1288984 7-Aminocephalosporanic acid derivatives CIBA GEIGY AG 8 Dec 1969 [11 Dec 1968 23 April 1969 24 June 1969] 59714/69 Heading C2A 7-Aminocephalosporanic acid derivatives of the formula in which R 1 is a tetrazole residue bound through a nitrogen atom and R 2 represents a hydrogen atom, a free hydroxyl group or a hydroxyl group esterified by a carboxylic acid, in which the ester oxygen atoms may be replaced by sulphur atoms (with the exception of the acetoxy group). an unsubstituted or N-sub...

In order to protect the penicillinamidase activity in bacterial suspensions, the activity of penicillinase is selectively inactivated by treating the suspensions with an org. solvent non-immiscible with water (pref. toluene, methylcyclohexane, o-xylene, n-heptane, CCl4, methyl isobutyl-ketone, butylacetate, pentanol-(I) or hexanol-(I)) in amounts of 0.01.2.0% and stirring 1-10 hrs. at 10-40 degrees C. On adding penicillin-G, the yield of 6-amino-penicillanic acid is improved.