| 摘要 |
Cephalosporins of the formula WHEREIN R stands for a six-membered cyclic hydrocarbon residue which is either substitued or unsubstituted and either saturated or unsaturated, or an unsaturated five-membered heterocyclic residue containing one hetero-atom in its ring; R1 stands for a hydrogen atom or -OR2 wherein R2 is an organic group; n is 1 or 2; and X is -OR3, -SOmR3, -NH2 or -CN, where R3 stands for an alkyl group of 1 to 3 carbon atoms or a phenyl group and m is 0, 1 or 2, are produced by condensation between (1) an alpha -substituted- alpha -amino acid of the formula WHEREIN R has the aforementioned significance, or its reactive derivative and (2) a 7-aminocephem compound of the formula WHEREIN R1, n an X have the aforementioned significances through the utilization of a microorganism having a cephalosporin-synthesizing activity. |
