Amphotericin X1 is a derivative of Amphotericin B with good antifungal activity. Amphotericin X1 inhibits Candida albicans 33/079, Cryptococcus neoformans 451, C.parapsilosis 937A, Aspergillus niger 57A and A.fumigatus (MICs: 1 ug/mL, 1 ug/mL, 8 ug/mL, 2 ug/mL and 2 ug/mL).