title: Photostability of 2-hydroxymethyl-4,8-dibenzo[1,2-b:5,4-b']dithiophene-4,8-dione (NSC 656240), a potential anticancer drug.
abstract: Stability studies of 2-hydroxymethyl-4,8-dibenzo[1,2-B:5,4-b']dithiophene-4,8-dione (NSC 656240, dithiophene), a poorly water-soluble (approximately 5 microg/ml) potential anticancer drug are reported. Dithiophene stability turned out to be very sensitive to laboratory fluorescent lighting. The rate of photodegradation of dithiophene was studied in aqueous solutions at room temperature (approximately 25 degrees C) at various pH values, in MeOH, CH(3)CN, DMF, DMA, and in mixed nonbuffered aqueous/organic solutions. The aqueous pH-rate profile indicated no sensitivity to changing pH values. 1H NMR and LC/MS methods were used to characterize the degradation products. Dithiophene photodegradation in the presence of air followed an apparent autoxidation pathway with dithiophene-2-aldehyde and dithiophene-2-carboxylic acid as the major degradants. The structures were confirmed against authentic samples. Dithiophene photodegradation under anaerobic conditions followed an apparent disproportionation pathway with only one identified major product, dithiophene-2-aldehyde.
authors.affiliation: Department of Pharmaceutical Chemistry, University of Kansas, 2095 Constant Avenue, Lawrence, KS 66047, USA.
authors.forename: S
authors.initials: S
authors.lastname: Silchenko
authors.forename: C
authors.initials: C
authors.lastname: Schöneich
authors.forename: B J
authors.initials: BJ
authors.lastname: Carlson
authors.forename: V J
authors.initials: VJ
authors.lastname: Stella
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000528:radiation effects*; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D013058:Mass Spectrometry; D012995:Solubility; D012997:Solvents; D013876:Thiophenes / Q000737:chemistry / Q000528:radiation effects*; D013997:Time Factors
chemical_list: C120943:2-hydroxymethyl-4,8-dihydrobenzo(1,2-b-5,4-b')dithiophene-48-dione; D000970:Antineoplastic Agents; D012997:Solvents; D013876:Thiophenes