['We present work that demonstrates that cisplatin reacts rapidly with dimethyl sulfoxide (DMSO) in solution and identify the structure and reactivity of the resulting compound.', 'Electrospray ionization-mass spectrometry (ESI-MS) and NMR were used to identify the chemical structure of compounds formed when DMSO reacts with cisplatin. We studied the reactivity of the identified compound with DNA. In vitro toxicity studies in neurons and cancer cells and in vivo toxicity studies in rats were used to determine both the cancer chemotherapeutic and toxic effects of the identified compound.', 'Cisplatin binds rapidly with DMSO to form a DMSO adduct. The resulting compound has reduced ability to bind to double-stranded DNA both in vitro and in cells. This compound has reduced toxicity for cancer cells and neurons in vitro. In vivo nephrotoxicity studies show that the adducted compound has different nephrotoxicity and elimination characteristics than cisplatin.'] Do cisplatin and dimethyl sulfoxide react to form an adducted compound with reduced cytotoxicity and neurotoxicity?