从克拉霉素的结晶母液中分离出具生物活性的6,11-O-双甲基红霉素

在国产克拉霉素（６－Ｏ－甲基红霉素）的结晶母液中，有一个主要杂质，相对含量约占３０％左右，采用一种简便有效的化学分离方法。经乙酸乙酯重结晶后，可得到纯度约９４％的上述物质，经紫外、红外、质谱和核磁共振谱测试后，确证其结构为６，１１－Ｏ－双甲基红霉素。

An effective and facile method of isolating 6,11-O-dimethyl-erythromycin A from the mother liquid of clarithromycin

Compound B was a major related substance in clarithromycin and showed comparable in vitro antibacterial activities and acid stability to clarithromycin. An efficient method of separating both B and clarithromycin from the mother liquid of clarithromycin was reported. For example, the mixture, which contained 36% B and 57% clarithromycin was treated with ethyl acetate at first and followed by the procedure as reported. Clarithromycian with good purity was obtained in 70% rate of recovery, and B was obtained in 94% purity. By means of physical properties and spectrum analysis (IR, UV, MS EI, 1 H NMR, 13 C NMR, DEPT, 1 H 1H COSY, HMBC, HMQC), the structure of B was elucidated to be 6,11 O dimethyl erythromycin A.