biostudies-literatureBilan MIInstitute of Oceanography, Vietnam Academy of Science and TechnologyRussian Science Foundation10326https://www.ebi.ac.uk/biostudies/studies/S-EPMC12609645biostudies-literatureUnknown26(21)A water-soluble high-molecular neutral polysaccharide (<b>NP</b>) was isolated from the eggs of the sea urchin <i>Tripneustes gratilla</i>. The formation of glucose only upon the treatment of <b>NP</b> by amyloglucosidase and the value of its optical rotation [α]_D +233.5 (c 0.2, water) confirmed its belonging to the family of α-d-glucans. According to the results of NMR spectroscopy and methylation analysis, the chains of <b>NP</b> are built up of non-reducing terminal, 4-linked and 4,6-disubstituted glucose residues at a ratio of 1:8:1. A branched structure with an average linear chain length of about five glucose residues was calculated from the spectrum of iodine complex. Contrary to the previously published structure of branched α-d-glucan from the sea urchin <i>StrongylocenInternational journal of molecular sciencesChemical Structure of a Branched α-d-Glucan from the Eggs of Sea Urchin &lt;i&gt;Tripneustes gratilla&lt;/i&gt;.PMC12609645KC.09.10/21-3019-73-30017-PDmitrenok ASUsov AIBilan MICao HTTNifantiev NETrung DTTorgov VIArgunov DAPham TDfalseChemical Structure of a Branched α-d-Glucan from the Eggs of Sea Urchin &lt;i&gt;Tripneustes gratilla&lt;/i&gt;.A water-soluble high-molecular neutral polysaccharide (<b>NP</b>) was isolated from the eggs of the sea urchin <i>Tripneustes gratilla</i>. The formation of glucose only upon the treatment of <b>NP</b> by amyloglucosidase and the value of its optical rotation [α]_D +233.5 (c 0.2, water) confirmed its belonging to the family of α-d-glucans. According to the results of NMR spectroscopy and methylation analysis, the chains of <b>NP</b> are built up of non-reducing terminal, 4-linked and 4,6-disubstituted glucose residues at a ratio of 1:8:1. A branched structure with an average linear chain length of about five glucose residues was calculated from the spectrum of iodine complex. Contrary to the previously published structure of branched α-d-glucan from the sea urchin <i>Strongylocen2025-01-01T00:00:00Z2025 Oct2026-05-18T03:20:02.448Z2026-05-18T03:13:06.659ZS-EPMC126096454122636710.3390/ijms262110326