1-[(4R)-N2-[(10R,12S)-10,12-Dimethyl-1-oxotetradecyl]-4-hydroxy-5-(phenylthio)-L-ornithine]-5-[(3R)-3-hydroxy-L-ornithine]pneumocandin B0 is an intermediate in the synthesis of Caspofungin Acetate, an echinocandin that inhibits the synthesis of β (1,3)-D-glucan, an integral component of the fungal cell wall.