Antibiotic X-5108. IX. Chemical conversion of mocimycin to aurodox and derivatives of aurodox, goldinamine and mocimycin.

Mocimycin was converted to the acylesters by selective acylation of the hydroxyl group of the 4-hydroxy-1-methyl-2(1H)pyridinone moiety. Subsequent N-methylation at the nuclear nitrogen and removal of the protective group from the resulting reaction products afforded aurodox. Mono-O-acetylmocimycin and several analogous aurodox esters thus prepared possess antibacterial activity in vitro and growth-promotion properties in poultry. Esters of aurodox involving the hydroxyl group of the 4-hydroxy-1-methyl-2(1H)pyridinone moiety are activated. Accordingly, acetic acid treatment of the aurodox esters generates O-acylgoldinamines which undergo transacylation furnishing N-acylgoldinamines. Alternatively, N-acylgoldinamines can be prepared by selective mono--o-arylsulfonylation of aurodox, liberating o-arylsulfonylgoldinamine by treatment with acetic acid followed by N-acylation and removal of the protective arylsulfonyl group. A third approach to N-acylgoldinamines consists in direct N-acylation of goldinamine itself which is prepared by acetic acid treatment of aurodox. None of these derivatives prepared, however, exhibited significant antimicrobial or growth-promoting properties, suggesting that goldinonic acid moiety, or a closely related derivative thereof, is required for biological activity.