 The reactive site is a beta-lactam nucleus, while the main peripheral functional groups are a quaternary quinolinium, an aminothiazolyl moiety and an unusual "O"-alkylated oxime.Cefquinome acts by inhibition of the cell wall synthesis, but it has a relatively short half-life of about 2.5 hours.It is less than 5% protein bound and is excreted unchanged in the urine.