Title

Synthesis and application studies of novel coumarin derivatives

Date of Award

2002

Availability

Article

Degree Name

Doctor of Philosophy (Ph.D.)

First Committee Member

Roger M. Leblanc, Committee Chair

Abstract

Current dissertation explores the possible uses of newly synthesized 4- and 7-substituted coumarin derivatives. In the initial phase of this work, the synthesis and surface properties of an amphiphilic coumarin derivative is discussed, along with its spectroscopic features as building-blocks of a monolayer at the air-water interface. Such amphiphilic fluorophores can be used for fluorescent probes in investigation of molecular organization of monolayers.The latter portion of this study deals with novel, fluorescent coumaryl sensor switch molecules that were used for the detection of a naturally occurring toxin, saxitoxin. This toxin, produced by certain algae species and accumulates in shellfish, is responsible for a symptom called paralytic shellfish poisoning (PSP) an expanding threat along the coasts of the Atlantic Ocean. Using these coumaryl sensor molecules it was possible to detect the toxin in aqueous solutions. In addition to solution work, monolayer studies of an amphiphilic coumaryl derivative were also carried out. These monolayer results prompted the synthesis of a self-assembly of related coumaryl sensor on quartz substrate. Using this self-assembled monolayer it was possible to detect saxitoxin. These results will contribute to the fabrication of a saxitoxin sensor that consists of an optical fiber with a fluorescent sensor self-assembled monolayer on its surface.The final portion of this study investigates the preliminary results obtained from coumarin-based isothiocyanate tags that were used for labeling enzymes that were covalently bound on quartz surface. A related bifunctional tag was used to covalently anchor (and label at the same time) the enzyme. In a preliminary study a coumarin tag was used to label organophosphorous hydrolase (OPH) enzyme. OPH can hydrolase toxins such as paraoxon, parathion or VX and used for decontamination of samples from these toxic agents. Labeling OPH with the fluorophore made it possible to detect the toxins by the changes in the fluorescence signal.

Keywords

Health Sciences, Toxicology; Chemistry, Organic

Link to Full Text

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