Determination by high-performance liquid chromatography of some compounds involved in the biosynthesis of penicillin and cephalosporin.

A sensitive and convenient method for the simultaneous determination of several of the compounds involved in the biosynthesis of penicillin and cephalosporin is described. The method involves derivatization with a chiral fluorogen (o-phthaldialdehyde with an optically active thiol N-acetyl-L-cysteine), followed by high-performance liquid chromatography on a reverse-phase column as described by Aswad (D. W. Aswad, 1984, Anal. Biochem. 137, 405-409). With an analysis time of 1 h it was possible to determine simultaneously most of the common L-amino acids, L- and D-alpha-aminoadipic acid, L- and D-valine, delta-(L-alpha-aminoadipyl)-L-cysteine (AC), delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV), glutathione, isopenicillin N, penicillin N, desacetoxycephalosporin C, desacetylcephalosporin C, and cephalosporin C. Using o-phthaldialdehyde alone it was possible to determine specifically the thiol-containing peptides AC, ACV, and glutathione.