College of Computer, Mathematical and Natural Sciences

Philip DeShong

Professor

Personal Data

Office Phone: 301-405-1892
Office Address: 2101
Email: deshong@umd.edu
URL:

Education

  • B.S. Chemistry with Honors and Special Honors in Chemistry
  • University of Texas at Austin, 1971. Sc. D. in Organic Chemistry (with Professor George H. Büchi)
  • Massachusetts Institute of Technology, 1976.  Postdoctoral:  (a)  Swiss Federal Institute of Technology, Zürich (with Professor Duilio Arigoni), 1976-1979.  (b)  Massachusetts Institute of Technology (with Professor Christopher Walsh), 1979.

Professional Experience

  • Assistant Professor, The Pennsylvania State University, 1979-1986
  • Visiting Scientist, University of Würzburg, Federal Republic of Germany, 1986
  • Associate Professor, The University of Maryland, 1986 -1990
  • Professor, The University of Maryland, 1990-present
  • Academic Guest (Adjunct Appointment), Institute of Organic Chemistry, University of Zürich, Zürich, Switzerland, 1990-1994
  • Adjunct Professor, Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland, 1994
  • Adjunct Professor, Institute of Organic Chemistry, University of Zürich, Zürich, Switzerland, 1996.   Chair, Department of Chemistry and Biochemistry, University of Maryland, 2000-2003
  • Member, Bioengineering Program, University of Maryland, 2005-present
  • Member, Center for Nanomedicine and Cellular Delivery, University of Maryland Medical School, Baltimore, Maryland, 2005-present
  • Member, Maryland Nanocenter, University of Maryland, 2009-present

Research Interests

Total synthesis of heterocyclic natural products, development of methodology for organic synthesis, mechanistic organometallic chemistry, synthesis of complex oligosaccharides and glycoprotein derivatives, chemistry of hypervalent silicon derivatives, synthesis of nanoparticles and functionalized nanomaterials for applications in drug delivery, diagnostics and biosensing.

Major Recognitions and Honors

  • NSF Undergraduate Research Fellow, 1969.
  • Robert A. Welch Outstanding Undergraduate, University of Texas at Austin, 1969, 1970, 1971. 
  • Goodyear Graduate Fellow, Massachusetts Institute of Technology, 1972. 
  • Texaco Graduate Fellow, Massachusetts Institute of Technology, 1973. 
  • Givaudan Postdoctoral Fellow, Swiss Federal Institute of Technology, 1976-1978. 
  • Phi Lambda Upsilon, Chemistry Honor Society. 
  • Alpha Chi Sigma, Science Honor Society. 
  • Phi Kappa Phi, National Honor Society. 
  • Sigma Xi, National Science Honor Society. 
  • American Cyanamid Science Faculty Award, 1986. 
  • Swiss Chemical Society Lectureship, 1989. 
  • University of Maryland Distinguished Scholar-Teacher, 1996. 
  • Lilly-CTE Teaching Fellow, 1997-1998. 
  • DuPont Faculty Award, 1999-2000. 
  • Fellow, American Association for the Advancement of Science, 2001. 
  • University of Maryland Regents' Award for Public Service, 2007.
  • University of Maryland Undergraduate Mentor of the Year, 2008.
  • Outstanding Academic Advisor Award, Maryland Parents Association, 2009. 

Significant Professional Service and Activities

Dr. DeShong is the founder and Chief Scientific Officer of SD Nanosciences, Inc. of Beltsville, MD.  The focus of the company is to develop novel methods for the detection and treatment of pathogenic infections and cancer.  In addition, Dr. DeShong has consulted for >15 companies on problems related to synthetic and pharmaceutical chemistry. 

Students Mentored

Dr. DeShong has supervised the Ph.D. and Masters theses of 50 graduate students.  In addition, 8 postdoctorals and 45 undergraduates have performed research in his laboratory.

Siloxane Chemistry.  A significant area of research in Professor DeShong's group focuses on development of new strategies  for the stereoselective synthesis of heterocyclic systems and the application of these approaches to the preparation of natural products and biologically active substances.
The DeShong group has demonstrated that hypervalent silicates can be employed for carbon-carbon bond couplings employing  palladium catalysis. This coupling strategy that is similar to Suzuki (boron compounds) and Stille (tin compounds) couplings has been employed for the synthesis of unsymmetrical biaryls and allylic couplings. Applications of this strategy to the synthesis of antimitotic agents colchicine and steptonigrin, and the antitumor antibiotic pancratistatin are underway.  These investigations include new methods for the synthesis of siloxane derivatives and the use of siloxane polymers for the synthesis of combinatorial libraries.  


Carbohydrate and Glycoprotein Synthesis.  Another area of research has been the discovery that hypervalent silicate anions are able to function as nucleophilic surrogates for fluoride, cyanide, and azide anions as shown in the scheme below.  Silicate anions are produced by the reaction of ammonium fluorides with the appropriate trisubstituted silane. The resulting silicate anion has proven to be a "super nucleophile" under extremely mild conditions in substitution sequences. This approach is being extended to the transfer of other nucleophiles, including carbon nucleophiles such as acetylides and enolates. The azide chemistry developed in this project has been utilized for the synthesis of glycoconjugates such as N-linked glycoproteins (see below), lipid A toxins and inhibitors of glycosyltransferases.

Functionalized Nanomaterials.  Applications of the carbohydrate technology to the the preparation of functionalized nanomaterials for diagnostics and drug delivery are underway.  This multidisciplinary collaboration with materials engineers and cell biologists (Drs. English, Zachariah, Stein, Dagenais, Ghandehari, Nan) has demonstrated that nanostructures (gold, silica, alumina, and other materials) with interesting morphologies and/or properties can be functionalized with complex oligosaccharide and peptide conjugates that impart a variety of unique characteristics to the nanomaterial.  First, these coatings typically result in the formation of materials that are stable in biological fluids indefinitely.  In addition, the coatings can be tailored to target the nanostructures to specific cell types resulting in systems that are ideal for diagnostic and drug delivery applications.  

The focus of our studies are to develop a "Molecular Toolbox" of general methodology for the functionalization of a wide variety of materials, to synthesize oligosaccharide conjugates that will "target" specific cell populations (pathogens and tumors), and to measure the release profiles of the functionalized nanomaterials.  


A.  TEM image of porous silica nanoparticles coated with oligosaccharide cell surface conjugates.  B.  Hollow silica nanoparticles. C.  Confocal microscope image of porous silica nanoparticles filled with antitumor antibiotic doxorubicin.