Search

A glycosaminoglycan was isolated from the sea cucumber Holothuria coluber (HcFG). A series of oligosaccharide fragments (dp range 3-11) were prepared from its β-eliminative depolymerized product (dHcFG). Extensive NMR characterization of the oligosaccharides indicated the d-GlcA-β1,3-d-GalNAc 4S6S repeating disaccharide backbone was substituted by monosaccharide branches comprising of Fuc 2S4S , Fuc 3S4S and Fuc 4S , linked to O-3 of d-GlcA. For the prevailing Fuc 3S4S at nonreducing end of dHcFG, the β-eliminative depolymerization process of HcFG was compared with those of the FGs from Actinopyga miliaris (AmFG, branched with Fuc 3S4S ) and Stichopus variegatus (SvFG, branched with Fuc 2S4S ). The result suggested that d-GlcA substituted with Fuc 3S4S was more susceptible to depolymerization than that with Fuc 2S4S . It might be due to the larger steric hindrance effects from Fuc 2S4S on the esterification of GlcA. Biological assays confirmed that the minimum chain length (dp8), regardless of the Fuc branch types, was required for the potent anti-iXase and anticoagulant activities in FG fragments., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A new glycosaminoglycan (LF-GAG) was purified from the slug Limacus flavus. Its unique chemical structure and heparanase inhibitory activity were studied in this work. The native LF-GAG was composed of L-iduronic acid (L-IdoA) and N-acetyl-D-glucosamine (D-GlcNAc), with a Mw of 22,700 Da. To elucidate the precise structure and structure-activity relationship, its deacetylation-deaminative depolymerized product (dLF-GAG) was prepared, and from which four oligosaccharides were purified. Combining the NMR spectral analysis of LF-GAG and its derived oligosaccharides, the structure of LF-GAG was deduced to be -4)-L-IdoA 2R -(α1,4)-D-GlcNAc-(α1-, in which R was -OH (˜80%) or -OSO 3 - (˜20%). Bioactivity assays showed that LF-GAG could potently inhibit human heparanase (IC 50 , 0.10 μM). dLF-GAG and LF-3 were less potent but also active for heparanase inhibition. Structure-activity relationship analysis indicated that the chain length and sulfate substitution of LF-GAG are essential for its heparanase inhibitory activity., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Edible snails have been widely used as a health food and medicine in many countries. A unique glycosaminoglycan (AF-GAG) was purified from Achatina fulica. Its structure was analyzed and characterized by chemical and instrumental methods, such as Fourier transform infrared spectroscopy, analysis of monosaccharide composition, and 1D/2D nuclear magnetic resonance spectroscopy. Chemical composition analysis indicated that AF-GAG is composed of iduronic acid (IdoA) and N-acetyl-glucosamine (GlcNAc) and its average molecular weight is 118kDa. Structural analysis clarified that the uronic acid unit in glycosaminoglycan (GAG) is the fully epimerized and the sequence of AF-GAG is →4)-α-GlcNAc (1→4)-α-IdoA2S (1→. Although its structure with a uniform repeating disaccharide is similar to those of heparin and heparan sulfate, this GAG is structurally highly regular and homogeneous. Anticoagulant activity assays indicated that AF-GAG exhibits no anticoagulant activities, but considering its structural characteristic, other bioactivities such as heparanase inhibition may be worthy of further study., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

• A novel FG (AmFG) were extracted from sea cucumber Acaudina molpadioides. • The structures of eight oligosaccharides from depolymerized AmFG were determined. • AmFG branched with unusual disaccharide GalNAc-α1,2-Fuc, besides monosaccharides. • The anticoagulant and anti-iXase activities of AmFG and oligomers were discussed. A fucosylated glycosaminoglycan (AmFG) was extracted from the sea cucumber Acaudina molpadioides. And a series of oligosaccharides were purified from the size-homogeneous fractions, which were prepared from the β-eliminative depolymerized AmFG. According to "bottom-up" strategy, the precise structure of AmFG was elucidated by analyzing the structures of these purified oligosaccharides, combining with NMR analysis of its free-radical depolymerized product. It contained a CS-E-like backbone, and each GlcUA was branched with a mono- or di-sulfated fucose (Fuc) at O -3. Intriguingly, besides two types of monosaccharide branches, Fuc 2S4S (60 %) and Fuc 4S (25 %), that were common in FG, AmFG also contained an unusual disaccharide branch GalNAc-α1,2-Fuc 3S4S (15 %); this is the first report of such a structure in a glycosaminoglycan. Biological assays indicated that native AmFG and its oligosaccharides had potent anticoagulant and intrinsic tenase (iXase) inhibitory activities in a chain length-dependent manner. For these oligosaccharides, octasaccharide was the minimum structural fragment for potent anti-iXase activity, and the disaccharide branch might enhance this activity. [ABSTRACT FROM AUTHOR]