DEGRADATION OF CEPHALORIDINE ON ALKALINE-HYDROLYSIS

A kinetic study on the alkaline hydrolysis of cephaloridine (1) at pH 10.5 and 37-degrees was carried out using ion-pair reversed-phase HPLC . The main resulting degradation products, the 7-epimer 2 of 1, the DE LTA2-isomer 3 of 1, and the 3-methylidene compound 4 were identified. The presence of a pyridinio group at C(3(1)) results in a slightly inc reased formation constant for the 3-methylidene compound 4 and the 7-e pimer 2, and introduces a new reaction: the isomerization of the doubl e bond at C(3) in the dihydrothiazine ring to C(2).