Octanol: Water partition coefficients (P): Measurement, estimation, and interpretation, particularly for chemicals with P &gt; 105

Brooke, David N.; Dobbs, A.J.; Williams, Neil

doi:10.1016/0147-6513(86)90099-0

Cited by 147 publications

(63 citation statements)

References 13 publications

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“…Scientists initially did just that with a shake-flask method, until they found that the approach leaves enough octanol in the water phase to act as a detergent. Slow stir is now the method of choice (2,3). Among the best slow-stir log K ow values for DDT are 6.91 and 6.22, according to ecotoxicologist Johannes Tolls at Utrecht University's Institute for Risk Assessment Sciences in the Netherlands, who has just finished an interlaboratory comparison for determining K ow values for highly hydrophobic organic compounds.…”

Section: Three Concernsmentioning

confidence: 99%

The KOW Controversy

Renner¹

2002

Environ. Sci. Technol.

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Section: Three Concernsmentioning

confidence: 99%

The KOW Controversy

Renner¹

2002

Environ. Sci. Technol.

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“…This f value was then used to calculate log P for all compounds. Octanol-partition coefficients were determined using the 'slow-stirring' method as outlined by Brooke et al (1986). The classical shake flask method was found to be less useful, since various of the compounds tested lead to the formation of rather stable emulsions.…”

Section: Partition Coefficientsmentioning

confidence: 99%

A quantitative structure-activity relationship for the acute toxicity of some epoxy compounds to the guppy

et al. 1988

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The 14 day LCso values of various epoxy compounds to the guppy (Poecilia reticulata) were determined, and investigated through the construction of a quantitative structure-activity relationship (QSAR). Both hydrophobicity and alkylating potency of the compounds are found to be necessary parameters for the satisfactory description of the LCs0 data. The findings of the present study are compared to results published for halogenated alkylating agents (Hermens, 1985), some of which are considerably more toxic than predicted on the basis of the QSAR established for the epoxy compounds.

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“…284 phase, as described by Brooke et al (1986). Partition coefficients were determined at three different concentrations of the compounds.…”

Section: Incubation Mixturesmentioning

confidence: 99%

Interaction of 7-n-alkoxycoumarins with cytochrome P-4502 and their partitioning into liposomal membranes. Assessment of methods for determination of membrane partition coefficients

Vermeir

Boens

Heirwegh

1992

Biochemical Journal

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A study was made of the binding of 7-ethoxy-, 7-n-propoxy-and 7-n-pentoxy-coumarin to cytochrome P-4502 reconstituted into large unilamellar liposomes composed of a mixture of egg L-a-phosphatidylcholine, egg phosphatidylethanolamine and dipalmitoyl phosphatidic acid (2:1:0.06, by weight). The apparent spectral dissociation constants QPP-increased linearly with increasing proteoliposomal concentration. When both cytochrome P-4502 and NADPH:cytochrome P-450 reductase were reconstituted into liposomes, the apparent Michaelis constants KmPP for 0-dealkylation of 7-methoxy-, 7-ethoxy-and 7-n-propoxy-coumarin showed a similar dependence on the proteoliposomal concentration. The results were in accordance with models for kinetic or equilibrium processes in biphasic systems containing membrane-bound catalytic or acceptor sites, in which a linear solute partition in the bilayer membrane is postulated. The methyl, ethyl and n-propyl ether were readily dealkylated. However, the O-dealkylation rate of 7-nbutoxycoumarin was low and became very small for longer alkyl ethers. Both the effective dissociation constants and effective Michaelis constants decreased with elongation of the alkyl side chain of the coumarins. From plots of the apparent dissociation constants and apparent Michaelis constants against the lipid volume fraction of the proteoliposomes, the membrane partition coefficients for several homologues were calculated. When protein-free liposomes were added to 7-n-alkoxycoumarin solutions, the fluorescence intensity of the coumarins decreased and eventually became negligible in the presence of an excess of liposomal material. On the assumption that the overall fluorescence can be ascribed exclusively to the fraction of 7-n-alkoxycoumarin molecules present in the aqueous phase, partition coefficients for liposomal accumulation of the test compounds could be determined directly. For several coumarin ethers, comparable values were derived for the membrane partition coefficients from binding, kinetic and fluorescence intensity measurements. The change in free energy per methylene group of the 7-n-alkoxycoumarins for partitioning between n-octanol and buffer was significantly different from the value for liposome partitioning.

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Octanol: Water partition coefficients (P): Measurement, estimation, and interpretation, particularly for chemicals with P > 105

Cited by 147 publications

References 13 publications

The KOW Controversy

The KOW Controversy

A quantitative structure-activity relationship for the acute toxicity of some epoxy compounds to the guppy

Interaction of 7-n-alkoxycoumarins with cytochrome P-4502 and their partitioning into liposomal membranes. Assessment of methods for determination of membrane partition coefficients

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