title: One-electron reduction of adriamycin: properties of the semiquinone.
abstract: Pulse radiolysis of aqueous solutions containing adriamycin and redox indicators of known one-electron reduction potential (E1) shows that its E1 at pH 7 is -328 mV (vs NHE). The variation E1 with pH in the range 6-12 shows that the net charge on the semiquinone at pH 7 is zero. As well as the pKa values of 2.9 and greater than or equal to 14 established independently, the semiquinone has a pKa close to 9.2. The new data enable the structure and likely reactivity of the semiquinone to be specified.
mesh_terms: D016227:Benzoquinones; D055598:Chemical Phenomena; D002621:Chemistry; D004317:Doxorubicin; D004583:Electrons; D008433:Mathematics; D008956:Models, Chemical; D010084:Oxidation-Reduction; D011809:Quinones
chemical_list: D016227:Benzoquinones; D011809:Quinones; C025232:semiquinone radicals; D004317:Doxorubicin