

Type of Document Dissertation Author Hsu, Danny Chung Author's Email Address dhsu@vt.edu URN etd-10042007-161139 Title Mechanistic Studies on Memory of Chirality Alkylations of 1,4-Benzodiazepin-2-ones & Structure-based Design of Insecticidal AChE Inhibitors for Malaria Mosquito, Anopheles gambiae Degree PhD Department Chemistry Advisory Committee
Advisor Name Title Carlier, Paul R. Committee Chair Deck, Paul A. Committee Member Etzkorn, Felicia A. Committee Member Kingston, David G. I. Committee Member Tanko, James M. Committee Member Taylor, Larry T. Committee Member Keywords
- Asymmetric Synthesis
- Memory of Chirality
- Anopheles gambiae
- Sulfhydryl Reagents
- Free Cysteine Targeting
- Acetylcholinesterase
- Kinetics
- Freeze Frame Observation
- Enolate Chemistry
- 1 4-Benzodiazepin-2-one
- Density Functional Theory
Date of Defense 2007-09-18 Availability unrestricted Abstract Memory of chirality (MOC) is an emerging strategy for asymmetric synthesis which relies upon the intermediacy of transiently non-racemic reactive species. In these reactions the configuration of the sole stereogenic center of the enantiopure starting material is "memorized" by a chiral non-racemic conformation in the intermediate; trapping then captures the stereochemical information, and generates a new stereogenic center with high fidelity. We experimentally and computationally studied the highly retentive deprotonation/alkylations of 1,4-benzodiazepin-2-ones (BZDs) that rely upon this strategy. We captured a transiently non-racemic BZD enolate intermediate in enantiopure form, then released the enolate and observed its subsequent reaction. This approach allowed the first ever step-wise observation of the stereochemical course of such a MOC process.Approximately 2 million deaths are caused by malaria every year in the world. In total roughly 3.2 billion people are living under the risk of malaria transmission. Current use of anticholinesterase insecticides has been limited by their toxicity to human beings. A major African malaria insect vector, Anopheles gambiae (Ag), was targeted. Based on sequence alignment and homology models of AgAChE, a strategy of dual-site binding was adopted that targets Trp84 in the active site and Cys286 at the peripheral site. Selective AChE inhibitors have been designed and synthesized.
Files
Filename Size Approximate Download Time (Hours:Minutes:Seconds)
28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access DannyHsuThesis.pdf 4.74 Mb 00:21:56 00:11:16 00:09:52 00:04:56 00:00:25
If you have questions or technical problems, please Contact DLA.