ORGN 446 |
| The spectrophotometric monitoring of pH in proliferating tumors requires active delivery of the fluorescent dyes into the cellular cytosol. The molecular delivery systems promise significant advantages over the conventional microinjection or hydrolytic sequestering of the reporter dye. In this regard, we have designed a ditopic receptor cyclen 1, capable of strong cooperative binding of the pH-sensitive dye pyranine and sodium cation. This receptor comprises the cyclen tetraester core outfitted with four naphthyl urea termini. Coordination of Na+ to the receptor ester groups alters the orientation of thiourea moieties and triggers the binding of pyranine. This cooperative binding serves as a basis for the active delivery of pyranine from the Na+-rich extracellular plasma into the K+-rich cytosol. The synthesis, evaluation of relevance of structural elements present in cyclen 1 to pyranine recognition, its binding affinity and transport efficacy will be discussed.
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Bioorganic, Metal-Mediated Reactions, and Molecular Recognition
8:00 PM-10:00 PM, Tuesday, 30 August 2005 Washington DC Convention Center -- Hall A, Poster
Division of Organic Chemistry |
