Identification of the cephalosporin human serum albumin binding sites

We have demonstrated that the cephalosporins which possess heterozyclic pentagonal group substituents bind to the bilirubin binding site on albumin, while the cephalosporins which possess hexagonal hydrocarbon cycle substituents bind to the benzodizepine binding sites (site II) on albumin. No binding of cephalosporins to the so-called site I and fatty acids binding site on human albumin was demonstrated.