Twenty-two years of dedicated research has finally resulted in success: In the journal Angewandte Chemie, a British team headed by Steven V. Ley at the University of Cambridge reports the first synthesis of azadirachtin, a natural compound that stops predatory insects from feeding.
Plants have a variety of defense mechanisms to deter insect attack. Investigation of these mechanisms often allows researchers to discover molecules with interesting biological properties. One such compound is azadirachtin, which was first isolated from the neem tree (also known as the Indian lilac) in 1968. The name of this natural product is derived from the botanical name of the plant, Azadiracta indica. Azadirachtin is a highly active substance that inhibits the development of the larvae of a broad spectrum of destructive insects but is harmless to mammals and beneficial insects, such as bees and ladybugs.
The structure of this complicated molecule was published in 1985, after a long, intensive research effort, but all attempts to make this compound have thus far been unsuccessful. The difficulty of the synthesis stems in part from the 16 stereocenters in the molecule, the complex pattern of oxygen-containing functional groups, and a conformation and reactivity that are strongly dependent on intramolecular bridging hydrogen bonds. The compound is highly light sensitive and can readily undergo structural rearrangement.
Ley and his team have been interested in solving the problem of the synthesis of this compound for 22 years. Their endurance has now been abundantly rewarded. The key steps in making this molecule involve a Claisen rearrangement and a novel radical cyclization reaction.
“While we have been working on this complex synthesis,” says Ley, “we have also developed a number of new methods that are of general use for the construction of other important molecules.” Ley expects that using the successful synthetic route will allow the development of simpler derivatives of azadirachtin that are stable and may lead to a new generation of environmentally acceptable insecticides.
Author: Steven V. Ley, University of Cambridge (UK), http://leygroup.ch.cam.ac.uk/
Title: Synthesis of Azadirachtin: A Long but Successful Journey / A Relay Route for the Synthesis of Azadirachtin
Angewandte Chemie International Edition 2007, 46, No. 40, doi: 10.1002/anie.200703028
Research team creates new possibilities for medicine and materials sciences
22.01.2018 | Humboldt-Universität zu Berlin
Saarland University bioinformaticians compute gene sequences inherited from each parent
22.01.2018 | Universität des Saarlandes
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
22.01.2018 | Materials Sciences
22.01.2018 | Earth Sciences
22.01.2018 | Life Sciences