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Bu Wins Henry Dreyfus Teacher-Scholar Award

Published: December 15, 2008

Xianhui Bu, an assistant professor in the Department of Chemistry and Biochemistry at CSULB, is one of five national winners of the 2008 Henry Dreyfus Teacher-Scholar Award presented by the Camille and Henry Dreyfus Foundation.

The $60,000 award recognizes faculty members from United States bachelor’s and master’s colleges and universities who “have demonstrated leadership in original scholarly research of outstanding quality with undergraduates and excellence and dedication in undergraduate education.”

Bu joined CSULB in 2003 and earned his Ph.D. in 1992 from the State University of New York at Buffalo and his B.S. in 1985 from Fudan University in Shanghai, China. In 2008, his co-authored articles appeared on the covers of the journals Angewandte Chemie (Applied Chemistry) International Edition of the German Chemical Society and Chemical Communications of the Royal Chemical Society. He also has published in Science, Nature and Journal of the American Chemical Society and received a $676,118 grant from the National Institutes of Health to support his research.

In addition to including undergraduate and graduate students in his research, Bu currently has a postdoctoral researcher working in his lab.

Bu’s group is focusing on developing new forms of porous crystals that promote chemical reactions by providing increased surface area or shape selectivity for separating different types of molecules. These porous materials are widely used in industry such as to crack crude oil down into gasoline and separate air into oxygen and nitrogen for medical and other uses.

“My group is moving into a different direction. The overall theme is still porous materials, but for different types of applications relating to medicine,” Bu said. His particular interest is based on a concept called chirality, or handedness, in which objects, including molecules, may or may not be mirror images of each other. Gloves, for example, are chiral, since they are either right- or left-handed. “If you look at us from the outside, we are symmetrical, but inside of us, we have no symmetry. Even molecules inside of us like proteins and DNA have no mirror symmetry. They’re only one-handed. Some important biological processes are based on this chirality,” he explained.

“The drug molecules that go into your body will have different effects if one is right-handed and one is left-handed,” he continued. “One form of medicine may have therapeutic value while the other form may be totally useless or even have a harmful effect. In principle, you only want to deliver the correct form that’s usable. In practice, if you make this medicine by a typical chemical process, they will give you two forms that are really identical in chemical properties. If you put something into a non-chiral environment, then it doesn’t matter if it’s right-handed or left-handed. But since medicine goes into our body, which has handedness, our body can tell the difference.”

Portrait of Xianhui Bu

Photo by Victoria Sanchez
Xianhui Bu

Bu said that because conventional chemical processes for making medicines generally produce both handed forms, “when you make them, you want to use a catalyst to only promote one form. The materials that my group will make would be porous but its environment would be chiral, so if you run chemical reactions in that chiral environment, it would prefer only one form. If you make them in the mixture of right-handed and left-handed and you flow them through the pore holes, one would be preferentially trapped inside the holes and the other would flow through, which allows you to separate them. That’s one of my goals,” he said.

Moreover, “Just the fact that we are chiral is a mystery,” Bu said. “Why do our biological processes depend on this right-handed form? DNA is right-handed and proteins also form right-handed helices. People don’t know the origin of this homochirality.”

Sugar molecules in DNA are chiral molecules, he said. “In DNA, these sugar molecules are wrapped into helices. I take some chiral molecules like sugar, and I can also build helices. I also want to study these systems, how helices are formed and what factors affect it. Why is it right-handed and in some cases, left-handed? I’m an inorganic chemist, but I use these simple systems to find the clues to how these chiralities are generated. Hopefully, we want to just learn from these systems and gain a better understanding about chiral features in biological systems.”

The Camille and Henry Dreyfus Foundation Inc. advances chemistry, chemical engineering and related sciences as a means of improving human relations and circumstances. The Dreyfus brothers were key leaders in the scientific and commercial development of cellulose acetate and founded several firms including Celanese Corp. of America.