'Conjugate strategy' of lanthanide porphyrinate with crown ether toward synergistic binding and chirality sensing of biological substrates

Erbium porphyrinate/benzo-18-crown-6 conjugate extracted amino acids and bi ogenetic amines more effectively than a mixture of erbium porphyrinate and benzo-18-crown ether, while such an enhancement was rarely observed with ga dolinium or ytterbium conjugate. The erbium conjugate further offered 'indu ced circular dichroism signals' at Soret regions via synergistic binding of zwitterionic amino acids, the sign of which depended on the absolute confi guration of the bound substrates. (C) 2001 Elsevier Science B.V. All rights reserved.