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Address and deliver: A gold catalyst can be delivered to a target organ in a higher organism where it performs a chemical transformation visualized by bioimaging. This intriguing approach has been introduced by a Japanese team of scientists in the journal Angewandte Chemie. It could make organometallic catalysis applicable for therapy or diagnostics.
Plants are capable of producing powerful movement that is initiated at the molecular level. This fast motion is often supported by helix-based architectures, for example in vetches or orchids that spread seeds by explosive opening of their pods. Researchers now demonstrate in the journal Angewandte Chemie that these biological strategies can be re-engineered by interfacing molecular switches with man-made materials.
Direct Radiolabeling of Nanomaterials: Directly radiolabeled nanographene materials without chelators are suitable for bioimaging applications
Positron emission tomography plays a pivotal role for monitoring the distribution and accumulation of radiolabeled nanomaterials in living subjects. The radioactive metals are usually connected to the nanomaterial through an anchor, a so-called chelator, but this chemical binding can be omitted if nanographene is used, as American scientists report in the journal Angewandte Chemie. The replacement of chelator-based labeling by intrinsic labeling significantly enhances the bioimaging accuracy and reduces biases.
Pharmaceuticals from a Coal Mine? Novel microbial geldanamycin derivatives and cyclopentenone ansamycins from an abandoned coal mine
Digging around in the dark can sometimes lead to interesting results: in the acidic waters of an abandoned coal mine in Kentucky (USA), researchers discovered ten previously unknown microbial natural products from a strain of Streptomyces. They have now introduced these compounds in the journal Angewandte Chemie. Four of the molecules contain a cyclopentenone ring, which is rare in this class of substances.
Nature-Based Sunscreens: Boosting the solar protection factor with rationally designed, nature-inspired sunscreens
The ideal sunscreen should block UVB and UVA radiation while being safe and stable. In the journal Angewandte Chemie, Spanish scientists have introduced a new family of UVA and UVB filters based on natural sunscreen substances found in algae and cyanobacteria. They are highly stable and enhance the effectivity of commercial sunscreens.
Microscopic Submarines for Your Stomach: Micromotors neutralize gastric acid and release drugs depending on pH
Tiny “submarines” that speed independently through the stomach, use gastric acid for fuel (while rapidly neutralizing it), and release their cargo precisely at the desired pH: Though it may sound like science fiction, this is a new method for treating stomach diseases with acid-sensitive drugs introduced by scientists in the journal Angewandte Chemie. The technique is based on proton-driven micromotors with a pH-dependent polymer coating that can be loaded with drugs.
Tough Aqua Material for Water Purification: Decontamination of water with a robust and sustainable membrane assembled from two synergistically working components
Water purification processes usually make use of robust membranes for filtering off contaminants while working at high pressures. Can materials employing water as major component be made strong enough to suit such a demanding application? Israeli scientists now report in the journal Angewandte Chemie that a supramolecular aqua material can be utilized as a sustainable membrane for water purification at high pressures.
Composite Material for Water Purification: Removal of multiple contaminants from water by supported ionic liquid phases
Fresh, clean water coming directly from the tap is a true luxury. In developing countries, people often have no choice but to use a contaminated river for drinking water. Water filters can help by quickly converting polluted surface or ground water into safe drinking water. In the journal Angewandte Chemie, researchers have now introduced a novel multifunctional composite material that removes inorganic, organic, radioactive, and microbial impurities from water.
Speeding Up 19th Century Oil Paintings: Lead acetate and mastic resin in paint mixtures helped artists 200 years ago
The fluid and loose brushwork used by J.W.M. Turner and other innovative 19th century artists to capture the momentary effects of light was technically made possible by the addition of "gumtion" or "megilp" to the paint matrix, which gave the paints the jelly-like consistency needed for their impasto-rich paintwork. In the journal Angewandte Chemie, scientists unveil the crucial role lead acetate played in this gelation process.
Harmonization Needed! Standardized analytic protocols will help to assess the amount, quality, and risk of microplastic contaminants in aquatic ecosystems, says a review
Since the first reports on a dramatic increase in microplastic contamination in the sea twenty years ago, research efforts have intensified worldwide. A review in the journal Angewandte Chemie has critically evaluated these studies and concludes that the analytical methods have to be harmonized to get comparable data. Further development is needed to assess particles in the lower micrometer range and below as well, as these pose the highest risks for aquatic ecosystems.
Anti-Tumor Synergy: Nanomedical treatment concept combines NO gas therapy with starvation of tumor cells
Biocompatible nanocapsules, loaded with an amino acid and equipped with an enzyme now combine two anti-tumor strategies into a synergistic treatment concept. Researchers hope this increases effectiveness and decreases side effects. In the journal Angewandte Chemie, the scientists explain the concept: tumor cells are deprived of their nutrient glucose as this is converted to toxic nitrogen monoxide (NO) and hydrogen peroxide (H2O2).
Hydrogen from Sunlight—But As a Dark Reaction: Generation, storage, and time-delayed release of electrons in graphitic carbon nitride material for artificial photosynthesis
The storage of photogenerated electric energy and its release on demand are still among the main obstacles in artificial photosynthesis. One of the most promising, recently identified photocatalytic new materials is inexpensive graphitic carbon nitride. Scientists have now explored a modified form that can produce light-generated electrons and store them for catalytic hydrogen production even after the light has been switched off. They present this biomimetic photosynthesis approach in the journal Angewandte Chemie.
Polymerization by chemical vapor deposition (CVD) is a simple method for modifying surfaces by which topologically challenging substrates can be evenly coated with polymers. In the journal Angewandte Chemie, researchers have now introduced the first CVD method for producing degradable polymers. Biomolecules or drugs can be attached by means of special side groups. This introduces new possibilities for applications like the coating of biodegradable implants.
Light Switch in Autumn Leaves: Yellow chlorophyll decomposition products are environment-responsive photoswitches
Before trees lose their leaves in the winter, they offer us a bright autumnal display of reds, oranges, and yellows. This results from the decomposition of the compound that makes leaves green: chlorophyll. Among the decomposition products are yellow phyllobilins that demonstrate unusual chemical properties. As reported by Austrian scientists in the journal Angewandte Chemie, these compounds act as four-step molecular “switches” that are triggered by light in different ways depending on the environment.
Implantable Catalyst Against Cancer: Biocompatible heterogeneous copper catalyst for click chemistry in living organisms
Assembling a drug from harmless components at the target location, such as a tumor, would help reduce the side effects of treatment. In the journal Angewandte Chemie, British and Malaysian scientists present a new, nontoxic catalyst made of copper nanoparticles that can be used to specifically and selectively assemble building blocks in a living system. It was shown to be possible to make an anti-tumor drug from two benign components in situ.
Safe Fog: Phosphorus nitride could be used as a friction-stable, fast-burning, and very effective pyrotechnic obscurant
Safety combined with power and effectiveness is one of the most important targets in the development of pyrotechnic obscurants. In the journal Angewandte Chemie, German and Polish scientists introduced phosphorus nitride as a safe but very powerful alternative to the well-known red phosphorus formulations, which have been used in military and civilian applications for decades.
Salty Batteries: Sodium-oxygen batteries have improved cycle life due to highly concentrated electrolytes
Smartphones, laptops, electric cars—whatever the device, an efficient battery is high on any user’s wish list. The search for the next-generation battery has recently focused on sodium– oxygen batteries. Theoretically, these should provide previously unattainable efficiency but their practical implementation has proven to be a stumbling block. Researchers now report in the journal Angewandte Chemie, that a highly concentrated electrolyte solution may make the sodium–oxygen battery more stable, and therefore more practicable.
Lithium Ion Extraction: A combined polymer/metal–organic composite membrane allows for the effective separation of lithium from contaminants in brines
The increasing usage of lithium for batteries or high-performance metals requires improved extraction techniques of lithium from primary sources such as salt lake brines. Chinese scientists have now designed a solid composite membrane that combines the mimicking of the chemical selection process in biological ion channels with molecular sieve technology. In the journal Angewandte Chemie, they report the effective and fast separation of lithium ions from brines with that membrane.
Fighting the Gram-Negatives: Natural products inspire the design of molecular agents against drug-resistant bacterial strains
Many microorganisms produce secondary natural products, the potential antibiotic effects of which are extensively investigated. German scientists have now examined a class of quinone-like substances containing an additional epoxide functional group for their antibiotic activities. As they report in the journal Angewandte Chemie, the compounds can kill problematic Salmonella pathogens, probably by interfering with their bacterial stress response system.
Directed motion seems simple to us, but the coordinated interplay of complex processes is needed, even for seemingly simple crawling motions of worms or snails. By using a gel that periodically swells and shrinks, researchers developed a model for the waves of muscular contraction and relaxation involved in crawling. As reported in the journal Angewandte Chemie, they were able to produce two types of crawling motion by using inhomogeneous irradiation.