ChemWeb Newsletter

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overview

Ancient oxygen levels were higher than The Alchemist thought, but they existed in submarine oxygen oases rather than in the atmosphere. We also learn this week that a sweet solution to modulating pharmaceutical activity is possible, that micro-onions could serve as magnetic ink for digital displays, that there is more sulfur involved in the nitrogen cycle than we thought and how cat litter has the key to a productive sex life for the Toxoplasma parasite that infects rats. Finally, NIH is funding new research to protect us from viral-based bioweapons.




Researchers at MIT have demonstrated that oxygen gas may have been present on Earth hundreds of millions of years before its debut in the atmosphere, locked in submarine "oxygen oases." The team has published evidence that tiny aerobic organisms, akin to yeasts, may have evolved to survive on extremely low levels of the gas in this environment eons before the "Great Oxidation Event," the GOE, which occurred almost nearly 2.3 billion years ago and allowed aerobic life to thrive on land. The results might reconcile a split in the earth sciences community that arose with the discovery about a decade ago of oxygen-rich molecular fossils present in sedimentary rocks, hinting at much older oxygen-using life before the GOE.





Sugars attached to drugs can enhance, change or neutralize their effects, according to Jon Thorson and colleagues at the University of Wisconsin-Madison. They have now developed a new approach to help them exploit this phenomenon. Their simple process separates sugars from carrier molecules and allows them to attach them to a drug. The process also involves a color change in those molecules that accept the sugary payload, which could be used in screening. "One can put 1,000 drug varieties on a plate and tell by color how many of them have received the added sugar," Thorson explains. He adds that, "If we can build a toolbox that allows us to make these molecules on demand, we can ask, 'What will sugar A do when it's attached to drug B?'"





US researchers have developed a relatively simple method for making microscopic capsules that have the layered appearance of an onion, but on a much smaller scale. They used microfluidics to synthesize the tiny layered objects in a single step. Possible applications include magnetic inks for display technologies. A black inner core remains at the center of the particles so the outer transparent layers scatter light making the particle appear white. Applying a magnetic field pulls the black cores towards the surface, so "writing" on the screen. Related particles could be used as transport systems for multicomponent pharmaceuticals and controlled release delivery of a cocktail of drugs in a specific sequence one released as each layer peels away within the body or at the target site of the disease.





The greenhouse gas nitrous oxide undergoes partial decomposition depending on environmental conditions. Now researchers in Germany have determined the structure of an enzyme that breaks down the gas. Surprisingly, the team found that the active center of the N2O-reductase enzyme is made up of four copper atoms and two sulfur atoms, whereas biochemists had assumed incorrectly that it had only a single sulfur atom. The revelation has now led to a new mechanism that explains the decomposition of N2O. Nitrous oxide and nitrogen production on farmland and in forests depends on a multitude of opposing effects, the new study helps fill a gap in our understanding of the nitrogen cycle.





Toxoplasma gondii has sex in the feline gut and nowhere else. But, how does this kissing cousin of malaria find its way to the parasitic love nest inside a cat? Apparently, it finds its place to make baby T gondii from infected rats. A new study published in Plos One, suggests that infection of the rats disturbs their normal response to particular odors causing them to effectively lose their fear of cats by mistaking the warning smell in cat urine for a sexually-arousing chemical that hints at good times ahead for the rat, but brings about its early demise if cornered by the cat. The researchers explain that Toxoplasma infection alters neural activity in limbic brain areas necessary usually reserved for innate defensive behavior in response to the cat urine odor and causes the rats to fail to turn tail. This is a remarkable example of a remarkable example of a parasite manipulating a mammalian host for the benefit of its life cycle.





Pejman Naraghi-Arani of the Lawrence Livermore National Laboratory will receive $2.4 million from the National Institutes of Health under its Partnerships for Biodefense Program to help him develop tools for detecting biological weapons and protecting against their effects. Naraghi-Arani and colleagues at the University of Texas Medical Branch, the University of California San Francisco and NanoString Technologies Corp., will use the funding to develop assays for detecting 35 category A, B and C viral pathogens, including Ebola, Marburg, Dengue and Chikungunya. The platform being developed will be able to test more than 100 samples each day with only five minutes of patient contact each and return results within 24 hours.