April 17, 2012

Organic Chemistry Profs Receive Awards: Prof. Ganem and Prof. Dichtel recognized for their achievements

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Prof. Bruce Ganem and Prof. William Dichtel have more in common than just being the instructors for the first and second semesters of organic chemistry, respectively. They have also just been awarded, separately, for their achievements and contributions: Ganem for his proven past and Dichtel for his present ambition.

Ganem, chemistry, will receive this year’s Esselen Award for Chemistry in the public interest, a recognition of his contributions to public health through his scientific and technical work.

The award, which has been given annually since 1987, recognizes chemists who have communicated positive values of the chemical profession. It is something of a life-time achievement award for chemists.

“The awards committee recognized work I did starting in the early 80’s on some interesting carbohydrate chemistry, which is a hot subject now for organic chemists,” Ganem said.

Ganem worked in the then nascent field of glycobiology, which aims to understand the biological significance of sugars. Ganem’s lab designed small molecules that structurally mimicked simple sugars by replacing the oxygen atom typically in their ring with a nitrogen atom.

“We found a way to make these nitrogen analogs of any sugar found in nature, whether it is glucose or galactose or mannose,” Ganem said.

The nitrogen analogs of sugars developed by Ganem originally allowed his lab to study enzyme mechanisms to better understand how enzymes catalyze reactions, but they had a series of unintended applications as well.

“Let’s say you had a big meal of pasta. This small molecule would block the digestive enzyme in your stomach and you would not absorb all those calories,” Ganem said.  These compounds, nicknamed “starch blockers,” could be used to treat patients who have to be careful about their blood sugar levels, such as those with diabetes.

But according to Ganem, this application had a problem. Once all that undigested carbohydrate reached the microbes in the lower intestine, they would feast on those carbohydrates.  As a result, patients were likely to experience unpleasant side effects such as gas, and the therapy was abandoned.

By the mid-90’s scientists found a new therapeutic application for these enzyme inhibitors.  The inhibitors helped treat central nervous system disorders such as  Gaucher’s disease and Fabry’s disease.

Now, however, since the early 2000’s these compounds have been put to new use as enzyme restorers rather than inhibitors. Unfolded proteins wrap themselves around these small molecules because the compounds resemble the substrate.   This helps the unfolded proteins adopt the correct shapes needed to become physiologically active. These molecules are called “chaperones” because they guide and assist misfolded proteins to reconfigure into the right shape.

According to Ganem,  a compound with that many multiple repeat performances in therapeutic applications is uncommon in human medicine.

At the award ceremony, Ganem will give an acceptance talk titled, “Lost (Sometimes) in Translation: Advancing Chemical Discoveries Beyond the Laboratory.”

Ganem said he is looking forward to the award ceremony, which is taking place this Thursday at Harvard University, where he studied as an undergraduate.

“I’m going to see some of my former students, even some of my former professors,” Ganem said. “It is a real reunion for me.”

In addition to Ganem, the Cornell Chemistry and Chemical Biology Department welcomes another award to one of its organic chemistry professors.

Research Corporation for Science Advancement announced earlier this week that Prof. William Dichtel has received the Cottrell Scholar Award for his scientific research and passion for teaching.

Dichtel was one of 11 early career faculty members to recieve The Cottrell Scholar Award and  a $75,000 grant. Applicants for the award must develop a proposal for the selection committee that showcases both their cutting-edge research and excellence in undergraduate education.

In his proposal, Dichtel showed his commitment to advancing undergraduate education by proposing a change to Cornell’s current chemistry curriculum.  His changes would offer more flexibility to the freshman chemistry curriculum and allow students within the major to specialize their studies,  as well as pursue outside interests while at Cornell.

“Here at Cornell, we came to the conclusion that our chemistry major is rigorous and it really prepares people well for chemistry and many other pursuits. But the one thing that we felt is that it’s really rather rigid hw said.  Students take specific classes at specific times in their career without being able to tailor the chemistry major to their particular interests.”

According to Dichtel, the chemistry department has a rigid curriculum because it has historically been a smaller, more defined field. But over the past few decades the department has grown to work with other scientific disciplines, such as biology, material sciences and environmental engineering.

Dichtel, along with his colleague Prof. Jiwoong Park, chemistry, developed two new courses on nanomaterials for chemistry majors.  Nanomaterials is a field of study that combines material science with nanotechnology.  For these classes, Dichtel will draw on concepts from organic, inorganic, physical and analytical chemistry and apply them to nanoscience.

“These concentrations are not going to be huge departures from the chemistry majors, but they will build off of a baseline of classes that are similar to the chemistry major now,” Dichtel said.

In addition to new concentrations in nanomaterials, the proposed changes to the chemistry major also include a restructuring of Cornell’s introductory chemistry course.  The plans include a new organic chemistry course for freshman coming to Cornell with strong chemistry backgrounds.

Though the proposed changes are not set in stone, the chemistry department is still studying how to implement the changes.  Recent changes to the chemistry department have begun to pave the way to giving students more flexibility to be able to take those concentration classes later in their careers according to Dichtel.

Dichtel was also given the CSA award for his dynamic research.

His research combines organic chemistry with material science and nanotechnology to create materials that are structurally precise. “The specific goal of our research in this proposal is to better control how organic molecules assemble into specific structures,” Dichtel said.  This concept is known as “self-assembly,” or the process by which molecules assume a structured position without outside guidance.

For the CSA proposal, Dichtel applied his research with self-assembly molecules to improving the performance of solar cells.  By using organic polymers, which are series of repeating one-dimensional molecules found in common things like soda bottles and textiles, Dichtel is trying to increase the amount of energy that can be absorbed from the sun.

His work combines double conjugated organic polymers, which can carry electric charges due to their double bonds, with covalent organic frameworks, or COFs.  COFs are two or three dimensional crystalline molecular structures with covalently linked building blocks. Successful combination of polymers with COF materials are created into lightweight materials that can be used in catalytic applications and molecule storage.

“The hope here is that by controlling how molecules assemble in very specific places, we can improve the efficiency of solar cells without significantly increasing their costs,” he said.

Outside of solar cells, self-assembling nanomaterial have “almost too many” applications, according to Dichtel.  Current scientific research has shown that self-assembly molecules can be used in storing energy, capturing CO2 from smoke stacks and containing hydrogen atoms, among other uses.

According to Dichtel, research involving nanomaterials belongs to a much larger class of study which undergraduates should learn about. “The new interface in nanomaterials would get students exposed to a broad range of new materials that have only really emerged in the past ten or twenty years and  aren’t a part of traditional chemistry,” Dichtel said. “It is our responsibility to make sure that the chemistry department at Cornell stays at the cutting edge.”

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Original Author: Bob Hackett