3′-O-β-Glucosyl-4′,5′-didehydro-5′-deoxyadenosine Is a Natural Product of the Nucleocidin Producers Streptomyces virens and Streptomyces calvus

[Image: see text] 3′-O-β-Glucosyl-4′,5′-didehydro-5′-deoxyadenosine 13 is identified as a natural product of Streptomyces calvus and Streptomyces virens. It is also generated in vitro by direct β-glucosylation of 4′,5′-didehydro-5′-deoxyadenosine 12 with the enzyme NucGT. The intact incorporation of oxygen-18 and deuterium isotopes from (±)[1-(18)O,1-(2)H(2)]-glycerol 14 into C-5′ of nucleocidin 1 and its related metabolites precludes 3′-O-β-glucosyl-4′,5′-didehydro-5′-deoxyadenosine 13 as a biosynthetic precursor to nucleocidin 1.