Lagosin, a polyene macrolide antibiotic, has first been extracted from an isolate of a Streptomyces species present in a sample of soil collected in Lagos, Nigeria [1]. It has been reported that the three polyene macrolide antibiotics, fungichromin, lagosin, and cogomycin, showed some stereochemical differences at one or more centers [1].

Lagosin was the most polar member of the filipin family of fungicides with broad spectrum antifungal and antitumor activity, acting via interaction with cell membrane sterols. The antibiotic lagosin, which appeared to be identical to, or a stereoisomer of, fungichromin, and was very similar in structure to the filipins [2]. The equilibrium constants for association of the polyene antibiotics with aqueous suspensions of cholesterol follow the order filipin IIl >amphotericin B >nystatin >lagosin, in agreement with the order reported for the extent of damage these antibiotics cause in natural and model membranes [2].

Reference:
[1] Pandey R C, Guenther E C, AszALos A A, et al.  Physicochemical and biological comparison of polyene macrolide antibiotics fungichromin, lagosin and cogomycin[J]. The Journal of antibiotics, 1982, 35(8): 988-996.
[2] Bittman R, Fischkoff S A.  Fluorescence studies of the binding of the polyene antibiotics filipin III, amphotericin B, nystatin, and lagosin to cholesterol[J]. Proceedings of the National Academy of Sciences, 1972, 69(12): 3795-3799.