Conversion of17O/18O-labelled δ-(L-α-aminoadipyl)–L-cycteinyl–D-valine into17O/18O-labelled isopenicillin N in a cell-free extract of C. acremonium

Abstract

δ-(L-α-Amino[1,1,6-¹⁷O/¹⁸O]-adipyl)-L-cysteiny-D-valine was converted into isopenicillin N in cell-free extracts of Cephalosporium acremonium with no loss of ¹⁷O/¹⁸O label as shown by ¹⁷O n.m.r. spectroscopy and mass spectrometry; incubation of unlabelled tripeptide in cell-free system containing ¹⁷O/¹⁸O-enriched water produced isopenicillin N with no incorporation of ¹⁷O/¹⁸O.