1. A cephalosporin derivatives of the general formula
wherein
R1 is an a-, β- or y-amino acid residue (bonded by the ester linkage), which may optionally be substituted by one or two lower alkyl groups at the amino group thereof,
R2 is an 1-alkanoyloxyalkyl, 1-alkoxycarbonyloxyalkyl, phthalidyl or 5-methyl-1,3-dioxolen-2-on-4-ylmethyl group,
R3 is a carbamoyloxymethyl group, which may optionally be substituted by one or two lower alkyl groups, or a heterocyclothiomethyl group, which may optionally be substituted by one or more appropriate substituents, and
R4 is a hydrogen atom or a hydroxy group, or its non- toxic salt are found to be useful as orally administrable antibiotics having broad antimicrobial activities against both gram-positive and gram-negative bacteria.
1.通式如下的
头孢菌素衍
生物
其中
R1 是 a-、β- 或 y-
氨基酸残基(通过酯键连接),其
氨基可任选被一个或两个低级烷基取代、
R2 是 1-烷酰氧基烷基、1-烷氧基羰酰氧基烷基、
酞酰基或 5-甲基-1,3-二氧
戊烯-2-4-基甲基、
R3 是
氨基甲酰氧基甲基,可任选被一个或两个低级烷基取代,或杂环
硫甲基,可任选被一个或多个适当的取代基取代,以及
R4 是氢原子或羟基,或其无毒盐,可用作口服抗生素,对革兰氏阳性和革兰氏阴性细菌具有广泛的抗菌活性。