Abstract: There are disclosed a .beta.-lactam compound represented by the formula (I): ##STR1## wherein R.sub.1 represents an acyl group; M represents a hydrogen atom, a protective group or an eliminatable group which is easily hydrolyzable in a human body; B represents a group represented by the formula (b): ##STR2## where at least one of R.sub.2, R.sub.3 and R.sub.9 represent a group represented by the formula: --A--OR.sub.4 where R.sub.4 represents a hydrogen or a lower alkyl group; and A represents a straight or branched alkylene group having 1 to 6 carbon atoms; and a remaining group or groups are each independently a hydrogen atom; a cyano group; a lower alkyl group which may be substituted by a halogen atom; a carbamoyl group which may be substituted by a lower alkyl group; a cycloalkyl group; or a carboxyl group which may be substituted by a protective group or an eliminatable group which is easily hydrolyzable in a human body, and also when R.sub.9 is --A--OR.sub.4, and R.sub.

Abstract: There are disclosed a .beta.-lactam compound represented by the formula (I): ##STR1## wherein R.sub.1 and R.sub.2 are independently a hydrogen atom or a lower alkyl group; M is a hydrogen atom, a protective group or an eliminatable group which is easily hydrolyzable in a human body; R' and R" are independently a hydrogen atom or a protective group; A is a mercapto group substituted by a substituted or unsubstituted polycyclic nitrogen-containing heterocyclic ring or a group represented by the following formula (a):--OOCNR.sub.3 R.sub.4 (a)where R.sub.3 and R.sub.4 are independently a hydrogen atom or a lower alkyl group, provided that R.sub.1 and R.sub.2 are both hydrogen atoms, both R.sub.3 and R.sub.4 being hydrogen atoms are excluded,or its pharmaceutically acceptable salt, and a method for preparing the same , medicinal composition for microbism therapy containing the same and intermediates for synthesis of the same.

Abstract: There are disclosed a .beta.-lactam compound represented by the formula (I): ##STR1## wherein R.sub.1 represents an acyl group; M represents a hydrogen atom, a protective group of an eliminatable group which is easily hydrolyzable in a human body; B represents a group represented by the formula (b): ##STR2## where at least one of R.sub.2, R.sub.3 and R.sub.9 represent a group represented by the formula: -A-OR.sub.4 where R.sub.4 represents a hydrogen or a lower alkyl group; and A represents a straight or branched alkylene group having 1 to 6 carbon atoms; and a remaining group or groups are each independently a hydrogen atom; a cyano group; a lower alkyl group which may be substituted by a halogen atom; a carbamoyl group which may be substituted by a lower alkyl group; a cycloalkyl group; or a carboxyl group which may be substituted by a protective group of an eliminatable group which is easily hydrolyzable in a human body, and also when R.sub.9 is -A-OR.sub.4, R.sub.2 and R.sub.

Abstract: There is disclosed a novel .beta.-lactam antibiotics represented by the formula: ##STR1## wherein A is a group represented by the formulae -NHCO--, --NHCONHCO--, --NHCOCH.dbd.CH-- or ##STR2## where R.sub.6 is a hydrogen atom or a lower alkyl group; R.sub.1 and R.sub.2 are independently a hydrogen atom or a protective group; R.sub.3 is a hydrogen atom or a methoxy group; X is a hydrogen atom, a hydroxyl group, a protected hydroxyl group, a halogen atom, a lower alkoxy group or a nitro group; n is an integer of 1 or 2; Y is a group represented by the formulae: ##STR3## provided that a carbon atom which is bonded by a carboxyl group being bonded to nitrogen atom; M is a hydrogen atom, a protective group or an easily hydrolyzable group in a human body; R.sub.7 is a hydrogen atom, a methyl group a lower alkoxy-methyl group or a group represented by the formula: --CH.sub.