The bafilomycins are fungal plecomacrolide antibiotics with a 16-membered lactone ring. They inhibit the growth of Gram-positive bacteria and fungi. Bafilomycin D is a potent inhibitor of vacuolar H+ ATPases (V-ATPases) that inhibits the V-ATPase from the fungus N. crassa with an IC50 value of approximately 2 nM. It is about 1,000-fold less effective against the K+-dependent ATPase of E. coli.
