Pyralomicins, novel antibiotics from Microtetraspora spiralis. II. Structure determination

Novel antibiotics, pyralomicins 1a approximately 1d, 2a approximately 2c were isolated from the culture broth of Microtetraspora spiralis MI178-34F18. The structures of pyralomicins were determined by various NMR spectral analyses including 1H-15N HMBC and 13C¿1H¿ NOE difference experiments.