Physicochemical properties/descriptors governing the solubility and partitioning of chemicals in water-solvent-gas systems. Part 1. Partitioning between octanol and air.
QSPR analyses of a data set containing experimental partition coefficients in the three systems octanol-water, water-gas, and octanol-gas for 98 chemicals have shown that it is possible to calculate any partition coefficient in the system 'gas phase/octanol/water' by three different approaches: (1) from experimental partition coefficients obtained in the corresponding two other subsystems. However, in many cases these data may not be available. Therefore, a solution may be approached (2), a traditional QSPR analysis based on e.g. HYBOT descriptors (hydrogen bond acceptor and donor factors, SigmaCa and SigmaCd, together with polarisability alpha, a steric bulk effect descriptor) and supplemented with substructural indicator variables. (3) A very promising approach which is a combination of the similarity concept and QSPR based on HYBOT descriptors. In this approach observed partition coefficients of structurally nearest neighbours of a compound-of-interest are used. In addition, contributions arising from differences in alpha, SigmaCa, and SigmaCd values between the compound-of-interest and its nearest neighbour(s), respectively, are considered. In this investigation highly significant relationships were obtained by approaches (1) and (3) for the octanol/gas phase partition coefficient (log Log).
Raevsky
O A
OA
Department of Computer-Aided Molecular Design, Institute of Physiologically Active Compounds of the Russian Academy of Sciences, 142432 Chernogolovka, Moscow Region, Russia. raevsky@ipac.ac.ru
Grigor'ev
V J
VJ
Raevskaja
O E
OE
Schaper
K-J
KJ
D020003:1-Octanol / Q000737:chemistry*; D000388:Air; D005740:Gases / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry*; D021281:Quantitative Structure-Activity Relationship; D012984:Software; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry*
D005740:Gases; D009930:Organic Chemicals; D012997:Solvents; D014867:Water; D020003:1-Octanol