News From The American Chemical Society

Main Category: Biology / Biochemistry
Also Included In: Infectious Diseases / Bacteria / Viruses;  Dentistry;  Cancer / Oncology
Article Date: 20 Nov 2007 - 7:00 PDT

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Magnetic nanoparticles detect and remove harmful bacteria

Researchers in Ohio report the development of magnetic nanoparticles that show promise for quickly detecting and eliminating E. coli, anthrax, and other harmful bacteria. In laboratory studies, the nanoparticles helped detect a strain of E. coli within five minutes and removed 88 percent of the target bacteria, the scientists say. Their study was published in the Journal of the American Chemical Society, a weekly publication.

Xuefei Huang and colleagues point out that ongoing incidents of produce contamination and the threat of bioterrorist attacks have created an urgent need for quicker, more effective ways to detect bacterial decontamination. To meet that need, they developed a "magnetic glyco-nanoparticle (MGNP)," a unique compound that combines magnetic nanoparticles with sugars.

Sugars (or carbohydrates) on cell surfaces are used by many bacteria to attach to their host cells in order to facilitate infection. The scientists exposed a group of E. coli bacteria to the sugar-coated nano-magnets to mark the microbes so they could be easily identified and removed by a magnetic device. The researchers also used the particles to distinguish between three different E. coli strains.

The study represents "the first time that magnetic nanoparticles have been used to detect, quantify, and differentiate E. coli cells," the researchers state.

"Magnetic Glyco-nanoparticles: A Unique Tool for Rapid Pathogen Detection, Decontamination, and Strain Differentiation"

Contact:
Xuefei Huang, Ph.D.
The University of Toledo
Toledo, Ohio 43606

Sweet magnolia: Tree bark extract fights bad breath and tooth decay

"Sweet magnolia" does more than describe the fragrant blossoms of a popular evergreen tree. It also applies to magnolia bark's effects on human breath. Scientists in Illinois are reporting that breath mints made with magnolia bark extract kill most oral bacteria that cause bad breath and tooth decay within 30 minutes. The extract could be a boon for oral health when added to chewing gum and mints, they report in a study published in the ACS' Journal of Agricultural and Food Chemistry, a bi-weekly publication.

Consumers often turn to flavored chewing gum and mints to battle bad breath. However, those products only temporarily mask the odor of bad breath, which is caused by bacteria. Existing anti-bacterial products for bad breath are far from ideal, with some having side effects like tooth staining.

In the new study, Minmin Tian and Michael Greenberg tested the germ-killing power of magnolia bark extract using saliva samples taken from volunteers following a regular meal. Mints containing the extract killed more than 61 percent of the germs that cause bad breath within 30 minutes, compared with only a 3.6 percent germ-kill for the same flavorless mints without the extract, the researchers say.

The extract also showed strong antibacterial activity against a group of bacteria known to cause cavities. Mints and chewing gum containing the extract may also provide a "portable oral care supplement to dentifrice (toothpaste), where brushing is not possible," the study states.

"Compressed Mints and Chewing Gum Containing Magnolia Bark Extract Are Effective against Bacteria Responsible for Oral Malodor"

Contact:
Minmin Tian, Ph.D.
Wm. Wrigley Jr. Company
Chicago, Illinois 60622

New database screening criteria improves identification of anticancer drugs

Scientists in Indiana and Michigan have developed a better way of mining a vast computerized database for chemical nuggets that could become tomorrow's cancer medications. The new "data mining" method pinpoints chemical structures with drug-like activity. It could speed the identification and development of new, more effective drugs against breast, prostate, lung and other cancers, according to a report scheduled for the Nov./Dec. issue of ACS' Journal of Chemical Information and Modeling, a bi-monthly publication.

Computers have become a mainstay in the drug discovery process and have led to the identification of dozens of promising anticancer drugs. However, as the amount and complexity of information in a chemical

In the new report, David J. Wild and colleagues analyzed data from the National Cancer Institute Developmental Therapeutics Program, a database of 40,000 compounds that have been tested against 60 tumor cell lines. The researchers identified a set of common structural features that can be used to more accurately predict which compounds are most active against cancer cells. In a series of experiments, they showed that applying these new criteria significantly increased the accuracy rate of identifying drug-like molecules in comparison to standard screening methods.

"Chemical Data Mining of the NCI Human Tumor Cell Line Database"

Contact:
David J. Wild, Ph.D.
Indiana University
Bloomington, Indiana 47408

The American Chemical Society -- the world's largest scientific society -- is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Source: Michael Woods
American Chemical Society