Subject: (Fwd) Re: CCL:Octanol/Water Partitioning

From: David Livingstone <[email-masked]>
Date: Thu, 14 Dec 1995 08:57:31 +0100

I sent this answer back to Thomas directly but thought it was worth 
posting to the list as others might find this information useful.

Dave.

Date:          Fri, 17 Nov 1995 10:43:20

Thomas R. Cundari  writes:

> Are there any basic introductory articles which describe water/octanol
> partition coefficients?
> 
> >From what little I have read, it seems they are a popular measure of
> hydrophilicity of a compound and
> are also popular in structure-activity studies since a large number of them
> databased by the folks
> at Pomona.

It's nice to see someone "discovering" log P.  Yes, partition 
coefficients are a pretty popular parameter for QSAR - I reported 
that in 1988 over 40% of the 337 studies listed in the QSAR journal 
and its abstract service involved a hydrophobicity descriptor (D.J. 
Livingstone, "Quantitative Structure-Activity Relationships" in: 
Similarity Models in Organic Chemistry, Biochemistry and Related 
Fields (Eds, R.I. Zalewski, T.M. Krygowski & J. Shorter), Elsevier, 
1991, pp 557-627).  There is a bit of discussion of log P measurement 
and calculation in this chapter, along with a few references.

> 
> Mainly I'm interested in knowing how to do the experiments to measurw logP.
> Are the experiments  involved? Any applications/examples for metal
> complexes would be most interesting.
> 

There are numerous reviews and introductory articles that deal with 
the experimental determination of log P, far too many to list here, 
but some good places to look are:

Chapter 4 (The hydrophobic parameter: measurement and calculation) of 
the new book by Hansch & Leo (Exploring QSAR Fundamentals and 
Applications in Chemistry and Biology, ACS, 1995, ISBN 0-8412-2987-2)

"Partition Coefficient Determination and Estimation", (Eds W. Dunn, 
J. Block & R. Pearlman), Pergamon, 1986, ISBN ????

The chapter by Peter Taylor in that mammoth multi-volume set 
"Comprehensive Medicinal Chemistry.......".  It is actually in Vol. 4 
(Quantitative Drug design (ed. C.A. Ramsden) Pergamon, Oxford, 1990, 
pp 241-294)

Chapter 3 (Parameters) of Hugo Kubinyi's book (QSAR: Hansch Analysis 
and related Approaches, VCH, Weinheim, 1993, ISBN 3-527-30035-X).

Partition coefficients are actually very easy and very difficult to 
measure !

I hope this helps.

Cheers,

		Dave.
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