Benzoquinone ansamycin antibiotic. Herbicidal compound. Potent, selective, irreversible and cell permeable protein tyrosine kinase inhibitor. Inhibitor of v-Src, Yes, Fps, Ros, Bcr-Abl and ErbB oncogene products. Antitumor compound. Antiangiogenic. Inhibits NF-kappaB activation and phosphorylation of phospholipase C-gamma1. Inhibitor of heat shock protein 90 (Hsp90). Binds Hsp90 and destabilizes client proteins leading to their ubiquitination and proteasomal degradation. Increases the sensitivity of certain cancer cells to chemotherapeutic agents. Neuroprotective. Antiparasitic, antischistosomal agent. Antiviral. Increase microtubules sensitivity to cold in plants.