| 摘要 |
Cpds. of formula (I) and their salts are new. In (I) R is 2-7C alkyl or lower hydroxyalkyl. Pref. R is ethyl; 2-hydroxyethyl; n-hexyl; 4-hydroxybutyl; 2- or 3-hydroxypropyl, or S or R 3-hydroxybutyl. (I) are made from antibiotics X-14868A (i.e. the cpd. where R is H) by reaction with ROH in presence of ion-exchange resin, in acid form. The alcohol or diol may be used as solvent and is typically at room temp. The same method can also be used to prepare the known methyl ether. (I) are useful as antibiotics, anticoccidiosis and antimalarial agents, antiinflammatories and also for improving food utilisation in ruminants and pigs. The pref. daily dose is 0.03-0.075 mg/kg. - |
