摘要 |
The present invention provides a purification process of K-252a, which comprises: treating microorganism cells containing K-252a represented by formula (I): <CHEM> with an alkaline solution to convert K-252a into K-252b represented by formula (II): <CHEM> or alkali salts thereof, which are then released out of the cells, methylating K-252b or alkali salts thereof to convert them into K-252a again, and isolating and collecting the resulting K-252a. w |