title: Bioassay for A-56268 (TE-031) and identification of its major metabolite, 14-hydroxy-6-O-methyl erythromycin.
abstract: A-56268 is a new macrolide which is generally two-fold more potent than erythromycin. A new bioassay is described in which plasma samples are extracted with acetonitrile prior to bioassay. The concentration range for the assay is between 0.05-4.0 micrograms/ml, and the concentrations measured are within 6% of those measured by high-power liquid chromatography. An active metabolite which is as active as erythromycin was identified in the plasma. The plasma half-life and area under the plasma curve values of A-56268, as determined by bioassay, were significantly greater than those of erythromycin.
authors.affiliation: Anti-infective Discovery Division, Abbott Laboratories, Illinois 60064.
authors.forename: P B
authors.initials: PB
authors.lastname: Fernandes
authors.forename: N
authors.initials: N
authors.lastname: Ramer
authors.forename: R A
authors.initials: RA
authors.lastname: Rode
authors.forename: L
authors.initials: L
authors.lastname: Freiberg
mesh_terms: D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D017291:Clarithromycin / Q000031:analogs & derivatives; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology; D006801:Humans; D008837:Micrococcus / Q000187:drug effects
chemical_list: C056228:14-hydroxyclarithromycin; D004917:Erythromycin; D017291:Clarithromycin