Although a number of new antibiotics have been discovered in recent decades, our armory against infection is continually being depleted, as our microscopically small enemies are crafty warriors that develop resistance to current antibiotics.
Multiresistant bacteria are a big problem, especially in hospitals. Already weakened patients are easy victims, for which an infection that cannot be treated with antibiotics can quickly become life-threatening. What is needed are active agents that act on completely different sites in the physiological sequence of pathogens than current medicaments. Platensimycin, recently isolated from the mushroom Streptomyces platensis, is such an agent. A Californian team of researchers is now the first to synthesize this natural product completely in the laboratory—a crucial step on the way to a new class of antibiotics.
Platensimycin inhibits an important step of bacterial fatty acid biosynthesis and in this way paralyzes a broad spectrum of Gram-positive bacterial strains. Thus, this natural product in able to kill dangerous germs that have developed resistance not only to established antibiotics but also to standby products. Examples of these include various resistant strains of Staphylococcus aureus and Enterococcus faecium.
To isolate a complex natural product in sufficient quantity and purity for further experiments is usually a difficult and time-consuming, if not impossible, task. Chemists thus follow a different path: They reproduce the natural product in the laboratory from the ground up. This approach is known as total synthesis. To devise such a total synthesis is an enormous scientific challenge. A way must be found to assemble a complicated synthetic molecule faultlessly from simple, available components—and in sufficiently high yield in each reaction step. The total synthesis of platensimycin has now been accomplished by a team headed by the renowned natural products chemist K. C. Nicolaou (The Scripps Research Institute, La Jolla, and University of California, San Diego). Platensimycin consists of an unusual aromatic ring coupled through an amide group to a compact cage structure. The team built these two components—each a veritable challenge for synthetic chemists—separately and then joined them in the final step of the synthesis. "The described chemistry," says Nicolaou, "sets the stage for the synthesis of designed analogues for structure–activity relationship studies in the search for new antibacterial agents."
K.C. Nicolaou, Ph.D. | EurekAlert!
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Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
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In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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