It is an antibiotic produced by the fungus Papularia sphaerosperma. It has strong anti-yeast effect, but has no effect on filamentous fungi, bacteria and protozoa. It has no cross-resistance with polyene antibiotics, Conocandin and azole antifungal chemotherapies, but has partial cross-resistance with Echinocandin B. Among the four components A, B, C and D, C has the strongest activity, while D has the weakest activity. The mechanism of B is to inhibit the synthesis of glucan in yeast cell wall. Saccharomyces albicans infected mice ED50 (mg/kg) A 180 (subcutaneous), B 80 (subcutaneous).