title: Correlation of contraceptive activity of norethisterone and levonorgestrel esters with VR(w) values and hydrolysis rates.
abstract: The relationships between contraceptive activity, hydrophobic character and alkaline hydrolysis rates were studied in three homologous series of norethisterone and levonorgestrel esters. Hydrophobic character was expressed by the high-performance liquid chromatographic retention term, VR(w) or retention volume at 100% aqueous mobile phase. A parabolic and bilinear relationship was shown between log VR(w) and log biological response. No correlation between second-order alkaline hydrolysis rates, k2, measured in 70% (v/v) aqueous dioxan and contraceptive activity was established.
authors.affiliation: Department of Pharmacy, National University of Singapore.
authors.forename: R
authors.initials: R
authors.lastname: Karunanithy
authors.forename: S H
authors.initials: SH
authors.lastname: Yeo
authors.forename: S L
authors.initials: SL
authors.lastname: Leung
mesh_terms: D000089:Acetic Anhydrides; D002851:Chromatography, High Pressure Liquid; D003271:Contraceptive Agents, Female / Q000494:pharmacology*; D004951:Esterification; D004952:Esters / Q000494:pharmacology; D005463:Fluoroacetates; D006868:Hydrolysis; D016912:Levonorgestrel; D009640:Norethindrone / Q000031:analogs & derivatives* / Q000494:pharmacology; D009644:Norgestrel / Q000494:pharmacology*; D012044:Regression Analysis; D012995:Solubility; D013461:Sulfur Oxides; D013816:Thermodynamics
chemical_list: D000089:Acetic Anhydrides; D003271:Contraceptive Agents, Female; D004952:Esters; D005463:Fluoroacetates; D013461:Sulfur Oxides; D009644:Norgestrel; C023589:thionyl chloride; C017958:trifluoroacetic anhydride; D016912:Levonorgestrel; D009640:Norethindrone