David Bradley – Page 328

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.

Fuel Cell Hydrogen Economy

Hydrogen fuel cells have been relatively neglected through insufficient support from industry and government, according to a study published today funded by the Economic and Social Research Council (ESRC).

‘Fuel cells are a genuine ‘clean’ technology,’ says study investigators, Chris Hendry of the Cass Business School, London, ‘But re-investment in nuclear technology is likely to squeeze out the investment necessary to make fuel cells competitive with existing energy sources and with other non-nuclear alternative energy options.’

I asked him about the true “cleanness” of fuel cells in the light of new infrastructure requirements, sourcing the requisite hydrogen and the recycling of equipment past its use by date.

“The ideal is to produce the hydrogen by electrolysis, using another renewable source,” he told Sciencebase, “Wind action in particular is intermittent – so when there’s too much generating electricity that can’t be used, it can be diverted to produce the hydrogen. Other countries can use solar for this purpose.”

But, what about sourcing that hydrogen before such technologies are fully viable?

“In the short-term, however, you’re right, the hydrogen will come from other hydrocarbons, particularly natural gas,” he adds, “This will enable fuel cells to become established using existing infrastructure, while a hydrogen infrastructure is developed.”

“In the end, the question is, which energy source has the most efficient
‘well-to-wheels’ costs, and which has also the least recycling costs?”

The study, co-written by Prof. Hendry, Dr. Paul Harborne, James Brown and Prof. Dinos Arcoumanis, gives a strong clue to one of the major obstacles to development by referring to fuel cell technology as a disruptive innovation. A disruptive innovation, if successful, eventually overturns the existing product on the market. Recent examples include the digital camera and the compact disc. Disruptive innovations are radically different from the existing dominant technology and to begin with they are often not as good. The result is two-fold. First the proponents of existing technology are likely to fear and so resist the new development. Second, because profits are unlikely to be immediate, funding can be problematic.

The automotive industry and stationary power provide examples of fuel cells as a disruptive innovation. However, while their potential is being pursued in the UK, Germany, North America and Japan, interviews with seventy companies in these countries show the UK fuel cell industry is lagging behind.

Jewelry Made with Molecules

Molecular jewelry Precious jewelry is usually made with metals rather than molecules, although there is plenty of costume jewelry made with polymers and other materials which are of course composed of molecules. But, that’s not really a concern for madewithmolecules.com who are touting a chemically aware range of chokers, keychains, necklaces, charm bracelets, and even boxer shorts, sporting your favourite molecule.

So, for the chemist in your life, how about a serotonin necklace, or a pair of testosterone boxers, perhaps. A dopamine keychain tells the world you’re into love and pleasure (or that you’re on medication, perhaps) while acetylcholine earrings really show your neurones are firing on all four!

Then there are the estrogen items, for women who want to rejoice in their hormonal surges or for guys hoping to reveal their feminine side.

There are even glucose and oxytocin baby suits. Glucose being the key sugar molecule we all need right from birth and oxytocin being the feel-good hormone that completes the breast feeding cycle.

This post might look like an ad, but they didn’t pay me a dime for the privilege, I just had to tell sciencebase readers, many of whom are chemists.

Cranberry Against Tooth Decay

Cranberries have a special place in modern herbal folklore, the presence of antioxidant flavonoids in these tart but edible berries are thought to have antimicrobial activity. Now, US researchers have demonstrated that the extracts of the red fruit can prevent Streptococcus mutans, the bacterium responsible for dental caries, from having its wicked way with your teeth and so potentially halt tooth decay.

“We are not offering the solution for the elimination of dental caries,” team leader Hyun Koo of Rochester University told me, “but rather an alternative approach to help to reduce it.”

He adds that using cranberry or its food products for oral hygiene purposes is not recommended because they contain too much sugar (both natural and added) and are very acidic. However, “We have shown that there are some specific compounds that may help to reduce caries. The challenge is to find those that are biologically active. Then, we can think about one day using them in mouthwash or toothpaste,” he explains.

Read the full story in the Reactive Reports Summer Special

Alchemical happenings

The second July issue of The Alchemist is now online. In it I report on the latest on the origins of life as well as the heady subject of the European ban on chemicals used in hair dyes. Also, discussed this week, US researchers have made “ice cubes full of crumpled paper” on the microscopic scale while others have built an organic transistor that has environmental potential. Finally, for chemists under pressure, cellulose is really cooking.

Get the chemical low down here

Rust Never Sleeps

Rust never sleeps Dumb materials succumb to rust, but smart materials might be able to heal themselves.

Researchers in Europe have devised a novel nano coating for metals and alloys that forms a very thin gel-like layer on the material. If this coating is damaged, the metal would normally be exposed to the elements. However, the nano particles contain a preservative that instead spreads to fill any microscopic cracks and holes that appear and quickly blocks them; preventing further attack from whatever corrosive agent was eating at the metal.

The current materials can heal cracks of up to 100 micrometres in size in water and in salt solutions. “The next stage is to develop the self-healing coatings to adapt them for other metals, such as steel,” Shchukin adds, “and to provide faster release of the inhibitor from the nanoreservoirs resulting in faster healing of the defects.”

Sandra Tsing Loh gives voice to science news

The first of a swathe of broadcast science news items from the desk of David Bradley Science Writer aired today on the Loh Down on Science radio show, broadcast out of Caltch and available on the net here. The item in question discusses the Japanese peptide nanotubes I reported on recently for SpectroscopyNOW but with Sandra’s unique voice and style adding a new twist to this fascinating scientific research thread.

Check out the current podcast and the archive of daily Loh Downs. Oh, and click the speak button in this post to listen inline.