Spectroscopic studies of organic and biological systems

The research presented herein covers four distinct projects, all of which use various Nuclear Magnetic Resonance (NMR) spectroscopic techniques in addition to other analytical tools to gain insight into the structure and dynamics of the systems.; In the first chapter, the mode of action of anesthetics is discussed. Specifically, the interactions and possible binding of several anesthetics and a control non-anesthetic to the enzyme-substrate pair of Alcohol Dehydrogenase and Nicotinamide Adenine Dinucleotide (NAD+) were probed. A clear-cut anesthetic effect was not defined, but rather it was proposed that the observed interaction was likely due to a more general hydrophobic effect.; The second chapter, which is in collaboration with scientists at Riga Technical University, discusses the kinetics of an organic intramolecular transamination. The isomerization between 2-(2-amino-3-pyridylaminomethylene)- and 2-(3-amino-2-pyridylaminomethylene)-5,5-dimethyl-1,3-cyclohexanedione was determined to be a first order reaction with ΔGo = −0.7 kJ/mol ± 0.2 kJ/mol, ΔHo = 4 kJ/mol ± 1 kJ/mol and ΔSo = 12 J/(mol·K) ± 2 J/(mol·K). Further, the activation energy was defined to be 70 kJ/mol ± 4 kJ/mol. The interconversion, which is catalyzed by base, may qualify as the first example of 1,4-N,N′-migration of acyl group vinylogs.; In the third chapter, several one- and two-dimensional 1H and 13C NMR techniques were employed to partially characterize the structure of a triterpene saponin purified from the leaves of Phytolacca dioica L by collaborators. The molecule may have use as a molluscicidal agent for the control of the devastating disease shistosomiasis. Much of the structure is precisely defined and a proposed complete structure that is consistent with the NMR data is presented.; Finally in the fourth chapter, which is in collaboration with scientists at the University of Latvia, possible sequence/structure relationships of DNA oligonucleotides that may affect electrophoretic mobility are discussed. 1H NMR, circular dichroism, electrophoresis and UV-Vis spectrophotometric techniques were all utilized to investigate possible conformations of model DNA fragments. While detailed sequence/structure relationships were not precisely defined, some possible sequence dependent conformations are discussed.