Hydrophobic atom constants

Broto-Moreau-Vandicke hydrophobic atomic constants -> lipophilicity descriptors... 

A is the number of atoms, MW the molecular weight, q the atomic charges, (i the total dipole moment, and/the hydrophobic atomic constants. 

The regression coefficients h,- are the Klopman hydrophobic atomic constants measuring the hydrophobic contributions of atom types in the same way as the hydrophobic fragmental constants fi defined in Rekker and Leo-Hansch approaches. The best evaluation of 64 atomic constants plus 30 correction factors was obtained by a training set of 1663 compounds, p- = 0.93, s = 0.38, F = 218. 

Broto-Morean-Vandycke hydrophobic atomic constants... 

The Broto-Moreau-Vandicke contribution method is based on hydrophobic atomic constants a measuring the lipophilic contributions of atoms, each described by its nature, neighbouring atoms and associated connectivities, thus implicitly considering some proximity effects and interactions in conjugated systems [Broto etal, 1984b]. Hydrogen atoms and correction factors are not explicitly considered. The model is defined as ... 

The atomic properties constitute the weights used to characterize molecule atoms the most common atomic properties are atomic mass, - atomic charge, -> van der Waals radius, -> atomic polarizability, and hydrophobic atomic constants. Atomic properties can also be defined by the - local vertex invariants (LOVIs) derived from graph therory. 

Ghose-Crippen hydrophobic atomic constants for the ith atom (or fragments) in the target molecule, and is the distance between the considered atom (or fragments) and the kth grid point. Only non-hydrogen atoms A of the molecule are usually considered. 

Ghose-Crippen descriptors lipophilicity descriptors (0 Ghose-Crippen hydrophobic atomic constants)... 

Klopman hydrophobic atomic constants lipophilidty descriptors ( Klopman hydro-phobic models)... 

These are hydrophobic atomic constants a measuring the lipophilic contribution of atoms in the molecule, each described by its neighboring atoms [Ghose and Crippen, 1986 Ghose, Pritchett et al, 1988 Viswanadhan, Ghose et al, 1989]. The model for log P calculation is defined as... 

Here S is the solvent-accessible surface area for atom /, a, is the hydrophobic atom constant for atom /, and R , = e, where r is the distance between atom i and grid point t. In addition to supplementing standard CoMFA fields, HINT has been demonstrated to effectively model experimentally determined log P values in cases where CLOGP values fail. A different fragment-based, distance-dependent method to estimate lipophilicity, the molecular lipophilic potential (MLP), has been recently shown to be useful in docking and as a third field in CoMFA studies. 

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