Tetrocarcins E1,E2,F and F-1, new antibiotics. Fermentation, isolation and characterization.

Abstract
New components of tetrocarcins (E1, E2, F and F-1) were found in the culture broth of Micromonospora chalcea KY 11091 that was known to produce tetrocarcins A, B and C. Tetrocarcin F-1 consisted of tetronolide and nitro sugar (tetronitrose). Tetrocarcins E1 and E2 consisted of F-1 and deoxy sugar (L-digitoxose). Tetrocarcin F consisted of F-1 and 2 deoxy sugars (their structures have not yet been determined). They all showed antibacterial activities against gram-positive bacteria, and the specific activity decreased with a decrease in the numbers of deoxy sugars attached to the aglycone.