中文摘要：

目的 检测水杨酸及水杨酸的19个类似物对分离自铜绿假单胞菌的β-内酰胺酶的抑制活性，初步探讨它们的构效关系。方法 采用Nitrocefin法。结果 水杨酸对该酶的50％抑制浓度（IC50）为22mmo1·L^-1；4个类似物的IC50比水杨酸低，其余类似物的活性比水杨酸差。结论 水杨酸苯环上的羧基及邻位羟基是活性基团之一。水杨酸邻位上的羟基被羧基取代后能提高抑制活性。在水杨酸的苯环上增加磺酸基或硝基能提高抑制活性。苯环E的氨基可降低水杨酸的抑制活性。在苯甲酸的苯环上连接氯或氟与抑制活性无关。

英文摘要：

Aim Nineteen compounds related to salicylic acid were evaluated for their in vitro activity of inhibiting fl-lactamase isolated from a resistant strain of Pseudomonas aeruginosa, and their structure- activity relationships were examined. Methods Nitrocefin method was used. Results The 50% inhibitory concentration （ ICso ） of salicylic acid inhibiting fl-lactamase was 22 mmol·L^-1 ; four analogs had IC50 lower than that of salicylic acid; fifteen analogs had IC50 higher than that of salicylic acid. Conclusion Examination of the structure-activity relationships of the compounds revealed that earboxyl group and adjoining hydroxyl group were active group, and replacement of adjoining hydroxyl by carboxyl increased activity nearly 4-fold. Moreover, addition of a sulfonic group at C-5 and nitro group at C-3,5 of benzenoic ring of salicylic acid resulted in a 2-fold to 3-fold increase in activity, addition of a amino group at C-5 of benzenoic ring of salicylic acid decreased activity, add addition of -C1 or -F at C-2,4 position of benzenoic ring of benzoic acid did not show activity.