title: Quantitative structure-activity relationship and quantitative structure-pharmacokinetics relationship of 1,4-dihydropyridines and pyridines as multidrug resistance modulators.
abstract: OBJECTIVE
  The aim of this study was to develop quantitative structure-activity/pharmacokinetic relationships (QSAR/QSPKR) for a series of synthesized 1,4-dihydropyridines (DHPs) and pyridines as P-glycoprotein (P-gp) inhibitors.
  
  
  METHODS
  Molecular descriptors of test compounds were generated by 3D molecular modeling using SYBYL and KowWin programs. Forward inclusion coupled with multiple linear regression (MLR) was used to derive a QSAR equation for Ca2+ channel binding. A multivariate statistical technique, partial least square (PLS) regression, was applied to derive a QSAR model for P-gp inhibition and QSPKR models. Cross-validation using the "leave-one-out" method was performed to evaluate the predictive performance of models.
  
  
  RESULTS
  For Ca2+ channel binding, the MLR equation indicated a good correlation between observed and predicted values (R2 = 0.90), and cross-validation confirmed the predictive ability of the model (Q2 = 0.67). For P-gp reversal, the model obtained by PLS could account for most of the variation in P-gp inhibition (R2 = 0.76) with fair predictive performance (Q2 = 0.62). Nine structurally related 1,4-DHP drugs were used for QSPKR analysis. The models could explain the majority of the variation in clearance (R2 = 0.90), and cross-validation confirmed the prediction ability (Q2 = 0.69).
  
  
  CONCLUSIONS
  QSAR/QSPKR models were developed, and the QSAR models were capable of identifying synthesized 1,4-DHPs and pyridines with potent P-gp inhibition and reduced Ca2+ channel binding. The QSPKR models provide insight into the contribution of electronic, steric, and lipophilic factors to the clearance of DHPs.
authors.affiliation: Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, 517 Hochstetter Hall, Amherst, New York 14260-1200, USA.
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Zhou
authors.forename: Qingxiang
authors.initials: Q
authors.lastname: Shao
authors.forename: Robert A
authors.initials: RA
authors.lastname: Coburn
authors.forename: Marilyn E
authors.initials: ME
authors.lastname: Morris
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000465:Algorithms; D000972:Antineoplastic Agents, Phytogenic / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004095:Dihydropyridines / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology*; D018432:Drug Resistance, Multiple / Q000502:physiology*; D008958:Models, Molecular; D011725:Pyridines / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology*; D021281:Quantitative Structure-Activity Relationship; D014747:Vinblastine / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000972:Antineoplastic Agents, Phytogenic; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D004095:Dihydropyridines; D011725:Pyridines; D014747:Vinblastine