On the proposed intermediacy of β-hydroxyvaline- and thiazepinone-containing peptides in penicillin biosynthesis
Abstract
The two thiazepinone-containing peptides (5) and (7), as well as the β-hydroxyvaline peptide (3), have been synthesised and tested as substrates for isopenicillin N synthesis in a cell-free extract from Cephalosporium acremonium; none of these compounds behaved as substrates, in contradiction to a recent proposal.