Chemical modification of deltamycins. I. 4''-O-acyl analogs of deltamycins.

Using 4''-O-deacyldeltamycin as a starting material, various 4''-O-acyl derivatives were chemically synthesized by the following scheme: 2'-O-acetylation leads to 4''-O-acylation leads to 2'-O-deacetylation. 4''-O-Deacyldeltamycin is produced during the fermentation of deltamycin producing organisms or can be prepared by the biological deacylation of the deltamycins. 4''-O-Phenylacetyl-4''-O-deacyldeltamycin (PAD) showed good activity against various bacteria and mycoplasma. Among para-substituted PAD derivatives, NPAD (p-nitrophenylacetyl-) and SPAD (p-methylsulfonylphenylacetyl-) showed increased potency as compared to PAD against certain bacteria. The PAD was evaluated by in vivo experiments for plasma levels in mice and dogs and curative activity on the infected mice with Staphylococcus aureus Smith by subcutaneous or oral administration.