• Journal of Microbiology
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• v.38 no.3
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• pp.122-131
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• 2000

Phylogenetic classification of the Aphyllophorales was conducted based on the analysis of nuclear small subunit ribosomal RNA (nuc SSU rDNA) sequence. Based on phylogenetic groupings and taxonomic characters, 16 families were recognized and discussed. Although many of the characters had more or less homoplasies, miroscopic characters such ad the mitic system and clamp, spore amyloidity and rot type appeared to be important in the classification of the Aphyllophorales. Phylogenetically significant families were newly defined to improve the classification of the order Aphyllophorales.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1547-1550
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• 2012

Second-order rate constants ($k_N$) have been measured spectrophotometrically for the reactions of benzyl 2-pyridyl carbonate $\mathbf{3}$ and $t$-butyl 2-pyridyl carbonate $\mathbf{3}$ with a series of alicyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. Substrate $\mathbf{4}$ is much less reactive than $\mathbf{3}$ and the steric hindrance exerted by the bulky $t$-Bu group in $\mathbf{4}$ has been attributed to its decreased reactivity. The Br${\o}$nsted-type plots for the reactions of $\mathbf{3}$ and $\mathbf{4}$ are linear with ${\beta}_{nuc}=0.57$ and 0.45, respectively. Thus, the reactions have been concluded to proceed through a concerted mechanism, although the current reactions were expected to proceed through a stepwise mechanism with a zwitterionic tetrahedral intermediate $T^{\pm}$. It has been proposed that the rate of leaving-group expulsion is accelerated by the intramolecular H-bonding interaction in $T^{\pm}$ and the "push" provided by the RO group through the resonance interaction. Thus, the enhanced nucleofugality forces the reactions to proceed through a concerted mechanism. The reactivity-selectivity principle (RSP) is not applicable to the current reaction systems, since the reaction of the less reactive $\mathbf{4}$ results in a smaller ${\beta}_{nuc}$ than that of the more reactive $\mathbf{3}$. Steric hindrance exerted by the bulky $t$-Bu group in $\mathbf{4}$ has been suggested to be responsible for the failure of the RSP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.130-136
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• 1997

Total parenteral nutritional effect was induced by surgical creation of Thiry-Vella fistula(TVFs) in rats. Glutamine, glycine or nucleosides/nucleotide mixture in solution was injected into the loops for 2, 4, 6, 8 days. Control animals received a 0.9％ saline solution. Results include weight gain, total protein, DNA, ［$^3$H］ thymidine incorporation into DNA, morphometry of the intestine in both TVFs and intestine in continuity. Perfusion of nucleosides/nucleotide mixture into the bypassed loops caused an increase in total protein, DNA content, villous height, villous surface area in loops. The injection of glycine into loops caused an increase in ［$^3$H］ thymidine incorporation but the mean values of the protein and DNA contents were not significantly different from those in group Cont and group Nuc. Overall values for group Gln were slightly higher than those of the control but the differences were not statistically significant. This study suggests that this animal model may be useful for studying the effect of dietary factors on intestinal growth and maturation, separating the direct effect of diet from systemic effect on the intestine.

• The Korea Journal of Herbology
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• v.26 no.1
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• pp.111-117
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• 2011

Objectives : The present study was designed to investigate effects of mixed extract from korean medicinal herbs (MIX) on oxidation/reduction reaction-related and aging-related enzyme in vitro. Methods : We performed MTT assay, collagenase inhibition assay, elastase inhibition assay, tyrosinase inhibition assay, DPPH free radical scavenging assay, SOD-like activity and xanthine oxidase inhibition assay. Results : Recently, many studies have reported that elastin is also involved in inhibiting or repairing wrinkle formation, although collagen is a major factor in the skin wrinkle formation. The MIX showed 97% inhibition of collagenase activity, and 64% inhibition of elastase activity at 1 mg/ml concentration of MIX, next only to positive control, which indicate good efficacy for anti-wrinkle ingredient. Also it's treatment showed 34% inhibition of tyrosinase activity, to relate whitening effect, at the same dose of MIX. Antioxidant activities were determined by DPPH radical scavenging, xanthine oxidase (XO) inhibiting activity and SOD-like activity. Also these scavenging, XO-inhibiting and SOD-like activities were measured in 91%, 80%, and 63% inhibition, respectively, at a treated dose of 1 mg/ml, compare to control. Conclusions : These results suggest that possibility of mixed korean medicinal herbs as a functional ingredient for anti-wrinkle and whitening, anti-oxidation and anti-aging cosmetic formula.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2403-2407
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• 2009

Second-order rate constants have been measured for two series of nucleophilic displacement reactions, i.e., reactions of 4-nitrophenyl benzoate with Z-substituted phenoxides and those of Y-substituted phenyl benzoates (1a-h) with 4-chlorophenoxide (4-ClPhO–) in 80 mol% $H_2O$/20 mol% DMSO at 25.0 ${\pm}\;0.1\;{^{\circ}C}$. The Br$\phi$nsted-type plot for reactions of 4-nitrophenyl benzoate with Z-substituted phenoxides exhibits an excellent linear correlation with ${\beta}_{nuc}$ = 0.72. Reactions of 1a-h with 4-chlorophenoxide result in also a linear Br$\phi$nsted-type plot with ${\beta}_{lg}$ = –0.62, a typical ${\beta}_{lg}$ value for a concerted mechanism. The Hammett plots correlated with ${\sigma}^o\;and\;{\sigma}^-$ constants show many scattered points for reactions of 1a-h with 4-chlorophenoxide. In contrast, the corresponding Yukawa-Tsuno plot exhibits an excellent linear correlation with $\rho_Y$ = 2.26 and r = 0.53, indicating that expulsion of the leaving group occurs at the rate-determining step (RDS) either in a concerted mechanism or in a stepwise pathway. However, a stepwise mechanism with leaving group departure being the RDS is excluded since the leaving Y-substituted phenoxide is less basic and a better nucleofuge than the incoming 4-ClPh$O^-$. Thus, the reactions have been concluded to proceed through a concerted mechanism, in which bond formation between the nucleophile and electrophilic center is more advanced than expulsion of the leaving group in the transition state on the basis of the magnitude of ${\beta}_{nuc}\;and\;{\beta}_{lg}$ values.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.93-97
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• 2014

A kinetic study is reported on nucleophilic substitution reactions of 4-nitrophenyl X-substituted-2-methylbenzoates (5a-e) with a series of cyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. The Hammett plots for the aminolysis of 5a-e are nonlinear, e.g., substrates possessing an electron-donating group (EDG) in the benzoyl moiety deviate negatively from the linear line composed of substrates bearing no EDG. In contrast, the Yukawa-Tsuno plots for the same reactions exhibit excellent linear correlations with ${\rho}_X$ = 0.30-0.59 and r = 0.90-1.15, indicating that the nonlinear Hammett plots are caused by stabilization of the substrates possessing an EDG through resonance interactions but are not due to a change in the rate-determining step (RDS). The Br${\phi}$nsted-type plots are linear with ${\beta}_{nuc}$ = 0.66-0.82. Thus, the aminolysis of 5a-e has been suggested to proceed through a stepwise mechanism in which departure of the leaving group occurs at the RDS. The ${\rho}_X$ and ${\beta}_{nuc}$ values for the aminolysis of 5a-e increase as the reactivity of the substrates and amines increases, indicating that the reactivity-selectivity principle is not applicable to the current reactions.

• Journal of Preventive Medicine and Public Health
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• v.45 no.4
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• pp.235-243
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• 2012

Objectives: Nail has been a substitute DNA source for genotyping. To investigate the integrity and consistency of nail DNA amplification for biomarker study, nail clippings from 12 subjects were collected at monthly intervals. The possibility of longer amplification and existence of GAPDH RNA/protein, were also investigated with three nail samples. Methods: Three primer sets were designed for quantitative amplification of nuclear and mitochondrial genes and analysis of their consistency. The mean threshold cycles in amplification of the target genes were compared to test the consistency of polymerase chain reaction (PCR) performance among individual factors including age groups, sex, family, the nail source, and by the size of the amplification segments. Results: The amplification of the target genes from nail DNA showed similar integrity and consistency between the nail sources, and among the serial collections. However, nail DNA from those in their forties showed earlier threshold cycles in amplification than those in their teens or seventies. Mitochondrial DNA (mtDNA) showed better DNA integrity and consistency in amplification of all three targets than did nuclear DNA (nucDNA). Over 9 kb of mtDNA was successfully amplified, and nested quantitative PCR showed reliable copy numbers (%) between the two loci. Reverse transcription PCR for mRNA and immunoblotting for GAPDH protein successfully reflected their corresponding amounts. Regarding the existence of RNA and protein in nails, more effective extraction and detection methods need to be set up to validate the feasibility in biomarker study. Conclusions: Nail DNA might be a feasible intra-individual monitoring biomarker. Considering integrity and consistency in target amplification, mtDNA would be a better target for biomarker research than nucDNA.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.24-37
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• 2005

This study was conducted to analyze the molecular epidemiological properties and to select the most efficient and reliable PCR method on 116 of Staphylococcus aureus (S. aureus) isolates from Korean cattle, black goat, pig, dog, chicken, mouse and also human clinical cases from hospital. The distribution patterns of SSG [species specific genes; coagulase (coa), protein A (spa), nuclease (nuc) and aroA (RsaI) gene] were analyzed by PCR method. Among the SSGs, the nuc-gene was found in all strains $(100\%)$ tested and followed by coa-gene $(87.9\%)$, spa-gene $(91.4\%)$ and aroA-gene $(26.7\%)$, in order. The genetic subtyping by RFLP method was performed on the coa [AluI] and aroA-gene [RsaI] PCR products. The mecA-gene PCR and PCR-RFLP techniques were chosen to detect and verify of MRSA strains. Only the human strains $(12.1\%)$ were detected the positive mecA-gene products (533 bp), which were divided into two specific bands [201 & 332 bp] by HhaI enzyme digestion. On coa-gene and spa-gene typing, coa-gene was typed with ten kinds of genotype and coa-3 type were determined as the most predominant genotype, while spa-gene was divided into eleven kinds of genotype and also spa-7 type were selected the most prevalent genotype based on their genetic variations. On the aroA and coa-gene subtyping by PCR-RFLP, aroA-gene products were discriminated with only seven types of genotype, while coa-gene products were further divided into an eleven genotype, respectively. In comparison of SID values of five PCR based typing methods, the coa-PCR-RFLP (SID0.894) was evaluated the most efficient and reliable tools and followed by coa-PCR (SID0.883) and aroA-PCR-RFLP (SID0.462), in order. In conclusion, we could determined that the coa-PCR-RFLP method was the most suitable genetic analysis tool for S. aureus and MRSA strains from domestic animals and humans.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1539-1542
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• 2011

The aminolysis of O-methyl S-aryl thiocarbonates with benzylamines are studied in acetonitrile at -45.0$^{\circ}C$. The ${\beta}_X$(${\beta}_{nuc}$) values are in the range 0.62-0.80 with a negative cross-interaction constant, ${\rho}_{XZ}$ = -0.42, which are interpreted to indicate a concerted mechanism. The kinetic isotope effects involving deuterated benzylamine nucleophiles ($XC_6H_4CH_2ND_2$) are large, $k_H/k_D$ = 1.29-1.75, suggesting that the N-H(D) bond is partially broken in the transition state by forming a hydrogen-bonded four-center cyclic structure. The concerted mechanism is enforced by the strong push provided by the MeO group which enhances the nucleofugalities of both benzylamine and arenethiolate from the putative zwitterionic tetrahedral intermediate.

• Journal of Sensor Science and Technology
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• v.18 no.1
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• pp.72-76
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• 2009

The sensing system was designed and fabricated to investigate the ferment environment of soybeans. $NH_3$ gas was saturated after about 7 h and $CO_2$ gas was reached the peak after about 8 h in the inoculation of Bacillus subtilis. However, times that $CO_2$ gas and $NH_3$ gas were reached maximum value without Bacillus subtilis were about 15 h and 18 h, respectively. The sample that inoculated Bacillus subtils had deeper taste than one without it. We found that the peak time of $CO_2$ gas means the starting time of fermentation. If we control the operating time after the start of fermentation, it is expected to make a suitable Chungkukjang to individual preference.