Monazomycin is a macrocyclic polyol lactone isolated from several species of Streptoverticillium, first reported in 1963. Monazomycin is active against Gram positive bacteria with weak Gram negative activity. In solution, monazomycin exists as hydrophilic clusters which, when adsorbed onto a lipid bilayer, can induce channel formation. Monazomycin is an important bioprobe for understanding membrane channels.