The use of 13C n.m.r. (c.m.r.) spectroscopy in biosynthetic studies of β-lactam antibiotics I. The incorporation of [1-13C]- and [2-13C] sodium acetate, and dl-[1-13C]- and dl-[2-13C] valine into cephalosporin C

The unique chemical and biological properties of β-lactam antibiotics and, in particular, the importance of penicillins and cephalosporins in the treatment of a variety of bacterial infections have stimulated investigations in various laboratories concerned with elucidation of the biosynthetic pathways leading to the formation of these antibiotics. Most of the present knowledge of some of these processes has been obtained from tracer studies involving 14C labelled precursors (Abraham & Newton 1967). The recent advances in the instrumentation required for recording 13C n.m.r.(c.m.r.) spectra, as well as commercial availability of simple 13C enriched compounds suitable for the synthesis of appropriate precursors, prompted us to examine the usefulness of c.m.r. spectroscopy in biosynthetic studies of cephalosporin C (Neuss, Nash, Lemke & Grutzner 1971).