Image credit: first-nature.com
Pholiota squarrosa, commonly known as the Shaggy Scalycap or Dry Scaly Pholiota, is a prominent forest basidiomycete that serves as the taxonomic type species of its genus. Easily recognized by its dry, recurved scales and dramatic autumn clusters, this conspicuous mushroom is a double-agent of the temperate forest, operating as both a wood-decaying saprotroph and an opportunistic heartwood parasite. Yet, while foresters traditionally viewed it as a destructive pathogen, modern glycobiology and biochemistry have transformed this woodland fungus into a cornerstone of contemporary clinical research. From its complex secondary pigments that block enzymes linked to gout, to its highly stable, 40-amino-acid “mini-lectin” capable of early cancer detection and broad-spectrum viral neutralization, this species represents one of the most scientifically productive organisms in modern mycology.
What is Pholiota squarrosa?
Pholiota squarrosa is a conspicuous, cluster-forming woodland mushroom characterized by its dry, yellowish cap covered in coarse, recurved scales. Operating as an opportunistic plant parasite and white-rot decomposer, this species has transitioned from forest pathology to a vital scientific resource, yielding compounds that inhibit gout and a highly stable, disease-detecting protein.
This basidiomycete belongs to the family Strophariaceae and the order Agaricales. It was officially established in its modern genus in 1871 by German mycologist Paul Kummer, who transferred it from the historically broad Agaricus classification. As the type species of the genus, its macroscopic features—including a scaly pileus and stipe, attached gills, a partial veil, and brown spores—anchor the taxonomic definition for more than a hundred related species described in modern mycological classifications.
Beyond its systematic classification, the mushroom has minimal representation in historical ethnomycological records or traditional folk medicine. Unlike highly publicized fungi with deep spiritual or cultural backgrounds, this species has spent its history primarily inside field identification guides and scientific journals. Its rise to scientific prominence began only recently, driven by bioprospecting campaigns designed to map the chemical warfare waged between wood-decaying fungi and living trees.
Ultimately, Pholiota squarrosa serves as a prime example of how a familiar, non-edible woodland fungus can transition from a forestry nuisance to a clinical goldmine.
How do you identify the Shaggy Scalycap in the wild?
Identifying this mushroom requires evaluating its completely dry, scaly pileus, greenish-yellow young gills, and brown spore print. It forms dense clumps at the base of broadleaf trees and conifers, releasing a pungent radish-to-garlic odor when bruised. This shaggy appearance prevents confusion with other wood-decaying fungi under close scrutiny.
The cap of the Shaggy Scalycap measures between 3 and 12 centimeters in diameter. It begins convex before expanding to a flat, bell-shaped profile with a characteristically in-rolled, shaggy margin. The pileus flesh is firm and ranges from white to pale yellow. The most distinguishing macroscopic feature is the dense covering of dry, upturned, triangular scales that vary from buff to tawny or reddish-brown, starkly contrasting with the straw-yellow base color.
When young, a woolly, cobweb-like partial veil covers the gills. As the cap expands, this veil tears apart to leave a distinct, shaggy ring zone (annulus) on the upper stem. Above this ring, the stipe is smooth; below it, it is heavily adorned with the same coarse, recurved scales found on the cap.
The gills are closely spaced and attached to the stem. In young specimens, the gills pass through a highly characteristic greenish-yellow stage before turning a deep, rusty cinnamon-brown as the spores mature. The resulting spore print is a rich, rusty brown. Bruising the cap or slicing the flesh releases a strong, pungent odor. While many field guides describe this aroma as radish-like, regional populations—particularly in western North America—frequently display a powerful garlic-lemon or onion-skunk odor.
Morphological Comparison: Pholiota squarrosa vs. Common Lookalikes
To avoid toxic ingestions and ensure accurate field surveys, foragers and mycologists rely on the diagnostic key below:
| Species | Cap Surface Texture | Young to Mature Gill Color | Spore Size & Print Color | Odor Profile | Key Distinguishing Feature |
|---|---|---|---|---|---|
| Pholiota squarrosa | Completely dry, non-viscid, yellow-white with tawny, recurved scales | Greenish-yellow, then rusty brown | 5.5–9.0 × 3.5–5.0 μm; cinnamon-brown | Pungent radish, garlic-lemon, or skunk-like | Dry cap, a greenish-yellow young gill stage, and garlic-like odor |
| Pholiota squarrosoides | Sticky, viscid, or glutinous beneath the scales | Whitish, then rusty brown (lacks any green stage) | 4.0–6.0 × 2.5–3.5 μm; cinnamon-brown | Mild, non-distinctive | Sticky cap surface, white cap flesh, and significantly smaller spores |
| Pholiota flammans | Completely dry, bright orange-yellow with matching scales | Bright yellow, then rusty brown | 5.0–6.5 × 3.0–4.0 μm; brown | Mild, non-distinctive | Uniformly brilliant orange-yellow coloration across the entire fruit body |
| Armillaria mellea (Honey Mushroom) | Dry to moist, yellowish-brown with fine, flat hairs | Whitish, eventually developing pinkish-tan spots | 7.0–10.0 × 5.0–7.0 μm; white | Mild, sweet, fungal | Pure white spore print, and gills that never turn green or cinnamon |
| Leucopholiota decorosa | Dry, densely covered in small, erect, pointy brown scales | Pure white, with finely scalloped gill edges | 5.5–7.5 × 3.5–5.0 μm; white | Mild, non-distinctive | Pure white, adnexed gills and a white spore print |
(Author’s Note: If you spot this mushroom on your autumn walks, take a moment to gently bruise the gills of a mature specimen. Depending on your geography, you may experience a sharp radish scent or a heavy lemon-garlic perfume. Let us know what notes you detect in the comment section below!)
Precise morphological identification, particularly verifying a completely dry cap surface and a rusty-brown spore print, remains the primary line of defense against accidental poisoning.
How does the chemistry of Pholiota squarrosa inhibit gout?
This species synthesizes unique yellow pigments called squarrosidine and pinillidine, which belong to the 3,3′-fused bis(styrylpyrone) class. These compounds act as potent, non-purine inhibitors of xanthine oxidase, the enzyme that produces joint-crystallizing uric acid. By blocking this pathway, they prevent both the painful symptoms of gout and cellular oxidative stress.
To survive inside living trees, the Shaggy Scalycap must overcome the host’s chemical defenses. Living trees respond to fungal invasion by generating localized oxidative bursts—flooding the infected area with reactive oxygen species (ROS) such as superoxide radicals to degrade the fungal cell membranes. In response, the mycelium of the Shaggy Scalycap synthesizes unique secondary metabolites that act as chemical shields to quench these host oxidants.
As detailed in a 2007 structural isolation study by Hans-Wilhelm Wangun and Christian Hertweck, these protective compounds include squarrosidine and pinillidine. Structurally, these yellow pigments represent an unprecedented class of 3,3′-fused bis(styrylpyrones) derived from phenylpropanoid polyketide pathways.
When evaluated against human metabolic pathways, these compounds act as highly effective, non-purine inhibitors of xanthine oxidase. Xanthine oxidase is the metalloflavoprotein enzyme responsible for the sequential oxidation of hypoxanthine to xanthine, and subsequently to uric acid, during purine metabolism.
In humans, the accumulation of excess uric acid leads to hyperuricemia, resulting in the crystallization of monosodium urate inside the joints—a highly painful condition known as gouty arthritis. Clinical management of chronic gout has long relied on synthetic inhibitors like allopurinol. However, allopurinol frequently causes adverse side effects, including severe hypersensitivity, renal toxicity, and skin rashes.
A 2026 pharmacological screening study published in the journal Molecules demonstrated that natural planar flavonoids and chalcones (which share structural features with the bis(styrylpyrones) of P. squarrosa) dock directly into the active site of xanthine oxidase. The planar conjugated aromatic skeleton of these compounds mediates strong π-π stacking and hydrogen-bonding with key residues around the enzyme’s catalytic pocket, physically blocking hypoxanthine and xanthine from entering. By halting enzyme activity, these natural compounds not only suppress uric acid synthesis but also prevent the enzyme from generating its own superoxide byproduct, mitigating systemic oxidative stress.
Through an elegant evolutionary loop, the identical chemical weapons evolved by the Shaggy Scalycap to survive plant defenses serve as highly effective structural templates for non-purine human gout therapies.
What makes the PhoSL mini-lectin a structural breakthrough?
The Pholiota squarrosa lectin, or PhoSL, is an ultra-small, 40-amino-acid peptide that assembles into a symmetrical, three-fold beta-prism trimer. This tiny protein possesses absolute, exclusive specificity for core-fucosylated N-glycans. Lacking structural precedent, its rigid binding pocket and central electrostatic core grant it exceptional stability across extreme temperatures and pH ranges.
In 2012, a research team led by Yuka Kobayashi purified a novel, highly specific fucose-binding protein from the Shaggy Scalycap, naming it PhoSL (Pholiota squarrosa lectin). While typical plant and animal lectins are large, complex glycoproteins, the original isolation paper published in the Journal of Biological Chemistry revealed that PhoSL is an exceptionally compact “mini-lectin” consisting of only 40 amino acids with a molecular mass of just 4.5 kilodaltons (kDa).
The genetic architecture of this protein is highly unusual. The native PhoSL gene does not code for an isolated 40-amino-acid peptide; instead, it codes for a 180-amino-acid precursor protein containing three tandem repeats of the 40-residue motif, separated by short linker regions. In the living mushroom, proteolytic enzymes cleave these linkers to release the individual 40-amino-acid peptide monomers, which display identical carbohydrate-binding activity.
The Beta-Prism III Motif
As resolved by X-ray crystallography and NMR spectroscopy in a study led by Kazuhiko Yamasaki and colleagues, these 40-residue monomers self-assemble into a symmetrical homotrimer with a molecular mass of approximately 13.5 kDa. This assembly displays an unprecedented, novel protein fold designated as the β-prism III motif.
This compact prism is characterized by a three-fold rotational symmetry (\(C_3\)) where three antiparallel β-sheets are stabilized by the swapping of β-strands between adjacent monomers. The core of this prism is held together by a central triad of tryptophan residues (specifically Trp28). The indole rings of these tryptophans form highly stable NH-π electrostatic interactions that lock the trimeric scaffold together.
Because of this rigid, self-stabilizing fold, PhoSL exhibits extraordinary physical and chemical durability. According to stability assays, the protein remains fully functional across an extreme pH range of 2.0 to 11.0, and survives heating at 100 °C for 30 minutes without denaturing.
The Binding Pocket and N-Terminal Integrity
The carbohydrate-binding mechanism of PhoSL is exceptionally precise. Three identical sugar-binding pockets are formed at the junction of the β-sheet edges between adjacent polypeptide chains in the trimer. PhoSL displays absolute, exclusive specificity for core α1-6-fucosylated N-glycans—a modification where a fucose sugar is attached to the innermost N-acetylglucosamine (GlcNAc) residue of a complex glycoprotein carbohydrate chain.
When a core-fucosylated glycan enters the pocket, the fucose pyranose ring forms a favorable CH-π attractive interaction with the aromatic ring of Tyr23, while its hydroxyl groups establish key hydrogen bonds with the carboxyl group of Asp13 and the free N-terminal amine of alanine (Ala1).
Other fucosylated glycans, such as H-type glycans (characterized by α1-2 fucose linkages) or Lewis-type glycans (α1-3 or α1-4 linkages), are physically locked out. When these alternative structures attempt to dock in their energetically stable conformations, they experience severe steric clashes with the rigid aromatic walls of the pocket, specifically colliding with the bulky side chains of Tyr23 and Trp28.
A 2023 structural study led by Dr. Yi-Sheng Hsu emphasized that the integrity of the N-terminus is absolutely critical for this binding mechanism. The free N-terminal amine of Ala1 is directly responsible for coordinating fucose recognition and maintaining the overall structural pocket. Recombinant expression systems that leave behind extra amino acids or fusion tags at the N-terminus destabilize this cavity, reducing PhoSL’s carbohydrate-binding affinity by several orders of magnitude.
The compact, strand-swapping β-prism structure of PhoSL represents an entirely new class of protein folding, utilizing a highly stabilized tryptophan core and a pristine N-terminus to achieve absolute carbohydrate selectivity.
How is PhoSL used in cancer diagnostics and clinical care?
In clinical oncology, PhoSL serves as a highly precise biomarker probe to detect core fucosylation, an alteration strongly linked to aggressive tumor progression. It specifically binds to alpha-fetoprotein L3, facilitating early, automated risk screening for hepatocellular carcinoma. Furthermore, PhoSL staining can distinguish primary colorectal tumors from invasive metastatic tissues.
Core fucosylation, driven by the intracellular enzyme α1-6 fucosyltransferase (encoded by the Fut8 gene), is a critical clinical biomarker for several highly aggressive cancers. When healthy liver cells undergo malignant transformation, they secrete a heavily core-fucosylated isoform of alpha-fetoprotein, designated as AFP-L3.
In clinical diagnostics, tracking the proportion of core-fucosylated AFP relative to total AFP (known as the AFP-L3% value) is a standard method to evaluate the risk of developing hepatocellular carcinoma (HCC)—the most common form of primary liver cancer. Patients with chronic liver disease who exhibit an AFP-L3% elevation above 10% carry a highly elevated risk of developing active HCC, making early clinical intervention possible.
Historically, laboratories detected AFP-L3 using Lens culinaris agglutinin (LCA). However, LCA has moderate affinity and binds to other non-fucosylated sugars, requiring complex electrophoretic separation. Because PhoSL possesses absolute specificity for core fucose, it binds directly to AFP-L3 while completely ignoring non-fucosylated isoforms, enabling the development of rapid, highly sensitive, and automated diagnostic assays.
Beyond primary liver cancer, PhoSL is a powerful tool in histopathology and diagnostic imaging:
- Colorectal Malignancies: Staining biopsy tissues with biotinylated PhoSL allows pathologists to clearly differentiate primary colon tumors from invasive metastatic lesions. Core fucosylation levels rise dramatically as tumor cells acquire metastatic capabilities, making PhoSL a reliable prognostic indicator.
- Nonalcoholic Steatohepatitis (NASH): In research models of chronic liver disease, PhoSL staining reveals a progressive increase in hepatocyte core fucosylation as benign fatty liver (steatosis) advances to severe liver fibrosis and cirrhosis.
- Targeted Cytotoxicity: Due to its small size and chemical synthesis compatibility, researchers can conjugate fluorescent dyes or therapeutic payloads directly to the PhoSL peptide framework. This creates a highly specific platform for intraoperative tumor imaging and targeted cancer-cell destruction.
By providing a reliable molecular scalpel that targets core fucosylation, this miniature fungal protein has significantly enhanced the early detection and prognostic tracking of aggressive cancers.
How does PhoSL act as a broad-spectrum antiviral agent against SARS-CoV-2?
PhoSL neutralizes SARS-CoV-2 variants by targeting the invariant, core-fucosylated N-glycans that stud the viral spike glycoprotein. Because both the spike protein and PhoSL exist as trimers, their interaction creates a highly multivalent cross-linked lattice. This physical aggregation immobilizes the virion, blocking receptor binding and preventing viral entry with low-nanomolar affinity.
The outer envelope of the SARS-CoV-2 virion is heavily studded with trimeric spike (S) glycoproteins, which the virus uses to bind to human ACE2 receptors and invade host cells. To evade the host’s immune system, the virus coats these spike proteins in a dense, host-derived carbohydrate layer known as a “glycan shield.” However, mass spectrometric profiling has revealed that approximately 52% of these shielding N-glycans are core-fucosylated.
In a landmark 2023 study published in The FEBS Journal by a collaborative research team, investigators demonstrated that PhoSL binds with extraordinary, low-nanomolar affinity (around 3.4 to 3.9 nM) to the spike glycoproteins of both the ancestral Wuhan strain and the highly mutated Omicron variant. This interaction is approximately 1,000-fold stronger than the micromolar affinity typically observed between PhoSL and a free core-fucose sugar.
This remarkable affinity is driven by a dual-binding mechanism. When the pocket of the PhoSL trimer locks onto the spike’s core fucose, the compact peptide framework of the mini-lectin establishes secondary hydrophobic and non-polar contacts with the adjacent amino acids on the spike protein’s surface.
Furthermore, cryogenic electron microscopy (cryo-EM) revealed that because both the viral spike and PhoSL are natural trimers, their mixture triggers massive, rapid aggregation. A single PhoSL trimer can bridge up to three independent spike trimers, cross-linking the virions into large, insoluble molecular lattices. This physical immobilization locks the spike’s receptor-binding domain in a closed conformation, preventing ACE2 receptor docking and neutralizing viral entry.
Because the host-derived glycosylation sites on the spike protein are essential for proper folding and viral stability, they are highly conserved. While emerging mutations constantly allow new variants to escape synthetic monoclonal antibodies, they cannot alter these vital glycan structures. Consequently, PhoSL’s neutralization efficiency remains unaffected across variants, presenting a highly robust, mutation-resistant therapeutic template.
By physically cross-linking viral spike proteins into insoluble lattices, PhoSL exploits the virus’s own glycan shield to achieve broad-spectrum, variant-proof neutralization.
What are the safety risks, toxicities, and drug interactions of this mushroom?
Ingesting this toxic mushroom triggers severe gastrointestinal distress, characterized by violent vomiting, abdominal cramping, and acute diarrhea. When consumed alongside alcohol, it induces a severe, delayed disulfiram-like poisoning syndrome. Due to unresolved chemical toxicities and lookalike confusion with edible honey mushrooms, foraging or self-medicating is strictly contraindicated.
Despite the profound clinical and pharmacological value of its isolated molecules, the raw fruiting bodies of Pholiota squarrosa are strictly toxic and entirely unfit for human consumption. Historically, foraging literature was inconsistent, with some older guides listing the Shaggy Scalycap as edible if thoroughly cooked. However, toxicological reports of severe poisonings have steadily accumulated, leading modern poison control centers to issue unambiguous warnings against its ingestion.
Ingesting the mushroom primarily results in severe gastrointestinal poisoning. Symptoms typically manifest within 20 minutes to four hours postprandially, starting with sudden, violent nausea and abdominal pain, followed by intense muscle cramping, vomiting, and severe diarrhea. While rarely fatal, the poisoning causes rapid dehydration and electrolyte depletion, frequently requiring emergency hospitalization for supportive intravenous rehydration.
The most notorious toxicological hazard associated with this species is its highly adverse, delayed reaction with alcohol. Consuming the mushroom alongside or within several days of drinking alcohol triggers a severe poisoning reaction that clinically mirrors Coprinus syndrome (Tippler’s Bane). Under normal metabolic conditions, ethanol is cleared by the liver via alcohol dehydrogenase into acetaldehyde, which is then oxidized into acetate by the enzyme acetaldehyde dehydrogenase.
In the classic common ink cap (Coprinopsis atramentaria), this syndrome is caused by the non-protein amino acid coprine, which metabolizes into a potent inhibitor of acetaldehyde dehydrogenase, leading to a toxic accumulation of acetaldehyde in the blood. However, multiple phytochemical analyses of Pholiota squarrosa have failed to confirm the presence of coprine.
This indicates that the mushroom’s severe alcohol-intolerance syndrome is driven by an entirely different, yet-to-be-characterized class of secondary metabolites, or by an unresolved synergy between its unique phenylpropanoids and human metabolic pathways. Because of this unconfirmed chemical etiology, anyone who accidentally ingests Pholiota squarrosa must strictly abstain from alcohol for at least 72 hours.
Furthermore, because the intense vomiting and diarrhea induced by the mushroom can severely disrupt the bioavailability and absorption of oral prescription medications, accidental ingestion represents a significant pharmaceutical risk.
Due to its unpredictable toxic profile and highly adverse, unresolved metabolic interactions with alcohol, Pholiota squarrosa is strictly contraindicated for any dietary or medicinal use.
Technical Comparison: PhoSL vs. Standard Fucose-Binding Lectins
To highlight the unique biochemical capabilities of the Shaggy Scalycap mini-lectin, the table below contrasts PhoSL with historically utilized fucose-binding lectins in clinical glycobiology:
| Lectin Name | Source Organism | Molecular Mass (Assembly) | Core Fucose Specificity (α1-6) | Off-Target Glycan Binding | Environmental & Thermal Stability |
|---|---|---|---|---|---|
| PhoSL | Pholiota squarrosa (Mushroom) | 13.5 kDa (homotrimer) | Absolute; binds exclusively to core fucose | None; completely blocked by steric hindrance | Exceptional; fully active from pH 2.0 to 11.0, and up to 100 °C |
| LCA (Lens culinaris agglutinin) | Lens culinaris (Lentil) | ~49.0 kDa (homodimer) | Moderate; requires additional α-mannose residues | Binds glucose, mannose, and non-fucosylated glycans | Moderate; highly sensitive to heat and pH deviations |
| AAL (Aleuria aurantia lectin) | Aleuria aurantia (Orange Peel Fungus) | ~72.0 kDa (homodimer) | Low; recognizes all linkages of fucose | High affinity for α1-2, α1-3, and α1-4 linkages | Moderate thermal and pH stability |
| AOL (Aspergillus oryzae lectin) | Aspergillus oryzae (Mold) | ~35.0 kDa (homodimer) | High; strong core-fucose binding | Binds to α1-2-fucosylated (H-type) glycans | Moderate stability; denatures at high temperatures |
Frequently Asked Questions
Can Pholiota squarrosa be made edible by boiling or drying?
No. Boil-treating or drying the mushroom does not degrade its gastrointestinal toxins or eliminate the compounds responsible for its severe, disulfiram-like alcohol reactions. The mushroom remains toxic regardless of preparation method and must never be consumed.
Is the Shaggy Scalycap a primary killer of living trees?
No, it is generally considered an opportunistic, secondary parasite. The fungus primarily enters trees through mechanical wounds, insect damage, or root systems already weakened by primary pathogens, subsequently causing a selective-to-simultaneous white rot in the heartwood.
What should I do if I accidentally consume the Shaggy Scalycap?
Immediate medical attention is required. Hospital treatment typically involves administering activated charcoal to bind remaining toxins, intravenous hydration to manage fluid loss, and antiemetic medications. You must inform medical staff of all current prescriptions and strictly avoid alcohol for at least 72 hours.
Why is the pristine N-terminus of PhoSL so important to researchers?
The free N-terminal amine of the first amino acid (alanine) directly coordinates the hydrogen bonds that lock fucose into the binding pocket. If even a single extra amino acid or fusion tag is left on the N-terminus during synthesis or expression, the binding pocket is disrupted, reducing binding affinity by several orders of magnitude.
Glossary of Key Terms
- Beta-prism III Fold: A novel, highly compact protein fold characterized by three antiparallel β-sheets arranged in a three-fold rotational symmetry.
- Core Fucosylation: The enzymatic attachment of a fucose sugar via an α1-6 linkage to the innermost N-acetylglucosamine residue of an N-glycan.
- Disulfiram-like Reaction: A toxic physiological response to alcohol characterized by intense nausea, vomiting, facial flushing, and rapid heart rate, caused by the inhibition of acetaldehyde dehydrogenase.
- Lectin: A highly specific carbohydrate-binding protein that agglutinates cells or precipitates glycoconjugates without displaying enzymatic activity.
- N-Glycan: A complex carbohydrate chain covalently linked to the amide nitrogen of an asparagine residue within a polypeptide.
- Saprotroph: An organism that feeds, grows, and derives its energy by digesting non-living or decaying organic wood matter.
- Simultaneous White Rot: A form of wood decay in which a fungus degrades both lignin and cellulose concurrently, leaving the wood soft, white, and structurally compromised.
- Type Species: The designated species that permanently anchors the taxonomic definition and physical characteristics of a genus.
- Xanthine Oxidase: A molybdenum-containing metabolic enzyme that catalyzes the oxidation of hypoxanthine and xanthine to uric acid in purine catabolism.
Selected Bibliography & References
- Cabanettes, A., Perkams, L., Spies, C., Unverzagt, C., Varrot, A. (2018). “Recognition of complex core fucosylated N-glycans by a mini lectin.” Angewandte Chemie International Edition, 57(32), 10178-10181. DOI: https://doi.org/10.1002/anie.201805165.
- Kobayashi, Y., Tateno, H., Dohra, H., Moriwaki, K., Miyoshi, E., Hirabayashi, J., Kawagishi, H. (2012). “A novel core fucose-specific lectin from the mushroom Pholiota squarrosa.” Journal of Biological Chemistry, 287(41), 33973-33982. DOI: https://doi.org/10.1074/jbc.M111.327692.
- Lou, Y.C., Tu, C.F., Chou, C.C., Yeh, H.H., Chien, C.Y., Sadotra, S., Chen, C., Yang, R.B., Hsu, C.H. (2023). “Structural insights into the role of N-terminal integrity in PhoSL for core-fucosylated N-glycan recognition.” International Journal of Biological Macromolecules, 255, 128309. DOI: https://doi.org/10.1016/j.ijbiomac.2023.128309.
- Wangun, H.V., Hertweck, C. (2007). “Squarrosidine and pinillidine: 3,3′-fused bis(styrylpyrones) from Pholiota squarrosa and Phellinus pini.” European Journal of Organic Chemistry, 2007(20), 3292-3295. DOI: https://doi.org/10.1002/ejoc.200700090.
- Yamasaki, K., Yamasaki, T., Tateno, H. (2018). “The trimeric solution structure and fucose-binding mechanism of the core fucosylation-specific lectin PhoSL.” Scientific Reports, 8, 7740. DOI: https://doi.org/10.1038/s41598-018-25630-2.
- Yamasaki, K., Kubota, T., Yamasaki, T., Nagashima, I., Shimizu, H., Terada, R.I., Nishigami, H., Kang, J., Tateno, M., Tateno, H. (2019). “Structural basis for specific recognition of core fucosylation in N-glycans by Pholiota squarrosa lectin (PhoSL).” Glycobiology, 29(7), 576-587. DOI: https://doi.org/10.1093/glycob/cwz025.
- Yamasaki, K., Adachi, N., Ngwe Tun, M.M., Ikeda, A., Moriya, T., Kawasaki, M., Yamasaki, T., Kubota, T., Nagashima, I., Shimizu, H., Tateno, H., Morita, K. (2023). “Core fucose-specific Pholiota squarrosa lectin (PhoSL) as a potent broad-spectrum inhibitor of SARS-CoV-2 infection.” The FEBS Journal, 290(2), 412-427. DOI: https://doi.org/10.1111/febs.16599.
Freshness & Editorial Note
This guide reflects peer-reviewed research and taxonomic classifications updated through August 2026. Because structural virology, variant-specific antiviral research, and clinical trials of non-purine gout therapies are actively evolving, readers are encouraged to periodically verify the links and clinical statuses of the referenced studies on PubMed. Foragers must consult local mycological societies and professional poison control resources before attempting to identify or handle wild species.
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