title: Synthesis and quantitative structure-activity relationship of hydrazones of N-amino-N'-hydroxyguanidine as electron acceptors for xanthine oxidase.
abstract: A series of new N-hydroxyguanidines were synthesized and tested for electron acceptor activity on bovine milk xanthine oxidase using xanthine as reducing substrate. Manual inspection of the structure-activity data revealed that molecules containing nitro groups ("set A") show a different structure-activity relationship pattern compared to non-nitro compounds ("set B"). Accordingly separate QSAR models were built and validated for the two sets. Substantial differences were found in properties governing acceptor activity for the models, the only common property being sterical access to the imino nitrogen atom of the hydroxyguanidinimines. For set A molecules the presence of a nitro substituent at a certain distance range from the hydroxuguanidino group was most important. In addition, the presence of a nitro group in the ortho position interacting with NH(2) of the hydroxyguanidino group, and the mutual geometry of the phenyl ring, hydroxyguanidine, and imine groups was important for this set. By contrast, for set B molecules the acceptor activity was most influenced by the geometry of methoxy groups and the size and geometry of meta and para substituents of the phenyl ring.
authors.affiliation: Department of Pharmaceutical Biosciences, Division of Pharmacology, Uppsala University, SE 751 24 Uppsala, Sweden.
authors.forename: Peteris
authors.initials: P
authors.lastname: Prusis
authors.forename: Maija
authors.initials: M
authors.lastname: Dambrova
authors.forename: Victor
authors.initials: V
authors.lastname: Andrianov
authors.forename: Eugene
authors.initials: E
authors.lastname: Rozhkov
authors.forename: Valentina
authors.initials: V
authors.lastname: Semenikhina
authors.forename: Irena
authors.initials: I
authors.lastname: Piskunova
authors.forename: Enock
authors.initials: E
authors.lastname: Ongwae
authors.forename: Torbjörn
authors.initials: T
authors.lastname: Lundstedt
authors.forename: Ivars
authors.initials: I
authors.lastname: Kalvinsh
authors.forename: Jarl E S
authors.initials: JE
authors.lastname: Wikberg
mesh_terms: D000818:Animals; D002417:Cattle; D006146:Guanidines / Q000138:chemical synthesis* / Q000737:chemistry; D006835:Hydrazones / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D021281:Quantitative Structure-Activity Relationship; D014969:Xanthine Oxidase / Q000737:chemistry*
chemical_list: D006146:Guanidines; D006835:Hydrazones; C062817:N-hydroxy-N'-aminoguanidine; D014969:Xanthine Oxidase