Over the past 30 years, more than 260 apparently healthy villagers in Yunnan Province, southwest China, have died suddenly of an unknown cause. Yunnan Sudden Unexplained Death (SUD) often strikes in time-space clusters during the rainy season, from June to August, in villages between 1800 and 2600 m above sea level. The state and local governments attached great importance to this situation and organized experts in diverse areas to discover the risk factor. However, it was too complicated to discover the truth.
Through long term intensive studies, undertaken by Professor LIU Jikai’s group in the Kunming Institute of Botany, Chinese Academy of Sciences and professor ZENG Guang’s group in the Chinese Center for Disease Control and Prevention, the mushroom, Trogiavenenata was implicated as a risk factor. Two new non-protein amino acids were isolated and characterized from the fruiting bodies of this mushroom by oral toxicity tests in mice. The structure and absolute configuration of one amino acid were confirmed by a total synthesis. One amino acid was present in the LC-MS/MS of the blood sample from a victim. This finding served as direct evidence that the man had eaten the mushroom before he died. The mechanism of the toxins remains a riddle. It is suggested that the toxins affect cardiac muscle and metabolism. Mice that were treated with the toxins increase in serum CK levels relative to control mice that received water. An extract of T. venenatacaused profound hypoglycemia in mice within 2 h of oral exposure.
According to the research results, a campaign to warn Yunnan villagers against eating the mushroom has reduced reports of SUD in the affected area of Yunnan to zero in 2010 and 2011. This study have been reported in Angewandte Chemie International Edition (2012, 51(10): 2368-2370). http://onlinelibrary.wiley.com/doi/10.1002/anie.201106502/full
This project was supported by grants from the following organizations: The Major State Basic Research Development Program of China (973 Program); the National Natural Science Foundation of China (Key Program); the Ministry of Health and the Knowledge Innovation Program of the Chinese Academy of Sciences.
Toxic Mushroom Trogia venenata Zhu L. Yang. (image by KIB)
