title: E-state fields: applications to 3D QSAR.
abstract: The derivation of a new 3D QSAR field based on the electrotopological state (E-state) formalism is described. A complementary index and its associated field, the HE-state, describing the polarity of hydrogens is also defined. These new fields are constructed from a nonempirical index that incorporates electronegativity, the inductive influence of neighboring atoms, and the topological state into a single atomistic descriptor. The classic CoMFA steroid test data set was examined with models incorporating the E-state and HE-state fields alone and in combination with steric, electrostatic and hydropathic fields. The single best model was the E-state/HE-state combination with q2 = 0.803 (three components) and r2 = 0.979. Using the E-state and/or HE-state fields with other fields consistently produced models with improved statistics, where the E-state fields provided a significant, if not dominant, contribution.
authors.affiliation: Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond 23298-0540, USA.
authors.forename: G E
authors.initials: GE
authors.lastname: Kellogg
authors.forename: L B
authors.initials: LB
authors.lastname: Kier
authors.forename: P
authors.initials: P
authors.lastname: Gaillard
authors.forename: L H
authors.initials: LH
authors.lastname: Hall
mesh_terms: D001665:Binding Sites; D017076:Computer-Aided Design; D015195:Drug Design; D004563:Electrochemistry; D006859:Hydrogen / Q000737:chemistry; D008958:Models, Molecular; D011987:Receptors, Steroid / Q000737:chemistry; D013256:Steroids / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D011987:Receptors, Steroid; D013256:Steroids; D006859:Hydrogen