| 摘要 |
<p>Compound of formula (I) or salts thereof wherein R1 is hydrogen, methoxy or formamido; R2 is an acyl group; CO¿2R?3 is a carboxy group or a carboxylate anion, or R3 is a readily removable carboxy protecting group or a pharmaceutically acceptable salt-forming group or in vivo hydrolysable ester group; R4 represents hydrogen or up to four substituents; X is S, SO, SO¿2? or CH2; Y is O, S, SO or SO2; n is 0 or 1; m is 1 or 2; and wherein in the (a) ring system the dotted line indicates that one pair of adjacent ring carbon atoms is joined by a C=C double bond. These compounds have antibacterial activity.</p> |
