N-Octanol-water

Budiwald, P., Bodor, N. Octanol-water partition searching for predictive models. Curr. Med. Chem. 1998, 5, 353-380. 

A, B and V are constant for a given solute (Eig. 12.4 shows the value of A, 0.78, for atenolol). This means that the balance between intermolecular forces varies with the system investigated as would be expected from a careful reading of Section 12.1.1.3. This can also be demonstrated by using a completely different approach to factorize log P, i.e. a computational method based on molecular interaction fields [10]. Volsurf descriptors [11] have been used to calculate log P of neutral species both in n-octanol-water and in alkane-water [10]. 

Breindl, A., Beck, B., Qark, T., Glen, R. C. Prediction of the n-octanol/water partition coefficient, log P, using a combination of semiempirical MO-calculations and a neural network. J. Mol. Model. 1997, 3, 142-155. 

Gombar, V. K., Enslein, K. Assessment of n-octanol/water partition coefficient when is the assessment reliable. J. Chem. Inf Comput. Sci. 1996, 36, 1127-1134. 

Tetko, I. V., Tandiuk, V. Y., Villa, A. E. Prediction of n-octanol/water partition coeffidents from PHYSPROP database using artifidal neural networks and E-state indices./. Chem. Inf. Comput. Sci. 2001,... 

Bouchard, G., Galland, A., Garrupt, P. A., Gulaboski, R., Mirceski, V., Scholz, F., Girault, H. H. Standard partition coefficients of anionic drugs in the n-octanol/water system determined by voltammetry at three-phase electrodes. Phys. Chem. Chem. Phys. 2003, 5, 3748-3751. 

The following physico-chemical properties of the analyte(s) are important in method development considerations vapor pressure, ultraviolet (UV) absorption spectrum, solubility in water and in solvents, dissociation constant(s), n-octanol/water partition coefficient, stability vs hydrolysis and possible thermal, photo- or chemical degradation. These valuable data enable the analytical chemist to develop the most promising analytical approach, drawing from the literature and from his or her experience with related analytical problems, as exemplified below. Gas chromatography (GC) methods, for example, require a measurable vapor pressure and a certain thermal stability as the analytes move as vaporized molecules within the mobile phase. On the other hand, compounds that have a high vapor pressure will require careful extract concentration by evaporation of volatile solvents. 

Water solubility, dissociation constant(s) and n-octanol/water partition coefficients allow one to predict how an analyte may behave on normal-phase (NP), reversed-phase (RP), or ion-exchange solid-phase extraction (SPE) for sample enrichment and cleanup. 

Kristi, A. Tukker, J. J., Negative correlation of n-octanol/water partition coefficient and transport of some guanine derivatives through rat jejunum in vitro, Pharm. Res. 15, 499-501 (1998). 

Barton, P. Davis, A. M. McCarthy, D. J. Webbom, P. J. H., Drug-phospholipid interactions. 2. Predicting the sites of drug distribution using n-octanol/water and membrane/water distribution coefficients. J. Pharm. Set 86, 1034—1039 (1997). 

Danielsson, L.-G. Zhang, Y.-H., Methods for determining n-octanol-water partition constants, Trends Anal. Chem. 15, 188-196 (1996). 

The summary of Pe values for the steroids as a function of stirring rates is found in Table 11 and their correlations with log PC (n-octanol-water) in Figure 20. The transport kinetics of the relatively hydrophilic hydrocortisone and dexa-methasone are controlled by passive diffusion across the cell monolayer. On the other hand, the Pe values of testosterone and progesterone are highly dependent on stirring rate. The results for testosterone are used to obtain the relationships between the effective permeability coefficients of the ABL on the donor and receiver sides and the stirring rate, using the linear expression (see Eq. (69)]... 

Figure 20 Correlation of appearance kinetics of steroid permeants across Caco-2 cell monolayers in the Trans well system with log partition coefficients (n-octanol/water) and stirring dependency. 

Figure 22 Correlation between the log permeability coefficient for a series of peptides across a Caco-2 cell monolayer in the Transwell system and A log PC, which is defined as log PC(n-octanol/water) — log PC (isooctane/water). [Redrawn from Burton et al. (1992) with permission from the publisher.]...

In this model, one can argue that a peptide must have both an affinity for the interface (favorable n-octanol partition coefficient) and small desolvation energy (favorable A log PC) in order to efficiently cross a cell membrane. On the other hand, this model also predicts that a peptide with a large n-octanol/water partition coefficient and large desolvation energy, due to a significant number of polar groups, should adsorb and remain at the membrane interface. Both of these predicted events have been observed in the laboratory. 

Burkhard, L. P, Kuehl, D. W., Veith G. D. (1985c) Evaluation of reversed phase liquid chromatograph/mass spectrometry for estimation of n-octanol/water partition coefficients of organic chemicals. Chemosphere 14, 1551-1560. 

Yoshida, K., Shigeoka, T., Yamauchi, F. (1983) Relationship between molar refraction and n-octanol/water partition coefficient. Ecotox. Environ. Saf. 7, 558-565. 

Geyer, H.J., Politzki, G., Freitag, D. (1984) Prediction of ecotoxicological behaviour of chemicals relationship between n-octanol/water partition coefficient and bioaccumulation of organic chemicals by alga chlorella. Chemosphere 13(2), 269-284. 

De Maagd, P.G.-J., ten Hulscher, T.E.M., Van den Heuvel, H., Opperhuizen, A., Sijm, D.T.H.M. (1998) Physicochemical properties of polycyclic aromatic hydrocarbons aqueous solubilities, n-octanol/water partition coefficients, and Henry s law constants. Environ. Toxicol. Chem. 17, 252-257. 

Isnard, P., Lambert, S. (1989) Aqueous solubility and n-octanol/water partition coefficient correlations. Chemosphere 18, 1837-1853. 

Kishi, H., Hashimoto, Y. (1989) Evaluation of the procedures for the measurements of water solubility and n-octanol/water partition coefficient of chemicals results of a ring test in Japan. Chemosphere 18(9/10), 1749-1759. 

Lei, Y.D., Wania, F., Shiu, W.Y., Boocock, G.B. (2000) HPLC-based method for estimating the temperature dependence of n-octanol-water partition coefficients. J. Chem. Eng. Data 45, 738-742. 

Wang, L., Wang, X., Xu, O., Tian, L. (1986) Determination of the n-octanol/water partition coefficients of polycyclic aromatic hydrocarbons by HPLC and estimation of their aqueous solubilities. Huanjing Kexue Xuebao 6, 491 497. 

Absorption - desorption - N-octanol/water coefficient - Henry constant - Biodegradation and/or abiotic degr. disappearance coef. - Bioaccumulation - Aquatic Ecotox Fish 24 to 96 hours Daphnia 24 to 48 hours - Air/soil/sediment Ecotox ... 

The lipophilicity of a substance, that is, the tendency of a substance to become dissolved in a lipid, is often measured by the tendency of a substance to become dissolved in a nonpolar solvent, for example, by the n-octanol-water distribution coefficient. The lipophilicity of a substance is inversely proportional to its water solubility. 

J.C. Kraak, H.H. van Rooij, and J.L.G. Thus, Reversed-phase ion-pair systems for the prediction of n-octanol/water partition coefficients of basic compounds by high-performance liquid chromatography , J. Chromatogr., 1986, 352,455. 

Boto, P., Moreau, G., and Vandycke, C. Molecular structures perception, autocorrelation descriptor and SAR studies. System of atomic contributions for the calculation of n-octanol/water partition coefficients, Eur.J.Med. Chem.-Chim. Then, 19 71-78, 1984. 

Burkhard, L.P. and Kuehl, D.W. n-Octanol/water partition coefficients by reverse phase liquid chromatography/mass spectrometry for eight tetrachlorinated planar molecules, Chemosphere, 15(2) 163-167,1986. 

Kralj, F. and Sincic, D. Mutual solubilities of phenol, salicyaldehyde, phenol-salicyaldehyde mixture, and water with and without the presence of sodium chloride and sodium chloride plus sodium sulfate, J. Chem. Eng. Data, 25 (4) 335-338,1980. Kramer, C.R. and Henze, U. Partitioning properties of benzene derivatives. 1. Temperature dependence of the partitioning of monosubstituted benzenes and nitrobenzenes in the n-octanol/water system, Z. Phys. Chem., 271(3) 503-513,1990. Krasnoshchekova, R.Ya. and Gubergrits, M. Solubility of paraffin hydrocarbons in fresh and salt water, Neftekhlmlya, 13(6) 885-888, 1973. 

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