title: The stereochemistry of beta-lactam formation in cephalosporin biosynthesis.
abstract: 3H and 14C from (2R,3S)[U-14C,3-3H1]cysteine and (2R,3R)-[U-14C,2,3-3H2]cysteine were incorporated into cephalosporin C by Cephalosporium acremonium. Analysis of the radioactive cephalosporin C indicated that the formation of its beta-lactam ring occurs stereospecifically and with retention of configuration at C-3 of cysteine.
mesh_terms: D000164:Acremonium / Q000378:metabolism*; D002511:Cephalosporins / Q000096:biosynthesis*; D003545:Cysteine / Q000378:metabolism; D008968:Molecular Conformation; D013237:Stereoisomerism; D047090:beta-Lactams / Q000378:metabolism*
chemical_list: D002511:Cephalosporins; D047090:beta-Lactams; D003545:Cysteine