• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.124-128
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• 1999

The photochemistry of the derivatives of o-nitrobenzylcarboxyl esters or benzylsulfonyl derivatives has been well studied separately. But little attempt has been made to combine the fruits these two studies. Being photochemically active, benzylsulphonyl and intro groups should influence the reactivity of each other's, especially when the excited states are fully mixed due to the proximity of their location. The questions which should be clearly answered are; what kind of effect will be excerted to the other group, and whether these two functional groups are coupled in the course of the reaction. To answer the questions raised above, wer have synthesized two sulfonyl esters and four amides from the newly available starting material, 2-nitro-${\alpha}$-toluenesulfonyl chloride. The products identified from the exploratory solution photochemistry were cyclohexanol, phenol, cyclohexylamine, and sulfur dioxide. The results are not much different from the products originally anticipated. It has been temporarily concluded that there is little interaction between the benzyl sulfonyl group and ortho-nitro chromophore. The fact that a base (an amine) has been photochemically generated in solution photochemistry was further confirmed by and utilized in the solid phase quantitative photochemistry done on the film, so as to carry out the photochemical epoxide cure.

• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.25-35
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• 2024

Background: There are concerns about the health effects of various environmental pollution exposures among residents living near coal-fired power plants (CFPP). Objectives: This study attempted to compare the concentrations of heavy metals in blood and urine and those of urinary volatile organic compound (VOC) metabolites according to the residential separation distance. Methods: Participants in the study totaled 334 people who have lived for more than 10 years in areas within 10 km of a CFPP. The separation distance was analyzed in quartiles by dividing it into Q1 (88 people), Q2 (89 people), Q3 (89 people), and Q4 (68 people). We explained the purpose of this study to the participants and collected blood and urine after obtaining signatures on a participation agreement. Results: The study participants were 102 males (30.5%) and 232 females (69.5%), with an average age of 71. The average length of residence and distance were 43.8 years and 4,800 meters. The geometric mean concentrations of Pb, Cd, and Hg in blood and As and Cd in urine were respective 1.35 ㎍/dL, 1.43 ㎍/L, 3.16 ㎍/L. They were 167.88 ㎍/g for creatinine and 1.58 ㎍/g creatinine. The metabolite concentrations of VOCs were 50.67 ㎍/g creatinine in t, t-muconic acid (t, t-MA), 10.73 ㎍/g creatinine in benzyl mercapturic acid, 317.05 ㎍/g creatinine in phenylglyoxylic acid, 123.55 ㎍/g creatinine in methylhippuric acid, and 190.82 ㎍/g creatinine in mandelic acid. The concentration of Pb in the blood and Cd and t, t-MA in the urine of residents within affected area of the CFPP showed statistically significant differences among distance groups. Conclusions: The concentration of urinary VOCs metabolites, especially t, t-MA, differed according to the distance groups of residents within the affected area of CFPP (p<0.05).

• Journal of Pharmaceutical Investigation
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• v.40 no.1
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• pp.51-57
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• 2010

Losartan potassium, 2-butyl-4-chloro-1-[p-(o-1H-tetrazol-5-ylphenyl)benzyl]imidazole-5-methanol mono-potassium salt, is a new class of antihypertensive agents, and is an antagonist in angiotensin receptor. The purpose of the present study was to evaluate the bioequivalence of two Losartan potassium tablets, Cozaar tablet (MSD Pharmaceutical Co., Ltd.) and Losata tablet (Kyung Dong Pharmaceutical Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of losartan from the two losartan potassium formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media. Twenty eight healthy male subjects, $23.86{\pm}1.80$ years in age and $67.27{\pm}6.60\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a single tablet containing 50 mg as losartan potassium was orally administered, blood samples were taken at predetermined time intervals, and the concentrations of losartan in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar in all tested dissolution media. The pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated, and Equiv Test/K-BE Test 2002 was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, Cozaar, were -2.70%, 1.45% and 2.31% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 (e.g., log 0.8852~log 1.0655 and log 0.8319~log 1.2342 for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Losata tablet was bioequivalent to Cozaar tablet.

• Journal of the Korean Chemical Society
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• v.26 no.5
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• pp.333-339
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• 1982

Substituent effects of substrate and leaving group for the reaction of substituted ${\beta}$-phenylethyl arenesulfonates with pyridine were determined conductometrically in acetonitrile at 50∼70$^{\circ}$C. The substituent effect in substrate is not so significant than expected, but still the electron donating substituent shows the slight acceleration to give a small negative ${\rho}$ value and Hammett plots show slight curvature on the acting substituents, even though it is not so remarkable than that of benzyl system. These results represent a little bit the favorable bond breaking at the transition state by the electron donating substituents. The effects of leaving group in the arenesulfonates in which the rate constants are decreased by electron donating substituents, while electron withdrawing groups presented the reverse effects. Hammett ${\rho}$ value is significantly smaller than that of p-nitrobenzyl arenesulfonates and thus, the mechanism should be closer to tight $S_N2$ one. Especially 2,5-dichlorobenzenesulfonate was more accelerated than expected at the additivity of substituents. This facts showed that dichlorobenzenesulfonate anion is more stabilized by the great electron withdrawing substituents at transition state.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.425-429
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• 1997

Polyisobutenylsuccinic anhydride(PIBSA), an intermediate for the lubricating oil additive, was prepared by the reaction of polyisobutylene(PIB) with maleic anhydride (MA). The functionality, which indicates the extent of reaction of PIB-a and MA, was determined in the various reaction conditions : fuctionality was 0.98 under the reaction conditions of no solvent for 12 hours at $190^{\circ}C$, 0.21 in benzyl alcohol solvent for 12 hours at $190^{\circ}C$, and 0.03~0.20 with various Lewis acids such as $AlCl_3$, $SnCl_4$, $Et_2AlCl$, and $TiCl_4$. The fuctionality also depended on the structure of PIBs. As ${\alpha}$-olefin content (exo-form) in PIB increased, the fuctionality had a higher value. The structure of PIBSA prepared from PIB and MA was determined with FT IR and $^1H$ NMR spectroscopy. Two strong anhydride IR bands at 1782 and $1855cm^{-1}$ were obserbed and two IR bands at 1639 and $897cm^{-1}$ for unsaturated groups of PIB disappeared. The presence of the anhydride was difficult to find by $^1H$ NMR spectroscopy because the anhydride protons gave relatively small peaks over a 2.0~3.0 range. Polyisobutenylsccinimide (PIBSI), a lublicating oil additive, was prepared by the reaction of PIBSA with diaminoethane.

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.131-137
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• 2007

CoMFA and CoMSIA model were derived and reviewed on the insecticidal activities of N-substituents (X) on the imidazol ring in imidacloprid analogues at the different alignment condition. Regarding the predictability ($q^2$ or $r_{cv.}^2$) and fitness ($r_{ncv.}^2$) of the two optimized models, the atom based fit (A) alignments were better than that of the field fit (F) alignment and, on the other hand, CoMSIA (A10) model was better than CoMFA (A5) model. Also, from the most optimized CoMSIA (A10) model, the insecticidal activity by N-substituents (X) was dependence on the electrostatic field and H-bond acceptor field. It is predicted that, from the contour maps with optimized CoMSIA (A10) model, H-bond acceptors at ortho- and meta- position will contribute for improving of insecticidal activities and, as the functional groups of carbonyl oxygen atom are charged negatively and positively charged at the ortho- position of benzyl group, insecticidal activities will also be improved.

• Journal of Nutrition and Health
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• v.4 no.4
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• pp.39-46
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• 1971

Since ${\beta}-aminoethylphosphonic$ acid was discovered in the living organism, the biosynthesis and biological function of aminophosphonic acids have been extensively studied. The purpose of this project consists in the two parts: 1)the preparation of DL-1-amino-2-phenylethylphosphonic acid (Phenylalanine aminophosphonic acid) and DL-1-amino-3-methylbutyl-phosphonic acid (Isoleucine aminophosphonic acid) by the method of Chamber and Isbell. 2) the study of metabolism and biological functions of those synthetic materials by the animal experiment (white rats) The importance of this project proved to be the first experience fed by animals for the elucidation of biochemical and metabolic functions in the animal body. The following organic synthesis of DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenylethylphosphonic acid are studied. 1)Synthesis of DL-1-amino-3-methylbutylphosphonic acid a) Synthesis of Iso-butylbromide b) Synthesis of Ethyl iso-butylmalonate c) Synthesis of Iso-caproic acid d) Synthesis of $Ethyl-{\alpha}-bromo$ iso-caproate e) Synthesis of $Triethyl-{\alpha}-phosphono$ iso-caproate f) Synthesis of DL-1-amino-3-methylbutylphosphonic acid 2)Synthesis of DL-1-amino-2-phenylethylphosphonic acid a) Synthesis of Diethyl phosphite b) Synthesis of Ethylchloro acetate c) Synthesis of Triethyl phospho acetate d) Synthesis of Triethyl benzyl phospho acetate e) Synthesis of DL-1-amino-2-phenylethylphosphonic acid The synthetic compounds; DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenyl ethylphosphonic acid which are essential amino acid (isoleucine, phenylalanine)analogue are supplemented to the animal diet at the level of 0.2% and 0.4% for isoleucine analogue and 0.35% and 0.7% for phenylalanine analogue. The plain isoleucine and phenylalanine at the same level in the diet are fercilitated as comparable groups in this study. Two sets of experience including 100 male rats were carried out for seven weeks each total 14 weeks. During this period, urine samples, and each big organs were collected for the analysis of total nitrogen, phosphorus, and glycogen contents in the individual samples by Micro Kjeldahl Fisk & Subbarow and Nelson Somogye, method. 1) The result of the project a) The yield of DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenylethylphosphonic acid showed low tendency at the level of 12.5% and 20% Melting point of those two compounds were very high and the ${\alpha}-amino$ group in the synthetic compounds showed positive reaction with ninhydrin in the violet color. b) Ail the experimental groups included in this study revealed statistically no significant difference in the organ weight, total body nitrogen retention and urinary phosphorus excretion This means isoleucine aminophosphonic acid and Phenylalanine aminophosphonic acid were utilized in the body as much as the plain amino acids, isoleucine and phenylalanine did. c) The glycogen contents in the liver of the phenylalaine aminophosphonic acid gruop showed higher statistically significant(p<0.05) in the comparision with the group of the Phenylalanine and the Standard-2. It was noteworthy that the higher glycogen content in the liver might indicate the significance in the incorporation of phenylalanine aminophosphonic acid into the intermediate of tricarboxylic acid cycle as activated state.