Assessment of the distribution coefficient of peptides in the octanol-water system by a structure-property correlation

A simple structure-property correlation for calculating the logarithm of the distribution coefficient (log P) of N-acetyl derivatives of carboxylic acid amides and peptides with neutral side radicals in the octanol-water system was proposed. Oligomers with a length of up to four amino-acid residues were considered. The molecular volume and number of polar groups capable of forming hydrogen bonds were chosen as the structural characteristics. Although the proposed correlation contains a small number of adjustable parameters, it satisfactorily describes the available experimental values of log P.