• Journal of the Korean Chemical Society
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• v.45 no.1
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• pp.7-13
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• 2001

The interaction of benzenesulfonate anion and its derivatives ($C_6H_5SO_3^-, p-$CH_3C_6H_4SO_3^-, and $p-C_2H_5C_6H_4SO_3^-$) with the micellar system of cationic surfactant TTAB(tetradecyltrimethylammonium bromide) was studied by UV/Vis spectrophotometric method. The solubilization constants($K_s$) of benzenesulfonate anions into the micellar phase of this surfactant have been measured with the change of temperature. The effects of additives(n-pentanol and NaBr) on the solubilization of benzenesulfonate anions by this surfactant system have been also measured. There was a great decrease on the values of $K_s$ and CMC simultaneously with these additives so that the measured values of ln$K_s$ were linear relationships with the values of lnCMC. For the thermodynamic study, various thermodynamic parameters(${\Delta}G^0_s$, ${\Delta}H^0_s$ and ${\Delta}S^0_s$) have been calculated and analyzed from the dependence of Ks values on temperature.

• Food Science and Preservation
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• v.6 no.2
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• pp.216-220
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• 1999

Lipoxygenase(LOX) activity of black rice(Chindo) was measured by spectrophotometric method at In m. Studies at different pH levels revealed that the optimal activity was exhibited at pH 7.0 with 24.97 unit/mg. Enzyme activity was tested at different concentration of the substrate. The apparent Vmax and Km values were determined from the Lineweaver-Burk plot to be 53.85 unit/mg and 0.21 mM. Enzyme activity due to storage temperature (-40, 4 and 25$^{\circ}C$) and period were decreased at all storage temperature. LOX activity of black rice was significantly decreased during the microwave heating.

• Journal of the Korean Chemical Society
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• v.43 no.1
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• pp.85-91
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• 1999

The second order rate constants for the hydrolysis of substituted phenyl N,N-diethyl-P-benzylphosphonamidates (2,4-$(NO_2)_2$, 4-$NO_2$, 4-CN, 4-Cl, 4-H)in 20% dioxane-water (v/v) have been determined by UV/Vis spectrophotometric method at various temperatures. The activation parameters (Ea, ${\Delta}H^{\neq}$,${\Delta}S^{\neq}$) were calculated from the rate constants and the reaction constant ($\rho$) was also estimated by Hammett equation. The activation entropies of the title reactions show considerably negative values, this result is not consistent with a dissociative mechanism (EA) in which a positive or a slightly negative value of the entropy of activation should be expected. Further, kinetic evidence for an associative mechanism (AE) was obtained from the linear free energy relationship. By the results of kinetic study for the alkaline hydrolysis of substituted phenyl N,N-diethyl-P-benzylphosphonamidates, it may be concluded that these reactions proceed through an associative mechanism.

• Journal of the Korean Chemical Society
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• v.44 no.3
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• pp.177-183
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• 2000

The interaction of phenoxide anion with .the mixed micelles of CTAB(Cetyl-trimethylammonium bromide) and TTAB(Tetradecyltrimethylammonium bromide) was studied by UV/Vis spectrophotometric method. The solubilization constants($K_s$) of phenoxide anion into the mixed micellar phase and the critical micellar concentrations(CMC) of those mixed surfactant systems have been measured and analyzed with the change of overall mole fraction of CTAB($\alpha_{CTAB}$) The effects of additives(n-pentanol and NaBr) on the solubilization of phenoxide anion by those mixed surfactant systems have been also measured. There was a great decrease on the values of solubilization constant and CMC with these additives. For the thermodynamic study, the dependence of $K_s$ values on temperature has been measured and various thermodynamic parameters(${\Delta}G^0_s$, ${\Delta}H^0_s$ and ${\Delta}S^0_s$) have been also calculated. The results show that all the values of ${\Delta}G^0_s$ and ${\Delta}H^0_s$ are negative within the measured temperature region but the values of ${\Delta}S^0_s$ are positive.

• Analytical Science and Technology
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• v.10 no.4
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• pp.231-239
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• 1997

We developed a procedure that can effectively separate and determine tertiary amines and quaternary ammonium salts in some samples with reverse phase ion-pair high performance chromatography, employing indirect spectrophotometric detection method. Detection and ion-pairing reagents used in this study were benzyl trimethylammonium chloride (BTMACl) and sodium dodecyl sulfate(DDSANa), respectively. Eluting the electrolyte solutions of some commercial electrolytic capacitors with a MeOH(40):water(60) eluent (pH 8.5 adjusted with NH4Cl-NH3 buffer) containing 0.010M DDSANa and 0.004 M BTMACl through Supelco LC-18 or ${\mu}$-Bondapak phenyl column, amines and ammonium salts contained in the sample were successfully separated and determined. Varying the composition, especially the content of quaternary ammonium salts, of electrolyte solutions based on this analysis. we could prepare the low impedance(0.08~0.13) electrolytic capacitors with excellent electrical properties and it was a confirmation that the analysis is favorable.

• Journal of Community Nutrition
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• v.7 no.1
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• pp.49-57
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• 2005

Nutrition factors play an important role in the pathogenesis of osteoporosis. The purpose of this study is to investigate the relationship between nutritional status and bone mineral density of elderly women. Three hundred thirty five elderly women (over 65 years) in Asan were divided into three age groups (group 1, less than 70 y ; group 2, from 70 to 75 y ; group 3, 75 y or more). Total alkaline phosphatase and serum calcium (Ca) were analyzed using spectrophotometric procedure. Data for food and nutrient intakes were obtained by a 24-hour recall method. Bone density was measured by broadband ultrasound attenuation (BUA) using QUS-2. Age differences were tested with the X 2 test for categorical variables and with ANOVA and Tukey's test for continuous variables. Correlation was conducted to test the association between bone density and nutrient intake. The subjects in age groups 1,2 and 3 were $36.7\%$, $32.8\%$ and $30.4\%$, respectively. Height and body weight of the subjects were significantly decreased with age. Average bone density of the subjects in group 3 was lower than the other age groups. Osteoporosis determined by t-score is $17.9\%$ for group 1, $24.5\%$ for group 2 and $55.9\%$ for group 3 (p < 0.001). The serum Ca level of the subjects in group 2 was significantly lower than that of group 1 although mean values in all age groups are within the normal range. Dietary Ca intake, nutrient adequacy ratio (NAR) and index of nutrient quality (INQ) were decreased with age. Bone density was negatively correlated with age (p < 0.001), while body mass index (p < 0.01) was positively related with bone density. Although partial correlation did not reveal the significant correlation of BMD and dietary calcium after controlling for age, since calcium intake was very poor compared to sodium and phosphorous intakes, recommendation of more calcium intake for elderly women especially those over 75 years must be continuously emphasized.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.1018-1023
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• 2001

Oleamide (cis-9-octadecenamide) is endogenous primary amide of fatty acid that is produced in small amounts in animal brains. It is known to induce sleep and to lower temperature by destroying the lipid plasma membrane structure of cells, thereby disclosing gap junction channels. To develop a new biological production method for oleamide, a screening program was conducted to isolate a microorganism producing oleamide. Among 1,500 soil microorganisms tested, KK90378 exhibited a potent positive reaction with Dragendoff`s reagent, used to detect the primary amide of oleamide. KK90378 was identified as a Streptomyces species based on cultural and morpohological characteristics, the presence of diaminopimelic acid in the cell wall, and the sugar patterns for the whole-cell extrat. Streptomyces sp. KK90378 produced oleamide 3 days after culture at $28^{\circ}C$, pH 7.2 A series of purification steps, including hexane extraction, silica gel column, and preparative thin layer chromatographies, were performed for the purification of oleamide. A spectrophotometric analysis using $^1H$, $^13C$-NMR, and GC-MS confirmed that the chemical structure of the purified oleamide was identical to that of authentic oleamide.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.803-809
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• 2015

Background: Colorectal cancer (CRC) is a leading cause of cancer-related death. Oxidative DNA damage may contribute to cancer risk and the antioxidant paraoxonase is one endogenous free radical scavenger in the human body which could therefore exert an influeence. Purpose: Aim of this study was to determine the role of serum arylesterase (ARE) and paraoxonase 1(PON1) activities in CRC patients and to find any association between (PON1) Q192R and L55M gene polymorphisms in CRC patients. Also the serum ARE and PON1 activities in CRC patients will be investigated before and after surgery Materials and Methods: This study involved a total of 50 patients with newly diagnosed CRC and 80 healthy controls. PON1 and ARE activities were determined using an enzymatic spectrophotometric method. PON1 Q192R and L55M gene polymorphisms were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) based restriction fragment analysis. The restriction enzyme AlwI was used to examine the Q192R polymorphism and Hsp92II for the L55M polymorphism. Results: Significant differences in the PON1 Q192R polymorphism were found between patients and controls. The Q allele was more frequent in the patient group than in controls, while the R allele was more frequent in the controls. Significant differences were found in the L55M polymorphism. Additionally, there were significant differences in L and M allele frequencies (p=0.001). The serum activities of PON1 and ARE were low in QQ and MM genotype. Conclusions: serum PON1 and ARE activities were significantly lower in CRC patients compared to healthy subjects. The R allele may protect against colorectal cancer.

• Journal of the Korean Chemical Society
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• v.30 no.3
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• pp.307-311
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• 1986

The rates of hydrolysis of the complex, $trans^-[Cr(en)_2F(H_2O)]^{2+}$, have been investigated using spectrophotometric method at various temperatures and pressure. Temperature was 30${\circ}C$ to 50${\circ}C$ and pressure was varied up to 1500bar. The rate constant measured at 30${\circ}C$ is $2.632{\times}10^{-5}sec^{-1}$. The rate constants are decrease with increasing pressure at constants temperature. Activation volume and other activation parameters are calculated from these rate constants. The activation volumes are all positive and lie in the limited range 0.447 ∼ 3.152$cm^3$/mol and the activation entropies are small values. From the results, it was found that this reaction was endothermic and enthalphy controlled reaction in the experimental temperature.

• Journal of the Korean Chemical Society
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• v.34 no.2
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• pp.123-129
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• 1990

The rate constants for the solvolysis of $trans-[Cr(en)_2Br_2]^+$ ion were determined by the spectrophotometric method in methanol-, ethanol-, acetone-, and acetonitrile-water mixtures, at 20, 25, 30, and 35$^{\circ}C$, respectively. The rate constants increased with increasing co-solvent compositions. The rate constant did not show any relation with the reciprocal of dielectric constant of the solvent-mixtures. The m values of Grunwald-Winstein equation for methanol-, ethanol-, acetonitrile-, and acetone-water mixtures are 0.109, 0.103, 0.101, and 0.095, respectively. A free energy cycle for the process from the initial state to the transition state in water and water + co-solvent mixtures shows that the change in solvation at the transition state has a dominant effect on the rate. From the above results, it is believed that the mechanism for the aquation of this complex is the Id mechanism.