News From The American Chemical Society, Sept. 17, 2008

Calorie-free natural sweetener moves one step closer to use in the U. S.




Researchers in Georgia are reporting an advance toward the possible use of a new natural non-caloric sweetener in soft drinks and other food products in the United States. Stevia, which is 300 times more potent than sugar but calorie-free, is already used in some countries as a food and beverage additive to help fight obesity and diabetes. Their study is scheduled for the October 8 issue of ACS' Journal of Agricultural and Food Chemistry, a bi-weekly publication.



Indra Prakash, John F. Clos, and Grant E. DuBois note that so-called stevia sweeteners, derived from a South American plant, have been popular for years as a food and beverage additive in Latin America and Asia. But several factors have prevented its use as a sweetener in Europe and the United States. Those include concerns about safety and hints that exposure to sunlight degrades one of the key components of stevia.



In research that eases concerns about stevia's stability, the scientists studied clear glass containers of cola and lemon-lime sodas containing the two major naturally sweet components in stevia. After exposing the beverages to sunlight for one week, they found no significant degradation in either component of the natural sweetener. - MTS



"Photostability of Rebaudioside A and Stevioside in Beverages"



DOWNLOAD FULL TEXT ARTICLE dx.doi/10.1021/jf801343e



CONTACT:



Indra Prakash, Ph.D.

The Coca-Cola Company

Atlanta, Georgia 30313



Toward a fast, life-saving test for identifying the purity of heroin




Scientists in Spain are reporting an advance toward a new method for determining the purity of heroin that could save lives by allowing investigators to quickly identify impure and more toxic forms of the drug being sold on the street. Unlike conventional tests, it does not destroy the original drug sample, according to their report. It is scheduled for the Oct. 1 issue of ACS' Analytical Chemistry, a semi-monthly journal.



In the new study, Salvador Garrigues and colleagues point out that the purity of heroin can vary widely, since pushers often mix it with chalk, flour, or other "cutting agents." Because heroin users do not know the exact purity of the drug, they are more at risk for overdose and even death. Conventional tests for determining the purity of street heroin involve destructive and time-consuming sample preparation, the scientists say.



They studied 31 illicit drug samples from Spain that contained six to 34 percent heroin. The scientists tested the samples using the new analytical method, called Diffuse Reflectance Near-Infrared Spectroscopy (DR-NIR). It involves shooting a beam of infrared light into a sample to determine its chemical composition based on the wavelength of light emitted. The method quickly and accurately determined the chemical content of the samples without any prior sample preparation, the scientists say. ?­ - MTS
















"Nondestructive Direct Determination of Heroin in Seized Illicit Street Drugs by Diffuse Reflectance near-Infrared Spectroscopy"



DOWNLOAD FULL TEXT ARTICLE dx.doi/10.1021/ac800781c



CONTACT:



Salvador Garrigues, Ph.D.

Universitat de Valencia

Valencia, Spain



Key proteins identified in the quest for male contraceptive



In an advance toward a long-sought new male contraceptive, researchers in China have identified key proteins in men that suppress production of sperm and could become new targets for a future male birth control pill. Their study is scheduled for the October 3 issue of ACS' monthly Journal of Proteome Research.



Jiahao Sha and colleagues point out that scientists do not understand one effect of the male sex hormone, testosterone - how injections of the hormone suppress production of sperm. Building on a previous study showing almost total sperm suppression with an injectable testosterone combined with a synthetic hormone called levonorgestrel (LNG), the researchers sought new insights into how hormones affect sperm-producing cells in the testicles.



In a new study on men, they found that testosterone combined with LNG changed the body's production of 31 proteins compared to only 13 proteins for men given only testosterone. The scientists identified proteins that could serve as both targets for new male contraceptives as well as medications for treating infertility. - JS



"Proteomic Analysis of Testis Biopsies in Men Treated with Injectable Testosterone Undecanoate Alone or in Combination with Oral Levonorgestrel as Potential Male Contraceptive"



DOWNLOAD FULL TEXT ARTICLE dx.doi/10.1021/pr800259t



CONTACT:



Jiahao Sha, Ph.D.

Nanjing Medical University

Jiangsu Province, People's Republic of China, 210029



Toward more effective drugs, vaccines for fighting HIV



Researchers are reporting progress toward a wave of new drugs and vaccines that could significantly improve the health and lifespan of millions infected with or at risk for HIV, the virus that causes AIDS, according to an article (pubs.acs/cen/coverstory/86/8638cover.html) scheduled for the Sept. 22 issue of Chemical & Engineering News, ACS' weekly newsmagazine. The findings offer hope for the estimated 33 million people worldwide who are currently infected with the virus.



In the C&EN cover story, Senior Correspondent Ann Thayer notes that when HIV was first identified almost 25 years ago, the life expectancy of an infected person was only about one year. Today, with more than 20 so-called antiretroviral drugs now available to treat the disease, an infected person can expect to live many years, at least in developed countries. With new insights into how the virus works in the body, pharmaceutical companies are now attempting to develop even more effective drugs that are safer and easier to use.



While there's still no cure for the disease, Thayer notes in a companion article in C&EN, researchers are working hard to develop an effective HIV vaccine, considered the ultimate way to prevent infection. But there's still a lot to learn about the virus itself and the human body's response, as setbacks in recent clinical trials have shown, according to the article. "Failure is the norm in product development, particularly for something as difficult as HIV," notes one researcher.



"New Antiretrovirals Change HIV Treatment"



This story is available at pubs.acs/cen/coverstory/86/8638cover.html







The American Chemical Society - the world's largest scientific society - is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.



Source: Michael Bernstein


American Chemical Society