Date of Award
Summer 2008
Document Type
Dissertation - Restricted
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry
First Advisor
Steinmetz, Mark G.
Second Advisor
Rathore, Rajendra
Third Advisor
Rathore, Rajendra
Abstract
Neurons in human brain communicate primarily by the release of small quantities of chemical messengers commonly called neurotransmitters. These chemicals alter the electrical activity of neurons after they interact with receptors on cell surfaces. Photochemically removable protecting groups (PRPG) can be covalently attached to a functional group of a molecule in order to make it inert to some particular set of reaction conditions. Deprotection is then accomplished at some point in time by photolysis, in which case the released functional group would be a leaving group such as a carboxylate group, a carbonate group, or a carbamate group. PRPG find uses not only in biophvsical studies but also in multistep syntheses were they are often called "caged molecules" or "phototriggers" 1,2 ,3. In this application the biologically active molecules, i.e., substrates LG (Figure 1), must be released rapidly and efficiently with a flash of light or with laser pulse of short duration. Since nearly all cage compounds function with UV light, which can damage cellular components, there had been considerable need for cage compounds that can function with visible light. To be useful in biological applications, cage compounds must possess sufficient stability towards premature release of substrate. The cage compound and its photochemical byproducts must be biologically inert. High chemical yields and quantum yields for substrate release are needed at wavelengths above 300 nm to minimize photolysis of cellular components such as proteins and DNA Studies of rapid biological processes may also require substrate release on the microsecond or shorter timescale...