What is "filipin"

n. A potent antifungal chemical first isolated from the actinomycete ''Streptomyces filipinensis'', widely used as a histochemical stain for cholesterol.

Filipin is a mixture of chemical compounds first isolated by chemists at the Upjohn company in 1955 from the mycelium and culture filtrates of a previously unknown actinomycete, Streptomyces filipinensis. It was discovered in a soil sample collected in the Philippine Islands, hence the name filipin. The isolate possessed potent antifungal activity. It was identified as a polyene macrolide based on its characteristic UV-Vis and IR spectra.