Octanol-water partition coefficient description

The flic presented contains 11 data items. The header lines arc property names as used by CACTVS [64, 65], and arc sufficiently self-descriptive. For example, E NHDONORS is the number of hydrogen bond donor.s, E SM1LES" is the SMILES string representing the structure of sulfamidc, and E LOGP is the logP value (octanol/water partition coefficient) for this substance. 

Hawker, D. W. (1990a) Vapor pressures and Henry s law constants of polychlorinated biphenyls. Environ. Sci. Technol. 23, 1250-1253. Hawker, D. W. (1990b) Description of fish bioconcentration factors in terms of solvatochromic parameters. Chemosphere 20, 267-477. Hawker, D. W., Connell, D. W. (1988) Octanol-water partition coefficients of polychlorinated biphenyl congeners. Environ. Sci. Technol. 22, 382-387. 

In view of the predictive properties of the octanol-water partition coefficient, logP, in the description of enzymatic activity [79], this parameter has received much attention. However, as argued in an early but still authoritative review compiled by Carrea and coworkers [80], its usefulness in the correlation of solvent effects on enantioselectivity appears to be limited. The problem is exemplified by the entries in Figure... 

Kim, K.H. (1995c). Description of the Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC) Capacity Factors and Octanol-Water Partition Coefficients of 2-Pyrazine and 2- ridine Analogues Directly from the Three-Dimensional Structures Using Comparative Molecular Field Analysis (CoMFA) Approach. Quant.Struct.-Act.Relat., 14, 8-18. 

Koc can be estimated from Kow, the octanol-water partition coefficient (defined in Section 1.8.3). Table 3-5 shows some correlations between Koc and Kow for different classes of hydrophobic organic compounds. For further descriptions of the hydrophobic behavior of chemicals, the reader is referred to Schwarzenbach et al. (1993). 

The octanol-water partition coefficient, logP, has a long history of applications in environmental and pharmaceutical studies. Already more than 100 years ago the activity of local anesthetics was described by Overton [60] and Meyer [61] in terms of oil-water partition coefficients. The logP was recognized as a standard property for description of the lipophilicity of chemicals due to the works of Corwin Hansch in the 1960s [62],... 

Kim, K.H. (1995c) Description of the reversed-phase high-performance liquid chromatography (RP-HPLC) capacity factors and octanol—water partition coefficients of 2-pyrazine and 2-pyridine analogues directly from the three-dimensional structures using comparative molecular field analysis (CoMFA) approach. Quant. Struct. -Act. Rdat., 14, 8-18. 

Turning to the K, and Kj parameters, we have observed that these are relatively insensitive to the identity of the solute, but that they depend upon the cosolvent, whose polarity is a controlling factor. Table 5.5.3 gives some empirical correlations that provide routes to the prediction of Kj and KjKj. In Table 5.5.3, Pm is the 1-octanol/water partition coefficient of the pure cosolvent,and Ef is the Dimroth-Reichardt solvatochromic polarity parameter. We thus have the capability of predicting gA, Kj, and K,K2, which extends the utility of eq. [5.5.23] from the merely descriptive to the predictive. 

In general, the interactions between xenobiotics and ecosystem constituents are reversible and tend to establish steady states conditioned by the rate-limiting steps. The reversibility applies, of course, only to the interactions at the molecular level, not to the (long-term) impacts on ecosystems. With respect to hazard and risk assessment, parameters regarding the distribution (e.g. bioconcentration and soil sorption), the reactivity (e.g. degradation) and the toxicity (e.g. aquatic species such as fish, crustaceans, algae) are considered. For the description of the chemicals, mostly structurally derived physico-chemical properties are used, among which the most prominent is the 1-octanol/water partition coefficient. The log parameter quanti-... 

Values of Henry s law constant k =plc, where p is the partial pressure of the solute in the gas above the solution and c is the concentration of the solute) is a quantity frequently apphed in the thermodynamic description of dilute aqueous solutions, which is used in environmental chemistry and atmospheric physics as a major criterion for describing air-water partitioning of solutes at near ambient conditions. It plays amajor role in evaluating the transport of pollutants between atmosphere and aquatic systems, rainwater and aerosols. The octanol-water partition coefficient is a dimensionless number defined as the ratio of the compound s concentration in a known volume of octan-l-ol (Cq) to its concentration in a known volume of water (c ) after the octan-l-ol and water have reached equihbrium. It has been found to be related to water solubility, soil/sediment absorption coefficients and bioconcentration factors of pollutants for aquatic life. The adsorption coefficient normalised to the organic carbon content of the soil (sediment) is a useful indicator of the binding capacity of... 

C in equation (2) is a molar concentration which produces a certain biological effect, P is the -octanol/water partition coefficient (see Octanol/Water Partition Coefficients), and a is the electronic Hammett constant (equation 1). The definition of a parabolic model and the combination of different physicochemical properties in one model allowed for the first time the description of structure-activity relationships which could not be correlated with a single linear term. As an alternative to log P values, a lipophilicity parameter n can be used which is defined in an analogous manner as the electronic a parameter (1 equation 3). " ... 

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