The complete assignment of the 13C NMR spectra of lasalocid and the sodium salt-complex of the antibiotic.

All thirty-four signals observed in the 13C nmr of both the free acid form (Ia) and sodium salt (Ib) of the polyether antibiotic lasalocid have been assigned. This was achieved using model compounds such as 3-methylsalicylic acid, the retroaldol ketones from both lasalocid and lysocellin and a gamma-lactone from a third polyether, salinomycin. The last assignments to be made were accomplished using biosynthetically enriched samples of the antibiotic.