Antibiotics DO-248-A and B and process for preparing the same

摘要

Antibiotics DO-248-A and DO-248-B of the following Formula I: <IMAGE> (I) wherein R is ethyl or isopropyl, have antibacterial activity against acid-fast bacteria. DO-248-A, DO-248-B, or their pharmaceutically acceptable salts are, as an active ingredient of anti-fast-acid drugs, orally or parenterally administered to human beings or animal. DO-248-A and DO-248-B are prepared by incubating an antibiotic DO-248-A- and/or DO-248-B-producing microorganism belonging to genus Streptoverticillium in a medium and recovering antibiotic DO-248-A and/or DO-248-B from the culture broth.