RUG. Mededelingen van de Faculteit Landbouwwetenschappen vol:58 issue:4b pages:1973-1980
L-cysteine, L-cystenyl-L-valine and L-cysteinyl-D-valine showed an apparent inhibition of the isopenicillin N synthase that was due to inactivation of isopenicillin N during bioassay. In contrast to their phenylacetylated analogs (prepared by a new chemical synthesis procedure), these aminothiols caused a concentration and pH-dependent hydrolysis of the beta-lactam ring. Other compounds related to the biosynthetic pathway of the penicillins, such as alpha-aminoadipic acid, phenylacetic acid, L-valine, isopenicillin N, penicillin G, 6-aminopenicillanic acid and their corresponding penicilloic acids did not show any effect on the isopenicillin N synthase of Penicillium chrysogenum.