Pawel Kolodziejczyk

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Daunorubicin can bind Cu (II) in Tris-HCl buffer (pH 7.4) and in the presence of NADH (100 microM). The complex is very stable. Cu (II) is not removed from the complex by cytochrome c reductase. The complexation of Cu (II) to daunorubicin gives rise to a modification of its redox properties. The complex, unlike the free drug, does not stimulate oxygen(More)
The clinical anticancer agent mitoxantrone is subject to irreversible oxidation by hydrogen peroxide catalyzed by horseradish peroxidase (HRP). The characteristic absorption changes that result provide evidence for an initial metabolite which is further oxidized enzymatically. The formation of the metabolite is accompanied by the concomitant generation of a(More)
Ambient temperature incubation of the anticancer agent mitoxantrone with horseradish peroxidase and hydrogen peroxide converts it into a hexahydronaphtho[2,3-f]quinoxaline-7,12-dione in which one side chain has cyclized to the chromophore. The structure of this cyclic metabolite was secured by independent synthesis. This peroxidative conversion of(More)
The antitumor agent mitoxantrone undergoes horseradish peroxidase-catalyzed oxidation by hydrogen peroxide to an identifiable cyclic metabolite which is a substituted hexahydronaphtho[2,3-f]-quinoxaline-7,12-dione. Binding of mitoxantrone to DNA inhibited enzymatic oxidation of the drug. The metabolite of mitoxantrone, derived from the action of the(More)
A cell line of Catharanthus roseus (L.) G. Don coded PRL # 200, was characterized with respect to its biosynthetic capabilities for indolealkaloids, in particular catharanthine, in suspension cultures. Other alkaloids isolated are vallesiachotamine isomers, ajmalicine, hörhammericine, hörhammerinine, vindolinine, 19-epivindolinine and strictosidine lactam.
Horseradish peroxidase catalyzed oxidation of the antitumor agent 5-iminodaunorubicin by hydrogen peroxide was studied with both spectrophotometric and electron paramagnetic resonance methods. Kinetics of oxidation of the drug at pH 3, 6 and 8 were determined. Rapid formation of a nitrogen-centered free radical metabolite was demonstrated with electron(More)