Systemic fungal infections have become increasingly severe among immunocompromised or immunosuppressed patients including solid-organ or hematopoietic stem cell transplant recipients, and individuals who are on immunosuppressive drug regimens. There is still a high rate of morbidity and mortality associated with invasive fungal infections, because the currently available antifungal drugs have high toxicity, pharmacokinetic variability, and poor water solubility. The drugs primarily used to treat systemic fungal infections are polyene macrolides such as nystatin and amphotericin B, which comprise a family of polyketide-derived compounds bearing macrolactone rings with 20- to 40- carbon atoms including 3-8 conjugated double bonds. The primary antifungal mechanism of these polyene antibiotics include the formation of channels that mediate leakage of cellular K+ and Mg2+, leading to the death of the fungal cell. However, this process is dependent on the interactions between antibiotic molecules and ergosterol that appear to occur through the polyene region of the macrolactone core. The conjugated double bonds within this region also provide the rigidity of the antibiotic molecules that is presumably important for channel stability. However, the relatively high toxicity of polyene antibiotics toward mammalian cells and the poor distribution of these molecules in tissues have limited their general use for antifungal therapy. In order to improve the therapeutic efficacy and to reduce the toxicity of polyenes even at high doses, several strategies, including the use of combination therapy, structural modifications, and altering the physical state of the therapeutic agent in the drug delivery system have been employed. Previously, using a polyene cytochrome P450 hydroxylase-specific genome screening strategy, the Gram-positive rare actinomycetes Pseudonocardia autotrophica KCTC9441 was determined to contain genes potentially encoding polyene biosynthesis. The Biosynthetic gene cluster from P. autotrophica that specifies the biosynthesis of the Nystatin-like Pseudonocardia Polyene (NPP) molecule has been cloned and analyzed. Currently, we completed NPP structure bearing an aglycone identical to nystatin with a unique di-sugar moiety, mycosamine (a1-4)-N-acetyl-glucosamine. Remarkably, when the disaccharide containing NPP was compared with a mycosamine-containing nystatin, the former exhibited approximately 300-fold higher water solubility and 10-fold reduced hemolytic activity, while retaining about 50% of its antifungal activity. These results suggests that NPP is a promising lead compound for further development into a pharmacokinetically improved, and less cytotoxic polyene antifungal agent.