Biological activities of racemomycin-B, beta-lysine rich streptothricin antibiotic, the main component of Streptomyces lavendulae OP-2

Chem Pharm Bull (Tokyo). 1990 Aug;38(8):2296-8. doi: 10.1248/cpb.38.2296.


Racemomycin-B (RM-B), the main component of Streptomyces lavendulae OP-2 which is the basis of 50% of the antibiotics produced, is a streptothricin antibiotic which contains three beta-lysine moieties in the molecule. RM-B had antimicrobial activity against plant-pathogenic microorganisms and growth-inhibitory activity against the root of Brassica rapa L. at the concentration of 50 ppm. It strongly inhibited the growth of Pseudomonas syringae pv. tabaci IFO-3508 (minimum inhibitory concentration (MIC): 0.4 microgram/ml), and also showed antifungal activity against six kinds of Fusarium oxysporum species (MIC: 0.1-2.0 micrograms/ml). The antimicrobial activity of RM-B was much stronger than those of RM-A and -C which contain, respectively, one and two beta-lysine moieties in their molecules. The above activities of RM-A, -C and -B were thus in the order of -B greater than -C greater than -A: namely, the biological activity of racemomycin compounds tended to be stronger with increase in the number of beta-lysine moieties in the molecule.

MeSH terms

  • Fusarium / drug effects*
  • Lysine / analogs & derivatives*
  • Pseudomonas / drug effects*
  • Streptothricins / pharmacology*
  • Structure-Activity Relationship


  • racemomycin
  • beta-lysine
  • Streptothricins
  • Lysine