Novel cephalosporin compounds having antibacterial activity, which are represented by the following compounds of the general formula (I), ##STR1## wherein R.sub.1 represents an amino group or a protected amino group; .circle.A represents a 5- or 6-membered heterocyclic ring containing therein 1 to 4 nitrogen, oxygen or sulfur atoms; R.sub.2 represents a normal alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms; a cycloalkenyl group having 3 to 6 carbon atoms; an aromatic organic residue; a 3- to 6-membered heterocyclic ring containing 1 to 4 nitrogen, sulfur or oxygen atoms or, ##STR2## wherein Ra and Rb each, which may be the same or different, represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R.sub.3 represents an organic residue containing an amino group or a protected amino group and a carboxyl group or a protected carboxyl group; X represents a sulfur atom or an oxygen atom; and R.sub.4 represents a hydrogen atom or a protective group of carboxyl group. The general formula (I) described above can also be used as physiologically acceptable addition salts. The compounds exhibit excellent intestinal absorption as well as high blood concentration and longer biological half-life.
具有抗菌活性的新型
头孢菌素化合物,由以下的一般式(I)表示:##STR1## 其中,R.sub.1表示
氨基或保护的
氨基;.circle.A表示含有1至4个氮、氧或
硫原子的5-或6元杂环;R.sub.2表示具有1至6个碳原子的正烷基、具有3至6个碳原子的支链烷基、具有2至6个碳原子的烷氧基烷基、具有3至6个碳原子的环烷基、具有3至6个碳原子的环烯基、芳香有机残基、含有1至4个氮、
硫或氧原子的3-至6元杂环或,##STR2## 其中,Ra和Rb各自表示氢原子或具有1至4个碳原子的烷基;R.sub.3表示含有
氨基或保护
氨基和羧基或保护羧基的有机残基;X表示
硫原子或氧原子;R.sub.4表示氢原子或羧基的保护基团。上述的一般式(I)也可以用作生理上可接受的加盐物。这些化合物表现出优异的肠道吸收性能,以及高血浓度和较长的
生物半衰期。