Improved Methods for Production Isolation and Assay of Two New Chloroisoxazoline Amino Acid Antitumor Antimetabolites: U-42126 and U-43795

摘要

Improved fermentation and isolation procedures for antitumor antimetabolites U-42,126 and U-43,795 increased drug yields 30-fold. The sensitivity limit of a newly developed assay is 0.03 μg of U-42,126 and 2.0 μg of U-43,795 per ml. The in vitro antimicrobial effect of both drugs was antagonized by histidine.