INTRAMOLECULAR FLUORESCENCE QUENCHING IN COVALENT ACRYLAMIDE-INDOLE ADDUCTS |
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| Authors: | MAURICE R. EFTINK YI-WEI JIA DAVID E. GRAVES WIESLAW WICZK IGNACY GRYCZYNSKI JOSEPH R. LAKOWICZ |
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| Affiliation: | Department of Chemistry, University of Mississippi, University, MS 38677 USA;Department of Biological Chemistry, University of Maryland School of Medicine, Baltimore, MD 21201, USA |
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| Abstract: | Abstract— Indole derivatives have been prepared which have a covalently linked quencher, acrylamide. One of these adducts, N-acrylyltryptamine, has a flexible linkage and the other, N-acrylyl-1,2,3,4-tetrahydropyridoindole, has a rigid bridge between indole and the quencher. The intensity decays of these adducts were obtained using multi-frequency phase and modulation fluorometry. The fluorescence of these adducts appears to be dynamically quenched; dominant lifetimes of 64 ps and 31 ps are found for the flexible and rigid adducts. This indicates that very rapid intramolecular quenching occurs, even when the quencher and fluorophore cannot collide. Quenching in the rigid molecule probably involves electron transfer through two sigma bonds. Anisotropy decay data were also collected and rotational correlation times of 62 ps and 163 ps are reported for the flexibile and rigid adducts, respectively. |
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