The carbon-13 NMR spectrum of gougerotin.

Gougerotin was isolated from Streptomyces gougerotii in 1962", its structure was established in 19692' and total syntheses were announced in 1972" and in 19754'. In the course of a soil screen we isolated gougerotin from an organism identified as Streptom}ices puniceus subsp. doliceus subsp. nov. (NRRL 11160). It was co-produced with the clazamycins''". The ultraviolet'' and proton magnetic resonance' spectra of our sample were in good agreement with those published for gougerotin. Identification was completed when we interpreted the C-13 NMR spectrum. Since the assigned spectrum can facilitate early identification of this antibiotic and its analogs" and be useful in biosynthetic studies", we present it here. The CMR spectrum of gougerotin in D_O consists of 15 lines. The chemical shifts and assignments of these are shown in Fig. 1. The cytosine assignments"' were the simplest to make in view of the certainty of the presence of a cytosine residue (the UV and PMR spectra). The remainder of the spectrum can easily be misinterpreted to be that of a furanoside ring to which was attached a carbon bridge as in the ezomycins. However, comparison with the published spectra of hikizimycint" (for corrected structure see references 12 and 13), showed that a 4-amino-4-deoxypyranose ring was present. The remainder of the spectrum was assignable on the basis of chemical shifts once it was accepted that a uronamide was present and that the 8 62 triplet was assignable to a serine moiety. The remainder of the spectrum was assigned from chemical shift tables.