A novel rifamycin derivative having the formula (I): ##STR1## wherein X.sup.1 is an alkyl group with 1 to 6 carbon atoms or a cycloalkyl group with 3 to 8 carbon atoms; X.sup.2 is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms; R.sup.1 is hydrogen atom or acetyl group; A is a group represented by the formula: ##STR2## wherein R.sup.2 is an alkyl group with 1 to 4 carbon atoms or an alkoxyalkyl group with 2 to 6 carbon atoms and R.sup.3 is an alkyl group with 1 to 6 carbon atoms or an alkoxyalkyl group with 2 to 6 carbon atoms, or a group represented by the formula ##STR3## wherein ##STR4## is a 3 to 9 membered cyclic amino group with 2 to 8 carbon atoms, R.sup.4 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or salts thereof, a process for preparing the same and antibacterial agents containing the same as an effective ingredient. The rifamycin derivative of the present invention having the formula (I) shows a strong antibacterial activity against the Gram-positive bacteria and the acid-fast bacteria.
具有以下式子(I)的新型
利福霉素衍
生物:##STR1##
其中X1为具有1到6个碳原子的烷基或具有3到8个碳原子的环烷基;X2为氢原子或具有1到4个碳原子的烷基;R1为氢原子或乙酰基;A为由以下式子表示的基团:##STR2##
其中R2为具有1到4个碳原子的烷基或具有2到6个碳原子的烷氧基烷基,R3为具有1到6个碳原子的烷基或具有2到6个碳原子的烷氧基烷基,或由以下式子表示的基团:##STR3##
其中##STR4##为具有2到8个碳原子的3到9元环
氨基基团,R4为氢原子或具有1到4个碳原子的烷基,或其盐。本发明的
利福霉素衍
生物具有式(I),对革兰氏阳性菌和酸性快速菌表现出强烈的抗菌活性。本发明还提供了一种制备该
利福霉素衍
生物的方法和含有该
利福霉素衍
生物作为有效成分的抗菌剂。