• Bulletin of the Korean Chemical Society
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• 제28권7호
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• pp.1183-1186
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• 2007

A shake-flask method was used to determine the n-octanol/water partition coefficients of sulfamethazine, sulfadimethoxine, sulfamethoxydiazine, sulfamonomethoxine, sulfamethoxazole, sulfaquinoxaline and sulfachloropyrazine from (298.15 to 333.15) K. The results showed that the n-octanol/water partition coefficient of each sulfonamide decreased with the increase of temperature. Based on the fluid phase equilibrium theory, the thermodynamic relationship of n-octanol/water partition coefficient depending on the temperature is proposed, and the changes of enthalpy, entropy, and the Gibbs free energy function for sulfonamides partitioning in n-octanol/ water are determined, respectively. Sulfonamides molecules partitioning in n-octanol/water is mainly an enthalpy driving process, during which the order degrees of system increased. The temperature effect coefficient of n-octanol/water partition coefficient is discussed. The results show that its magnitude is the same as that of values in the literature.

• Environmental Analysis Health and Toxicology
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• 제16권4호
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• pp.189-196
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• 2001

Octanol/water partition coefficients of 52 chemicals were calculated using RP-HPLC estimation method and predicted by computer program, PCHEM. The result showed relationship between literature values and RP-HPLC observed values (relative coefficient r$^2$＝0.916), but the relationship of PCHEM values with literature values was lower than RP-HPLC value (relative coefficient r$^2$＝0.795). The average difference in partition coefficient between the RP-HPLC method and flask-shaking method was log Kow＝0.54, while the average difference between the values predicted form the computer program and flask- shaking method was log Kow = 0.36 Compared to octanol/water partition coefficients by 3 methods (Flask-shaking, RP-HPLC, computer prediction), the octanol/water partition coefficient values based on the flask-shaking method were very similar to the literature values, while the octanol/water partition coefficient values by RP-HPLC method without to consider the dead time, and computer prediction values did not significantly differ with the literature values.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1996년도 경북지부 결성 및 추계학술발표회 논문집
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• pp.50-53
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• 1996

This paper reports the experimental results for the determination of the overall partition coefficient of VOCs in unsaturated soil, A chromatographic method was used for the determination of gaseous partition coefficients to natural soil under various water content conditions. The equilibrium vapor pressure of water over saturated salt solution was used to fix the relative humidity of the air and control the water content of the soil systems. The transport behavior was studied for dichloromethane, trichloroethane and dichlorobenzene pollutants, with log octanol-water partition coefficients(log $K_{ow}$ ) which range from 1.25 to 3.39, or water to soil partitioning which varies by 135 times; water solubility constants which vary by 3 times; and vapor pressures which range from 1 to 362 torr. Water content of the soil had a pronounced effect on the effective partition coefficient(between gas and soil + water stationary phase) as well as on the effective dispersion coefficient.

• Advances in environmental research
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• 제7권2호
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• pp.139-159
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• 2018

Green Leaf Volatiles (GLVs) is a class of biogenically emitted oxygenated hydrocarbons that have been identified as a potential source of Secondary Organic Aerosols (SOA) via aqueous oxidation. The physico-chemical properties of GLVs are vital to understanding their fate and transport in the atmosphere via fog processing, but few experimental data are available. We studied the aqueous solubility, 1-octanol/water partition coefficient, and Henry's law constant ($K_H$) of five GLVs at $25^{\circ}C$: methyl jasmonate, methyl salicylate, 2-methyl-3-buten-2-ol, cis-3-hexen-1-ol, and cis-3-hexenyl acetate. Henry's law constant was also measured at temperatures and ionic strengths typical of fog. Experimental values are compared to scarcely-available literature values, as well as estimations using group and bond contribution methods, property-specific correlations and molecular dynamics simulations. From these values, the partition coefficients to the air-water interface were also calculated. The large Henry's law constant of methyl jasmonate ($8091{\pm}1121M{\cdot}atm^{-1}$) made it the most significant GLV for aqueous phase photochemistry. The HENRYWIN program's bond contribution method from the Estimation Programs Interface Suite (EPI Suite) produced the best estimate of the Henry's constant for GLVs. Estimations of 1-octanol/water partition coefficient and solubility are best when correlating an experimental value of one to find the other. Finally, the scavenging efficiency was calculated for each GLV indicating aqueous phase processing will be most important for methyl jasmonate.

• 약학회지
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• 제47권5호
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• pp.331-338
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• 2003

A butyrolactone ester of cefazolin (CFZ-BTL) was synthesized by the esterification of cefazolin (CFZ) with $\alpha$-bromo-${\gamma}$-butyrolactone. The synthesis was confirmed by the spectroscopic analysis. The CFZ-BTL was more lipophilic than the CFZ when assessed by n-octanol/water partition coefficients at various pH. The CFZ-BTL itself did not show any antimicrobial activity in vitro, but after oral administration of CFZ-BTL to rabbits, exerted significant anti-microbial activity in serum samples when measured by the inhibion zone method in nutrient agar plates, due to conversion of CFZ-BTL to an active metabolite, probably CFZ, in the body. The CFZ-BTL was also converted into CFZ as confirmed by in vitro incubation study, with tissue homogenates (liver, blood and intestine) of rabbits. The liver showed the fastest conversion rate, probably via the hydrolysis mechanism. In vivo metabolism of CFZ-BTL to CFZ was also confirmed in vivo serum samples by HPLC. The oral bioavailability of CFZ-BTL in rabbits was 1.6-fold increased when compared to CFZ, resulting from followed by enhanced lipophilicity increased passive absorption in the intestine.

• 분석과학
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• 제6권1호
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• pp.1-8
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• 1993

음이온 계면활성제인 sodium dodecyl sulfate(SDS)를 이동상으로 한 미셀 액체 크로마토그래피(micellar liquid chromatography : MLC)에서, 시료로 22종의 페놀과 벤젠 일치환체들을 선택하여 이 시료들의 용리거동을 조사하여 MLC계에서의 소수성 효과를 알아 보았다. MLC에서의 머무름과 미셀 농도간의 상관관계를 통해 시료들이 미셀-물간, 변형된 정지상-물 사이에서 분배될 때의 분배계수를 구하였고, 또 이를 이용하여 물-미셀간의 전이 자유 에너지를 구하였다. 이러한 MLC에서 얻은 소수성 파라미터들은 옥탄올-물계와 연관시켜 본 결과 좋은 상관관계를 보였다. 따라서 이 두 계에서 시료의 소수성이 머무름에 중요한 영향을 미침을 알 수 있었다. 한편, MLC를 이용하면 quantitative structure activity relationships(QSAR)에서의 소수성 정량 연구에 적용이 가능하다. 또한 알킬 치환체들에서 탄소 수의 증가에 따른 머무름 관계를 통하여 소수성의 선택성을 알아 보았고, 유기 변형제로 n-프로판올을 첨가하였을 때에도 마찬가지로 MLC계에서의 소수성 파라미터와 옥탄올-물계 사이에 상관관계가 있음을 알았다.

• 약학회지
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• 제33권4호
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• pp.211-218
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• 1989

Twenty-six injectable drug products, many of which are administered by i.v. infusion, were studied for loss from aqueous solutions stored in polyvinyl chloride (PVC) infusion bags for various periods of time. The PVC infusion bags were stored in the dark room at room temperature for up to one month. Drugs stored in glass bottle served as controls. The solutions were assayed Spectrophotometrically at regular intervals. The effect of drug concentration and pH on the loss of drug from solution were studied. Octanol-water partition coefficients were used as a guage of lipid solubility of drugs. The elution of di(2-ethylhexyl)phthalate(DEHT) from PVC infusion bags was studied. For most of the drug studied, minimal loss from the aqueous solutions were observed over periods of storage time. Six of the drug products - Thiopental sodium, Hydralazine HCl, Thioridazine HCl, Trifluoperazine 2HCl, Metronidazole, Chlorpromazine HCl - were found to be lost a substantial extent. DEHP was found to be migrating from PVC infusion bags.

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.54-61
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• 1999

Measurement of inhibition of bioluminescence in Photobacterium phosphoreum has been porposed as a sensitive and rapid procedure to monitor toxic substances. However, at first, $EC_{50}$ which shows degree of toxicity to each toxic substances must be calculated. QSAR (Quantitative Structure Activity Relationship) model can be used to estimate $EC_{50}$ to save time and endeavor. Moderately high correlation coefficients ($r^2{\geq}$ 0.97) were calculated from the linear correlation between $EC_{50}$ and molecular connectivity indices of CAHs (chlorinated aliphatic hydrocarbons)such as $^0X$, $^0X^V$, $^1X$, $^2X$ and $^3X^v_c$ and quadratic correlation between $EC_{50}$ and $^0X$, $^0X^V$, $^2X^V$, $^3X_c$, $^3X^V_c$ and P. It shows that the molecular connection indices in carbon structure is contributed to biological characters with linear relation and that in the other one with quadratic relation. The $EC_{50}$ of chlorophenol derivatives had quadratic relation with the value of octanol/water prtition coefficients ($r^2$=0.99) and linear and quadratic relation with the number of chlorine compound (($r^2{\geq}$0.94). This confirms the already known trend of increasing toxicity with increasing ability of a compound to diffuse through cell membrane and number of chlorine substitution.

• 공업화학
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• 제32권5호
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• pp.581-588
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• 2021

In this study, soil slurry bioreactors were used to treat soils containing 16 polycyclic aromatic hydrocarbons (PAHs) for 35 days. Five different soil samples were taken from manufactured gas plant (MGP) and coal tar disposal sites. Soil properties, such as carbon content and particle distribution, were measured. These properties were significantly correlated with percent biodegradation and degradation rate. The cumulative amount of PAH degraded (P), degradation rate (K_m), and lag phase (𝜆) constants of PAHs in different MGP soils for 16 PAHs were successfully obtained from nonlinear regression analysis using the Gompertz equation, but only those of naphthalene, anthracene, acenaphthene, fluoranthene, chrysene, benzo[k]fluoranthene, benzo(a)pyrene, and benzo(g,h,i)perylene are presented in this study. A comparison between total non-carcinogenic and carcinogenic PAHs indicated higher maximum amounts of PAH degraded in the former than that in the latter owing to lower partition coefficients and higher water solubilities (S). The degradation rates of total non-carcinogenic compounds for all soils were more than four times higher than those of total carcinogenic compounds. Carcinogenic PAHs have the highest partitioning coefficients (K_oc), resulting in lower bioavailability as the molecular weight (MW) increases. Good linear relationships of K_m, 𝜆, and P with the octanol-water partitioning coefficient (K_ow), MW, and S were used to estimate PAH remaining, lag time, and biodegradation rate for other PAHs.

• 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.