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Research on a treasure trove of amber has yielded evidence that France once was covered by a dense tropical rainforest with trees similar to those found in the modern-day Amazon. The report on 55-million-year-old pieces of amber from the Oise River area in northern France is scheduled for the Jan. 4 issue of ACS’ Journal of Organic Chemistry, a biweekly publication.
In the new study, Akino Jossang and colleagues used laboratory instruments to analyze the fossilized tree sap in an effort to link specific samples of amber to specific kinds of trees. The amber remained intact over the ages, while the trees from which it oozed disappeared. Efforts to make such connections have been difficult because amber from different sites tended to have very similar chemical compositions. The report describes discovery of a new organic compound in amber called “quesnoin,” whose precursor exists only in sap produced by a tree currently growing only in Brazil’s Amazon rainforest.
Researchers say that amber probably seeped out of a similar tree growing in a tropical forest that covered France millions of years ago before Earth’s continents drifted into their current positions. “The region corresponding to modern France could have been found in a geographically critical marshy zone belonging to Africa and a tropical zone 55 million years ago extending through North Africa to the Amazon,” the report states. — AD
Only nine percent of 199 beverage samples had benzene levels above the U. S. Environmental Protection Agency (EPA) limit of 5 parts per billion (ppb) for benzene in drinking water, according to a study by EPA and U. S. Food and Drug Administration (FDA) scientists. It is scheduled for the current issue of ACS’ Journal of Agricultural and Food Chemistry, a bi-weekly journal.
Products containing benzene above the EPA level were reformulated by the manufacturers to minimize or eliminate benzene and one product was discontinued, researchers said. Benzene levels in the reformulated products were 1.1 ppb or less. About 71 percent of beverage samples in the study contained less than 1 ppb. Based on results from the survey and actions taken by the beverage industry, FDA concluded that the levels of benzene found did not pose a safety concern for consumers.
In the study, FDA’s Patricia Nyman and colleagues point out that benzene can form at ppb levels in some beverages that contain a food preservative, benzoate salt, and ascorbic acid (vitamin C). In the early 1990s, the U.S. beverage industry discovered benzene in some beverages and reformulated those products. In 2005, the substance again was found in some beverages, likely because new manufacturers were unaware of the problem, the study says. Some manufacturers also have added vitamin C to drinks in response to consumers’ desire for healthier products.
The study found that product formulation, shelf-life, and storage conditions were important factors affecting benzene formation. The report also describes the in-house validation of FDA’s analytical method for determining benzene in beverages. — JS
Journal: Journal of Agricultural and Food Chemistry
Journal Article: “Survey Results of Benzene in Soft Drinks and Other Beverages by Headspace Gas Chromatography/Mass Spectrometry”
A mysterious and unpredictable group of side effects from modern medications called idiosyncratic drug reactions (IDRs) likely will persist as a major health care problem unless there is a dramatic increase in research funding, according to a 20-year review of research in the field scheduled for the January issue of ACS’ Chemical Research in Toxicology, a monthly journal.
The review, by Jack Uetrecht, defines IDRs as reactions that happen unexpectedly and with no obvious connection to the known effects of a medication’s ingredients or dosage. Although relatively rare, IDRs make an important contribution to the annual burden of death, illness, and increased health care costs from serious adverse drug reactions. In addition, serious IDRs that appear after a new drug has gone into wide use can force drug companies to withdraw products after R&D investments totaling hundreds of millions of dollars.
Two decades of research have produced significant progress, the report acknowledges. However, medical science still has only a “superficial” understanding of how and why IDRs occur and a growing recognition that the mechanisms behind IDRs may be as complicated as those involved in cancer or diabetes. The review describes a need for increased research funding, with more scientists focusing on IDRs, in order to achieve faster progress. — JS
Scientists in France and Japan report an advance toward unlocking the secrets of “tension wood (TW),” a step that could have practical applications in preventing costly warping and splitting of wood used in construction projects. The report is scheduled for the Jan. 14 issue of ACS’ Biomacromolecules, a bi-monthly journal.
In the study, Bruno Clair and colleagues point out that whereas normal wood tends to shrink a small amount when dried, TW undergoes surprisingly high shrinkage. This shrinkage makes it undesirable for use in sun decks and other construction applications. Now, researchers want a valid explanation for this phenomenon.
In the current study, Clair and colleagues collected TW and normal wood samples from a chestnut tree and exposed the samples to different drying conditions. Using nitrogen adsorption, a technique to measure the porosity of materials, they found that the TW was composed of a gel-like layer with a surface area more than 30 times higher than in normal wood. The collapse of this gel during drying likely caused TW’s high shrinkage rate, the scientists say. The finding could lead to ways to reduce this shrinkage in order to make TW more usable for construction applications. — MTS
Researchers have discovered a new structure for a key enzyme associated with celiac disease, a finding that could lead to the design of new medications for the common digestive disorder, according to an article scheduled for the Jan. 7 issue of Chemical & Engineering News, ACS’ weekly newsmagazine.
Celiac disease is a condition in which the stomach cannot properly digest wheat and other gluten-containing foods. The disease afflicts an estimated 2 million people in the United States alone.
In the article, C&EN Deputy Assistant Managing Editor Stu Borman notes that the disease is believed to occur when the protein gluten interacts with an enzyme called transglutaminase 2 (TG2), triggering an autoimmune reaction that damages the small intestine and causes diarrhea, abdominal pain and other symptoms. As a result, people with the disease are urged to follow a strict gluten-free diet.
Although scientists have previously obtained the X-ray crystal structure of human TG2, they have only revealed its “closed” or inactive form, the article points out. Now, Chaitan Khosla and colleagues at Stanford University report the first-ever determination of the “open” structure of the enzyme, in which its active site is accessible to substrates. The finding could help scientists design inhibitors of the enzyme that could serve as medications for celiac disease and other related conditions, according to the article.
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