The application of fluorescent species and their interactions for the development of methods in synthesis and biodetection.

摘要

This dissertation concerns the application of photochemistry in the synthesis of novel tricyclic structures which are analogues of alkaloids. The photophysical studies focused on the unusual mechanism of excited state intramolecular proton transfer (ESIPT). The previously reported ESIPT of a 3-hydroxyflavone (3HF) derivative and the [3+2] dipolar cycloaddition of the resulting oxidopyryllium species with methyl cinnamate inspired extension of the study to aza-analogues of 3HF. Irradiation of 1,2-dimethyl-3-hydroxyquinolinone (DMQ) led to the induced ESIPT product, a 3-oxidoquinolinium species that was, in turn, trapped by [3+2] dipolar cycloaddition with a series of dipolarophiles to give tricyclic (alkaloid-like) products. Photophysical studies were employed to establish a relationship between synthetic reactivity and the rate constant (kq) for quenching of quinolinone fluorescence by dipolarophiles. An efficient method for predicting reactivity resulted from the study, along with procedures for access to novel alkaloid derivatives having challenging structural features.;Sensitive and simple bioanalytical methods for rapid quantitative detection of potential biohazards are now required in a number of venues, such as biodefense, environmental monitoring, food processing and microbiological settings. In the second part of this dissertation, the characteristic spectroscopic signature for interaction of thioflavin T (TfT) with suspended bacterial endospores was studied. A fluorescent reporter library was designed and synthesized by a newly developed route using TfT as the lead compound. Besides information regarding structure-activity relationships (SAR), specific spectroscopic reactivity toward important classes of potential bioharzards including not only dormant bacterial spores, but also vegetative bacterial cells, has been achieved employing this panel of fluorescent probes.