An antibiotic with the chemical formula C₃₇H₆₇NO₁₃, isolated from a red-pigmented soil bacterium, Streptomyces erythreus. It is used in the treatment of a wide range of bacterial infections and is a useful alternative for those patients who are allergic to penicillin.

It is the chemical having molecular formula C₄₃H₇₅NO₁₆.