Purity of a commercial glucan preparation

What it acts on

1. Laminarin is a (1->3, 1->6)-beta-glucan that is widely reported to be a Dectin-1 antagonist, however there are reports that laminarin is also a Dectin-1 agonist, and of five preparations from three commercial sources all contained laminarin although their molecular mass varied considerably from 4400 to 34,400 daltons, all were bound by recombinant human and mouse Dectin-1 but the affinity varied considerably and binding affinity did not correlate with Dectin-1 agonism, antagonism or potency, two laminarins were Dectin-1 antagonists and two were agonists, and the remaining laminarin was an antagonist but became an agonist when the low molecular weight moieties were removed.

   Purity of a commercial glucan preparation → Ability of a bound glucan to produce a receptor signal source_derived_draftungraded
   Experimental context and source evidence

   availability_state

   biomarker_context Imported condition classification; unverified.

   evidence_span

   {"source_cache": "artifacts/glucan-research/29246954.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "5afc1ddc8e49971759dcdc432cedb4c22cad267cace1e3909dd577c8ebb9eaa6", "start_char": 0, "end_char": 1760, "text_sha256": "5afc1ddc8e49971759dcdc432cedb4c22cad267cace1e3909dd577c8ebb9eaa6"}

   experimental_model

   Physical, structural, purity, binding and functional comparison of five commercial laminarin preparations from three suppliers

   exposure

   Five laminarin preparations of molecular mass 4400 to 34,400 daltons, before and after extensive dialysis

   limitations

   Five preparations of one named natural product. Removing low molecular weight contaminants explained the behaviour of one preparation and not the others, so purity is one cause of the variation rather than the whole of it.

   nutrient_topic

   Beta-glucan research collection; topical membership is not evidence of a direct clinical effect, and each preparation is recorded as its own entity with no family link joining any pair. · Beta-glucan

   organism

   Human and mouse cells

   plain_language

   Five bottles with the same name on the label: two blocked the receptor, two switched it on, and cleaning up a fifth flipped it.

   primary_references

   [bg-p29246954] Immunoregulatory Activity of the Natural Product Laminarin Varies Widely as a Result of Its Physical Properties. (2018). https://pubmed.ncbi.nlm.nih.gov/29246954/ DOI: 10.4049/jimmunol.1701258

   tissue_or_cell_type

   Recombinant receptor and primary cells

   trigger_kind

   biomarker_context Imported condition classification; unverified.

   Beta-glucan: a structural family rather than an agent, what decides whether a bound glucan actually signals, the complement route that a cereal and a yeast preparation share, and the unequal human evidence behind each (2026-09-22) · lines 164–175

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Physical, structural, purity, binding and functional comparison of five commercial laminarin preparations from three suppliers · source_derived_draft · unverified_draft

   ### bg-same-name-opposite-activity Laminarin is a (1->3, 1->6)-beta-glucan that is widely reported to be a Dectin-1 antagonist, however there are reports that laminarin is also a Dectin-1 agonist, and of five preparations from three commercial sources all contained laminarin although their molecular mass varied considerably from 4400 to 34,400 daltons, all were bound by recombinant human and mouse Dectin-1 but the affinity varied considerably and binding affinity did not correlate with Dectin-1 agonism, antagonism or potency, two laminarins were Dectin-1 antagonists and two were agonists, and the remaining laminarin was an antagonist but became an agonist when the low molecular weight moieties were removed. Condition category: biomarker_context nutrient_topic: Beta-glucan research collection; topical membership is not evidence of a direct clinical effect, and each preparation is recorded as its own entity with no family link joining any pair. plain_language: Five bottles with the same name on the label: two blocked the receptor, two switched it on, and cleaning up a fifth flipped it. organism: Human and mouse cells tissue_or_cell_type: Recombinant receptor and primary cells experimental_model: Physical, structural, purity, binding and functional comparison of five commercial laminarin preparations from three suppliers limitations: Five preparations of one named natural product. Removing low molecular weight contaminants explained the behaviour of one preparation and not the others, so purity is one cause of the variation rather than the whole of it. exposure: Five laminarin preparations of molecular mass 4400 to 34,400 daltons, before and after extensive dialysis evidence_span: {"source_cache": "artifacts/glucan-research/29246954.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "5afc1ddc8e49971759dcdc432cedb4c22cad267cace1e3909dd577c8ebb9eaa6", "start_char": 0, "end_char": 1760, "text_sha256": "5afc1ddc8e49971759dcdc432cedb4c22cad267cace1e3909dd577c8ebb9eaa6"} [bg-p29246954] Immunoregulatory Activity of the Natural Product Laminarin Varies Widely as a Result of Its Physical Properties. (2018). https://pubmed.ncbi.nlm.nih.gov/29246954/ DOI: 10.4049/jimmunol.1701258

   Complete structured claim and evidence