MLOGP

One of the first but yet successful and weU known method, MLOGP, was developed by Moriguchi et al. [64]. MLOGP uses the sum of Hpophilic (carbons and halogens) and hydrophilic atoms (nitrogens and oxygens) as two basic descriptors. These two descriptors were able to explain 73% of the variance in the experimental log P values for 1230 compounds. The use of 11 correction factors covered 91% of the variance. Due to the simplicity of implementation, the MLOGP method was widely used as a calculation and reference approach for many years. 

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Methods that produced results not significantly different from the method with the minimal MAE received rank 1, i.e. all methods with rank 1 had a similar best performance. After determination of this group, the remaining methods with results significantly better than those of MLOGP or AAM received rank 11 and 111, respectively. Methods that had an MAE non-significantly different from (or even worse than) AAM received rank IV. 

MLOGP Logarithm of the calculated octanol/water partition coefficient MR Molar refraction... 

The analysis of the numerical values of these four parameters led to cutoff numbers close to five or multiples of five. This led to the formulation of the rule now famously called rule of five . The rule states that poor absorption or permeation are more likely to result when a compound has a molecular weight greater than 500 Daltons, has log P greater than five (or MlogP greater than 4.15), has more than five H-bond donors (expressed as the sum of OHs and NHs) and has more than ten H-bond acceptors (expressed as the sum of Ns and Os). 

MLOGP (= Moriguchi model based on structural parameters)... 

MLOGP Moriguchi LOGP OLS Ordinary Least Squares... 

The descriptors selected in PCA were ICS, Mor29m, 01 and MIogP, which represent four distinct t5 es of interactions related to the molecules, especially between the molecules and the biological receptor. These descriptors are classified as steric (IC5), 3D-morse Mor29m), electronic (Ol) and molecular (MlogP). The main properties of a drug that appear to influence its activity are its lipophilicity, the electronic effects within the molecule and the size and shape of the molecule (steric effects) (Gareth, 2003). 

Fig. 9. Variations in descriptors a) Variations in ICS for each cluster b) Variations in Mor29m for each cluster c) Variations in 01 for each cluster d) Variations in MlogP for each cluster...

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