近20年来,抗生素有了飞跃的发展,第三代青霉素和头孢菌素的出现,使抗生素的发展达到了新的高峰,但仍存在一些问题,如对革兰氏阳性菌(G~+)、厌氧菌等作用较差;易发生耐药性;多数品种不能口服以及价格昂贵等。因此人们又重新在合成药领域中, The development of antibiotics has reached a new peak in the past 20 years because of the rapid development of antibiotics. The emergence of the third generation of penicillins and cephalosporins has reached a new peak. However, there are still some problems such as Gram-positive bacteria (G ~ +) , Anaerobic bacteria, such as poor; prone to drug resistance; most varieties can not be oral and expensive. Therefore, people are again in the field of synthetic drugs,