Rudolph Ernest K. Winter

Rudolph Ernest K. Winter Professor Winter received his A.B. degree from Columbia University and M.S. and Ph.D. degrees from The Johns Hopkins University. He held postdoctoral positions at Karlsruhe Technische Hochschule and Harvard University and was a member of the Polytechnic Institute of Brooklyn faculty before joining U. M. St. Louis in 1969. He has been a Visiting Research Professor at Cornell University, Visiting Scholar at the ETH Zürich and was also a Visiting Associate Professor (Biology) at Washington University (St. Louis).

Sketch by Dr. A. Qureshi-Asraf (Ph.D. UM-St. Louis, 1982)

rekwintr@umsl.edu
Office: B315j
Phone: (314) 516-5337
Fax: (314) 516-5342

Research Interests

The chemistry of naturally occurring substances has long been an important part of organic chemistry, but in recent years there has been a renewed interest in natural product research. This revival has, in part, been stimulated by application of innovative separation and isolation techniques as well as the development of new instrumental methods for identification and structure determination. A better understanding of the associated biology has provided new perspectives for investigations in this area. Professor Winter's research involves the organic and bioorganic chemistry of secondary plant metabolites, in particular terpenes and alkaloids. Projects include isolation and identification of novel biologically significant compounds, the synthesis and chemical transformation among structurally related classes, and biosynthesis and chemical ecology of plant materials. Several projects of current described below.

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Oxidative Transformations of Guaiol
Oxidations of this readily available sesquiterpene alcohol are being reinvestigated with the aim of producing functionalities commonly found in more highly oxidized plant natural products. Present emphasis is on guaiol-derived hydroperoxides and on the study of their intramolecular reactions as methods for controlling the positions of oxidation.

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Isolation of Novel Compounds from Asarum canadensis (Wild Ginger) -
Wild Ginger is widely distributed in North America and has a long history of medicinal use. Previous work has characterized a sulfur-containing compound having antibiotic activity, however the identity of this material remains undefined. Present work is aimed at isolating sufficient quantities for structure elucidation.

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Biomimetic Synthesis of Taspine Analogues-
The latex of the South American jungle tree Croton lechleri is known as Sangre de grado (dragon s blood) and is used by indigenous peoples as a vulnerary agent. The unusual alkaloid taspine is a principal constituent of this preparation and has been shown to accelerate wound healing in controlled animal experiments. Current efforts are devoted to the synthesis of analogues by taking advantage of the biogenetic relationship with aporphine type alkaloids.

Selected Publications

"Unique properties of a perfluoroalkyl-modified 2,2'-bipyridyl ruthenium complex in a Nafion membrane: attenuated leaching of a potential biofuel cell redox mediator" P. A. Jelliss, S. D. Minteer, M. Patel, A. Siemiarczuk,M. Watt, Michelle and R. E. K. Winter, J. Mat. Chem. 2008, 18, 2104.

"Carboxylate anion diminishes chloride transport through a synthetic, self-assembled transmembrane pore" L. You, R. Ferdani, R. Li, J. P. Kramer, R. E. K. Winter and G. W. Gokel, Chem.--A Eur. Journal 2008, 14, 382.

"Transport of chloride and carboxyfluorescein through phospholipid vesicle membranes by heptapeptide amphiphiles", R. Ferdani, R. Li, R. Pajewski, J. Pajewska, R. E. K. Winter and G. W. Gokel, Org. Biomolec. Chem., 2007, 5, 2423.

"Discrimination by the potato leafhopper (Hemiptera: Cicadellidae) of host volatiles from resistant and susceptible alfalfa, Medicago sativa L", C. M. Ranger, R. E. K. Winter; E. A. Backus, G. E. Rottinghaus, M. R. Ellersieck and D. W. Johnson, Environmental Entomology, 2005, 34, 271.

"Degradation and modification of metallaboranes. Part 4: Synthesis and characterization of a series of hybrid bimetallaborane clusters of the type [2,2,2-(PPh₃)₂(CO)-nido-2-OsB₄H₇-3-(BH₂PPh₂)C_xH_yPPh₂RuCl₂(p-cym)]", P. McQuade, R. E. K. Winter, N. P. Rath and L. Barton. Inorg. Chim. Acta 2005, 358, 1545

"Mass spectral characterization of fatty acid amides from alfalfa trichomes and their deterrence against the potato leafhopper", C. M. Ranger, R. E. K. Winter; E. A. Backus, G. E. Rottinghaus, M. R. Ellersieck and D. W. Johnson, Phytochemistry 2005, 66, 529

"Bioactivity of Lipophilic Metabolites from Glandular Trichomes of Medicago sativa Against the Potato Leafhopper", C. M. Ranger, R. E. K. Winter; E. A. Backus, G. E. Rottinghaus, M. R. Ellersieck and D. W. Johnson, J. Chem. Ecol. 2004, 30, 1969

"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

"Glandular trichome extracts from Medicago sativa deter settling by the potato leafhopper Empoasca fabae", C. M. Ranger, R. E. K. Winter; E. A. Backus, G. E. Rottinghaus, M. R. Ellersieck and D. W. Johnson, J. Chem. Ecol. 2004, 30, 927

"The First Derivatives of [NHMe₃][m-HMeC-C(Me)B₁₀H₁₀]", J. Bould, A. Laromaine, C. Viñas, F. Teixidor, L. Barton, N. P. Rath, R. E. K. Winter, R. Kivekäs, R. Sillanpää. Organometallics 2004, 23, 3335.

"Degradation and Modification of Metallaboranes Part 3, Reactions of the Hexaborane(10) Analogue nido-(PPh₃)₂(CO)OsB₅H₉ with Bidentate Phosphines Containing a Rigid Backbone: Formation of Linked Cluster Systems", P. McQuade, R. E. K. Winter and L. Barton. J. Organomet. Chem. 2003, 688, 82.

, "Geographic distribution of three alkaloid chemotypes of Croton lechleri", D. Milanowski, R. E. K. Winter; M. P. F. Elvin-Lewis and W. H. Lewis J. Nat. Prod. 2002, 65, 814.

"Wound-Healing Composition and Method ", R. E. K. Winter, A. L. Okunde, M. P. F. Elvin-Lewis, W. E. Lewis and A. Kasiri (WoundFast Pharmaceuticals assignee), U. S. Patent Number 5932617, Aug 3, 1999.

"On Guaiol Oxygenation Products", R.E.K. Winter, J.A. Baker, B.V. Lam, A.G. Breite and Nigam P. Rath, Natural Products Letters, 1997, 10, 105.

"Triterpenoid Saponins from Gouania lupuloides", E.J. Kennelly, R.E.K. Winter, S. Johnson, M. Elvin-Lewis, J. Gossling and W.H. Lewis, Journal of Natural Products, 1993, 56, 402.