A team of University of Illinois at Chicago researchers has successfully synthesized two rare forms of carbohydrate molecules that may prove useful in biological and pharmacological research and development.
The syntheses were reported in the June 20 issue of the Journal of the American Chemical Society. The work is also highlighted in the Science Concentrates section of the June 25 Chemical and Engineering News.
Led by David Crich, distinguished professor of organic chemistry, the UIC team synthesized two different beta-mannans—oligosaccharides, or polymeric carbohydrates, containing only the beta-mannose type linkage. The researchers chose to synthesize the beta-mannans, in part, because of the challenge: the beta-mannoside linkage was one of the most difficult to prepare in carbohydrate chemistry until the problem was solved in 1997 by Crich and a previous graduate student, Sanxing Sun.
“We have now moved on to synthesize oligomeric beta-mannosides,” said Crich. “This is the first synthesis of beta-mannans, the oligosaccharides derived from beta mannose, in a controlled manner. If not the ‘Everest’ of carbohydrate chemistry, it’s certainly K2.”
The two beta-mannans Crich’s team selected are linked to disease states. One is the oligosaccharide found on Leptospira biflexa, a bacteria that causes leptospirosis, a painful and sometimes fatal disease common in subtropical Africa. The other is Candida albicans, a yeastlike fungus that causes candidiasis, or moniliasis, which affects the skin and sometimes the respiratory system.
Candida albicans “is an important clinical pathogen with an interesting activity in that it induces tumor necrosis factor-alpha, or TNF-alpha, which has implications in cancer chemotherapy,” Crich said.
All of the actual synthetic work on the molecules was done by two of Crich’s graduate students, Hongmei Li and Qingjia Yao. Research collaborators include UIC chemistry professor and department head Donald Wink, along with Roger Sommer and Arnold Rheingold of the University of Delaware, who carried out supporting X-ray crystallography studies.
University of Illinois at Chicago. June 2001.