A review on the diversity, phylogeography and population genetics of Amanita mushrooms

Investigation of Antioxidant Activity, Myco-Chemical Content, and GC-MS Based Molecular Docking Analysis of Bioactive Chemicals from Amanita konajensis (Agaricomycetes), a Tribal Myco-Food from India

In humans, a wide range of health disorders have been induced due to an imbalanced metabolism and an excess generation of reactive oxygen species (ROS). Different biological properties found in mushrooms seem to be the reason for their customary use as a favourite delicacy. Therefore, exploration of wild edible mushrooms as a source of various biological compounds is gaining much importance today. Amanita konajensis, one of the underutilized macrofungi popularly consumed in Eastern India, demands a systematic study of its medicinal values. The study aims to explore the myco-chemical contents of A. konajensis ethanolic extract (EtAK1) and screen their antioxidant potency through various in vitro assays. GC-MS analysis identified the chemical components of EtAK1. Further, structure-based virtual screening of the identified compounds was analysed for drug-like properties and molecular docking with the human p38 MAPK protein, a potent targeting pathway for human lung cancer. The morpho-molecular features proved the authenticity of the collected mushroom. The screening assays showed that EtAK1 was abundant in flavonoids, followed by phenolics, β-carotene, and lycopene, and had strong antioxidant activity with EC50 values of 640-710 μg/mL. The GC-MS analyses of EtAK1 identified the occurrence of 19 bioactive compounds in the mushroom. In silico analysis revealed that anthraergostatetraenol p-chlorobenzoate, one of the compounds identified, displayed high binding affinity (ΔG = -10.6 kcal/mol) with human p38 MAPK. The outcome of this study will pave the way for the invention of myco-medicine using A. konajensis, which may lead to a novel drug for human lung cancer.

Hypoadrenocorticism in a Dog Following Recovery from Alpha-Amanitin Intoxication

A 10-year-old, female spayed Labrador Retriever was referred for acute hepatopathy and urinary retention. Blood work from the initial presentation (day 0) revealed a severe, mixed hepatopathy. Over the course of the patient's hospitalization, the patient developed liver insufficiency. Urine was submitted for toxicological screening and revealed detection of a trace concentration of alpha-amanitin. The patient was treated supportively for alpha-amanitin intoxication and was discharged from the hospital on day 8, with most biochemical parameters being markedly improved. The patient was persistently hyporexic at the time of discharge. On day 15, at a recheck appointment, the patient had lost 2.4 kg and liver enzymology revealed improved values. On day 24, the patient was presented for anorexia and vomiting and had lost another 2.3 kg. Blood work and endocrinological testing at that time were consistent with hypoadrenocorticism. The patient was started on glucocorticoids and mineralocorticoids. At day 106, the patient was doing well clinically while receiving monthly mineralocorticoids and daily glucocorticoids. This case report is the first to describe the chronological association between alpha-amanitin-induced liver dysfunction and the subsequent development of adrenal insufficiency in a dog.

Analytical methods for amatoxins: A comprehensive review

Amatoxins are toxic bicyclic octapeptides found in certain wild mushroom species, particularly Amanita phalloides. These mushrooms contain predominantly α- and β-amanitin, which can lead to severe health risks for humans and animals if ingested. Rapid and accurate identification of these toxins in mushroom and biological samples is crucial for diagnosing and treating mushroom poisoning. Analytical methods for the determination of amatoxins are critical to ensure food safety and prompt medical treatment. This review provides a comprehensive overview of the research literature on the determination of amatoxins in clinical specimens, biological and mushroom samples. We discuss the physicochemical properties of toxins, highlighting their influence on the choice of the analytical method and the importance of sample preparation, particularly solid-phase extraction with cartridges. Chromatographic methods are emphasised with a focus on liquid chromatography coupled to mass spectrometry as one of the most relevant analytical method for the determination of amatoxins in complex matrices. Furthermore, current trends and future perspectives in amatoxin detection are also suggested.

Survey of Edible Amanita in Northern Thailand and Their Nutritional Value, Total Phenolic Content, Antioxidant and α-Glucosidase Inhibitory Activities

Edible wild mushrooms are extremely popular among consumers and are highly valued for their potential economic benefits in northern Thailand. In this present study, a total of 19 specimens of edible Amanita were collected during investigations of wild edible mushrooms in northern Thailand during the period from 2019 to 2022. Their morphological characteristics and the phylogenetic analyses of the internal transcribed spacer (ITS) and partial large subunit (nrLSU) of ribosomal RNA, RNA polymerase II second-largest subunit (rpb2) and partial translation elongation factor 1-alpha (tef-1) indicated that the collected specimens belonged to A. hemibapha, A. pseudoprinceps, A. rubromarginata, A. subhemibapha, and Amanita section Caesareae. This is the first report of A. pseudoprinceps and A. subhemibapha from Thailand. Full descriptions, illustrations and a phylogenetic placement of all specimens collected in this study are provided. Subsequently, the nutritional composition and total phenolic content, as well as the antioxidant and α-glucosidase inhibitory activities, of each species were investigated. The results indicate that the protein contents in both A. pseudoprinceps and A. subhemibapha were significantly higher than in A. hemibapha and A. rubromarginata. The highest total phenolic content was found in the extract of A. pseudoprinceps. In terms of antioxidant properties, the extract of A. pseudoprinceps also exhibited significantly high antioxidant activity by 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. However, the extract of A. rubromarginata had the lowest total phenolic content and level of antioxidant activity. Additionally, α-glucosidase inhibitory activity varied for different Amanita species and the highest level of α-glucosidase inhibitory activity was found in the extract of A. pseudoprinceps. This study provides valuable information on the nutrient content, phenolic content and the antioxidant and α-glucosidase inhibitory potential of edible Amanita species found in northern Thailand.

Historical biogeography and diversification of ringless Amanita (section Vaginatae) support an African origin and suggest niche conservatism in the Americas

Ectomycorrhizal fungi (ECM) sustain nutrient recycling in most terrestrial ecosystems, yet we know little about what major biogeographical events gave rise to present-day diversity and distribution patterns. Given the strict relationship between some ECM lineages and their hosts, geographically well-sampled phylogenies are central to understanding major evolutionary processes of fungal biodiversity patterns. Here, we focus on Amanita sect. Vaginatae to address global diversity and distribution patterns. Ancestral-state-reconstruction based on a 4-gene timetree with over 200 species supports an African origin between the late Paleocene and the early Eocene (ca. 56 Ma). Major biogeographic "out-of-Africa" events include multiple dispersal events to Southeast Asia (ca. 45-21 Ma), Madagascar (ca. 18 Ma), and the current Amazonian basin (ca. 45-36 Ma), the last two likely trans-oceanic. Later events originating in Southeast Asia involve Nearctic dispersal to North America (ca. 20-5 Ma), Oceania (Australia and New Zealand; ca. 15 Ma), and Europe (ca. 10-5 Ma). Subsequent dispersals were also inferred from Southeast Asia to East Asia (ca. 4 Ma); from North America to East Asia (ca. 11-8 Ma), Southeast Asia (ca. 19-2 Ma), Northern Andes (ca. 15 Ma), and Europe (ca. 15-2 Ma), respectively; and from the Amazon to the Caribbean region (ca. 25-20 Ma). Finally, we detected a significant increase in the net diversification rates in the branch leading to most northern temperate species in addition to higher state-dependent diversification rates in temperate lineages, consistent with previous findings. These results suggest that species of sect. Vaginatae likely have higher dispersal ability and higher adaptability to new environments, in particular compared to those of its sister clade, sect. Caesareae. Overall, the much wider distribution of A. sect. Vaginatae, from pan-tropical to pan-arctic, provides a unique window to understanding niche conservatism across a species-rich clade of ECM fungi.

Two Cases of Severe Amanita Muscaria Poisoning Including a Fatality

Ingestion of Amanita muscaria mushrooms results in transient central nervous system excitation and depression mediated by its components, ibotenic acid and muscimol. The mushroom is distributed worldwide and ingestions occur with some frequency. Although these ingestions have traditionally been considered benign, serious complications can occur. We present 2 cases of serious toxicity, including a fatality. The first case was a 44-y-old man who presented to the emergency department (ED) after cardiopulmonary arrest approximately 10 h after ingesting 4 to 5 dried A muscaria mushroom caps, which he used for their mind-altering effects. Despite successful resuscitation, he remained unresponsive and hypotensive and died 9 days later. The second case was a 75-y-old man who presented to the ED after accidentally consuming one large A muscaria mushroom cap he foraged in Eastern Turkey. The patient initially presented to the ED with hallucinations followed by lethargy, and he was intubated for airway protection. The patient's condition gradually improved, and he made a full recovery. A muscaria ingestion should not be considered benign as serious outcomes do occur. An understanding of how the main neuroactive chemicals, ibotenic acid and muscimol, affect the brain can help anticipate outcomes. Several high-risk features that portend a more serious course are identified.

Genetic Analyses of Discrete Geographic Samples of a Golden Chanterelle in Canada Reveal Evidence for Recent Regional Differentiation

The wild edible mushroom Cantharellus enelensis is a recently described species of the golden chanterelles found in eastern North America. At present, the genetic diversity and population structure of C. enelensis are not known. In this study, we analyzed a total of 230 fruiting bodies of C. enelensis that were collected from three regions of Canada: near the east and west coasts of Newfoundland (NFLD), with 110 fruiting bodies each, and around Hamilton, Ontario (10 fruiting bodies). Among the 110 fruiting bodies from each coast in NFLD, 10 from 2009 were without specific site information, while 100 sampled in 2010 were from each of five patches separated by at least 100 m from each other. Each fruiting body was genotyped at three microsatellite loci. Among the total 28 multilocus genotypes (MLGs) identified, 2 were shared among all three regions, 4 were shared between 2 of the t3hree regions, and the remaining 22 were each found in only 1 region. Minimal spanning network analyses revealed several region-specific MLG clusters, consistent with geographic specific mutation and expansion. Though the most frequently observed MLGs were shared among local (patch) and regional populations, population genetic analyses revealed that both local and regional geographic separations contributed significantly to the observed genetic variation in the total sample. All three regional populations showed excess heterozygosity; for the eastern NFLD population, we reject the null hypothesis of Hardy–Weinberg equilibrium (HWE) at all three loci. However, the analyses of clone-corrected samples revealed that most loci were in HWE. Together, our results suggest that the three discrete regional populations of C. enelensis were likely colonized from a common refugium since the last ice age. However, the local and regional populations are diverging from each other through mutation, drift, and selection at least partly due to heterozygous advantage.

Reannotation of Fly Amanita l-DOPA Dioxygenase Gene Enables Its Cloning and Heterologous Expression

The l-DOPA dioxygenase of Amanita muscaria (AmDODA) participates in the biosynthesis of betalain- and hygroaurin-type natural pigments. AmDODA is encoded by the dodA gene, whose DNA sequence was inferred from cDNA and gDNA libraries almost 30 years ago. However, reports on its heterologous expression rely on either the original 5'-truncated cDNA plasmid or artificial gene synthesis. We provide unequivocal evidence that the heterologous expression of AmDODA from A. muscaria specimens is not possible by using the coding sequence previously inferred for dodA. Here, we rectify and reannotate the full-length coding sequence for AmDODA and express a 205-aa His-tagged active enzyme, which was used to produce the l-DOPA hygroaurin, a rare fungal pigment. Moreover, AmDODA and other isozymes from bacteria were submitted to de novo folding using deep learning algorithms, and their putative active sites were inferred and compared. The wide catalytic pocket of AmDODA and the presence of the His-His-His and His-His-Asp motifs can provide insight into the dual cleavage of l-DOPA at positions 2,3 and 4,5 as per the mechanism proposed for nonheme dioxygenases.

Reviewing the world's edible mushroom species: A new evidence-based classification system

Wild mushrooms are a vital source of income and nutrition for many poor communities and of value to recreational foragers. Literature relating to the edibility of mushroom species continues to expand, driven by an increasing demand for wild mushrooms, a wider interest in foraging, and the study of traditional foods. Although numerous case reports have been published on edible mushrooms, doubt and confusion persist regarding which species are safe and suitable to consume. Case reports often differ, and the evidence supporting the stated properties of mushrooms can be incomplete or ambiguous. The need for greater clarity on edible species is further underlined by increases in mushroom-related poisonings. We propose a system for categorizing mushroom species and assigning a final edibility status. Using this system, we reviewed 2,786 mushroom species from 99 countries, accessing 9,783 case reports, from over 1,100 sources. We identified 2,189 edible species, of which 2,006 can be consumed safely, and a further 183 species which required some form of pretreatment prior to safe consumption or were associated with allergic reactions by some. We identified 471 species of uncertain edibility because of missing or incomplete evidence of consumption, and 76 unconfirmed species because of unresolved, differing opinions on edibility and toxicity. This is the most comprehensive list of edible mushrooms available to date, demonstrating the huge number of mushrooms species consumed. Our review highlights the need for further information on uncertain and clash species, and the need to present evidence in a clear, unambiguous, and consistent manner.

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.

Study of three interesting Amanita species from Thailand: Morphology, multiple-gene phylogeny and toxin analysis

Amanita ballerina and A. brunneitoxicaria spp. nov. are introduced from Thailand. Amanita fuligineoides is also reported for the first time from Thailand, increasing the known distribution of this taxon. Together, those findings support our view that many taxa are yet to be discovered in the region. While both morphological characters and a multiple-gene phylogeny clearly place A. brunneitoxicaria and A. fuligineoides in sect. Phalloideae (Fr.) Quél., the placement of A. ballerina is problematic. On the one hand, the morphology of A. ballerina shows clear affinities with stirps Limbatula of sect. Lepidella. On the other hand, in a multiple-gene phylogeny including taxa of all sections in subg. Lepidella, A. ballerina and two other species, including A. zangii, form a well-supported clade sister to the Phalloideae sensu Bas 1969, which include the lethal "death caps" and "destroying angels". Together, the A. ballerina-A. zangii clade and the Phalloideae sensu Bas 1969 also form a well-supported clade. We therefore screened for two of the most notorious toxins by HPLC-MS analysis of methanolic extracts from the basidiomata. Interestingly, neither α-amanitin nor phalloidin was found in A. ballerina, whereas Amanita fuligineoides was confirmed to contain both α-amanitin and phalloidin, and A. brunneitoxicaria contained only α-amanitin. Together with unique morphological characteristics, the position in the phylogeny indicates that A. ballerina is either an important link in the evolution of the deadly Amanita sect. Phalloideae species, or a member of a new section also including A. zangii.

Speciation in progress? A phylogeographic study among populations of Hemitrichia serpula (Myxomycetes)

Myxomycetes (plasmodial slime molds, Amoebozoa) are often perceived as widely distributed, confounding to the “everything is everywhere” hypothesis. To test if gene flow within these spore-dispersed protists is restricted by geographical barriers, we chose the widespread but morphologically unmistakable species Hemitrichia serpula for a phylogeographic study. Partial sequences from nuclear ribosomal RNA genes (SSU) revealed 40 ribotypes among 135 specimens, belonging to three major clades. Each clade is dominated by specimens from a certain region and by one of two morphological varieties which can be differentiated by SEM micrographs. Partial sequences of the protein elongation factor 1 alpha (EF1A) showed each clade to possess a unique combination of SSU and EF1A genotypes. This pattern is best explained assuming the existence of several putative biospecies dominating in a particular geographical region. However, occasional mismatches between molecular data and morphological characters, but as well heterogeneous SSU and heterozygous EF1A sequences, point to ongoing speciation. Environmental niche models suggest that the putative biospecies are rather restricted by geographical barriers than by macroecological conditions. Like other protists, myxomycetes seem to follow the moderate endemicity hypothesis and are in active speciation, which is most likely shaped by limited gene flow and reproductive isolation.