FR 901379 is a pneumocandin belonging to the echinocandin class of cyclic lipopeptides produced by Coleophoma empetri F11899, discovered as antifungals and patented in 1991 by Ueda and colleagues. FR 901379 inhibits the synthesis of 1,3-β-D glucan in the fungal cell wall. The sulfonic acid confers water solubility, a limitation with other echinocandins. Unfortunately, FR 901379 was also haemolytic, this limitation being overcome by selective hydrolysis using a cyclic lipopeptide acylase to yield FR 179642, the starting material for production of the commercial antifungal, micafungin.