| 摘要 |
NEW MATERIAL:compounds of the formula (R is H, lower alkyl, triphenylmethyl). EXAMPLE:PS - 6 of the formula where R is H. USE:Antibiotics: effective on gram-positive and negative bacteria, especially having strong antibiotic activity against bacteria resisting conventional beta-lactam antibiotics. PREPARATION:In an example, a novel mold of streptomyces SP, A 271 is aerobically cultivated in the medium containing L- and/or D-valine, L- and D-leucine at 4-9pH and 20-40 deg.C for 0-100hr to produce PS-6 of the formula where R is H and it is isolated. The resulting PS-6 or its salt is reacted with an ester-forming compound of RY (Y is removable group) or a lower diazoalkane to produce antibiotics other than R is H. |
