Skip to main content
An official website of the United States government
Government Funding Lapse
Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted.

The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov.

Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

silatecan AR-67

A synthetic, highly lipophilic derivative of camptothecin, with potential antineoplastic and radiosensitizing activities. Silatecan DB-67 binds to and stabilizes the topoisomerase I-DNA covalent complex, inhibiting the religation of topoisomerase I-mediated single-stranded DNA breaks and producing lethal double-stranded DNA breaks when encountered by the DNA replication machinery; inhibition of DNA replication and apoptosis follow. Camptothecin readily undergoes hydrolysis at physiological pH, changing its conformation from the active lactone structure to an inactive carboxylate form. Modifications on the E ring of camptothecin prevent binding of human serum albumin, which prefers the inactive carboxylate form, thereby enhancing the stability of the active lactone structure and resulting in prolonged agent activity. In addition, this agent may radiosensitize tumor cells.
Chemical structure:7-tert-butyldimethylsilyl-10-hydroxycamptothecin
Search NCI's Drug Dictionary