Compounds comprising flavin N-oxides for treatments of solid tumors, non-solid tumor masses, leukemias, and non-small cell lung cancers and for eradicating contaminants in blood products. Methods of treating patients having solid type cancers comprising administering a therapeutically effective amount of a flavin N-oxide to a subject in need of treatment and exposing the flavin N-oxide to an activator such that activation of the flavin N-oxide results in damage to the DNA in the cancer cells without substantial damage to the DNA of normal cells are also provided. Methods of using a flavin N-oxide as part of a combination therapy with chemotherapy, radiation therapy, or both are also provided. Methods of reducing pathogenic bacterial or viral contamination in a composition comprising a) mixing the composition with an efficacious amount of a flavin N-oxide and b) exposing the mixture of the composition and the flavin N-oxide to an activator for a period of time sufficient to activate the flavin N-oxide such that the flavin N-oxide reduces the contamination in the composition are also provided. Preferably, the composition is a blood product selected from plasma, platelets, and red blood cells and the activator is an enzyme.
