title: Quantitative structure-activity relationships. 2. A mixed approach, based on Hansch and Free-Wilson Analysis.
abstract: Based on the theoretical and numerical equivalence of Hansch's linear multiple regression model and the modified Free-Wilson model a mixed approach is developed. The mixed approach is a combination of both models which makes use of the advantages of each model and widens the applicability of Hansch and Free-Wilson analysis. The Free-Wilson approach now is applicable also in the case of parabolic dependence of biological activity on a particular physical property, e.g., log P or pi. A rational explanation is given for the use of dummy variables in Hansch equations and the derivation of Hansch correlations for de novo group contributions obtained from Free-Wilson analysis. Some examples illustrate the mixed approach and demonstrate its usefulness to establish biologically meaningful structure-activity relationships.
mesh_terms: D000818:Animals; D001234:Aspergillus niger / Q000187:drug effects; D001409:Bacillus cereus / Q000187:drug effects; D001412:Bacillus subtilis / Q000187:drug effects; D013293:Enterococcus faecalis / Q000187:drug effects; D006190:Haemophilus / Q000187:drug effects; D006834:Hydrazines / Q000494:pharmacology; D008689:Methacrylates / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008956:Models, Chemical; D008968:Molecular Conformation; D009169:Mycobacterium tuberculosis / Q000187:drug effects; D010636:Phenols / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D051381:Rats; D012044:Regression Analysis; D012294:Rifamycins / Q000494:pharmacology; D012505:Sarcina / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects; D013329:Structure-Activity Relationship; D013970:Thyronines / Q000031:analogs & derivatives; D013974:Thyroxine
chemical_list: D006834:Hydrazines; D008689:Methacrylates; D010636:Phenols; D000644:Quaternary Ammonium Compounds; D012294:Rifamycins; D013970:Thyronines; D013974:Thyroxine