Origin of Glycine from Acid Hydrolysis of the β-Lactam Antibiotic A16886B

Abstract
Structural analysis of two new β-lactam antibiotics, A16884A and A16886B, indicated that they, like cephalosporin C, were composed of modified valine and cysteine residues, and α-aminoadipic acid. However, acid hydrolysis of A16886B and A16884A produced three times as much glycine as did hydrolysis of cephalosporin C under the same conditions. Samples of A16886B- 14 C-6 and A16886B- 14 C-8 were prepared by the addition of cysteine- 14 C-3 and cystine- 14 C-1 to fermentations of Streptomyces clavuligerus . The specific activity of glycine obtained from hydrolysis of A16886B- 14 C-6 was considerably higher than that from hydrolysis of A16886B- 14 C-8 . An explanation for the difference in amounts of glycine obtained from hydrolysis of these antibiotics is discussed.