic phenoxide leaving group (Z) have been carried out using the PM3 MO method. The identity acyl transfer reactions (X=Z) are facilitated by an electron-withdrawing RY whereas they are inhibited by an electron-donating RY group. The results of non-identity acyl transfer reactions indicate that a more electron-donating RY group leads to a greater lowering of the higher barrier, TS2, with a greater degree of bond cleavage, and a greater negative charge development on the phenoxide oxygen atom, whereas the opposite is true for a more electron-withdrawing RY group, i.e., leads to a greater lowering of the lower barrier, TS1. The results provide theoretical basis for the signs of ρXY(>0) and ρYZ(<0) observations.

• Archives of Pharmacal Research
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• v.28 no.1
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• pp.49-54
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• 2005

The chromatographic separation of the hexane soluble fraction of the methanol extract of the aerial parts of Solidago virga-aurea var. gigantea Mo. (Compositae) led to the isolation of a new benzylbenzoate (1) together with four known benzylbenzoates (2-5). Their structures were determined as 2-methoxybenzyl-2-hydroxybenzoate (1), benzyl-2-hydroxy-6-methoxy­benzoate (2), 2-methoxybenzyl-2,6-dimethoxybenzoate (3), 2-methoxybenzyl-2-methoxy-6­hydroxybenzoate (4), and benzyl-2,6-dimethoxybenzoate (5). Their structures were established by spectroscopic methods. Biological effects of compounds, 1 and 2, were investigated in vitro usingherapeutic agents by stimulating macrophage functions, with potential use in the treat­ mouse peritoneal macrophages. The benzylbenzoates (1 and 2) could serve as immunotherapeutic agents by stimulating macrophage functions, with potential use in the treatment of infectious diseases.

• Archives of Pharmacal Research
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• v.15 no.1
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• pp.48-51
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• 1992

Achromobacter xylosoxidans KF701 and Pseudomonas putida (NAH7) were significantly different in degradative capability of aromatic compounds including benzoates, biphenyls, and naphthalene. However, both of the bacterial strains can grown on catechol as the sole carbon and energy source. Catechol 2, 3-dioxygenase gene for naphthalene oxidation or biphenyl oxidation was cloned into Escherichia coli HB 701. A E. coli HB 101 clone containing catechol 2, 3-dioxygenase gene from P. putida (NAH7) contains a recombinant plasmid with 3.60kb pBR322 and 6-kb insert DNA. Another E. coli HB101 clone containing catechol 2, 3-dioxygenase gene from A. xylosoxidans KF 701 has a recombinant plasmid with 4.4kb pBR322 and 10-kb insert DNA. Physical maps of the recombinant plasmids were constructed, and catechol 2, 3-dioxygenase gene in the recombinant plasmide was further localized and subcloned int M13. The cloned-catechol 2, 3-dioxygenase game products were identified as yellow bands on nondenaturaing polyacrylamide gel after electrophoresis followed by activity staining with catechol solution.

• BMB Reports
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• v.29 no.5
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• pp.462-467
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• 1996

Acetolactate synthase (ALS, EC 4.1.3.18) is the first common enzyme in the biosynthesis of leucine, isoleucine, and valine. It is the target enzyme for several classes of herbicides, including the sulfonylureas, the imidazolinones, the mazolopyrimidines, the pyrimidyl-oxy-benzoates, the pyrimidyl-thio-benzens, and the 4,6-dimethoxypyrimidines. An amino-terminal fragment of the sulfonylurea-resistant ALS gene (SurB) from Nicotiana tabaccum was cloned into the bacterial expression vector pGEX-2T. The resulting recombinant plasmid pGEX-ALS1 was used to transform Escherichia coli strain BL21, and the tobacco ALS was expressed in the bacteria as a protein fused with glutathione S-transferase (GST). Polyclonal antibodies against the fusion product (GST-ALS) were produced, and the sensitivity of GST-ALS with the rabbit anti-GST-ALS IgG was up to 50 ng. This antibody was used for Western blot analysis of the partially purified ALS from barley shoots. The results suggest that the polyclonal antibody produced in this study can be used to detect plant ALS.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.1939-1944
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• 2007

New liquid crystalline (biphenylcarbonyloxy)benzoates with an achiral swallow-tail derived from 3-alkoxy-2- (alkoxymethyl)-1-propanol [(ROCH2)2CHCH2OH, R = Me, Et, Pr, Bu] were prepared. These liquid crystals exhibited the phase sequence (I-SmA-SmCalt-(SmCX)-Cr) and showed antiferroelectric-like Smectic C phase (SmCalt) at temperature lower, and temperature range broader than do the compounds containing a branched alkyl group as a swallow-tail. The temperature ranges of antiferroelectric phase were found to be 30-90 oC and crystallization temperatures were 4-60 oC. The binary mixture of an achiral swallow-tailed liquid crystal and a chiral antiferroelectric liquid crystal, (S)-MHPOBC showed antiferroelectric smectic C phase at temperature much lower than the single chiral antiferroelectric liquid crystal does.

• Journal of Microbiology
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• v.38 no.4
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• pp.245-249
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• 2000

Catabolic pathways for the degradation of various aromatics by Sphingomonas yanoikuyae Bl are intertwined, joining at the level of substituted benzoates, which are further degraded vita ring cleavage reactions. The mutant strain EK497, which was constructed by deleting a large DNA region containing most of the genes for biphenyl, naphthalene, m-xylene, and m-toluate degradation, was unable to grow on all of the aromatics tested except for benzoate as the sole source of carbon and energy.S. yanoikuyae EK497 was found to possess only catechol ortho-ring cleavage activity due to deletion of the genes for the meta-cleavage pathway. Wild-type S. yanoikuyae Bl grown on benzoate has both catechol orthoand meta-cleavage activity. However, m-xylene and m-toluate, which are metabolized through methylbenzoate, and biphenyl, which is metabolized through benzoate, induce only the meta-cleavage pathway, suggesting the presence of a substrate-dependent induction mechanism.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2955-2959
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• 2011

Second-order rate constants for nucleophilic substitution reactions of 2,4-dinitrophenyl benzenesulfonate 1a with a series of alicyclic secondary amines in MeCN have been measured spectrophotometrically and compared with those reported previously for the corresponding reactions performed in aqueous medium to investigate the effect of medium on reactivity and reaction mechanism. The amines employed in this study are found to be more reactive in the aprotic solvent than in $H_2O$. The reactions of 1a in MeCN result in a linear Br${\o}$nsted-type plot with ${\beta}_{nuc}$ = 0.58, which contrasts to the curved Br${\o}$nsted-type plot reported previously for the corresponding reactions performed in the aqueous medium (i.e., ${\beta}_2$ = 0.86 and ${\beta}_1$ = 0.38). Accordingly, it has been concluded that the reaction mechanism changes from a stepwise mechanism to a concerted pathway upon changing the medium from $H_2O$ to MeCN. Reactions of Y-substituted phenyl benzenesulfonates 1a-c with piperidine in MeCN result in a linear Br${\o}$nsted-type plot with ${\beta}_{lg}$ = -1.31, indicating that expulsion of the leaving group is significantly more advanced than bond formation in the transition state. The trigonal bipyramidal intermediate ($TBPy^{\pm}$) proposed previously for the reactions in $H_2O$ would be highly unstable in MeCN due to strong repulsion between the negative charge in $TBPy^{\pm}$ and the negative dipole end of MeCN. Thus, destabilization of $TBPy^{\pm}$ in MeCN has been concluded to change the reaction mechanism from a stepwise mechanism to a concerted pathway.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.303-308
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• 2010

Pseudo-first-order rate constants ($k_{obsd}$) have been measured spectrophotometrically for nucleophilic substitution reactions of 4-nitrophenyl benzoate (5a), 4-nitrophenyl 4-methoxybenzoate (5b), and 4-nitrophenyl 4-hydroxybenzoate (5c) with alkali metal ethoxides, $EtO^-M^+$ ($M^+=Li^+$, $Na^+$ and $K^+$) in anhydrous ethanol (EtOH) at $25.0{\pm}0.1^{\circ}C$. The plots of $k_{obsd}$ vs. [$EtO^-M^+$] exhibit upward curvatures in all cases, indicating that $M^+$ ions catalyze the reactions and ionpaired $EtO^-M^+$ species are more reactive than dissociated $EtO^-$. Second-order rate constants for reactions with dissociated $EtO^-$ and ion-paired $EtO^-M^+$ (i.e., $k_{EtO^-}$ and $k_{EtO^-M^+}$, respectively) have been calculated from ion-pair treatment for the reactions of 5a and 5b. However, such ion-pair treatment has failed to determine $k_{EtO^-}$ and $k_{EtO^-M^+}$ values for the reactions of 5c. It has been concluded that reactions of 5a and 5b are catalyzed by one metal ion, which increases electrophilicity of the reaction center through coordination on the carbonyl oxygen. In contrast, reactions of 5c have been suggested to involve two metal ions, i.e., the one coordinated on the carbonyl oxygen increases the electrophilicity of the reaction center while the other one associated on the phenoxy oxygen decreases the charge repulsion between the anionic reagents (i.e., $EtO^-$ and deprotonated 5c). It has been found that the rate equation derived from the mechanism involving two metal ions fits nicely to the kinetic results obtained for the reactions of 5c.