NCI Drug Dictionary

The NCI Drug Dictionary contains technical definitions and synonyms for drugs/agents used to treat patients with cancer or conditions related to cancer. Each drug entry includes links to check for clinical trials listed in NCI's List of Cancer Clinical Trials.

A fluorescent dye of benzimidazole derivative. Pibenzimol binds to AT-specific sites in the minor groove of duplex DNA and inhibits topoisomerase I, and DNA polymerase, thereby preventing DNA replication. This agent prolongs the G2 phase of the cell cycle and initiates apoptosis in tumor cells. Check for active clinical trials using this agent. (NCI Thesaurus)

Hoechst dye 33258
pibenzimol hydrochloride
Code name:HOE 33258
Hoechst 33258
Chemical structure:
  • phenol, 4-(5-(4-methyl-1-piperazinyl)(2,5'-bi-1H-benzimidazol)-2'-yl)-, trihydrochloride
  • phenol, p-[5-[5-(4-methyl-1-piperazinyl)-2-benzimidazolyl]-2- benzimidazolyl]-, trihydrochloride