ANNUAL REPORT Kunming Institute of Botany, Chinese Academy ...

Kunming Institute of Botany, Chinese Academy of SciencesAnnual ReportThe Mushroom Toxins Asa: The Cause of SuddenUnexpected Death in Yunnan ProvinceOver the past 30 years, more than 260apparently healthy villagers in Yunnan Province,southwest China, have died suddenly of an unknowncause. Yunnan Sudden Unexplained Death (SUD)often strikes in time-space clusters during the rainyseason, from June to August, in villages between1800 and 2600 m above sea level. The state andlocal governments attached great importance tothis situation and organized experts in diverse areasto discover the risk factor. However, it was toocomplicated to discover the truth.Through long-term intensive studies, undertakenby Prof. LIU Ji-Kai's group in KIB and professorZENG Guang's group in the Chinese Center forDisease Control and Prevention, the mushroom,Trogia venenata was implicated as a risk factor.Two new non-protein amino acids were isolatedand characterized from the fruiting bodies of thismushroom by oral toxicity tests in mice. The structureand absolute configuration of one amino acid wereconfirmed by a total synthesis. One amino acid waspresent in the LC-MS/MS of the blood sample froma victim. This finding served as direct evidence thatthe man had eaten the mushroom before he died.The mechanism of the toxins remains a riddle. It issuggested that the toxins affect cardiac muscle andmetabolism. Mice that were treated with the toxinsincrease in serum CK levels relative to control micethat received water. An extract of T. venenata causedprofound hypoglycemia in mice within 2 h of oralexposure.According to the research results, a campaign towarn Yunnan villagers against eating the mushroomhas reduced reports of SUD in the affected area ofYunnan to zero in 2010 and 2011. This study havebeen reported in Angewandte Chemie InternationalEdition (2012, 51(10): 2368-2370).Trogia venenata —— HIGHLIGHTS OF ACHIEVEMENTS ——