The Alchemist Newsletter: May 9, 2006

In this week's Alchemist, testing times for tequila, spotting tumors using nanoparticles, and having the stomach for bacterial receptors. Also under the torchlight, new elemental discoveries, and bringing nitrogen into the search for ET.

	industry: Tequila time!
	biological: Rusty particles spot tumors
	pharma: Spiraling under control
	nuclear: Elemental fabrication
	astrochemistry: Chemical expansion in search for ET

Tequila time!

Researchers in Mexico and Germany have devised a quality assurance procedure that can distinguish between the real thing and faux tequila manufactured by fraudulent sources or using non-genuine starting materials. The findings provide a new shot of QC to the billion-dollar tequila market. The team used ion and gas chromatography together with Fourier Transform Infrared Spectroscopy (FTIR), to obtain the chemical fingerprints of genuine tequila. These fingerprints then allow them to identify adulterated or mixed-tequila that is made with processed sugar rather than the Agave plant. The researchers explain that combining spectroscopic and chromatographic methods provides a more accurate identification than previous attempts that focused on other chemicals or isotopic analysis. The same test works with other Agave spirits including including mezcal, sotol and bacanora.

Tequila! Chemists help assure quality of popular Mexican beverag

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Rusty particles spot tumors

Enzymes that can flip the magnetic properties of iron oxide nanoparticles could provide oncologists with a way to image tumors almost as quickly and easily as radiologists view broken bones with X-rays. Sangeeta Bhatia in Boston, Massachusetts and colleagues at the Harvard-MIT Division of Health Sciences and Technology have found that the aggregation properties of Fe₃O₄ nanoparticles can be used as a novel imaging agent in magnetic resonance imaging. They coated one half of a sample of the nanoparticles with the protein biotin and the other with neutravidin. They then added peptide-attached PEG as a protecting group to the proteins to prevent them sticking together spontaneously. The peptide anchor is cleaved only by the action of a tumor-specific enzyme, matrix metalloproteinase-2 (MMP-2). The nanoparticles can thus float freely until they reach a tumor, MMP-2 then cleaves off the protecting groups, leaving the biotin and neutravidin free to bond. Once this occurs the nanoparticles form significant clusters visible to MRI, allowing a precise picture of the tumor's shape to be obtained.

Tumor proteases change the magnetic properties of nanoparticles

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Spiraling under control

Researchers at Vanderbilt University have discovered the receptor that allows the corkscrew-shaped bacteria Helicobacter pylori to attach to the lining of the stomach. The findings could provide a new target for eradicating an infection without the need for an antibiotic cocktail. H. pylori infects the mucus lining of the stomach and is a leading cause of peptic ulcers and gastric cancer. Infection is widespread in the West but even more so in developing nations where up to 80% of children and 90% of adults are thought to carry H. pylori. Vanderbilt's Richard Peek and colleagues have now confirmed that the membrane-embedded protein, decay-accelerating factor (DAF), which is a known receptor for several bacterial pathogens, is also involved in H. pylori adherence. New drugs that interfere with DAF binding could prevent or treat peptic ulcer disease or distal gastric adenocarcinoma.

Stomach receptor for H. pylori discovered

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Elemental fabrication

The Periodic Table is deceptively simple. However, its apparent simplicity harbors a dark secret: we do not yet understand how all the elements it contains in its rank and file were first formed. Now, a European-led team has examined models of a supernova's earliest moments to try and fill our periodic knowledge gap. Carla Fröhlich of the University of Basel, Switzerland, and colleagues have found that protons in the proton-rich region surrounding a freshly formed neutron star, which lasts just seconds, can transform into neutrons by reacting with antineutrinos streaming from the neutron star. These extra neutrons are critical during this period when the material is still hot enough to make heavy, proton-rich isotopes, as nuclei packed with their fill of protons can grab these new neutrons. In so doing, they generate enough binding force to capture yet another proton shifting up the periodic table as they go. The work could explain the origins of isotopes of the metals molybdenum and ruthenium, which are proton heavy and contained in the sun and meteorites, but have no clear origin in accepted nuclear reactions.

A New Way to Make Elements

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Chemical expansion in search for ET

Geobiologists at the University of Southern California reckon that the narrow search for water could miss important clues to extraterrestrial life. They suggest the search should be widened to look for signs of organic nitrogen as a direct indicator of life, because nitrogen is essential to the chemistry of living organisms. "It's hard to imagine life without water," says Kenneth Nealson, "but it's easy to imagine water without life." On the other hand, the discovery of nitrogen on Mars, for instance, would be a different story. "If you found nitrogen in abundance on Mars, you would get extremely excited because it shouldn't be there," Nealson adds. Unlike carbon, nitrogen is not a major component of minerals, so the presence of any substantial organic nitrogen deposits in the Martian soil would have almost certainly have resulted from biological activity.

Follow the nitrogen to extraterrestrial life

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-- David Bradley, Science Journalist