Filipin complex comprises a family of pentaene macrocyclic lactones first isolated from Streptomyces filipinensis and reported by researchers at Upjohn in 1955. Filipin complex consists of four analogues, with filipin III comprising the bulk (>70%) of the complex. Filipin complex is a potent broad spectrum antifungal agent that also exhibits antitumor and antiviral activities. Filipin complex acts by binding cell membrane sterols, disrupting membrane integrity.