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Cometary chemistry enters The Alchemist's orbit this week, while manganese goes magnetic, and proteins are encapsulated. Browning enzymes point to new clues for pharma and agrochemistry, while nanoparticles give us dual-functional medical imaging sensors. Finally, three of ten scientific medallists are chemists.

Enzyme activity of tyrosinase is involved in insect development processes but also in human aging, the development of melanoma, wound healing, and even in the browning of fruits and vegetables. So, the discovery of inhibitors when screen insecticidal fungi is an important move towards novel agrochemicals and pharmaceuticals. Researchers at Anhui Agricultural University, in Hefei, China, have identified from Paecilomyces gunnii, the compound paecilomycone A, which is very similar to the known anti-HIV target funalenone, a phenalenone. This work may well point the way to not only new types of natural insecticides based on the fungal defence activity that side-step the potential harm to mammals of neurotoxic pesticides, but may also lead to a range of new drugs for various infectious human diseases.

Nanoparticles can simultaneously enable magnetic resonance imaging (MRI) and fluorescent imaging of living organisms for disease diagnostics, such as monitoring the progression of cancer and its response to therapy. Researchers at the Massachusetts Institute of Technology (MIT) have reported a proof of principle in which the bottlebrush polymer nanoparticles, carrying distinct sensors for fluorescence (Cy5.5) and MRI (a nitroxide contrast agent) are mixed to track vitamin C in mice. In regions of high vitamin C concentration, there is a strong fluorescent response but negligible MRI contrast. In low vitamin C conditions, the MRI signal becomes visible but the fluorescence glow is very weak.

Three of the ten scientists to win this year's National Medal of Science and National Medal of Technology and Innovation, the USA's highest honor for achievement and leadership in advancing the fields of science and technology, are chemists. "These scholars and innovators have expanded our understanding of the world, made invaluable contributions to their fields, and helped improve countless lives," President Obama said. Bruce Alberts is an internationally-renowned biochemist and Professor Emeritus at the University of California, San Francisco, Judith Klinman is a physical-organic chemist renowned for her work on enzymes. She is currently a professor of chemistry and of molecular and cell biology at the University of California, Berkeley, Jerrold Meinwald is considered one of the fathers of chemical ecology. He is currently the Goldwin Smith Professor of Chemistry Emeritus at Cornell University.

In an astounding first for space science, the European Space Agency (ESA) landed a probe on Comet 67P/Churyumov–Gerasimenko and, despite various technical problems, there was sufficient power onboard for the spacecraft to extract data from this distant object that orbits the Sun every 6.45 years at a maximum speed of 135 000 kilometers per hour. Among that data from COSAC (the COmetary SAmpling and Composition gas analyzer) was evidence of molecules containing carbon and hydrogen in the "atmosphere" of the comet. At the time of writing, the ESA team is still analyzing the spectroscopic data to determine what organic molecules are present. Various theories of how life on Earth began hint at a cometary origin to the seeds of life, the amino acid building blocks of proteins.

A new manganese compound that is produced by tension in thin layers of the crystal structure of terbium manganese oxide is magnetic unlike the parent compound, according to its discoverers at the University of Groningen. Beatriz Noheda and colleagues explain that by ignoring the usually undesirable formation of domain walls, the team could generate new properties by allowing such walls to form during growth of thin layers. Noheda hopes that this new material might be exploited in sub-microscopic circuitry and in nanoscale reaction vessels.

For decades chemists have been fascinated by molecular capsules for the potential of such entities in drug delivery, catalysis, as sensors and in other areas. Often these structures are self-assembled from synthetic subunits, but chemists at the University of California Los Angeles, led by Todd Yeates, turned to nature for inspiration and have now made the largest synthetic molecular capsule from self-assembling designer protein molecules. The cube-shaped cage comprises 24 copies of the designer protein and is not only larger, but more porous, than any other such protein cage. The hopes is that this structure might pave the way to synthetic vaccines for a wide range of lethal diseases, such as HIV/AIDS and influenza, perhaps even Ebola, in the long term.