gramicidin gramicidin B antibiotic_resistance ARO:3000223 Gramicidin B is one of the three gramicidins in gramicidin D, with a phenylalanine in position 11. It is structurally similar to gramicidin A, but its ability to induce the assembly of bilayers is reduced. Gramicidins form dimers in the bacterial membrane that increase the permeability of cations. PubChem:25244501