We developed a practical preparation procedure for K-252a by methylating K-252b on an industrial scale. The water-insoluble K-252a, which was present in the cell mass, was converted to the water-soluble K-252b Na salt in an alkaline solution. The obtained K-252b was methylated with dimethylsulfate in the presence of potassium carbonate in dimethylacetamide. We have already used this method to manufacture 90 kg of K-252b from the fermentation broth, and regenerated 65 kg of K-252a from K-252b.
我们通过工业规模甲基化 K-252b 开发了 K-252a 的实用制备程序。细胞团中存在的不溶于
水的 K-252a 在碱性溶液中转化为
水溶性 K-252b Na 盐。将获得的K-252b在二甲基乙酰胺中的
碳酸钾存在下用
硫酸二甲酯甲基化。我们已经使用这种方法从发酵液中生产了 90 公斤 K-252b,并从 K-252b 再生了 65 公斤 K-252a。