Chemistry News Archive July 2008

New materials for microwave cookware that heats faster with less energy

You may soon be enjoying microwave popcorn and other 'nuked' foods and beverages faster than ever before, while saving on electricity. Researchers in Pennsylvania and Japan report development of new ceramic materials that heat up faster and retain heat longer than conventional microwave cookware while using less energy. Their report is scheduled for the August 26 issue of ACS' Chemistry of Materials, a bi-weekly Journal.

In the new study, Sridhar Komarneni, Hiroaki Katsuki, and Nobuaki Kamochi note that researchers long have sought a commercially feasible method for using microwaves in the production of new genres of sturdy-heat-resistant ceramic materials. However, no optimal process had been developed.

The scientists describe preparation of ceramic plates from mixtures of magnetite and petalite, two naturally occurring minerals. Those new composite plates heated faster and retained heat for longer periods than commercially available microwave cookware, researchers say. The materials also show promise as an energy-saving component in microwave-based systems for cleaning up organic toxic waste in the environment. - MTS

Chemistry of Materials: "Novel Energy-Saving Materials for Microwave Heating?".

Toward designer bourbon whiskeys with custom-tailored aromas

In the latest chapter in a 40-year scientific quest to unravel the flavor and aroma secrets of the world's whiskeys, scientists in Germany are reporting discovery of key substances responsible for the distinctive bouquet of American bourbon whiskey. The study, which aims to help improve bourbon through a better understanding of its individual components, is scheduled for the July 23 issue of ACS' bi-weekly Journal of Agricultural and Food Chemistry.

Peter Schieberle and Luigi Poisson point out that more than 300 compounds have been identified over the years in whiskey. However, only a few studies have focused on the key aroma compounds, which are most responsible for the fruity, smoky, vanilla and other harmonics of whiskey.

In the study, Schieberle and Poisson analyzed more than 40 of Bourbon's compounds - 13 of them newly discovered - that blend to create its rich profile, a signature mixture of scents, including fruity, earthy and cooked apple. The new information could be useful in changing the recipe or manufacturing processes for bourbon in order to produce whiskey with distinctive flavors, they note. - JS

Journal of Agricultural and Food Chemistry:

"Characterization of the Most Odor-Active Compounds in an American Bourbon Whisky by Application of the Aroma Extract Dilution Analysis".

Diamonds may have been life's best friend on primordial Earth

Diamonds may have been life's best friend. Billions of years ago, the surface of these gems may have provided just the right conditions to foster the chemical reactions believed to have given rise to life on Earth, researchers in Germany report. Their study is scheduled for the August 6 issue of ACS' Crystal Growth & Design, a bi-monthly journal.

In the new study, Andrei Sommer, Dan Zhu, and Hans-Joerg Fecht point out that scientists have theorized for years that the chemical precursors of life gradually evolved from a so-called "primordial soup" of simpler molecules. But the details of how these simpler amino acids molecules, the building blocks of life, were assembled into complex polymers, remains one of science's long-standing mysteries.

To find out, the research team studied diamonds, crystallized forms of carbon which are older than the earliest forms of life on Earth. In a series of laboratory experiments, the scientists showed that after treatment with hydrogen, natural diamond forms crystalline layers of water on its surface, essential for the development of life, and involved in electrical conductivity. When primitive molecules landed on the surface of these hydrogenated diamonds in the atmosphere of early Earth, the resulting reaction may have been sufficient enough to generate more complex organic molecules that eventually gave rise to life, researchers say. - MTS

Crystal Growth & Design: "Genesis on Diamonds".

Water-stingy agriculture reduces arsenic in rice markedly

A new farming method first developed to conserve precious irrigation water may have the added benefit of producing rice containing much less arsenic than rice grown using traditional rice-farming methods, researchers in the United Kingdom report. Their study is scheduled for the August 1 issue of ACS' Environmental Science & Technology, a semi-monthly journal.

In the new study, Fang-Jie Zhao and colleagues point out that rice - a staple crop for 2.5 billion people worldwide - also is a major source of human exposure to arsenic in certain countries. Arsenic has been linked to cancer and other diseases. Arsenic gets in rice in countries such as Bangladesh and India when farmers flood rice paddies with arsenic-contaminated irrigation water.

The scientists compared rice plants grown in "flooded" soil in greenhouse conditions to rice plants grown under aerobic conditions. The other rice contained 10 to 15 times lower arsenic levels than the "flooded" rice, the scientists report. - MTS

Environmental Science & Technology: "Growing Rice Aerobically Markedly Decreases Arsenic Accumulation".

Air pollution worries cast cloud over Olympics in Beijing

Winning gold medals won't be the only thing on the mind of athletes during the Olympic games starting in Beijing next month. There's growing concern that the city's high air pollution levels may threaten their health and impair their performance, despite the Chinese government's pledge to clean-up the air in time for the events, according to an article scheduled for the July 28 issue of Chemical & Engineering News.

In a feature article in the magazine, C&EN Associate Editor Rachel Petkewich points out that Beijing's air pollution levels have been high for the past five years, exceeding China's standards for other major cities and stricter U.S. pollution standards. The air pollutants of most concern are ozone and particulate matter, which can cause respiratory problems. Some athletes have even threatened to arrive at the last possible minute before their own competitions - and skipping the opening ceremonies, for example - to minimize their exposure, the article notes.

But there's been some progress toward reducing air pollution levels in Beijing, including switching many of the city's coal-fired power plants to cleaner burning, natural gas facilities as well as stricter vehicle emissions controls. But these strides are being undercut by China's booming economy and increased construction, which have sparked pollution increases. Beijing's air pollution forecast during the Olympics and in the long-run remains uncertain, the article suggests.

Chemical & Engineering News: "Olympic Air Quality Questionable".

"Snow flea antifreeze protein" could help improve organ preservation

Scientists in Illinois and Pennsylvania are reporting development of a way to make the antifreeze protein that enables billions of Canadian snow fleas to survive frigid winter temperatures. Their laboratory-produced first-of-a-kind proteins could have practical uses in extending the storage life of donor organs and tissues for human transplantation, the researchers indicate in a report scheduled for the July 9 issue of the Journal of the American Chemical Society, a weekly publication.

In the study, Stephen B. H. Kent and colleagues point out that scientists have tried for years to decipher the molecular structure and produce from chemicals in a laboratory the so-called "snow flea antifreeze protein (sfAFP)." Those steps are critical for obtaining larger amounts of the protein, which exists naturally in only minute quantities in snow fleas. The larger synthetic quantities can be used for further research and potential medical and commercial uses, they say.

The researchers made synthetic sfAFP, and showed that it has the same activity as the natural protein. They also produced variants, including one form of sfAFP with a molecular architecture that is the reverse, or "mirror image," of natural sfAFP and different from any other protein found in living things on Earth. The mirror-image form of sfAFP appears less likely to trigger harmful antibodies and more resistant to destruction by natural enzymes, making it potentially more effective than the native form for use in organ and tissue preservation, the scientists note. "Our most significant advance was the use of the two mirror image forms of the protein to determine the previously unknown crystal structure of this unique protein," said Kent. "That is a first in the history of protein X-ray crystallography." - MTS

Journal of the American Chemical Society: "Mirror Image Forms of Snow Flea Antifreeze Protein Prepared by Total Chemical Synthesis Have Identical Antifreeze Activities".

New findings on Mother Earth's earthy scent

That evocative "earthy" scent of the soil returning to life in spring - and nasty earthy tastes and odors in fish and drinking water - actually results from two substances released by soil bacteria. Researchers in Rhode Island now report identifying how one of these substances forms, an understanding that could lead to improvements in the quality of water and food products. Their study, the first substantial research on the topic in 30 years, is scheduled for the July 23 issue of the weekly Journal of the American Chemical Society.

In the new study, David E. Cane and Chieh-Mei Wang point out that these two substances, geosmin and methylisoborneol, are volatile organic substances produced by certain soil bacteria. Although they are not harmful to health, these substances are difficult to remove from food and water products. The researchers recently identified the mechanism by which geosmin forms, but little is known about how methylisoborneol forms, they say.

To find out, the scientists studied the formation of methylisoborneol from Streptomyces coelicolor, a common soil bacterium. They found that that the substance is formed in an assembly line process directed by two recently discovered genes. A better understanding of this process could lead to new ways to prevent the formation of the odor-causing substance and may lead to consumer products with improved taste and smells, the researchers suggest. - MTS

Journal of the American Chemical Society: "Biochemistry and Molecular Genetics of the Biosynthesis of the Earthy Odorant Methylisoborneol in Streptomyces coelicolor".

A new-generation of simpler sensors for detecting disease-causing microbes and toxins

Scientists in Singapore are reporting development of a complete, palm-sized sensor that can detect disease-causing microbes, toxins, and other biological threats instantly without the need for an external power source or a computer. The long-awaited device, ideal for remote medical clinics, battlefields, and other sites, represents the next-generation of faster, simpler biosensors, according to a study scheduled for the August 1 issue of ACS' Analytical Chemistry, a semi-monthly journal.

In the new study, Pavel Neuzil and Julien Reboud explain that the new device uses an existing method for detecting DNA, proteins or cells based on their interaction with light shown on the nanostructured surface when these materials come into contact with it. Most existing biosensors of this type require the use of an external power source, a complex and costly analyzer and rely on an external personal computer to report the results.

Their self-contained analyzer relies on simpler components, such as four light-emitting diodes (LEDs) that light up in specific patters to produce test results without a computer, the researchers say. - MTS

Analytical Chemistry:

"Palm-Sized Biodetection System Based on Localized Surface Plasmon Resonance".

Killer Kevlar - clothing that shields from germs

Protective clothing worn by firemen and other emergency workers may soon get a germ-fighting upgrade. Researchers in South Dakota report progress toward the first Kevlar fabrics that can kill a wide range of infectious agents, including bacteria, viruses, and the spores that cause anthrax. Their study is scheduled for the August 6 issue of ACS' Industrial & Engineering Chemistry Research, a bi-weekly journal.

In the new study, Yuyu Sun and Jie Luo point out that Kevlar fabrics are widely used as fire-resistant materials for firefighters, police and emergency medical workers. But amid increased threats of bioterrorism, there's a growing need for new protective clothing that can also provide multiple protection against a wide variety of dangerous microorganisms.

The scientists developed a special process to coat Kevlar samples with acyclic N-Halamine, a potent germ-fighting substance. They then exposed coated and uncoated fabric samples to E. coli, Staphylococcus aureus, Candida tropicalis (a fungus), MS2 virus, and Bacillus subtilis spores (to mimic anthrax). After a short time, large amounts of microorganisms stuck to untreated fabric samples, but the coated fabrics showed little to no adherence of the infectious agents, the researchers say. The coating is long-lasting, can be reactivated, and does not cause any loss of fabric comfort or strength, they add. - MTS

Industrial & Engineering Chemistry Research: "Acyclic N-Halamine Coated Kevlar Fabric Materials: Preparation and Biocidal Functions".

Screening of tiny chemical fragments may pay big dividends in drug discovery

Scientists who develop new drugs are closely following the progress through clinical trials of a cache of drugs developed with counter-intuitive strategy that defies conventional wisdom, according to an article scheduled for the July 21 issue of Chemical & Engineering News.

In the cover story, C&EN Associate Editor Sarah Everts points out that in traditional drug discovery approaches researchers sort through millions of large, full-sized molecules to find promising substances that can bind strongly to their intended biological targets, a strategy called high-throughput screening (HTS). In so-called fragment-based lead discovery (FBLD), researchers instead sort through a few thousand tiny chemical fragments that bind weakly to their targets. After screening, these weakly-binding fragments are then expanded into more potent substances by adding chemical groups or linking a sequence of promising fragments together piece by piece, the article states.

Although no FBLD-based drugs are on the consumer market yet, about 10 are now in clinical trials. But whether the new strategy will be judged successful or not may have to wait until 2011, the earliest year that drugs developed from FBLD techniques will hit the market, the article notes.

Chemical & Engineering News: "Piece by Piece".

Detecting flu viruses in remote areas of the world

Researchers in Ohio and New Mexico are reporting an advance in the quest for a fast, sensitive test to detect flu viruses � one that requires no refrigeration and can be used in remote areas of the world where new flu viruses often emerge. Their new method, the first to use sugar molecules rather than antibodies, is in the July 2 issue of the Journal of the American Chemical Society, a weekly publication.

In the new study, Jurgen Schmidt, Suri Iyer, and colleagues point out that conventional tests for flu viruses - including bird flu - rely on antibodies, proteins produced by the immune system, to recognize viruses. But antibody-based tests can be expensive and require refrigeration to remain stable.

Their solution involved development of artificial forms of sialic acid, a sugar molecule found on the surface of cells that flu viruses attach to when they attack humans. In laboratory tests, the researchers showed that their highly-selective artificial sugars could be used to quickly capture and recognize two common strains of influenza viruses, H1N1, which infects birds, and H3N2, which infects pigs and humans. They used the molecules to differentiate between 2 strains (Sydney and Beijing) commonly found in human infections without isolating the viral RNA or surface glycoproteins. The sugars remain stable for several months, can be produced in large quantities, and exhibit extended shelf life. - MTS

Journal of the American Chemical Society: "Detection of Intact Influenza Viruses using Biotinylated Biantennary /S-/Sialosides".

Marine worm's jaws say "cutting-edge new aerospace materials"

Researchers in California and New Hampshire report the first detailed characterization of the protein composition of the hard, fang-like jaws of a common marine worm. Their work could lead to the design of a new class of super-strong, lightweight materials for use as construction and repair materials for spacecraft, airplanes, and other applications. Their study is scheduled for the July 14 issue of ACS' Biomacromolecules, a monthly journal.

In the new study, Chris C. Broomell and colleagues note that Nereis virens, also known as the sandworm or ragworm, is a burrowing marine worm found in shallow waters in the North Atlantic region. Researchers remain intrigued by the remarkable hardness of its jaws and long pincers, which rivals that of human teeth and exceed the hardness of many synthetic plastics. But little is known about the exact chemical composition of these structures.

Broomell and colleagues collected the jaws of 1,000 worms and analyzed their protein content using high-tech instrumentation. They found that the primary chemical in the jaws and pincers of the worm is a unique protein, named Nereis virens jaw protein-1 (Nvjp-1), which is rich in the amino acid histidine. The researchers also characterized the chemical conditions needed for its formation, such as the presence of zinc, which could allow researchers to create synthetic versions of this super-hard, lightweight material. - MTS

Biomacromolecules: "Cutting Edge Structural Protein from the Jaws of Nereis virens".

New "scrubber" speeds removal of powerful anthrax clean-up agent

Researchers in New Jersey report discovery of a fast, efficient method for removing a powerful pesticide used to sterilize buildings and equipment following anthrax attacks. Their chemical "scrubber" removes 99 percent of the pesticide following fumigation and could pave the way for its broader use in anthrax clean-up efforts, the scientists say. Their study is scheduled for the July 18 issue of ACS' Organic Process Research & Development, a bi-monthly journal.

In the new study, Roman Bielski and Peter J. Joyce note that the commonly used pesticide, methyl bromide, is superior to chlorine dioxide for destroying anthrax-causing bacteria and their spores. However, it is highly toxic to humans and may harm the environment by destroying the ozone layer. Researchers thus have sought an efficient method for removing this promising anthrax decontamination agent.

Bielski and Joyce documented the effectiveness of their removal method in experiments with an empty office trailer filled with air containing methyl bromide. They treated air exhausted from the trailer with a solution of sodium sulfide combined with a powerful catalyst. This chemical "scrubber" removed more than 99 percent of the methyl bromide from the air. - MTS

Organic Process Research & Development: "The Use of Methyltricaprylylammonium Chloride as a Phase Transfer Catalyst for the Destruction of methyl Bromide in Air Streams".

Snake venom tells tales about geography

Just as people give away their origins by that southern drawl or New England twang, poisonous snakes produce venom that differs distinctly from one geographic area to another, the first study of the "snake venomics" of one of the most common pit vipers in Latin America has found. The study is scheduled for the August 1 issue of ACS' monthly Journal of Proteome Research.

In the new study, Juan J. Calvete and colleagues point out that researchers have known for decades that venom collected from snakes of the same species from different geographic locations can differ in terms of their biological effects and symptoms on snakebite victims. However, scientists know little about the chemical differences behind these geographically different venoms.

To find out, the scientists collected venom samples from adult and newborn specimens of the lancehead pitviper from two geographically isolated populations from the Caribbean and Pacific regions of Costa Rica. After a detailed laboratory analysis of the proteins found in the venom - so-called "snake venomics" - the researchers found major differences in the venoms collected from the two regions. They also found distinct differences in proteins collected from newborns and adult snakes. The study "highlights the necessity of using pooled venoms as a statistically representative venom for antivenom production" for human snakebite victims, the report states. - MTS

Journal of Proteome Research: "Snake Venomics of the Lancehead Pitviper Bothrops asper: Geographic, Individual, and Ontogenetic Variations".

'Electronic chemicals' pave the way for brighter, more energy-efficient future

From solar power to computer chips to advanced lighting, new materials developed by chemists are helping consumers reap the benefits of advanced electronics, according to an article scheduled for the July 15 issue of Chemical & Engineering News. Some of these electronics will soon appear on store shelves and offices near you.

In the C&EN cover story, writers Michael McCoy, Alexander Tullo, and Jean-Francois Tremblay point out that so-called 'electronic chemicals' play key roles in today's advanced electronics but go largely unnoticed by consumers. These unsung materials, part of a multibillion dollar electronic materials market, provide improved solar panels that crank out more fossil fuel-free electricity and new computer chips that are smaller and more energy efficient than ever. These materials also fuel the development of organic light emitting diodes (OLEDs) that promise energy savings and could render today's incandescent light bulbs and fluorescent bulbs obsolete, according to the article.

But making advanced electronics comes with a steep price. Chemical companies now invest billions of dollars to build new manufacturing plants to produce raw materials for advanced electronics. Manufacturers are also spending heavily on research and development, as new electronic advances demand innovative new chemicals, the article states.

Chemical & Engineering News: "Electronic chemicals".

Boosting survival of insulin-cell transplants for Type 1 Diabetes

Researchers in Japan are reporting a discovery that could improve the effectiveness and expand the use of transplants of insulin-producing cells to treat diabetes. Their study is scheduled for the July 16 issue of ACS' Bioconjugate Chemistry, a monthly journal. Insulin-dependent, or Type 1, diabetes affects about 800,000 people in the United States.

In the new study, Yuji Teramura and Hiroo Iwata point out that transplantation of the pancreas's insulin producing cells, so-called islets of Langerhans, is a promising experimental technique for treating patients with insulin-dependent diabetes. However, the procedure is not sufficiently effective for many people. This is because the body destroys many of the islet cells right after transplantation in an inflammatory reaction triggered by blood clotting on the surface of the cells, the researchers say.

To address this problem, the scientists coated islet cells with a special polymer film containing heparin, an anticoagulant, or urokinase, a medication that dissolves blood clots. In laboratory studies, the researchers showed that the coatings delayed the clotting long enough to prevent the destruction that otherwise would occur immediately after transplantation. The coatings did not affect the ability of the cells to produce insulin, the researchers add. - MTS

Bioconjugate Chemistry: "Islets Surface Modification Prevents Blood-Mediated Inflammatory Responses".

First DNA molecule made almost entirely of artificial parts

Chemists in Japan report development of the world's first DNA molecule made almost entirely of artificial parts. The finding could lead to improvements in gene therapy, futuristic nano-sized computers, and other high-tech advances, they say. Their study is scheduled for the July 23 issue of the Journal of the American Chemical Society, a weekly publication.

In the new study, Masahiko Inouye and colleagues point out that scientists have tried for years to develop artificial versions of DNA in order to extend its amazing information storage capabilities. As the genetic blueprint of all life forms, DNA uses the same set of four basic building blocks, known as bases, to code for a variety of proteins used in cell functioning and development. Until now, scientists have only been able to craft DNA molecules with one or a few artificial parts, including certain bases.

The researchers used high-tech DNA synthesis equipment to stitch together four entirely new, artificial bases inside the sugar-based framework of a DNA molecule. This resulted in unusually stable, double-stranded structures resembling natural DNA. Like natural DNA, the new structures were right-handed and some easily formed triple-stranded structures. The unique chemistry of these structures and their high stability offer unprecedented possibilities for developing new biotech materials and applications, the researchers say. - MTS

Journal of the American Chemical Society: "Artificial DNA Made Exclusively of Nonnatural C-Nucleosides with Four Types of Nonnatural Bases".

Uncertainties prevail over human health benefits of polyphenols

Despite scores of studies documenting the effects of healthful plant nutrients called polyphenols in protecting nerves from damage, it would be "unwise" to assume that the same protective effects occur for Alzheimer's disease (AD) and other human disorders, a new report concludes. It is scheduled for the July 9 issue of ACS' bi-weekly Journal of Agricultural and Food Chemistry.

In the report, Charles Ramassamy and colleagues in Canada analyzed the results of more than 200 laboratory and animal studies on these materials, found in fruits, vegetables, wine, chocolate, coffee, tea, and other foods. They found abundant evidence that polyphenols do, indeed, protect nerves from the kind of damage that occurs in AD and other chronic brain disorders.

The researchers concluded, however, that "it is not at all clear whether these compounds reach the brain in sufficient concentrations and in a biologically active form to exert beneficial effects." Resolving those uncertainties will take years of additional research, they say in the report, which includes a list of the 50 foods containing the highest amounts of polyphenols. - AD

Journal of Agricultural and Food Chemistry: "Challenges for Research on Polyphenols from Foods in Alzheimer's Disease: Bioavailability, Metabolism and Cellular and Molecular Mechanisms".

Super strong antimicrobial coatings for medicine, defense

One of the world' strongest materials meets one of Nature's most powerful germ killers in a new research project that produced incredibly tough anti-bacterial surfaces with multiple applications in home appliances, medicine, aerospace, and national defense. A report on this long-awaited genre of stronger disinfectant surfaces is scheduled for the July 9 issue of ACS' Nano Letters, a monthly journal.

In the study, Virginia A. Davis and Aleksandr Simonian and colleagues point out that concern over the role of contaminated surfaces in the spread of infections has sparked a search for better antimicrobial coatings. Scientists want to harness a powerful natural enzyme called lysozyme in that quest. However, they have not found a material strong enough to hold the enzyme in the desired fashion for long periods.

Their solution involved the first successful merging of lysozyme with single-walled carbon nanotubes (SWNTs). Only 1/50th the width of a human hair, SWNTs have exceptional strength and hold lysozyme in place, while other coatings lose their antimicrobial activity over time. "The results of this research demonstrate the significant possibilities for the molecular design of hybrid structural materials from SWNTs and natural biopolymers," the report states. "Such robust, antimicrobial materials have significant promise in applications including medicine, aerospace engineering, public transportation, home appliances and sporting goods." - AD

Nano Letters: "Strong Antimicrobial Coatings: Single-Walled Carbon Nanotubes Armored with Biopolymers".

Consumers call for more government oversight of commercial genetic tests

With its promises of improved diagnostic and treatment outcomes for arthritis, breast cancer, and other conditions, genetic testing is on a trajectory to becoming a mainstay of the healthcare system. But the field is poorly regulated, prompting calls for more government oversight to help ensure patient privacy and testing accuracy, according to an article scheduled for the July 7 issue of Chemical & Engineering News.

In the article, C&EN Associate Editor Britt E. Erickson points out that genetic tests are now available for some 1,200 different clinical conditions and more tests are in the development pipeline. With more and more genetic information published on the Internet and the growth of direct-to-consumer genetic testing, there's an urgent need for more government action to help maintain patient privacy while ensuring that test claims are accurate and clinically useful, the article notes.

Changes are already in the works. The Food and Drug Administration (FDA) indicates that it plans to expand oversight of genetic testing in the future. "As the FDA moves to regulate some aspects of this testing area, congressional action will likely be needed to help manage the growth of this emerging health care issue," the article states. At least two states, New York and California, already require genetic-testing companies to prove the validity of their tests.

Chemical & Engineering News: "Barriers to Genetic-Based Medicine".