Discussion Chemical shifts for the carbon atoms of streptovaricins AE, G, and J (SVA-SVE, SVG, and SvJ, re~ pectively)~ and for compounds derived from the streptovaricins (all of whose structures are shown in Figure 1) were determined on proton decoupled spectra and are summarized in Table I. Assignments were made by comparison of the spectra with proton off-resonance decoupled spectra, by single-frequency proton decoupling ...