3.1-氧杂头孢菌素类 3.1结构和活性通过取代母核周围的残基制得半合成头孢菌素并成功地用于临床之后,多组研究人员开始对其母核进行结构改造。在一系列结构改造产物中,1-氧杂头孢菌素类的抗菌作用最引人注意。外消旋的1-氧杂噻孢霉素是该系列的第一个活性化合物,然后是D、L-1- 3.1-O-CTC 3.1 Structure and activity After semisynthetic cephalosporins were prepared by replacing the residues around the mother nucleus and successfully used in clinical practice, several groups of researchers began to structurally engineer their parent nuclei. Among a series of structural modifications, the antibacterial effects of 1-oxo cephalosporins are the most noticeable. Racemic 1-oxabacurcycline is the first active compound in this series, followed by D, L-1-