title: 3D QSAR studies on T-type calcium channel blockers using CoMFA and CoMSIA.
abstract: Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were performed on a series of isoxazolyl compounds as a potent T-type calcium channel blockers. A set of 24 structurally similar compounds served to establish the model. Four different conformations of the most active compound were used as template structures for the alignment, three of which were obtained from Catalyst pharmacophore modeling and one by using SYBYL random search option. All CoMFA and CoMSIA models gave cross-validated r(2) (q(2)) value of more than 0.5 and conventional r(2) value of more than 0.85. The predictive ability of the models was validated by an external test set of 10 compounds, which gave satisfactory pred r(2) values ranging from 0.577 to 0.866 for all models. Best predictions were obtained with CoMFA std model of Conformer no: 3 alignment (q(2)=0.756, r(2)=0.963), giving predictive r(2) value of 0.866 for the test set. CoMFA and CoMSIA contour maps were used to analyze the structural features of the ligands accounting for the activity in terms of positively contributing physicochemical properties: steric, electrostatic, hydrophobic and hydrogen bonding fields.
authors.affiliation: Biochemicals Research Center, Korea Institute of Science and Technology, PO Box 131, Cheongryang, Seoul 130-650, South Korea.
authors.forename: Munikumar Reddy
authors.initials: MR
authors.lastname: Doddareddy
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Jung
authors.forename: Joo Hwan
authors.initials: JH
authors.lastname: Cha
authors.forename: Yong Seo
authors.initials: YS
authors.lastname: Cho
authors.forename: Hun Yeong
authors.initials: HY
authors.lastname: Koh
authors.forename: Moon Ho
authors.initials: MH
authors.lastname: Chang
authors.forename: Ae Nim
authors.initials: AN
authors.lastname: Pae
mesh_terms: D002121:Calcium Channel Blockers / Q000737:chemistry*; D020747:Calcium Channels, T-Type / Q000737:chemistry*; D015195:Drug Design; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D011237:Predictive Value of Tests; D021281:Quantitative Structure-Activity Relationship; D015203:Reproducibility of Results
chemical_list: D002121:Calcium Channel Blockers; D020747:Calcium Channels, T-Type