Acromelic acid C. A new toxic constituent of clitocybe acromelalga : An efficient isolation of acromelic acids

Family matters inside the order Agaricales: systematic reorganization and classification of incertae sedis clitocyboid, pleurotoid and tricholomatoid taxa based on an updated 6-gene phylogeny

The phylogenetic position of several clitocyboid/pleurotoid/tricholomatoid genera previously considered incertae sedis is here resolved using an updated 6-gene dataset of Agaricales including newly sequenced lineages and more complete data from those already analyzed before. Results allowed to infer new phylogenetic relationships, and propose taxonomic novelties to accommodate them, including up to ten new families and a new suborder. Giacomia (for which a new species from China is here described) forms a monophyletic clade with Melanoleuca (Melanoleucaceae) nested inside suborder Pluteineae, together with the families Pluteaceae, Amanitaceae (including Leucocortinarius), Limnoperdaceae and Volvariellaceae. The recently described family Asproinocybaceae is shown to be a later synonym of Lyophyllaceae (which includes also Omphaliaster and Trichocybe) within suborder Tricholomatineae. The families Biannulariaceae, Callistosporiaceae, Clitocybaceae, Fayodiaceae, Macrocystidiaceae (which includes Pseudoclitopilus), Entolomataceae, Pseudoclitocybaceae (which includes Aspropaxillus), Omphalinaceae (Infundibulicybe and Omphalina) and the new families Paralepistaceae and Pseudoomphalinaceae belong also to Tricholomatineae. The delimitation of the suborder Pleurotineae (= Schizophyllineae) is discussed and revised, accepting five distinct families within it, viz. Pleurotaceae, Cyphellopsidaceae, Fistulinaceae, Resupinataceae and Schizophyllaceae. The recently proposed suborder Phyllotopsidineae (= Sarcomyxineae) is found to encompass the families Aphroditeolaceae, Pterulaceae, Phyllotopsidaceae, Radulomycetaceae, Sarcomyxaceae (which includes Tectella), and Stephanosporaceae, all of them unrelated to Pleurotaceae (suborder Pleurotineae) or Typhulaceae (suborder Typhulineae). The new family Xeromphalinaceae, encompassing the genera Xeromphalina and Heimiomyces, is proposed within Marasmiineae. The suborder Hygrophorineae is here reorganized into the families Hygrophoraceae, Cantharellulaceae, Cuphophyllaceae, Hygrocybaceae and Lichenomphaliaceae, to homogenize the taxonomic rank of the main clades inside all suborders of Agaricales. Finally, the genus Hygrophorocybe is shown to represent a distinct clade inside Cuphophyllaceae, and the new combination H. carolinensis is proposed. Taxonomic novelties: New suborder: Typhulineae Vizzini, Consiglio & P. Alvarado. New families: Aphroditeolaceae Vizzini, Consiglio & P. Alvarado, Melanoleucaceae Locq. ex Vizzini, Consiglio & P. Alvarado, Paralepistaceae Vizzini, Consiglio & P. Alvarado, Pseudoomphalinaceae Vizzini, Consiglio & P. Alvarado, Volvariellaceae Vizzini, Consiglio & P. Alvarado, Xeromphalinaceae Vizzini, Consiglio & P. Alvarado. New species: Giacomia sinensis J.Z. Xu. Stat. nov.: Cantharellulaceae (Lodge, Redhead, Norvell & Desjardin) Vizzini, Consiglio & P. Alvarado, Cuphophyllaceae (Z.M. He & Zhu L. Yang) Vizzini, Consiglio & P. Alvarado, Hygrocybaceae (Padamsee & Lodge) Vizzini, Consiglio & P. Alvarado, Lichenomphaliaceae (Lücking & Redhead) Vizzini, Consiglio & P. Alvarado. New combination: Hygrophorocybe carolinensis (H.E. Bigelow & Hesler) Vizzini, Consiglio & P. Alvarado. New synonyms: Sarcomyxineae Zhu L. Yang & G.S. Wang, Schizophyllineae Aime, Dentinger & Gaya, Asproinocybaceae T. Bau & G.F. Mou. Incertae sedis taxa placed at family level: Aphroditeola Redhead & Manfr. Binder, Giacomia Vizzini & Contu, Hygrophorocybe Vizzini & Contu, Leucocortinarius (J.E. Lange) Singer, Omphaliaster Lamoure, Pseudoclitopilus Vizzini & Contu, Resupinatus Nees ex Gray, Tectella Earle, Trichocybe Vizzini. New delimitations of taxa: Hygrophorineae Aime, Dentinger & Gaya, Phyllotopsidineae Zhu L. Yang & G.S. Wang, Pleurotineae Aime, Dentinger & Gaya, Pluteineae Aime, Dentinger & Gaya, Tricholomatineae Aime, Dentinger & Gaya. Resurrected taxa: Fayodiaceae Jülich, Resupinataceae Jülich. Citation: Vizzini A, Alvarado P, Consiglio G, Marchetti M, Xu J (2024). Family matters inside the order Agaricales: systematic reorganization and classification of incertae sedis clitocyboid, pleurotoid and tricholomatoid taxa based on an updated 6-gene phylogeny. Studies in Mycology 107: 67-148. doi: 10.3114/sim.2024.107.02.

Recent insights about pyrrolidine core skeletons in pharmacology

To overcome numerous health disorders, heterocyclic structures of synthetic or natural origin are utilized, and notably, the emergence of various side effects of existing drugs used for treatment or the resistance of disease-causing microorganisms renders drugs ineffective. Therefore, the discovery of potential therapeutic agents that utilize different modes of action is of utmost significance to circumvent these constraints. Pyrrolidines, pyrrolidine-alkaloids, and pyrrolidine-based hybrid molecules are present in many natural products and pharmacologically important agents. Their key roles in pharmacotherapy make them a versatile scaffold for designing and developing novel biologically active compounds and drug candidates. This review aims to provide an overview of recent advancements (especially during 2015-2023) in the exploration of pyrrolidine derivatives, emphasizing their significance as fundamental components of the skeletal structure. In contrast to previous reviews that have predominantly focused on a singular biological activity associated with these molecules, this review consolidates findings from various investigations encompassing a wide range of important activities (antimicrobial, antiviral, anticancer, anti-inflammatory, anticonvulsant, cholinesterase inhibition, and carbonic anhydrase inhibition) exhibited by pyrrolidine derivatives. This study is also anticipated to serve as a valuable resource for drug research and development endeavors, offering significant insights and guidance.

[Isolating Venomous Constituents of Paralepistopsis acromelalgaand Simultaneous Analysis of Its Compounds]

An isolation method for Acromelic acids A, B and Clitidine, which are venomous constituents of Paralepistopsis acromelalga was developed. Highly purified products were obtained from the mushroom extract using silica gel, ODS, ion-exchange column chromatography and preparative TLC. Using those results, we optimized the LC-MS/MS conditions. Finally we developed a method for simultaneous analysis. In recovery tests, the average recovery was 80.8-112.4%, repeatability was 1.4-3.8RSD%. The limits of quantification of the respective compounds were estimated as 0.25 μg/g. Based on the results, this method can reveal causes of food poisoning by Paralepistopsis acromelalga.

Non-peptide secondary metabolites from poisonous mushrooms: overview of chemistry, bioactivity, and biosynthesis

Covering: up to June 2021A wide variety of mushrooms have traditionally been recognized as edible fungi with high nutritional value and low calories, and abundantly produce structurally diverse and bioactive secondary metabolites. However, accidental ingestion of poisonous mushrooms can result in serious illnesses and even death. Chemically, mushroom poisoning is associated with secondary metabolites produced in poisonous mushrooms, causing specific toxicity. However, many poisonous mushrooms have not been fully investigated for their secondary metabolites, and the secondary metabolites of poisonous mushrooms have not been systematically summarized for details such as chemical composition and biosynthetic mechanisms. The isolation and identification of secondary metabolites from poisonous mushrooms have great research value since these compounds could be lethal toxins that contribute to the toxicity of mushrooms or could provide lead compounds with remarkable biological activities that can promote advances in other related disciplines, such as biochemistry and pharmacology. In this review, we summarize the structures and biological activities of secondary metabolites identified from poisonous mushrooms and provide an overview of the current information on these metabolites, focusing on their chemistry, bioactivity, and biosynthesis.

Pyridine alkaloids with activity in the central nervous system

This review discusses all pyridine alkaloids with CNS activity, their therapeutic potential, and the interesting array of sources whence they originate.

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.

Enantioselective total synthesis of (-)-kainic acid and (+)-acromelic acid C via Rh(i)-catalyzed asymmetric enyne cycloisomerization

A diversity-oriented synthetic strategy was developed for the total synthesis of kainoid amino acids, which led to the enantioselective synthesis of (-)-kainic acid and the first total synthesis of (+)-acromelic acid C. Rh(i)-catalyzed asymmetric enyne cycloisomerization served as the key reaction in this strategy for the rapid construction of highly functionalized lactam, and the resulting vinyl acetate moiety was further utilized as a versatile building block for the installation of both isopropylidene and 2-pyridone units existing in natural kainoids.

New syndromes in mushroom poisoning

Several new mushroom poisoning syndromes have been described since the early 1990s. In these syndromes, the onset of symptoms generally occurs >6 hours after ingestion. Treatment is mainly supportive. The syndrome induced by Amanita smithiana/proxima consists of acute tubulopathy, which appears earlier and does not have the same poor prognosis as the orellanine-induced syndrome. It has been described since 1992 in the US and Canada with A. smithiana; in France, Spain and Italy with A. proxima; and in Japan with A. pseudoporphyria. The responsible toxin is probably 2-amino-4,5-hexadienoic acid. The erythromelalgia syndrome has been described as early as the late 19th century in Japan and South Korea with Clitocybe acromelalga, and since 1996 in France and then Italy with C. amoenolens. Responsible toxins are probably acromelic acids identified in both species. Several cases of massive rhabdomyolysis have been reported since 1993 in France and 2001 in Poland after ingestion of large amounts of an edible and, until then, valuable species called Tricholoma equestre. These cases of rhabdomyolysis are associated with respiratory and cardiac (myocarditis) complications leading to death. Rhabdomyolysis with an apparently different mechanism was described in Taiwan in 2001 with Russula subnigricans. Finally, cases of encephalopathy were observed twice after ingestion of Hapalopilus rutilans in Germany in 1992 and Pleurocybella porrigens in Japan in 2004, where a convulsive encephalopathy outbreak was reported in patients with history of chronic renal failure.

Syndromic diagnosis and management of confirmed mushroom poisonings

OBJECTIVE

To assess the evolving global epidemiology of mushroom poisoning and to identify new and emerging mushroom poisonings and their treatments, a descriptive analysis and review of the world's salient scientific literature on mushroom poisoning was conducted.

DATA SOURCE

Data sources from observation studies conducted over the period 1959-2002, and describing 28,018 mushroom poisonings since 1951, were collected from case reports, case series, regional descriptive studies, meta-analyses, and laboratory studies of mushroom poisonings and the toxicokinetics of mycotoxins.

STUDY SELECTION

Studies included in the review were selected by a MEDLINE search, 1966-2004, an Ovid OLDMEDLINE search, 1951-1965, and a medical library search for sources published before 1951.

DATA EXTRACTION

To better guide clinicians in establishing diagnoses and implementing therapies, despite confusing ingestion histories, data were extracted to permit an expanded syndromic classification of mushroom poisoning based on presentation timing and target organ systemic toxicity.

DATA SYNTHESIS

The final 14 major syndromes of mushroom poisoning were stratified first by presentation timing and then by target organ systemic toxicity and included early (<6 hrs), late (6-24 hrs), and delayed syndromes (> or =1 day). There were eight early syndromes (four neurotoxic, two gastrointestinal, two allergic); three late syndromes (hepatotoxic, accelerated nephrotoxic, erythromelalgia); and three delayed syndromes (delayed nephrotoxic, delayed neurotoxic, rhabdomyolysis). Four new mushroom poisoning syndromes were classified including accelerated nephrotoxicity (Amanita proxima, Amanita smithiana), rhabdomyolysis (Tricholoma equestre, Russula subnigricans), erythromelalgia (Clitocybe amoenolens, Clitocybe acromelalgia), and delayed neurotoxicity (Hapalopilus rutilans). In addition, data sources were stratified by three chronological time periods with >1,000 confirmed mushroom ingestions reported and tested for any statistically significant secular trends in case fatalities from mushroom ingestions over the entire study period, 1951-2002.

CONCLUSIONS

Since the 1950s, reports of severe and fatal mushroom poisonings have increased worldwide. Clinicians must consider mushroom poisoning in the evaluation of all patients who may be intoxicated by natural substances. Since information on natural exposures is often insufficient and incorrect, a new syndromic classification of mushroom poisoning is recommended to guide clinicians in making earlier diagnoses, especially in cases where only advanced critical care, including organ transplantation, may be life saving.

Mass spectrometric determination of acromelic acid A from a new poisonous mushroom: Clitocybe amoenolens

As Clitocybe acromelalga, the mushroom Clitocybe amoenolens is responsible for erythermalgia. Acromelic acids isolated from C. acromelalga have been suspected to be to some extend the active principles. The objective was to develop a specific and sensitive liquid chromatographic-mass spectrometric method that would allow acromelic acid A identification and quantification in mushrooms. The method involved a single-step methanol-water extraction followed by a selective cleanup of the extract with solid-phase extraction cartridges (strong-anion exchange). The chromatographic separation was achieved on a porous graphitic carbon column with acetonitrile-water-formic acid as mobile phase. Detection was done with a mass analyzer equipped with a TurboIonSpray source, operated in the negative ionization mode. Acromelic acid A concentration was determined in dried mushroom at around 325 ng/mg in C. amoenolens and 283 ng/mg in C. acromelalga.

[Acute erythermalgia: look for mushrooms!]

INTRODUCTION

To describe the first European observation of erythromelalgia due to mushroom poisoning.

EXEGESIS

Seven cases observed and followed over 4 years are reported. All ill patients had eaten the same mushroom species, gathered in the same French alpine valley. Clinical features of erythromelalgia were observed. This syndrome was first described in Japan after Clitocybe acromelalga ingestion. It had never been observed in Europe before. Clitocybe acromelalga does not grow in Europe. Clitocybe amoenolens was identified as the possible cause of poisoning in our cases. This species can be confused with an edible mushroom, Lepista inversa.

CONCLUSIONS

Even in Europe, recent mushroom poisoning is a possible cause of erythromelalgia.

Erythromelalgia and mushroom poisoning

OBJECTIVE

To report the first European observations of erythromelalgia due to mushroom poisoning.

METHODS

Clinical features of erythromelalgia were observed in 7 cases seen over 3 years. All patients had eaten the same mushrooms species, gathered in the same French alpine valley. Erythromelalgia was first described in Japan after Clitocybe acromelalga ingestion. Clitocybe amoenolens was identified as the possible cause of poisoning in our cases.

Glutamate uptake

Brain tissue has a remarkable ability to accumulate glutamate. This ability is due to glutamate transporter proteins present in the plasma membranes of both glial cells and neurons. The transporter proteins represent the only (significant) mechanism for removal of glutamate from the extracellular fluid and their importance for the long-term maintenance of low and non-toxic concentrations of glutamate is now well documented. In addition to this simple, but essential glutamate removal role, the glutamate transporters appear to have more sophisticated functions in the modulation of neurotransmission. They may modify the time course of synaptic events, the extent and pattern of activation and desensitization of receptors outside the synaptic cleft and at neighboring synapses (intersynaptic cross-talk). Further, the glutamate transporters provide glutamate for synthesis of e.g. GABA, glutathione and protein, and for energy production. They also play roles in peripheral organs and tissues (e.g. bone, heart, intestine, kidneys, pancreas and placenta). Glutamate uptake appears to be modulated on virtually all possible levels, i.e. DNA transcription, mRNA splicing and degradation, protein synthesis and targeting, and actual amino acid transport activity and associated ion channel activities. A variety of soluble compounds (e.g. glutamate, cytokines and growth factors) influence glutamate transporter expression and activities. Neither the normal functioning of glutamatergic synapses nor the pathogenesis of major neurological diseases (e.g. cerebral ischemia, hypoglycemia, amyotrophic lateral sclerosis, Alzheimer's disease, traumatic brain injury, epilepsy and schizophrenia) as well as non-neurological diseases (e.g. osteoporosis) can be properly understood unless more is learned about these transporter proteins. Like glutamate itself, glutamate transporters are somehow involved in almost all aspects of normal and abnormal brain activity.

Novel C-4 heteroaromatic kainoid analogues: a parallel synthesis approach

New C-4 thiazole 4, 5 and aminothiazole 6, 7 kainoid analogues were efficiently synthesised in five steps from commercially available (-)-alpha-kainic acid I and exhibited strong binding to the kainate receptors. A reactive alpha-bromoketone 10 was generated and reacted with thioamides and thioureas to form thiazole and aminothiazole heterocycles 11-14. Deprotection gave the new kainoid amino acids 4-7 in excellent yield.

Simple Methods for Determining Relative Stereochemistry of Kainoid Amino Acids by (1)H NMR Chemical Shifts

The kainoid amino acids are biologically important compounds because they show remarkable neuroexcitatory and excitotoxic activities. For exhibiting potent activity, the stereochemical relationship of the substituents on the pyrrolidine ring is crucial. We found simple methods for determining the relative stereochemistry of these compounds on the basis of the (1)H NMR chemical shifts of H-2 and H-4 in D(2)O solution. The signals of H-2 appear at fields higher than 4.2 ppm when the compounds have 2,3-trans stereochemistry whereas, in the 2,3-cis compounds, they appear lower than 4.2 ppm, irrespective of the C-4 substituent. This criterion holds when the solution is in the range of pD 3-8. Moreover, when an epimeric pair at C-2 is available and the spectra are recorded at the same or nearly equal pD, the H-2 chemical shift of the 2,3-trans isomer is higher than that of the corresponding 2,3-cis isomer. Similarly, the relative stereochemistry between C-3 and C-4 can be determined from the chemical shift of H-4. The signals of H-4 of the 3,4-cis isomers appear at lower fields than those of the corresponding 3,4-trans isomers in each pair of C-4 epimers when the spectra are recorded at the same or nearly equal pD. This holds for the compounds bearing an unsaturated substituent at C-4. All these phenomena can be rationalized by the anisotropic effect of the pi-electron system in the C-2 and C-4 substituents.