• 한국환경농학회지
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• 제12권1호
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• pp.69-80
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• 1993

Environmental hazards of a chemical could be assessed by two different approaches : toxicity test and assessment of exposure potentials to human and environmental organisms. For the prediction of environmental fate of chemicals three available computer programs were compared each other and were verified. The results obtained by using these computer programs, PCHEM, EXAMS, and E4CHEM were summarized as follows. The estimated octanol/water partition coefficients by PCHEM were similar to the experimental values in the literature. But the other factors, water solubility and vapor pressure were different from the data in the literature. The simulation results of selected compounds by EXAMS showed similar tendency to the literature results of model field environment. Therefore, this computer program could be utilized to predict the environmental fate of chemicals. E4CHEM program is very simple and this program could predict the ultimate environmental fate of stable chemicals by input of two or three parameters. However, the validity should further be verified in the future field study using more compounds. It is suggested that these approaches could be fully utilized by understanding their limitations to predict the environmental fate of new chemicals under development, to screen the potential environmental pollutants among chemicals already-in use, and to devise measures to minimize the hazards to the environment.

• 약학회지
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• 제46권3호
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• pp.168-173
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• 2002

The physicochemical properties of aloesin, which has been recently found to reduce renal toxicity induced by cis-platin, were studied including solubility, partition coefficient ( $P_{c}$ ), osmolality, and stability. The solubility of aloesin was about 500 mg/mι, and the $P_{c}$ value for n-octanol/water was 1.01 $\pm$ 0.03. The degradation of aloesin followed the pseudo-first-order kinetics and was dependent on temperature, pH and ionic strength. From the pH-rate profile, the optimal pH was found to be 2.0~3.0. Some metal ions increased the degradation rate in the rank order of M $n^{2+}$ ＞ F $e^{3+}$ ＞ C $u^{2+}$ ＞ F $e^{2+}$. On the other hand, other metal ions such as B $i^{3+}$, $Ba^{2+}$, Z $n^{2+}$, N $i^{2+}$, $Co^{2+}$ and $Mg^{2+}$ did not show the unfavorable effects. After autoclaving, aloesin contents remaining were 81.8~98.8% of initial concentrations depending on pH. The most stable pH was 3.98 in the autoclaving. Osmolality increased linearly as concentration increased.sed.creased.sed.

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1742-1750
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• 2003

In order to characterize the hydrophobic parameters of N-acetyl amino acid amides in 1-octanol/water, a theoretical calculation was carried out using a solvation free energy density model. The hydrophobicity parameters of the molecules are obtained with the consideration of the solvation free energy over the solvent volume surrounding the solute, using a grid model. Our method can account for the solvent accessible surface area of the molecules according to conformational variations. Through a comparison of the hydrophobicity of our calculation and that of other experimental/theoretical works, the solvation free energy density model is proven to be a useful tool for the evaluation of the hydrophobicity of amino acids and peptides. In order to evaluate the solvation free energy density model as a method of calculating the activity of drugs using the hydrophobicity of its building blocks, the contracture of Bradykinin potentiating pentapeptide was also predicted from the hydrophobicity of each residue. The solvation free energy density model can be used to employ descriptors for the prediction of peptide activities in drug discovery, as well as to calculate the hydrophobicity of amino acids.

• 한국임상약학회지
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• 제8권2호
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• pp.133-138
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• 1998

Phthalimidyl ester of ceftezole (CFZ-PT) was synthesized as a prodrug by esterification of ceftezole (CFZ) with N-bromophthalimide. CFZ-PT was more lipophilic than CFZ when the lipophilicity was assessed by partition coefficients between n-octanol and water at various pH. The pharmacokinetic characteristic of CFZ-PT and CFZ preparations were compared following oral administrations of these compounds to rabbits. CFZ-PT is expected to be metabolized rapidly to CFZ in the body. The metabolism process appears to be hydrolysis of the ester to CFZ, the parent drug of CFZ-PT. In vivo metabolism of CFZ-PT to CFZ was confirmed in rabbit by HPLC analysis. CFZ concentration in the serum samples taken after oral administration of CFZ-PT(equivalent amount of CFZ) were released and higher than those of CFZ. Oral bioavailability of CFZ-PT was 1.9 fold higher than at of CFZ in rabbits because of enhanced lipophilicity and absorption. Finally, it was concluded that CFZ-PT appears useful as a prodrug of CFZ to improve the oral bioavailability of CFZ.

• Journal of Pharmaceutical Investigation
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• 제27권2호
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• pp.125-131
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• 1997

Ethoxycarbonyloxyethyl ester of ceftezole (CFZ-ET) was synthesized as a prodrug by esterification of ceftezole (CFZ) with ethoxycarbonyloxyethyl chloride and was confirmed by spectroscopic analyses. CFZ-ET was more lipophillic than CFZ as assessed by n-octanol and water partition coefficients at various pH. CFZ-ET itself did not show any microbiological activity in vitro, but showed substaintial microbiological activity after oral administration of CFZ-ET, indicating that CFZ-ET is converted to microbiologically active metabolite, probably CFZ, in the body. When CFZ-ET was incubated in blood, liver and intestine homogenates of rabbits, liver homogenate showed the fastest conversion of CFZ-ET. CFZ-ET appears rapidly metabolized in the liver when given orally due to the hydrolysis of the ester to CFZ, the parent drug of CFZ-ET. In vivo metabolism of CFZ-ET to CFZ was confirmed in rabbit by HPLC analysis. CFZ-ET were higher than those in the serum samples taken after oral administration of equivalent amount of CFZ. Oral bioavailability of CFZ-ET was 1.5-fold higher than that of CFZ in rabbits because of enhanced lipophilicity and absorption. Based on these findings, CFZ-ET appears useful as a prodrug of CFZ to improve the oral bioavailability of CFZ.

• Environmental Analysis Health and Toxicology
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• 제26권
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• pp.4.1-4.6
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• 2011

Objectives: This study was carried out to determine whether or not pine needles can be used as passive samplers of atmospheric polycyclic aromatic hydrocarbons (PAHs) using the correlation between accumulated PAH concentrations in air (Ca, ng/$m^3$) and those deposited on pine needles (Cp, ng/g dry). Methods: PAHs in ambient air was collected using low volume PUF sampler and pine needles was gathered at same place for 7 months. Results: A good correlation ($R^2$=0.8582, p<0.05) was found between Ca and Cp for PAHs with a higher gaseous state in air (AcPy, Acp, Flu, Phen, Ant, Flt, Pyr, BaA and Chry), but there was a poorer correlation ($R^2$=0.1491, p=0.5123) for the PAHs with a lower gaseous state (BbF, BkF, BaP, DahA, BghiP and Ind123). A positive correlation ($R^2$=0.8542) was revealed between the logarithm of the octanol-air partitioning coefficient ($logK_{oa}$) and Cp/Ca for the PAHs with a higher gaseous state in air, but there was a negative correlation ($R^2$=0.8131) for the PAHs with a lower gaseous state. The Ca-Cp model could not be used to estimate PAHs concentrations in air using deposited PAHs concentrations on pine needles, but the logKoa-Cp/Ca model could be used. Conclusions: It was found that pine needles can be used as passive samplers of atmospheric PAHs.

• 대한약리학회지
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• 제29권1호
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• pp.157-163
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• 1993

n-Alkanols의 분자적 약리작용기전 탐구에 기초자료를 제공하기 위하여 소의 신선한 대뇌피질로부터 분리한 synaptosomal plasma membrane vesicles (SPMV) 지질 이중층의 측방확산운동에 미치는 n-alkanols의 영향을 형광 probe법으로 검색하였다. n-Alkanols는 SPMV 지질 이중층의 측방확산운동 범위와 속도를 농도 의존적으로 증가시켰고 1-nonanol까지는 탄소수가 두개 증가될 때마다 그 효력은 약 10배 가량 증가되었으나 탄소수 10개인 1-decanol의 효력은 오히려 감소되는 경향을 나타내었다.

• 한국수산과학회지
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• 제53권3호
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• pp.273-280
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• 2020

Volatile compounds in fermented ascidians Halocynthia roretzi were analyzed to identify key flavor compounds using SPME/GC/MSD (solid phase microextraction/gas chromatography/mass selective detector) after 60 days of fermentation at 5℃. The control was chopped ascidians subject to anti-browning and 4% salt treatment. product A was made from product C by adding an alcohol extract of red peppers and onion peel, 0.1% of glucose, and 0.55% of mixed amino acids (MAA; 0.05% Glu, 0.1% Pro, 0.3% Ala, and 0.1% Gly). After blanching and anti-browning treatment of chopped ascidians, Product B1 was made by adding 3% anchovy sauce and 6% sorbitol. Product B2 was made by adding 0.1% glucose and 0.55% MAA to Product B1. In total, 78 compounds were identified, including 31 alcohols, 15 aldehydes, and 10 ketones. The alcohols included 12 compounds from the C8-C10 series with floral and fruit odors, including octanol, 3-methyloctanol, 2,6-dimethyl-1-heptanol, (E)-5-octen-1-ol, 6-methyloctanol, (E)-3-octen-1-ol, (E)-3-decen-1-ol, (Z)-1,5-octadien-3-ol, and nonanol. These were detected in high amounts in ascidians and all fermented products. Aldehydes (octanal, (E)-2-octenal, 2,4-heptadienal, and nonanal) and ketones (1-oten-3-one and 2-heptanone) with fatty and mushroom odors were detected as major compounds, whereas nine ethyl esters were detected only in product A.

• 한국축산식품학회지
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• 제32권6호
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• pp.810-819
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• 2012

본 연구의 목적은 한우 암소(2-15세) 총 126두를 연령그룹별(그룹 1, 5세 이하; 그룹 2, 6-8세; 그룹 3, 9세 이상)로 구분하여 등심(loin) 또는 우둔(top round) 부위의 이화학적 육질특성을 조사하여 비교하고자 실시하였다. 등심과 우둔 모두 연령그룹 1이 연령그룹 2 또는 3 보다 근내지방 함량이 높았고(p<0.05) 단백질함량은 등심에서는 연령그룹 1이 유의적으로 낮았으나 우둔부위에서는 연령그룹간에 차이가 없었다. 콜라겐 함량은 등심은 연령그룹간 유의적인 차이가 없었으나 우둔은 연령그룹 3이 다른 연령그룹들보다 유의적으로 낮았다(p<0.05). 육색은 등심의 경우 연령그룹 1이 연령그룹 3 보다 $L^*$값(백색도)과 $a^*$값(적색도)이 유의적으로 높았고(p<0.05) 우둔은 $a^*$값만 유의적으로 높았다(p<0.05). 또한 연령 그룹 1의 등심이 연령그룹 3보다 가열감량(%)이 낮고 보수력은 높았다(p<0.05). 전단력은 등심과 우둔 모두 연령그룹 3이 연령그룹 1과 2보다 높았다(p<0.05). 지방산 조성에서 총포화지방산(SFA) 함량은 등심은 연령그룹 3이 그룹 1보다 유의적으로 더 높았고 우둔은 연령그룹 1이 총단일불포화지방산(MUFA) 함량이 연령그룹 3보다 높았고(p<0.05), 다가불포화 지방산(PUFA) 함량은 낮았다(p<0.05). 유리아미노산 함량 비교에서 연령그룹에 관계없이 alanine이 가장 많았고 다음이 glutamine, glycine, isoleucine, proline 등이었다. 한편, threonine, alanine, valine, methionine, phenylalanine, leucine 및 lysine 함량은 연령그룹 1이 가장 높았다(p<0.05). 향기성분은 3-methylbutanal, furfural, octanal, 케톤류의 1-(acetyloxy)-2-propanone, 알코올류의 1-octanol, 피라진류의 2,5-dimethylpyrazine, 2-ethyl-2,5-dimethylpyrazine 성분함량이 연령층이 증가할수록 증가하는 경향을 나타냈다(p<0.05). 결론적으로 한우암소고기는 연령대에 따라 고기내 성분조성 및 육질에 차이가 있었으므로 이러한 특성을 고려하여 부위 또는 요리방법에 적합한 활용 또는 가공방법을 결정해야 할 것이다.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3637-3641
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• 2014

In this study, we analyzed the toxicity of mixtures of dimethylformamide (DMF) and methyl ethyl ketone (MEK) or DMF and toluene (TOL) and predicted their toxicity using quantitative structure-activity relationships (QSAR). A QSAR model for single substances and mixtures was analyzed using multiple linear regression (MLR) by taking into account the statistical parameters between the observed and predicted $EC_{50}$. After preprocessing, the best subsets of descriptors in the learning methods were determined using a 5-fold cross-validation method. Significant differences in physico-chemical properties such as boiling point (BP), specific gravity (SG), Reid vapor pressure (rVP), flash point (FP), low explosion limit (LEL), and octanol/water partition coefficient (Pow) were observed between the single substances and the mixtures. The $EC_{50}$ of the mixture of DMF and TOL was significantly lower than that of DMF. The mixture toxicity was directly related to the mixing ratio of TOL and MEK (MLR $EC_{50}$ equation = $1.76997-1.12249{\times}TOL+1.21045{\times}MEK$), as well as to SG, VP, and LEL (MLR equation $EC_{50}=15.44388-19.84549{\times}SG+0.05091{\times}VP+1.85846{\times}LEL$). These results show that QSAR-based models can be used to quantitatively predict the toxicity of mixtures used in manufacturing industries.