Toxic Mushroom Research Articles

Mushroom Toxins: Chemistry and Toxicology.

Mushroom consumption is a global tradition that is still gaining popularity. However, foraging for wild mushrooms and accidental ingestion of toxic mushrooms can result in serious illness and even death. The early diagnosis and treatment of mushroom poisoning are quite difficult, as the symptoms are similar to those caused by common diseases. Chemically, mushroom poisoning is related to very powerful toxins, suggesting that the isolation and identification of toxins have great research value, especially in determining the lethal components of toxic mushrooms. In contrast, most of these toxins have remarkable physiological properties that could promote advances in chemistry, biochemistry, physiology, and pharmacology. Although more than 100 toxins have been elucidated, there are a number of lethal mushrooms that have not been fully investigated. This review provides information on the chemistry (including chemical structures, total synthesis, and biosynthesis) and the toxicology of these toxins, hoping to inspire further research in this area.

Bioactivity-based analysis and chemical characterization of cytotoxic compounds from a poisonous mushroom, Amanita spissacea, in human lung cancer cells in vitro

As part of our systematic study on Korean toxic mushrooms, bioactivity-guided fractionation of the MeOH extract of Amanita spissacea (Amanitaceae) fruiting bodies and chemical investigation of its cytotoxic fractions led to the isolation of (9E)-8-oxo-9-octadecenoic acid (1), (10E)-9-oxo-10-octadecenoic acid (2), (9E)-8-oxo-9-octadecenoate methyl ester (3), (9Z)-9-octadecenoate-(2'S)-2',3'-dihydroxypropyl ester (4), (9Z)-9-octadecenoic acid (5), and palmitic acid (6). The structures of the isolates were elucidated by NMR spectroscopic analysis and LC/MS analysis. Among the isolated compounds, compounds 1 and 2 exhibited the most potent cytotoxic activity in all human lung cancer cell lines examined, with IC50 values ranging from 255.7 to 321.0 μM and 250.2 to 322.5 μM, respectively. The cytotoxicity of these compounds was also found to be mediated by apoptosis associated with caspase-3 activation. These findings provide experimental evidence suggesting the potential of A. spissacea as a promising natural source for the discovery of novel anticancer drug candidates.

Quantification of clitidine in caps and stems of poisonous mushroom Paralepistopsis acromelalga by hydrophilic interaction liquid chromatography–tandem mass spectrometry

A simple and high-throughput analytical method for determining clitidine in Paralepistopsis acromelalga using hydrophilic interaction liquid chromatography–tandem mass spectrometry (LC–MS/MS) was established. To determine clitidine in the mushrooms, a simple procedure including dilution with methanol solution and filtering by cartridge was employed just before quantification by LC–MS/MS for high-throughput analysis. In this report, concentrations of clitidine in mushrooms were determined by the standard addition method. The present established method was successfully applied to the analysis of fruit bodies of P. acromelalga, which were obtained from five different locations in Japan. Results on concentrations of clitidine in each stem and cap of P. acromelalga specimens tested showed that their concentrations were quite different, not only between stems and caps, but also among locations and strains; the concentrations of clitidine in stems and caps ranged from 1.41 to 9.30 mg/g and 3.17 to 14.4 mg/g, respectively. This is the first report to present a detailed quantitative analysis of clitidine by MS and the distribution of clitidine in stems and caps of P. acromelalga. This analytical method for clitidine was thought to be useful in P. acromelalga poisoning cases to identify the causative toxic mushroom.

An effective antidotal combination of polymyxin B and methylprednisolone for α-amanitin intoxication.

Amanita phalloides is one of the most toxic mushrooms worldwide, and it is involved in the majority of human fatal cases of mushroom poisoning. α-Amanitin, the most deleterious toxin of A. phalloides to humans, inhibits RNA polymerase II (RNAPII), causing hepatic and renal failure. Previously, we have shown that polymyxin B (polB) reverts α-amanitin inhibition of RNAPII, although it was not able to guarantee the full survival of α-amanitin-intoxicated mice or prevent α-amanitin pro-inflammatory effects. α-Amanitin is also a substrate of the organic-anion-transporting polypeptide 1B3 (OATP1B3) and Na(+)-taurocholate cotransporter polypeptide (NTCP) transporters. Therefore, in the present work, we used a combination of polB [(2.5mg/kg intraperitoneal (i.p.)] with the anti-inflammatory and NTCP inhibitor drug, methylprednisolone (MP) (10mg/kg i.p.), as an attempt to fully revert α-amanitin-induced toxicity (0.33mg/kg i.p.) in CD-1 mice. Results showed that the administration of the polB + MP combination, 4h after α-amanitin, led to the full survival of the intoxicated animals, with a significant attenuation of α-amanitin-induced renal and hepatic necrosis. Also, the combination polB + MP led to a decrease of aminotransferase plasma levels, of the renal myeloperoxidase activity and of renal inflammatory cell infiltrate promoted by α-amanitin, although not preventing any of the hepatic pro-inflammatory effect of the toxin. The obtained results indicate that this combination may represent an important and valuable therapeutic approach to be used against α-amanitin intoxication.

Toxicological profile of Amanita virosa - A narrative review.

Mushrooms account for a part of human diet due to their exquisite taste and protein content as well as their promising health effects unveiled by scientific research. Toxic and non-toxic mushrooms frequently share considerable morphological similarities, which mislead the collectors/consumers, resulting in mycotoxicity. Numerous mushroom species are considered "poisonous" as they produce dangerous toxins. For instance, members of the genus Amanita, especially A. phalloides, A. virosa and A. verna, are responsible for severe and even life-threatening noxious consequences. Globally, mushroom poisoning is a crucial healthcare issue as it leads to a considerable number of deaths annually. However, no definite antidote has been introduced to treat this poisoning. The present article discusses the characteristics of A. virosa in terms of epidemiology, mechanisms of toxicity, poisoning features and management.

Identification of trichothecene-type mycotoxins in toxic mushroom Podostroma cornu-damae and biological specimens from a fatal case by LC–QTOF/MS

In some autopsy cases, there are unknown natural toxins that are suspected to cause serious damage to the person. However, without reference materials, it is almost impossible to identify the suspicious natural toxins by GC–MS or LC–MS. In this case, a man drank mushroom −liquor with a meal at his home. Seven hours later, he was transported to the emergency room, and 12hours later, he died. In the ingested mushroom-infused-liquor, there were pieces of mushroom that were estimated to be Podostroma cornu-damae (Hypocreaceae) based on their morphological characteristics. To identify the species, chemical component analysis was conducted using LC–QTOF–MS/MS. Monoisotopic mass, fragment ions, and isotope distributions were obtained from the LC–QTOF–MS/MS analysis. In addition, fragment ions and structure matching were tested for target compound confirmation. In this analysis, several toxic trichothecene-type mycotoxins were identified including roridin D, roridin E, roridin Q, satratoxin G, satratoxin H, satratoxin H 12′-acetate, satratoxin H 13′-acetate, satratoxin H 12′,13′-diacetate, and verrucarol. At autopsy, heart blood, peripheral blood, and the stomach contents were collected, and only satratoxin H was detected in these samples. This is the first finding of a trichothecene-type mycotoxin in a human biological sample from an expected case of P. cornu-damae intoxication. We demonstrated that LC–QTOF–MS/MS analysis was an effective method for mushroom intoxication cases in the absence of reference materials. Additionally, the experience, knowledge, and analytical methods we obtained in this study will be great assets for solving other cases of possible natural toxin intoxication.

Rare case of Stevens-Johnson-TEN overlap syndrome caused by mycotoxins

Abstract: Mushroom poisoning is rarely associated with skin involvement. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening mucocutaneous reactions, characterized by extensive necrosis. SJS/TEN overlap includes patients with skin exfoliation between 10 to 30 percent of the body surface area. We report the case of a patient that was assumed to have ingested one type of toxic mushroom within the twelve hours prior to the appearance of skin lesions typical for SJS/TEN overlap syndrome.

Mushroom poisoning epidemiology in the United States

ABSTRACTIngestion of wild and potentially toxic mushrooms is common in the United States and many other parts of the world. US poison centers have been logging cases of mushroom exposure in The National Poison Data System (NPDS) annual publications for over 30 years. This study compiles and analyzes US mushroom exposures as reported by the NPDS from 1999 to 2016. Over the last 18 years, 133 700 cases (7428/year) of mushroom exposure, mostly by ingestion, have been reported. Cases are most frequently unintentional (83%, P < 0.001); cause no or only minor harm (86%, P < 0.001); and in children <6 years old (62%, P < 0.001). Approximately 704 (39/year) exposures have resulted in major harm. Fifty-two (2.9/year) fatalities have been reported, mostly from cyclopeptide (68–89%)-producing mushrooms ingested by older adults unintentionally. The vast majority of reported ingestions resulted in no or minor harm, although some groups of mushroom toxins or irritants, such as cyclopepides, ibotenic acid, and monomethylhydrazine, have been deadly. Misidentification of edible mushroom species appears to be the most common cause and may be preventable through education.

Sociodemographic differences in the cultural significance of edible and toxic mushrooms among Tsotsil towns in the Highlands of Chiapas, Mexico

BackgroundMushrooms are important forest resources, mostly as food, despite the serious health threat posed by toxic species. In the Highlands of Chiapas, numerous wild mushroom intoxications have been registered. While Chiapas has been vastly studied from an ethnomycological perspective, no certainty exists as to how nomenclature systems differentiate edible and toxic species, which species are most culturally significant, and whether sociodemographic factors relate to how well-known they are in the Highlands of Chiapas. This paper evaluates which are the most culturally significant edible and toxic wild mushroom species in seven Tsotsil communities from this region and whether differences exist in their knowledge relating to different sociodemographic subsets (gender, schooling, and occupation). The hypothesis that there is a difference in the number of species that people mention, as well as the number of times each ethno-taxon is mentioned, between people from different social groups was tested.MethodsWith consent, 133 Tsotsil people from seven communities were interviewed. Interviews focused on local systematics and free listings of edible and toxic mushrooms. Qualitative and quantitative analyses were performed, including multivariate methods and non-parametric statistics.ResultsTwenty-five edible and 15 toxic taxa were mentioned. Some directly correspond to Linneanean species, while others are subdifferentiated or supradifferentiated. Only 62% of the interviewees named toxic mushrooms. The most frequently mentioned edible taxa were Amanita hayalyuy and A. jacksoniii, Agaricus spp., and Armillaria mellea. The most frequently mentioned toxic species were Amanita muscaria, Suillellus luridus, and Russula emetica. Significant differences in the number of mentioned edible ethnotaxa were found only among different occupations and schooling. The models including schooling interacting with either gender or occupation are better supported. Significant differences in the number of times toxic ethnotaxa are mentioned were found only between men and women.ConclusionsThe Tsotsil region of the Highlands of Chiapas is where the most average mushroom species are recognized state-wide. Schooling and occupation seem most determinant for people to know more or less species of mushrooms, while gender appears irrelevant. People with no studies and field-related occupations name more species. Identification criteria to distinguish edible from toxic species seem to rest not on detailed recognition of the second set but precise knowledge of the first.

Drosophila, destroying angels, and deathcaps! Oh my! A review of mycotoxin tolerance in the genus Drosophila

Evolutionary novelties, be they morphological or biochemical, fascinate both scientists and non-scientists alike. These types of adaptations can significantly impact the biodiversity of the organisms in which they occur. While much work has been invested in the evolution of novel morphological traits, substantially less is known about the evolution of biochemical adaptations. In this review, we present the results of literature searches relating to one such biochemical adaptation: α-amanitin tolerance/resistance in the genus Drosophila. Amatoxins, including α-amanitin, are one of several toxin classes found in Amanita mushrooms. They act by binding to RNA polymerase II and inhibiting RNA transcription. Although these toxins are lethal to most eukaryotic organisms, 17 mushroom-feeding Drosophila species are tolerant of natural concentrations of amatoxins and can develop in toxic mushrooms. The use of toxic mushrooms allows these species to avoid infection by parasitic nematodes and lowers competition. Their amatoxin tolerance is not due to mutations that would inhibit α-amanitin from binding to RNA polymerase II. Furthermore, the mushroom-feeding flies are able to detoxify the other toxin classes that occur in their mushroom hosts. In addition, resistance has evolved independently in several D. melanogaster strains. Only one of the strains exhibits resistance due to mutations in the target of the toxin. Given our current understanding of the evolutionary relationships among the mushroom-feeding flies, it appears that amatoxin tolerance evolved multiple times. Furthermore, independent lines of evidence suggest that multiple mechanisms confer α-amanitin tolerance/resistance in Drosophila.

Toxicity Assessment of Wild Mushrooms from the Western Ghats, India: An in Vitro and Sub-Acute in Vivo Study.

Background: Poisoning by different kinds of toxic mushrooms is unfortunately becoming an increasingly important medical problem, evident from the growing number of reports worldwide since the 1950s. Mycetism being a health concern, deserves scientific attention. In this perspective, the present study aims to assess the potential effects of ingesting the selected wild mushrooms from regions of the Western Ghats, India.Methods: The preliminary cytotoxicity of the selected mushrooms was studied in vitro on the intestinal NCM460 and the Chang's liver cell lines on the basis of cell viability. Further, the hepatotoxicity was assessed by measuring biologically relevant endpoints such as membrane integrity, mitochondrial stress and oxidative status. A 28 day sub-acute toxicity study was carried out by orally administering the mushroom extracts to mice at 250 and 500 mg/kg body weight. The hematological and serum analysis as well as histological examinations were carried out to evaluate their in vivo toxicity. GC-MS analysis of the mushrooms facilitated the identification of their volatile chemical profile.Result: The in vitro intestinal cytotoxicity exhibited by these wild mushrooms in comparison to the edible mushroom indicated their potential gastrointestinal toxicity. The pathological findings in small intestine on exposure to Chlorophyllum molybdites and Agaricus endoxanthus also validates the speculations about their intestinal toxicity. The toxic insult to the hepatocytes due to Amanita angustilamellata, Entoloma crassum, and Clarkeinda trachodes was predictive of the observed in vivo hepatotoxicity which was also accompanied by renal toxicity at the higher dose of 500 mg/kg bwt.Conclusion: The potential toxicity exhibited by these representative mushrooms from the wild warrants caution about their consumption. The present work could also have broader implications for global mycetism.

Investigation and analysis of Galerina sulciceps poisoning in a canteen

Introduction: Guizhou Province in China has an abundant resource of wild mushrooms, including numerous poisonous species which contain various toxins. The mortality rate from wild mushroom poisoning has been high in this area in recent years. Galerina sulciceps is a dangerously toxic mushroom which can be fatal if ingested.Methods: we report on an epidemiological investigation of G. sulciceps poisoning which occurred in Duyun City of Guizhou Province. The characteristics of this species, its toxicity, observed clinical features, laboratory data, treatment modality, and prognosis were investigated in order to provide a reference point for the prevention and treatment of this kind of mushroom poisoning.Results: Thirteen employees showed toxic symptoms after ingesting wild mushrooms the previous day in a company canteen. Clinical manifestation varied from gastroenteritis to hepatic and renal dysfunction. Most of the 13 patients presented with nausea, vomiting, abdominal pain, diarrhea, and elevated levels of biochemical indices of hepatic and renal function, during which transaminase concentration peaked within 48–72 h. At 48 hours post-ingestion, all patients had hemodialysis, in addition to supportive care for hepatic and renal injury with oral Silibinin and Shenshuaining. All acute renal injury had resolved by day 10, and liver transaminases had trended toward normal in all patients and they were discharged. At follow-up in 30 days, both liver and renal function had completely recovered in all.Conclusion: This poisoning occurs as a result of unintentional consumption of G. sulciceps, which is relatively rare in mushroom poisonings. All patients recovered fully after timely diagnosis and treatment. To prevent wild mushroom poisoning, the best preventive measure is to educate the public not to gather and eat any unidentified wild mushrooms.

PCR-Based Method for the Detection of Toxic Mushrooms Causing Food-Poisoning Incidents.

In this study, species-specific identification of five toxic mushrooms, Chlorophyllum molybdites, Gymnopilus junonius, Hypholoma fasciculare, Pleurocybella porrigens, and Tricholoma ustale, which have been involved in food-poisoning incidents in Japan, was investigated. Specific primer pairs targeting internal transcribed spacer (ITS) regions were designed for PCR detection. The specific amplicons were obtained from fresh, cooked, and simulated gastric fluid (SGF)-treated samples. No amplicons were detected from other mushrooms with similar morphology. Our method using one-step extraction of mushrooms allows rapid detection within 2.5 hr. It could be utilized for rapid identification or screening of toxic mushrooms.

Features of Patients With Severe Hepatitis Due to Mushroom Poisoning and Factors Associated With Outcome.

Acute liver failure after ingestion of toxic mushrooms is a significant medical problem. Most exposures to toxic mushrooms produce no symptoms or only mild gastroenteritis, but some lead to severe hepatic necrosis and fulminant hepatic failure requiring liver transplantation. We aimed to assess mortality from mushroom poisoning and identify variables associated with survival and liver transplantation. We collected information from 27 patients (13 male; median age, 47 years) admitted to the emergency department within 24 hours of ingesting wild mushrooms. They developed severe liver injury (serum levels of transaminases greater than 400 IU/L) and were treated with activated charcoal and N-acetylcysteine at a tertiary medical center in San Francisco, California from January 1997 through December 2014. Viral hepatitis, autoimmune liver disease, acetaminophen, salicylate toxicity, and chronic liver diseases were ruled out for all patients. We analyzed patient demographics, time since ingestion, presenting symptoms, laboratory values, and therapies administered. A good outcome was defined as survival without need for liver transplant. A poor outcome was defined as death or liver transplant. Positive predictive values were calculated, and the χ2 test was used to analyze dichotomous variables. Liver injury was attributed to ingestion of Amanita phalloides in 24 patients and Amanita ocreata in 3 patients. Twenty-four of the patients ingested mushrooms with meals and 3 patients for hallucinogenic purpose. At 24-48 hours after ingestion, all patients had serum levels of alanine aminotransferase ranging from 554 to 4546 IU/L (median, 2185 IU/L). Acute renal impairment developed in 5 patients. Twenty-three patients survived without liver transplantation, and 4 patients had poor outcomes (1 woman underwent liver transplantation on day 20 after mushroom ingestion, and 3 women died of hepatic failure). Of the 23 patients with peak levels of total bilirubin of 2 mg/dL or more during hospitalization, only 4 had a poor outcome. Peak serum level of aspartate aminotransferase less than 4000 IU/L, peak international normalized ratio less than 2, and a value of serum factor V greater than 30% identified patients with good outcomes with 100% positive predictive value; if these peak values were used as a cutoff, 10 of 27 patients (37%), 7 of 27 patients (26%), and 6 of 12 patients (50%), respectively, could have avoided transfer to a transplant center. In an analysis of 27 patients with hepatocellular damage due to mushroom (Amanita) poisoning and peak levels of total bilirubin greater than 2 mg/dL, the probability of liver transplantation or death is 17%, fulfilling Hy's law. Patients with peak levels of aspartate aminotransferase less than 4000 IU/L can be monitored in a local hospital, whereas patients with higher levels should be transferred to liver transplant centers. Women and older patients were more likely to have a poor outcome than men and younger patients.

Mushroom Poisoning in the Northeast of Iran; a Retrospective 6-Year Epidemiologic Study.

Toxic mushrooms are distributed across the globe with over 5000 species. Among them, 100 species are responsible for most of the cases of mushroom poisoning. This study aimed to evaluate the epidemiologic pattern of mushroom poisoning among patients referred to the main toxicology center of Mashhad province located in North-east of Iran. This cross-sectional study was conducted on patients with final diagnosis of mushroom poisoning referred to the toxicology center of Mashhad, Iran, from February 2005 to 2011. Patients' demographic characteristics, clinical presentations, laboratory findings, outcomes, and therapeutic measures were collected using a predesigned checklist and searching patient's profile. 32 cases with the mean age of 24.6 ± 16.7 years were presented to the toxicology center following mushroom poisoning (59% female). Mushroom poisoning accounted for 0.1% of all admitted cases. The mean time elapsed from consumption to referral to poisoning department was 61.9 ± 49.4 hours. 19 (59%) cases were discharged with complete recovery, 7 (22%) expired, and 6 (19%) cases left hospital against medical advice. Mushroom poisoning mortality accounted for 1.5% of deceased cases in the studied center. There was significant relationship between mortality rate and higher values of INR (p = 0.035), PT (p = 0.011) and PTT (p = 0.003). Likewise, there was significant relationship between the need for mechanical ventilation and higher values of INR (p = 0.035), PT (p = 0.006) and PTT (p = 0.014). The relationships between the need for ICU admission, mechanical ventilation, and mortality rate with the rise of hepatic transaminases and serum bilirubin were not significant. Based on the findings, the prevalence of mushroom poisoning among patients referred to Mashhad toxicology center was very low (0.1%), but with a high mortality rate of 22%. Nausea and vomiting were the most common early symptoms of intoxication and higher values of coagulation profile were correlated with poor outcome.

Selection and analysis of a DNA aptamer binding α-amanitin from Amanita phalloides.

Mushroom foraging is very popular in some regions of the world. Sometimes toxic and edible mushrooms are mistaken by mushroom collectors, leading to serious human poisoning. The group of mushrooms highly dangerous for human health includes Amanita phalloides. This mushroom produces a toxic octapeptide called α-amanitin which is an inhibitor of nuclear RNA polymerase II. The inhibition of this polymerase results in the abortion of mRNA synthesis. The ingestion of A. phalloides causes liver failure due to the fact that most of the toxin is uptaken by hepatocytes. The hospitalization of poisoned patients involves the removal of the toxin from the digestive tract, its dilution in the circulatory system and the administration of therapeutic adjuvants. Since there is no effective antidote against amanitin poisoning, in this study we developed a DNA aptamer exhibiting specific binding to α-amanitin. This aptamer was selected using the SELEX (Systematic Evolution of Ligands by Exponential Enrichment) method. Next, its ability of toxin removal from aqueous solution was confirmed by pull-down assay. The aptamer region sufficient for α-amanitin binding was determined. Finally, the dissociation constant of the α-amanitin/DNA aptamer complex was calculated.

Species identification, geographical distribution, poisoning symptoms and medical treatment of russula subnigricans

Objective To study species identification, geographical distribution poisoning symptoms of russula subnigricans in order to provide guidelines of prevention and proper treatment. Methods Based on the data of epidemiological investigation, clinical treatment data and suspicious poisonous mushrooms, the collected mushroom were identified by morphological and molecular analysis, and the poisoning symptoms and medical treatment of R. subnigricans were systematically summarized. Results From the present two poisoning case, Epidemiological investigation showed that both patients ate some mushrooms in an appearance of fired charcoal(huotanjuncalled by layman) in the evening on July 26th, 2015. The incubation period was 2-3 hours. The main poisoning symptoms were nausea, vomiting, myalgia, typical soy urine, rapid increased in serum creatine kinase (CK), alanine transaminase (ALT), aspartate aminotransferase (AST), creatine kinase MB (CK-MB) and serum creatinine (sCr) were found. Finally patients fell in kidney failure and respiratory failure. All these symptoms met the typical manifestion of mushroom poisoning reported caused by R. subnigricans. These two patients were treated with hemoperfusion, continuous veno-venous hemofiltration (CVVH), liver protecting treatment, protective renal treatment and antioxidant therapy.One patient died after 40 days after admission.Other patient was transferred to a better facility and experienced physicians, and the other patient was still in hospital without any improvement up to the end of Feb. 2016 with a gloomy prospect. The mushroom eaten by the patients was identified as russula subnigricans though morphological and molecular analysis. Conclusions Russula subnigricans is a very toxic mushroom, widely distributed in southern China. Morphological and molecular analysis (using ITS sequence) is suitable for species identification of R. subnigricans. The incubation period of R. subnigricans poisioning is usually short, its target organ is mainly striated muscle, and severe patients usually have unfavourable outcome. Key words: Poisonous mushrooms; Russula subnigricans; Species identification; Geographical distribution; Medical treatment

Remediation of Some Selected Heavy Metals from Water Using Modified and Unmodified Mushrooms

The dispersal of toxic heavy metals by water from natural and anthropogenic is a worldwide environmental concern due to pollution. Despite some metals playing an important role in body, they are toxic when the level exceeds the tolerance limits while others such as lead have no known physiological value to human beings. Since heavy metals cannot be degraded, then their removal from drinking water is necessary. Mushrooms are readily available in Bomet County and their metal removal ability was investigated. The study aimed at removing heavy metals from water by adsorption using mushroom, as a cost-effective and sustainable method. The raw mushroom was modified with sodium hydroxide and characterization of both the parent material and its modified form was done using Fourier Transform Infrared spectrometry (FTIR). Sorption experiments were carried out using the batch adsorption method and sorption parameters including pH, contact time, adsorbent dose and initial metal ion concentration investigated. The results found out that the sorption capacity for cadmium ions ranged from 1.826- 25.285 mg/g by the unmodified edible mushroom (UEM), the modified edible mushroom (EM), unmodified toxic mushroom (UTM) and modified toxic mushroom (TM). For copper ions, sorption capacity ranged from 0.002-4.097 mg/g, while that of the lead ions ranged from 1.345-2.593 mg/g by the UEM, EM, UTM and TM respectively. The sorption capacity showed improvement on modification as sorption of cadmium increased from 1.826-25.285 mg/g by the UEM, EM, UTM and TM. At a pH range of 4-6, the sorbent material was found to remove up to 90% of the metals. The sorbent material had a removal efficiency of 95% of the metals in less than 20 minutes. The UEM and UTM fitted well in Langmuir adsorption isotherm model for cadmium and lead ions. For copper ions, UEM, EM, UTM and TM fitted in the Freundlich model. TM for lead ions best fitted in the Freundlich model. The bio-sorption kinetics was determined by fitting first-order-Lagergreg and Pseudo-second-order kinetics models to the experimental data. It was found that the data for lead was better described by the pseudo-second-order model. For copper ion, the data was best described by Ho’s pseudo second order for UEM and UTM, cadmium ions for all sorbents was best described by Lagergreg’s first-order kinetics. The FTIR analysis suggested the possibility of the participation of carboxyl groups in metal uptake. The levels of dissolved organic carbon (DOC) were found to be 19.0 mg/L in the raw material and 2.19 mg/L after modification. It was confirmed that modification minimized secondary pollution. This indicated that mushrooms have a potential application for the remediation of metal polluted waters.

Identification of Cyclopropylacetyl-(R)-carnitine, a Unique Chemical Marker of the Fatally Toxic Mushroom Russula subnigricans.

A toxic mushroom, Russula subnigricans, causes fatal poisoning by mistaken ingestion. In spite of the potent bioactivity, the responsible toxin had not been identified for about 50 years since its first documentation. Recently, we isolated an unstable toxin and determined the structure. The slow elucidation was partly due to the instability of the toxin and also due to misidentification of R. subnigricans for similar mushrooms. To discriminate genuine Russula subnigricans from similar unidentified Russula species, we searched for a unique chemical marker contained in the mushroom. Cyclopropylacetyl-(R)-carnitine specific to R. subnigricans was identified as a novel compound whose (1)H-NMR signals appearing in the upfield region were easily recognizable among the complicated signals of the crude extract.

Practical Total Syntheses of Acromelic Acids A and B.

Practical total syntheses of acromelic acids A (1) and B (2), which were scarce natural products isolated from toxic mushroom by Shirahama and Matsumoto, were accomplished in 13 (36% total yield) and 17 steps (6.9% total yield), respectively, from 2,6-dichloropyridine (8). Beginning with regioselective transformation of symmetric 8 by either ortho-lithiation or bromination, nitroalkenes 15 and 16 were provided. Stereoselective construction of the vicinal stereocenters at the C-3, 4 positions of 1 and 2 was performed by a Ni-catalyzed asymmetric conjugate addition of α-ketoesters to the nitroalkenes. Construction of the pyrrolidine ring was accomplished in a single operation via a sequence consisting of reduction of the nitro group, intramolecular condensation with the ketone, and reduction of the resulting ketimine.