The Alchemist - February 2009

Graffiti-defeating coatings could protect buildings and statues, The Alchemist learns this week, while the glandular chemistry of the beaver is revealed in stereo. Perfect polymers could boost optical data storage several hundredfold and nano dots might help map out tumor sites in the body. In biochemistry, another reason not to opt for pate de foie gras is revealed. Finally, structural biology gets motoring and wins a French scientist a major award.

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Graffiti defeated

A new coating that can protect heritage sites from graffiti has been developed by The Construction and Territorial Development Unit of TECNALIA in Europe. Cultural heritage materials, buildings and statues are often porous and so susceptible to environmental erosion, but increasingly, damage by graffiti artists is a problem of esthetics and conservation. A new material - a pH-sensitive silicon-based polymer complex has been developed in the project and tested in five countries on culturally important buildings. The material is hydrophobic and so prevents water penetration, it adheres well even to porous surfaces, it does not change the appearance of the surface it coats and is resistant to sunlight, condensation, ageing and natural weathering. Importantly, the environmentally friendly composition prevents paint from soaking into stonework and other porous materials and so acts as an easy-to-clean anti-graffiti skin.

A new anti-graffiti coating

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Glandular chemistry

The dried scent glands of the Canadian beaver, known as castoreum, contain a complex mixture of nupharamine alkaloids. Now, Horst Kunz and colleagues at the University of Mainz, Germany, have used total synthesis to determine the stereochemistry of one of these compound, 5-(3'-furyl)-8-methylindolizidine. Beavers use their fat- and pheromone-containing gland secretions to groom their fur and to mark their territory. The same secretions were used in traditional medicine, although salicylic acid is considered the only major component with physiological activity. Nevertheless, the complexity and molecular diversity of minor components have potential as possible lead compounds in drug discovery.

The Beaver as Chemist

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Perfect polymers

A potentially "transformative" approach to polymer films could be useful in microelectronic storage and photovoltaic materials, according Tom Russell of the University of Massachusetts Amherst. Russell's team, working with colleagues at the University of California Berkeley, have developed a faster, more efficient way to produce defect-free polymer thin films that have the smallest domains of block copolymers so far achieved that are densely packed and ordered. The uniformity and density of these films exploited in optical storage could allow the equivalent of 250 DVDs to be stored on a surface no bigger than a quarter.

Making the Smallest, Most Perfect Polymer Films

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Join the dots

Biologically compatible nano dots that glow under certain physiological conditions can show surgeons precisely where tumor cells are in the body. According to researchers at the Memorial Sloan-Kettering Cancer Center, the "Cornell dots", or C dots, consist of several dye molecules encased in a silica shell just a few nanometers in diameter and coated with polyethylene glycol (PEG). Cornell materials scientist Ulrich Wiesner and colleagues explain that these nanoparticles can be transported into tissues, are safe and readily excreted by the kidneys after imaging of tumors, their blood vessels, and metastatic tissues have been obtained. Physician-scientist Michelle Bradbury explains that the Cornell dots are highly sensitive and can ensure the earliest possible detection of tumor cells.

Glowing 'Cornell dots' can show surgeons where tumors are

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What's sauce for the goose...

Researchers at the Michael Greger of The Humane Society of the United States, Washington DC, have suggested that stressed animals that succumb to spontaneous amyloidosis could represent a new health risk to people. Harmful proteins fragments known as amyloid fibrils associated with damage to brain cells in Alzheimer's disease and to pancreatic cells in Type II diabetes can be present in the meat of poultry and mammals. These amyloids are not destroyed even with high-temperature cooking process. Greger suggests that potentially harmful levels of these errant proteins could enter the food supply from force-fed animals. Pate de foie gras is the most likely and only known potential source at this time, however.

Give the foie gras a miss

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Motoring award

Anne Houdusse, head of the Structural Motility Team, CNRS/Institute Curie, Paris, France, is the winner of this years Women in Science Award given by The European Molecular Biology Organization (EMBO) and the Federation of European Biochemical Societies (FEBS). Nominally a structural biologist her work focuses on the chemistry, i.e. the molecular mechanism of action, of myosins. Houdusse clarified the molecular structure and function of the muscle-contracting proteins as well as motility processes within cells. Her atomic resolution structures provided pioneering functional insights into the movement of molecular motors during muscle contraction.

Structural biologist recognized for research on molecular motor structure and function

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-- David Bradley, Science Journalist