| 摘要 |
<p>compound of formula (I) (I) or a pharmaceutically acceptable salt or ester thereof wherein R1 is a hydrogen atom or methyl group; R1 is a hydrogen atom or methyl group; and X is a group of the sub-formula (a), (b), (c), or (d). -CHR3R4 (a) -CH2-CHR3R4 (b) -CH2-CH2-CHR3R4 (c) (d) herein R3 is a hydrogen atom or a lower alkyl, aryl, aralkyl or substituted alkyl group; and R4 is an amino group or a carboxylic acid group. These compounds possess .beta. -lactamase inhibitory and antibacterial activity.</p> |
