头孢菌素结构和其聚合反应关系的探讨——Ⅰ.结构对反应类型的影响

STUDIES ON RELATIONSHIP BETWEEN STRUCTURE OF CEPHALOSPORINS AND ITS POLYMERIZATION I.RELATIONSHIP BETWEEN STRUCTURE OF CEPHALOSPORINS AND TYPE OF ITS POLYMERIZATION

头孢菌素的聚合反应可分为:只和母核结构有关的N型聚合反应和7位侧链参与聚合的L型聚合反应两类。7位侧链不具有自由氨基等活性基团的头孢菌素,只能发生N型聚合反应;所形成的聚合物中保留有7位侧链取代基结构,但3位侧链的取代基结构消失。7位侧链中含有自由氨基的头孢菌素,在酸性条件下一般主要以N型聚合反应为主,在碱性条件下N型聚合反应和L型聚合反应可以同时发生;两类聚合反应的相对强度与化合物本身的结构有关。

(Two kinds of polymerizations of cephalosporinswere found out in aqu ecus solution of cephalosporins.These are 1) type N of polymerization which depends only on the structure of cephalosporinic nucleus and 2) type L of polyomeriza-tion which caused by the interaction between an active group in substituent at position 7 of cephalosporins and the necleus.Cephalosporins which have not any active group, i.e.free animo group, can only take place the type N reaction . The polymer keeps the structure of substituent at position 7 of cephalosporins, but the structure of side chain at the position 3 disappears. If there is afree amino group in a side chain at position 7 of cephalosporios, both type N and type L reaction occur in basic condition, but only type N reaction in acidic condition.The relativentensity of polymerization depends on structural natures of the cephalosporins.