Ophiobolin B is a fungal phytotoxin and inhibits calmodulin (a protein involved in calcium regulation). Ophiobolin B also exhibit antibacterial and antitumor activities.
Calmodulin is a calcium-sensing protein that regulates a wide array of proteins involved in diverse cellular functions. Ophiobolin B is a sesterterpenoid fungal phytotoxin that binds and irreversibly antagonizes calmodulin, producing cytotoxic and antimicrobial effects. It induces apoptosis in chronic lymphocytic leukemia cells with an LC50 value of 2 nM and in different zygomycetes with MIC values ranging from 25-50 μg/ml.[Cayman Chemical]
Ophiobolin B is a minor member of a class of phytotoxic metabolites produced by Bipolaris and other genera of plant pathogenic fungi. Ophiobolin B acts by inhibiting calmodulin action in calcium regulation.
