| abstract |
Prodn. of L-leupeptides (I) comprises culturing a (I)-producing strain of Streptomyces in a nutrient medium under aerobic conditions at pH 5-7, and isolating (I) from the culture broth at pH =7. (I) are enzyme inhibitors, e.g. with antiprotease, antiplasmin, antitrypsin and anti-inflammatory activity (see US 3840513). The process avoids racemisation of the active L-form to the less active DL-form. In an example, a leupeptine in 100% L-form is obtd. by culturing S. roseus ATCC 31245. |