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I. I. Baskin and N. I. Zhokhova
basis function). Easy differentiability of molecular field functions allows for applying very powerful although still unexplored in chemistry apparatus of data analysis
and visualization offered by a newly emerged branch of mathematical statistics,
functional data analysis [30], to visualize both molecular fields and fields of model
coefficients. One should also add that, by applying the above-discussed methodology, in the framework of CMF, due to modularity of kernel-based approaches, it is
Type of molecular field
Isosurfaces of the fields of regression
coefficients
Chemical interpretation
Electrostatic
Red color (marked with
sign “+”) means increase of biological activity upon increase of
partial electric positive
charge on the nearest
atoms
Steric
Green color (marked
with sign “+”) means
increase, yellow color
(marked with sign “-“)
means decrease of biological activity upon
increase of bulkiness of
the nearest atoms.
Hydrophobic
Yellow color (marked
with sign “+”) means
increase, violet color
(marked with sign “-“)
means decrease of biological activity upon
increase of lipophilicity
of the nearest atoms.
Table 13.1  Types of molecular fields, isosurfaces of KRR regression coefficients and chemical
interpretation for the case of thrombin inhibitors (2-amidinophenylalanines). In all cases the isosurfaces are superimposed over the structure of one of inhibitors