title: Normal-phase automated mass-directed HPLC purification of a pyrrolobenzodiazepine library with vasopressin agonist activity.
abstract: A 23-member library of pyrrolobenzodiazepine derivatives with vasopressin agonist activity was purified on a 100-mg per injection scale using normal-phase (NP) automated mass-directed HPLC. Analytical NP APCI-LC/MS on an experimental monolith silica CN column utilizing gradients of methanol in ethoxynonafluorobutane (hexane-like solvent) was used to provide data on chromatographic purity and ionization of the solutes. The analytical data collected were used to program a preparative LC/MS instrument for "smart" fraction collection based on the protonated molecular ion of the component of interest. Preparative HPLC was carried out on a preparative cyano column with gradients of polar organic solvents in heptane containing n-propylamine as a basic additive. Flow rates twice as high as conventional ones were used for purification of library compounds. Small aliquots of the preparative flow were mixed with makeup solvent and introduced into an APCI source of a quadrupole mass spectrometer, which triggered collection of solutes. Two methods with fixed instrument parameters were used for purification. The system utilized commercially available instrumentation and software, which provided excellent recovery and purity of the library components and appeared to be useful as a fast and efficient alternative to traditional purification technologies based on reversed-phase LC/MS.
authors.affiliation: Discovery Analytical Chemistry, Chemical Technologies, Wyeth Research, Princeton, New Jersey 08543, USA. kaganm@wyeth.com
authors.forename: Michael
authors.initials: M
authors.lastname: Kagan
authors.forename: Michael
authors.initials: M
authors.lastname: Chlenov
authors.forename: Sergey
authors.initials: S
authors.lastname: Melnikov
authors.forename: Oliver
authors.initials: O
authors.lastname: McConnell
authors.forename: Alvin C
authors.initials: AC
authors.lastname: Bach
authors.forename: Guy
authors.initials: G
authors.lastname: Carter
authors.forename: Amedeo
authors.initials: A
authors.lastname: Failli
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Caggiano
authors.forename: Jay S
authors.initials: JS
authors.lastname: Shumsky
authors.forename: Dieter
authors.initials: D
authors.lastname: Lubda
mesh_terms: D001569:Benzodiazepines / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D011758:Pyrroles / Q000737:chemistry / Q000302:isolation & purification*; D054852:Small Molecule Libraries / Q000737:chemistry / Q000302:isolation & purification*; D014667:Vasopressins / Q000819:agonists*
chemical_list: D011758:Pyrroles; D054852:Small Molecule Libraries; C438462:pyrrolo(2,1-c)(1,4)benzodiazepine; D014667:Vasopressins; D001569:Benzodiazepines