<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A nonsedating derivative of thiobarbituric acid and a novel catalytic topoisomerase II inhibitor with antineoplastic activity. Merbarone interferes with DNA replication via binding directly to topoisomerase II at a domain that maybe shared by other topoisomerase II cleavage-enhancing agents, ex., etoposide. Its mechanism of action appears to be a novel one, since merbarone does not intercalate DNA nor stabilize DNA-topoisomerase II cleavable complexes.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>