NOUVEAUX ANTIBIOTIQUES, LEUR PREPARATION ET LEUR UTILISATION

L'INVENTION CONCERNE LES ANTIBIOTIQUES DE TYPE A-30912H DE FORMULE:(CF DESSIN DANS BOPI)OU R EST UN GROUPEMENT LINOLEOYLE OU STEAROYLE ET R UN GROUPEMENT ALKYLE EN C-C, POURVU QUE, QUAND R EST CH, R SOIT UN GROUPEMENT LINOLEOYLE; LEUR PREPARATION ET LEUR UTILISATION COMME AGENTS ANTIFONGIQUES. A process for the preparation of antibiotic A-30912 factor H, its lower alkyl ether homologs and the tetrahydro derivatives of its homologs having the structural formula wherein R is linoleoyl or stearoyl and R is C1-C6 alkyl, subject to the proviso that when R is methyl, R is linoleoyl characterized by reacting antibiotic A-30912 factor A or its tetrahydro derivative with an acidic lower alkanol.