Geldanamycin

A benzoquinoid ansamycin antibiotic having antitumor activities. It suppresses DNA replication by inhibiting c-myc gene expression in lymphoblastoma L5178Y cells. It inhibits tyrosine kinases and induces increased p53 protein involved in cell-cycle arrests of human ovarian tumor cells. It inhibits the 90 kDa heat shock protein that reglates cell signal transduction, and telomerase activity, and induces apoptosis.