Amphotericin as a Topical Antifungal Antibiotic

A previously unknown Streptomyces species, isolated from a soil sample obtained at Tembladora, on the Orinoco River in South America, has been found to produce two amphoteric antifungal agents which have been named amphotericin A and amphotericin B.¹Studies of their physical properties reveal slight differences between the infrared absorption spectra of the two materials. Crystalline amphotericin A exhibits the ultraviolet absorption curve of a conjugated tetraene similar to rimocidin or nystatin, while the absorption curve for amphotericin B is characteristic of a conjugated heptaene, and is similar to ascosin and trichomycin. These compounds also have different solubilities in various organic solvents. Although the chemical structure is not known, elementary analysis indicates that both compounds contain carbon, hydrogen, and nitrogen in similar proportion and do not contain halogen, sulfur, methoxyl, or acetyl groups.²Pharmacological studies reveal that the two compounds are very poorly absorbed