Castoreum, the dried scent glands of the Canadian beaver, was once one of the most valuable scent components derived from animals.
Castoreum contains a complex mixture of substances, including a number of compounds known as nupharamine alkaloids. Many of these have been structurally characterized. Researchers working with Horst Kunz at the University of Mainz (Germany) have now, as they report in the journal Angewandte Chemie, determined the stereochemistry (precise spatial structure) of another castoreum component by using a total synthesis. A total synthesis is the complete chemical synthesis of a complex organic natural substance from simple, easily attainable starting materials.
Beavers use their fat- and pheromone-containing gland secretions to groom their fur and to mark their territory. In the past, the resin-like content of the dried glands was used as medicine to treat various complaints, such as cramps, “hysteria”, and nervousness. In antiquity it was even used to treat epilepsy. Castoreum’s effectiveness can be explained by the salicylic acid it contains—aspirin is also based on this substance. Castoreum was once in such demand that the beaver was threatened with extinction. Today, there are special beaver farms where the beavers rub their secretions off onto special collection containers. In addition, castoreum is now only used for homeopathic remedies and in some perfumes.
The team from Mainz undertook the synthesis of a minor component (5-(3’-furyl)-8-methylindolizidine), which makes up less than 0.0002% of castoreum. In principle, the structure of this nupharamine is known. It has an indolizidine skeleton (a special ring system made of one six-membered and two five-membered rings). However, one detail has remained unknown: the stereochemistry at one of the carbon atoms of the six-membered ring. The four bonds of a carbon atom point toward the corners of a tetrahedron. If there are four different bonding partners, there are two possible spatial arrangements possible, which are mirror images of each other. This type of carbon center is called “chiral”.
One of the two possible versions of the nupharamine, the cis-trans form, has previously been produced enantioselectively. The German team has now achieved the enantioselective total synthesis of both versions—the all cis form for the first time. To do this they used a carbohydrate as a chiral auxiliary. This is a molecule that is attached to a starting material in order to shield one side of the molecule in subsequent reaction steps so that only the desired stereochemical form of the product is formed.
Spectroscopic and mass-spectrometric analyses of both synthetic products and the nupharamine isolated from natural castoreum showed that the all-cis form is identical to the natural product.
Angewandte Chemie International Edition, doi: 10.1002/anie.200805606
Further reports about: > Angewandte Chemie > Canadian beaver > Castoreum > Epilepsy > beaver > chemist > cramps > enantiomerically pure nupharamine alkaloids > fat- and pheromone-containing gland secretions > hysteria > mass-spectrometric analyses > methylindolizidine > nervousness > nupharamine alkaloids
Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel
Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
22.05.2018 | Trade Fair News
22.05.2018 | Trade Fair News
22.05.2018 | Life Sciences