Valerian T.D'Souza
Dr.
D'Souza received his M.Sc. from Bombay University, and his
Ph.D from the University of Detroit. He held a postdoctoral
position at Northwestern University prior to joining the UM-St.
Louis faculty in 1987.
vally@umsl.edu
Office: B221
Phone: (314) 516-5324
Fax: (314) 516-5342
Research Interests
The main goal of our research project is to build redox catalysts based on the chemistry of biological redox enzymes. The incredible power of the enzymes to bring about chemical transformations with large acceleration and high specificity has been mainly attributed to their ability to bind the substrate and catalyze specific reactions of the bound substrate. Thus, these redox catalysts are designed to have a binding site to bind particular molecules and a catalytic site to catalyze redox enzymes. We have synthesized the first generation of these artificial enzymes using cyclodextrins as a binding site and flavin derivatives as catalytic site shown in the figure.
This
artificial enzyme can accelerate oxidation of benzyl alcohols
up to 650-fold over that catalyzed by riboflavin. We are
in the process of designing and synthesizing the second generation
of artificial redox enzymes which should have enhanced catalytic
ability. These enzymes are designed using computational
chemistry techniques.
In the process of developing the methodology to build these
artificial enzymes, we have also produced a method to synthesize
custom-designed cyclodextrins. Cyclodextrins
are cyclic oligosaccharides which have gained prominence in the last two decades
as complexing agents for various organic molecules in artificial enzymes, foods,
flavors, etc. However, the main shortcoming of this, otherwise remarkable,
molecule is that the functionalities available for useful chemical processes
are limited to simple hydroxyl groups. The new method developed by us enables
us to synthesize cyclodextrins with various desired functionalities. We
are presently investigating the binding and catalytic properties of these new
cyclodextrins.
Selected Publications
"Preparation and Characterization of Porous Gold and Its Application as a Platform for Immobilization of Acetylcholinene Esterase".O. V. Shulga, K. Jefferson, A. R. Khan, V. T. D'Souza, J. Liu, A. V. Demchenko and K. J. Stine. Chem. Materials 2007, 19, 3902.
"Synthetic methodology for cyclodextrin-dipyrromethane conjugates," J. N. Swamy, R. E. K. Winter, C. R. Jeffreys and V. T. D'Souza, Tet. Lett., 2004, 45, 7595.
"Modification of Cyclodextrins for Use as Artificial Enzymes," V. T. D'Souza, Supromolecular Chemistry, 2003, 15, , 221.
"Artificial redox enzymes," V. T. D'Souza, Biologicheskii Zhurnal Armenii, 2001, 53, 105.
"Synthesis and properties of modified cyclodextrins," A. R. Khan, P. Forgo, S. Tian and V. T. D'Souza, Proceedings, 10th International Cyclodextrin Symposium, Ann Arbor, MI, 2000, 673.
"Selectively Mono-Modified Cyclodextrins. Synthetic Strategies," S. Tian, H. Zhu, P. Forgo and V. T. D'Souza J. Org. Chem., 2000, 65, 2624 .
"Selective modifications of cyclodextrins,"A. R. Khan, P. Forgo, K. J. Stine and V. T. D'Souza, Proceedings, 9th International Symposium on Cyclodextrins, Santiago de Comostela, Spain, 1999, 33.
"The
Use of High Resolution NMR Spectroscopy in Supramolecular Systems," Peter
Forgo and Valerian T. D'Souza, Organic Letters, 1999, 1,
1543.
"An NMR Approach for Determination of the Substitution Pattern in Supramolecular
Systems," Peter Forgo and Valerian T. D'Souza Tetrahedron Letters, 1999, 40,
8533.
"Structure and Electrochemical Behavior of a Flavin Sulfide Monolayer Adsorbed
on Gold," K. J. Stine, D. M. Andrauskas, A. R. Khan, P. Forgo, V.
T. D'Souza, R. M. Friedman and J. Liu, Journal of Electroanalytical
Chemistry, 1999, 472, 147.
"Selective Modifications of Cyclodextrins," A. R. Khan, P. Forgo, K.
J. Stine and V. T. D'Souza Proceedings of the 9th International Symposium
on Cyclodextrins, Kluwer Academic Publishers, the Netherlands, 1999,
33.
"Electrochemical Study of Self-Assembled Monolayers of a ß-cyclodextrin Methyl
Sulfide Covalently Linked to Anthraquinone," K. J. Stine, D. M. Andrauskas,
A. R. Khan, P. Forgo and V. T. D'Souza, Journal of Electroanalytical
Chemistry, 1999, 465, 209.
"Application of Selective HSQC Experiment to Measure Interglycosidic Heteronuclear
Long-range Coupling Constants in Cyclodextrins," P. Forgo and V. T.
D'Souza Journal of Nuclear Magnetic Resonance, 1999, 37,
48.
"Unambiguous Identification of Regioisomers in Selectively Modified b -Cyclodextrins". P. Forgo and V. T. D'Souza, Journal of Organic Chemistry 1999, 64, 306.
"The application of selective ROE experiments to study solution structures of cyclomaltooligosacharide derivatives and complexes". P. Forgo and V. T. D'Souza Carbohydrate Research 1998, 306, 473.
"Methods for Selective Modifications of Cyclodextrins". A. R. Khan, P. Forgo, K. J. Stine and V. T. D'Souza, Chemical Reviews, 1998, 98, 1977.