The lipophilic behaviour of organic compounds: 1. An updating of the hydrophobic fragmental constant approach

In the first part of this paper we briefly describe experimental (octanol/w ater partitioning) as well as computational approaches to quantifying molec ular lipophilicity. The central section focuses on the hydrophobic fragmental constant approach (Cf-system) as developed by Rekker and his group, starting in the early se venties. The original approach has been extended and revised a number of ti mes; the most recent updating is presented here. It is followed by a detail ed description of how to apply the correction factor CM. The practical proc edure of Cf-calculations is described for some examples and the validity of these calculations is verified by comparison with other calculation method s and experimental data.