| abstract |
Novel ß-lactam compounds represented by the general formula [1]: [1] [wherein R1 is lower alkyl or hydroxyl-substituted lower alkyl; R2 is hydrogen or lower alkyl; R3 is hydrogen, hydroxyl, optionally substituted lower alkyl, or the like; R?4 and R5¿ are each hydrogen, hydroxyl, an amino-protecting group, optionally substituted lower alkyl, or the like; A is optionally substituted phenylene; and X is O, S, or NH]. These compounds exhibit excellent antibacterial activity against Gram-positive bacteria, particularly methicillin -resistant staphylococci and methicillin-resistant coagulase -negative staphylococci. |