Hydrophobic fragmental constant

Rekker, R. E. The Hydrophobic Fragmental Constant Its Derivation and Application with a Means of Characterizing Membrane Systems, Elsevier, Amsterdam, 1977. 

Mannhold, R., Rekker, R. F. The hydrophobic fragmental constant approach for calculating log P in octanol/ water and aliphatic hydrocarbon/water systems. Perspect. Drug Discov. Des. 2000, 18,1-18. 

Nys, G. G., Rekker, R. F. Statistical analysis of a series of partition coefficients with special reference to the predictability of folding of drug molecules. Introduction of hydrophobic fragmental constants (/-values). Chim. Therap. 1973, 8, 521-535. 

Rekker, R. F., Mannhold, R. Calculation of Drug Lipophilicity. The Hydrophobic Fragmental Constant Approach, VCH, Weinheim, 1992. 

Various methods by which the Kow of PAHs could be calculated are based on their molecular structures, i. e., a quantitative structure-property relationship (QSPR) approach [ 1,199,200]. One of the most famous techniques involves summation of hydrophobic fragmental constants (or f-values) for all groups in a molecule of a specific compound. On the other hand, Aboul-Kassim [1] and Aboul-Kassim et al. [202, 203] introduced a modeling technique based on the molecular connectivity indices of various PAHs, ranging from low- to high-molecular weight compounds. More details are given in Chap. 4 of this volume. 

Rekker RF (1977) The hydrophobic fragmental constant. Elsevier, Amsterdam/New York, NY, 220 pp... 

The measurement of the solubility of drugs in polar and non-polar media is very important in the pharmaceutical field. One method proposed to describe this solubility is the partition coefficient between octanol and water. The mathematical calculation of an octanol-water partition coefficient from values for functional groups was first proposed by Hansch et al. as Hansch s n constants,1 and was later developed by Rekker as hydrophobic fragmental constants (logP).2 This method was further improved by the use of molecular connectivities.17 The prediction of logP values can be performed by either a computer program or by manual calculation. For example, approximate partition coefficients (log P) have been calculated by Rekker s method ... 

The difference between the log k values measured and those predicted by Equations 6.1 and 6.2 from log P values calculated by Rekker s hydrophobic fragmental constant was within 5%. An example of logk values obtained experimentally compared with those predicted from Rekker s logP values is shown in Figure 6.2, where the predicted and measured retention factors of aromatic acids are shown. The correlation coefficient was 0.993 (n = 32), and the slope was 1.014. The precision is very high. 

The lipophilic behaviour of organic compounds 1. An updating of the hydrophobic fragmental constant approach. Quantitative Structure-Activity Relationships, 17, 517-536. 

R. F. Rekker (1977). The Hydrophobic Fragmental Constant. New York Elsevier. 

R. R. Rekker, "The Hydrophobic Fragmental Constant, Pharmacochemistry Library, Vol. 1, Elsevier, New York, 19TT-... 

Rekker, R.F. (1977) The Hydrophobic Fragmental Constant. Elsevier Sci. Publishers Co., New York. 

Rekker, R.F. (1977) The Hydrophobic Fragmental Constant. Its Derivation and Application. A Means of Characterizing Membrane Systems. Vol. 1, Pharmacochemistry Library, Nauta, W.T., Rekker, R.F., Editors. Elsevier Scientific Publishing Company, Oxford, U.K. 

Fig. 3.40 Plot of NMR binding (1/T2) (-A-) vs. N-alkyl hydrophobic fragment constants compared with an overlay plot of computed interaction energies vs. A/alkyl hydrophobic...

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