Nystatin is polyene antifungal containing a conjugated tetraene and a diene, isolated as a complex of three components A1, A2 and A3 from Streptomyces noursei and first reported in 1950. Nystatin, like most polyene antifungals, binds to sterols in the fungal cell membrane leading to formation of ion channels in the wall, ion imbalance and cell death. Nystatin is an established bioprobe and widely-used antifungal reagent with over 4,000 literature citations.