Efficiency of cephalosporin complexation with aromatic compounds

The cephalosporin antibiotics cephradine, cephalexin, cefaclor and cefadrox il form complexes with beta -naphthol and several other naphthalene derivat ives. In these clathrate-type complexes, the cephalosporins form the host l attice for the naphthalene derivatives, Complexation with beta -naphthol an alogues can be employed to withdraw cephalosporins selectively from an aque ous solution. In this process, the most important parameter is the complexa tion efficiency, which expresses the extent to which the cephalosporins can be withdrawn from a solution. The complexation efficiencies for a series o f guest molecules are explained in terms of both the thermodynamics of the complexation reaction and the structural features of the cephalosporin comp lexes. In this manner, insight is gained into the subtle relationship betwe en the molecular structure of naphthalene derivatives and the stability of their complexes with the antibiotics. It is shown which molecular propertie s of the guest molecules are the most important ones for an optimal complex ation efficiency of cephalosporins.