Compounds of formula (I) or salts thereof: ##STR1## wherein R.sup.1 is hydrogen, methoxy or formamido; R.sup.2 is an acyl group; CO.sub.2 R.sup.3 is a carboxy group or a carboxylate anion, or R.sup.3 is a carboxy protecting group, pharmaceutically acceptable salt-forming group or in vivo hydrolysable ester group; R.sup.4 represents hydrogen or up to four substituents; X is O, S, SO or SO.sub.2 ; Y is O, S, SO or SO.sub.2 ; n is 0 or 1; and m is 1 or 2. The compounds have antibacterial activity. Methods of synthesis of, and pharmaceutical formulations containing, compounds (I) are also described.
式(I)的化合物或其盐:##STR1## 其中R.sup.1是氢、甲氧基或甲酰胺基;R.sup.2是酰基;CO.sub.2R.sup.3是羧基或
羧酸盐阴离子,或R.sup.3是羧基保护基、药学上可接受的盐形成基或体内
水解酯基;R.sup.4代表氢或高达四个取代基;X是O、S、SO或SO.sub.2;Y是O、S、SO或SO.sub.2;n为0或1;m为1或2。这些化合物具有抗菌活性。还描述了合成方法和含有化合物(I)的药物配方。