Abstract
In the presence of S-adenosylmethionine, 2-oxoglutarate, Fe2+ and a reducing agent, cell-free extracts of S. clavuligerus convert cephalosporin C and O-carbamoyldeacetylcephalosporin C into 7.alpha.-methoxy derivatives. No synthesis of a 7.alpha.-methoxy derivative of deacetylcephalosporin C was detected in the system used, and the 7.alpha.-methoxy derivative of deacetoxycephalosporin C was produced only in relatively small amounts. The 7.alpha.-methoxy group is introduced after the cephalosporin ring system has been formed and its introduction may represent the final step in a biosynthetic pathway.