Biosynthesis of the spermidine moiety of glycocinnamoylspermidine antibiotic cinodine.

We have reported in this journal1) the biosynthesis of the glycocinnamoyl moieties of the antibiotic cinodine (Fig. 1), the broad-spectrum antibiotic discovered and identified at the Lederle Laboratories2,3). The glycocinnamoyl moieties were found to originate directly from D-glucosamine and L-tyrosine by isotope incorporation studies. The biosynthesis of the rest of the molecule, i.e., the spermidine moiety was also studied. Shaker-flask fermentations were carried out with Nocardia sp. strains LK-2558, LK-1034 and KL-5228 in media containing meat solubles and mineral salts as described in the previous paper. Carbon-14 labeled amino acids and amines were obtained from New England Nuclear Co. A study comparing the incorporation efficiencies of arginine, citrulline, ornithine and putrescine was conducted at doses of 13 iemol which are about half of the total Itmo1 of cinodine produced in 25 ml medium. Results shown in Table 1 indicate that all the amino acids involved in the urea cycle were incorporated into cinodine with good efficiencies. Ornithine and guanidolabeled arginine were incorporated to a degree comparable to tyrosine, the most efficiently incorporated amino acid studied previously. Citrulline and uniformly-labeled arginine were incorporated to a lesser degree than tyrosine. The high incorporation efficiency of [guauido"C]arginine indicated that the guanido carbon