RS-22A, B and C: new macrolide antibiotics from Streptomyces violaceusniger. II. Physico-chemical properties and structure elucidation.

RS-22A, B and C are novel 36-membered macrolide antibiotics produced by Streptomyces violaceusniger. The structures of these antibiotics were unambiguously determined by 1D and 2D NMR and tandem-mass analysis of the oxidative derivative of RS-22C.