David Bradley – Page 331

Pyridine joins the supersonic set

The pyridine chemical group, basically a benzene ring in which one of the six carbons and its attendant hydrogen atom have been swapped for a nitrogen atom, is one of the building blocks of a vast number of biological molecules and is a crucial component in the functionality of an almost as expansive selection of pharmaceuticals. As such, understanding its chemistry and physical properties are important in a fundamental way to the chemical and life sciences.
Now, chemists Yoshinori Nibu, Ryosuke Marui, and Hiroko Shimada of Fukuoka University, in Japan, have used infra-red spectroscopy to sniff out important new clues as to this aromatic compound’s behaviour.

You can read the full story in the first August edition of my science news round-up for spectroscopyNOW.com

Light Harvest for the World

In order to trap the energy from sunlight antenna plants construct chlorophyll groups through chemical self-assembly in a highly ordered manner. Emulating this system would not only improve our understanding of how plants function so effectively but could also lead to new materials for harvesting solar energy as an alternative to silicon-based photovoltaic devices.

Researchers have exploited long-range chemical order to creating aggregate compounds that can either trap light or transfer energy. Now, Tsutomu Ishi-i and Shuntaro Mataka of the Kurume National College of Technology and their colleagues have synthesised a new type of light harvester and by incorporating different materials into the aggregate structure they can induce energy transfer too. UV-Vis spectroscopy and other techniques were used to reveal the details of this novel group of artificial self-assembling light-harvesting compounds that will help us understand plant photosynthesis and may eventually lead to an alternative to semiconductor-based solar panels.

I offer a light report via SpectroscopyNOW

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Water waste

Water is commonly known as the universal solvent because it dissolves more substances than other compounds. But, water is commonly known as an enigmatic substance too, with many properties that seem at first glance paradoxical and others that chemists are yet to explain. Researchers at Argonne National Laboratory hoped to learn more about how ions interact with mineral surfaces in water and have used X-ray studies to open the door on understanding how contaminants travel in the environment.

Ions, ranging from nutrients such as calcium to contaminants such as lead, are present in natural waters across the globe. Their transportation through the environment is often controlled by the degree of adsorption to mineral surfaces. Understanding the adsorption and desorption processes involved could lead to new ways of controlling water quality.

Get the full story here.

The Art of ET

Extraterrestrial Art After centuries of speculation concerning the existence or otherwise of extraterrestrial intelligence, it has been discovered that a radio signal detected by the Arecibo Observatory in Puerto Rico contains artwork broadcast from deep space.

Initially dismissed by scientists as meaningless, the transmission – which originated between the constellations Aries and Pisces thousands of years ago – is now claimed to be the most significant addition to the artistic canon since the Mona Lisa, or even the Venus of Willendorf.

The artistic signal has been painstakingly decoded and transferred onto canvas by conceptual artist Jonathon Keats and is unveiled today at the Magnes Museum in Berkeley California. “This is the ultimate outsider art,” notes Keats, “Historically, our culture has ignored extraterrestrial artistic expression. Exhibited at the Magnes, the art becomes accessible to everyone.”

The discovery of artwork from beyond the solar system did not come as a surprise to Keats, who has frequently collaborated with scientists across multiple disciplines. “It’s a familiar story,” he says, “Researchers expect intelligent life elsewhere in the universe to behave just like them. Since scientists are mathematical, they expect extraterrestrials to broadcast the digits of pi or the Pythagorean theorem.”

The discovery augments earlier findings here on earth of artifacts dating back to a prehistoric alien landing, the so-called Shao-Shan object, they too are very aesthetically pleasing!

South African shards

Raman analysis of South African pottery (shards) dating from the 13th and 14th centuries reveals that the potters used a variety of clays and fired their wares at less than 800 Celsius using open fires rather than kilns. Such details could only be unearthed without damaging the artefacts using this powerful spectroscopic technique.

Chemists Malebogo Legodi and Danita de Waal of the University of Pretoria in South Africa examined samples from four archaeological sites – Rooiwal, Lydenburg, Makahane, and Graskop using normal dispersive Raman spectroscopy. They complemented this technique with X-ray fluorescence, X-ray diffraction and Fourier transform infrared spectroscopy.

Read the complete story in the latest online issue of SpectroscopyNOW.com

Moon Orbit Earth How Long

not the full moon photo by David Bradley It might seem like a trivial question, and most people would probably say 28 days. But, it isn’t so simple.

On average it takes 27.322 days (that’s a sidereal month, and a nice number of significant figures for something astronomical, especially when defining the day is not so clear cut) for the Moon to complete one orbit around Earth. However, the number of days between Full Moons is about 29.5306 days as the Moon has to “catch up with the sun” as it were. So, the actual number of days may differ from the average number by more than a half day. From one Full Moon to the next, the number of days in one lunation can vary between 29.272 and 29.833 days (another nice clutch of significant figures).

The age and apparent size of the Full Moon vary in a cycle of just under 14 synodic months, which is called the Full moon cycle.

The true Full Moon may differ from the calculated peak by up to about 14.5 hours, due to the normal irregularity in the Moon’s Keplerian orbit, and due to the periodic perturbations in that orbit caused by the Sun, the equatorial bulge of the Earth, and the proximity of other planets.

Anyway, I hope this little snippet answer the search query a recent visitor plugged into the sciencebase search box – “moon orbit earth how long”

Diesel to drugs

A new process for converting sugar into diesel fuel and feedstock chemicals for the manufacture of plastics, drugs, and other products, could help industry circumvent the problem of rising oil and natural gas prices. James Dumesic, of the University of Wisconsin-Madison has demonstrated how to make hydroxymethylfurfural (HMF) from the fruit sugar fructose using a straightforward acid-assisted dehydration process. Two additives reduce the formation of side products while butan-2-ol helps push the HMF into the non-aqueous phase ready for extraction. Yields are 80% of HMF with 90% fructose conversion. The HMF product can be used as an intermediate in polymer production and as a diesel-fuel additive, or even as biodiesel itself. Until now, the high cost of HMF has precluded its widespread use.

The latest on this now available at ReactiveReports.com

Hoodia gordonii FAQ

Hoodia gordonii from BBC site This southern African succulent plant tastes nasty but generations of San bushmen in the Kalahari Desert have eaten it to suppress their appetites on countless hunting trips. As such, it has become a focus of quick-fix weight loss programs.

What is Hoodia gordonii?
It’s a prickly succulent plant that grows in southern Africa and resembles a cactus but isn’t one.

What can it do?
Hoodia gordonii can apparently reduce calorie intake and lower body fat. A patented extract known as p57 and owned by Phytopharm is currently undergoing clinical safety and efficacy tests.

Why do the San bushmen use it?
They eat it for food, althouh H gordonii itself is bitter tasting and only eaten when the going gets really tough.

How was Hoodia’s appetite suppressing properties discovered?
It was investigated as part of a scientific research project established by the South African Council for Scientific and Industrial Research, which tested lots of bush foods and discovered that surprisingly Hoodia extracts made you feel fuller than you really were as well as lowering body weight without toxicity.

Do all Hoodia species reduce appetite?
Only Hoodia gordonii extract has been tested clinically on human volunteers, but that doesn’t necessarily mean that whole plant extract or other products won’t work.

So it definitely works?
Phytopharm’s 2001 double-blind, placebo-controlled clinical trial of overweight, but healthy volunteers showed a statistically significant fall in daily calorie intake as well as a drop in body fat percentage. [There is anecdotal evidence that products obtained from the plant (rather than isolated extract) can reduce body weigth]

Does it work quickly?
Large doses are needed but it takes just 15 days to see a calorie reduction on average of 1000 (kcal) per day.

What are the side-effects?
None have been found so far, but that does not mean that safety studies are not needed before it can get the green light for safety and efficacy.

Will the San bushmen benefit from the sales of Hoodia?
CSIR has entered a “benefit-sharing agreement” with a San representative organisation to ensure they benefit financially from the commercialisation of patented Hoodia gordonii extract. (Actually CSIR did not, allegedly, enter this agreement voluntarily but did so as a result of legal action).

Hoodia is CITES listed, what does that mean?
It means if you visit southern Africa and steal the succulent plant and try and take it out of the country or otherwise gain from it, you’ll get fined massively and face a jail sentence under the Convention on International Trade in Endangered Species of Wild Fauna and Flora.

The BBC reported on the Phytopharm trials in May 2003 and was saying then that potential users should be patient. In their report, they pointed out that the Hoodia tablets available via the internet that they had tested did not contain any of the active ingredient. A natural pill for obesity that really works will come, it just may be another few years in the making.

The original Phytopharm FAQ can be found here. More information on the various Hoodia species is available here.

Phytopharm has, I have been told, sold their licence to Unilever.

Celiac disease and food additive

An enzyme added to foods containing gluten could put an end to the misery of celiac disease for many sufferers, allowing them to eat almost anything they fancy without having to worry about the effects on their digestive system.

Celiac disease is an autoimmune disorder of the small intestine in which an abnormal reaction to the gluten protein in wheat, barley, and rye results in inflammation, which causes a temporary flattening of the nutrient absorbing villi that line the bowel. This prevents sufferers absorbing nutrients effectively from their diet. Until now, the only course of action is to avoid all foods containing gluten.

The full story is now available on chemistry news site Reactive Reports

Grape expectations controversy to put you to sleep

Certain Italian grape varieties used in popular red wines may contain high levels of the sleep hormone melatonin, according to an analysis by Marcello Iriti, Mara Rossoni, and Franco Faoro at the University of Milan. However, a melatonin expert in the US is unconvinced by the results citing the undefinitive nature of the analytical procedures used to test the wine.

Until recently, scientists considered melatonin to be a compound produced exclusively by mammals. Some researchers reckon plants too could produce this compound. Melatonin has also been shown to have antioxidant properties. Russel Reiter and colleagues at the University of Texas Health Science Center, in San Antonio, reviewed the literature and explained how melatonin directly detoxifies the hydroxyl radical (OH), hydrogen peroxide, nitric oxide, peroxynitrite anion, peroxynitrous acid, and hypochlorous acid.

Find out more in the latest chemistry news round up at Reactive Reports.