Organic compounds which contain one or more nitrogen atoms are especially important as they are disproportionately represented among biologically active molecules. As a result, significant effort has been focused on the development of methods for the synthesis of nitrogenous molecules. We identified the aminal as an under-explored functional group. Despite...
The fragmentation characteristics of protonated peptides have been investigated using
tandem mass spectrometry (MS/MS) under various fragmentation regimes and detailed
density functional theory (DFT) reaction pathway calculations. The DFT calculations
predict novel salt-bridge stabilized transition structures as well as consecutive reactions
occurring in proton-bound dimers for some of the ions...
The tosylhydrazones of exo-3-deuteriocamphor and 2- deuterio-2,4-dimethy1-3-pentanone were treated with Nbromosuccinimide (NBS) and pyruvic acid to regenerate the parent ketones. The ketones from the pyruvic acid cleavage show a significant loss of deuterium. The ketones from the NBS cleavage show no loss of deuterium, indicating that stereochemical integrity at. C[subscript...
In proteomic studies, separate experimental protocols have been necessary to identify proteins, determine their function, and predict their three-dimensional structure. In this study, a function-based separation of proteins was conceived to fractionate proteins prior to enzymatic digestion. In the initial demonstration of this technique, a DNA substrate was used to...
Studies toward synthesis of subunits of sanglifehrin A, an immunosuppressant featuring a highly substituted [5,5]-spirolactam moiety as well as a 22-membered macrocycle are described. The macrolactone contains a peptidic backbone characterized by an unusual [beta]-substituted (S)-piperazic acid and (S)-m-hydroxyphenylalanine units. These studies resulted in the synthesis of advanced intermediate 358...
Although 4- and 5-diacetamidopyrimidines have been reported
in the literature within the past eleven years, it was not until 1965
that a 2-diacetamidopyrimidine was reported. The current investigation
was undertaken to determine whether other 2-diacetamidopyrimi-dines could be synthesized and what the effect of various nuclear substituents would be on the...
In this Dissertation, the mechanism and stereomechanics of complex organocatalysis and reaction processes are disclosed. The technologies and protocols currently being developed and utilized to efficiently investigate these systems using theory are highlighted.
A detailed computational study of peptide-catalyzed acylations is disclosed. In particular, the magnitude of all possible non-bonding...