Was the consumption of toxic mushrooms responsible for a series of unusual deaths in China’s Yunnan province? A team led by Ji-Kai Liu (Beijing) has now found further proof of this hypothesis. In the journal Angewandte Chemie, the researchers now present two unusual toxic amino acids that they found in extracts from the suspect mushrooms.
Over the last 30 years, more than 260 otherwise perfectly healthy people in Yunnan province in southwestern China died suddenly for no apparent reason. This phenomenon was designated as “sudden unexplained death” and mainly occurred in time- and location-related groupings in the rainy period between June and August in locations between 1800 and 2400 m above sea level.
Epidemiological studies in 2005 proposed that the collection of mushrooms may have been a risk factor; later studies lent weight to the hypothesis that consumption of a previously unknown type of mushroom, which the researchers named “Trogia venenata Zhu L. Yang” for its discoverer, was responsible for the deaths.
The scientists of the Kunming Institute of Botany and the Chinese Center for Disease Control and Prevention have now isolated and characterized three toxic compounds from the fruiting bodies of these mushroom in order to further prove their hypothesis. The compounds include one previously known amino acid, ã-guanidinobutyric acid, as well as two previously unknown and unusual toxic amino acids.
A crude extract from the mushrooms was separated by liquid chromatography and the toxic amino acids were isolated. Various spectroscopic techniques were used to identify their structures. The compounds were then synthesized in the laboratory and compared to the natural products. The two newly discovered amino acids have a terminal ethynyl group in common, a triple bond between two carbon atoms.
The toxicity of the two amino acids was confirmed in trials with mice. In addition, the scientists analyzed a blood sample from one individual who died from “sudden unexplained death” and detected one of the toxic mushroom amino acids.
All previous observations indicate that the mushroom Trogia venenata is the cause for the unexplained deaths. A campaign to warn inhabitants of Yunnan against the consumption of the toxic mushrooms has since been successful: No further cases of “sudden unexplained death” were recorded in 2010 and 2011.About the Author
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201106502
Ji-Kai Liu | Angewandte Chemie
When fat cells change their colour
28.10.2016 | Albert-Ludwigs-Universität Freiburg im Breisgau
Aquaculture: Clear Water Thanks to Cork
28.10.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH
Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.
So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
28.10.2016 | Power and Electrical Engineering
28.10.2016 | Physics and Astronomy
28.10.2016 | Life Sciences