目的 設計合成具有抗菌活性的2-位亞甲基頭孢類抗生素。方法 以7-苯乙酰氨基-3-氯甲基-頭孢-3-烯-4-羧酸對甲氧基芐酯（GCLE）為起始原料，經Mannich反應、酶解、縮合等反應制得2-位亞甲基頭孢類抗生素。通過微量稀釋法測定了其對標準金黃色葡萄球菌、標準肺炎克雷伯桿菌的最小抑菌濃度。結果 合成了4個新化合物8a～8d，利用1H-NMR和MS確證了結構，初步測試顯示較好的抗菌活性。結論 初步生物活性試驗結果顯示化合物8a、8b和8d對標準金黃色葡萄球菌的抗菌活性均與頭孢克肟和頭孢地尼相當，化合物8a、8b對標準肺炎克雷伯桿菌的抗菌活性與頭孢克肟和頭孢地尼相當。

Objective To design and synthesize 2-methylene-cephalosporin antibiotics for antibacterial activity. Methods 2-methylene- cephalosporin antibiotics were synthesized from the starting material GCLE via Mannich reaction, enzymolysis, and condensation, etc. The study on antibacterial activity was carried out using micro-dilution to detect the minimum inhibitory concentrations (MIC) on standard Staphylococcus aureus and standard Bacillus canalis capsulatus. Results The four novel compounds were synthesized. All the compounds were characterized by 1H-NMR and MS. The preliminary test showed that the compound had good antibacterial activities. Conclusion Through the preliminary bioactivity test, the results show that the antibacterial activities of the compounds 8a, 8b, and 8d on standard Staphylococcus aureus are the same to those of cefixime and cefdinir, and the antibacterial activities of the compounds 8a and 8b on standard Bacillus canalis capsulatus are the same to those of cefixime and cefdinir.