citreamicin zeta

Isovaleric acid (1,2,3a,4,8,14,15,17-octahydro-12-hydroxy-11-methoxy-1,3a-dimethyl-2,8,14,15,17-pentaoxo[1]benzopyrano[2',3':6,7]naphth[2,1-g]oxazolo[3,2-b]isoquinolin)-1-ylmethyl ester