scholarly journals Precise Structure and Anticoagulant Activity of Fucosylated Glycosaminoglycan from Apostichopus japonicus: Analysis of Its Depolymerized Fragments

Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 195 ◽  
Author(s):  
Ruowei Guan ◽  
Yuan Peng ◽  
Lutan Zhou ◽  
Wenqi Zheng ◽  
Xixi Liu ◽  
...  
Keyword(s):  
Sea Cucumber ◽  
Apostichopus Japonicus ◽  
Anticoagulant Activity ◽  
Gel Permeation Chromatography ◽  
Structural Formula ◽  
2D Nmr ◽  
Pharmacological Activities ◽  
Important Species ◽  
Gel Permeation ◽  
Chondroitin Sulfate E

Apostichopus japonicus is one of the most economically important species in sea cucumber aquaculture in China. Fucosylated glycosaminoglycan from A. japonicus (AjFG) has shown multiple pharmacological activities. However, results from studies on the structure of AjFG are still controversial. In this study, the deaminative depolymerization method that is glycosidic bond-selective was used to prepare the depolymerized products from AjFG (dAjFG), and then a series of purified oligosaccharide fragments such as tri-, hexa-, nona-, and dodecasaccharides were obtained from dAjFG by gel permeation chromatography. The 1D/2D NMR and ESI-MS spectrometry analyses showed that these oligosaccharides had the structural formula of l-FucS-α1,3-d-GlcA-β1,3-{d-GalNAc4S6S-β1,4-[l-FucS-α1,3-]d-GlcA-β1,3-}n-d-anTal-diol4S6S (n = 0, 1, 2, 3; FucS represents Fuc2S4S, Fuc3S4S, or Fuc4S). Thus, the unambiguous structure of native AjFG can be rationally deduced: it had the backbone of {-4-d-GlcA-β1,3-d-GalNAc4S6S-β1-}n, which is similar to chondroitin sulfate E, and each d-GlcA residue in the backbone was branched with a l-FucS monosaccharide at O-3. Bioactivity assays confirmed that dAjFG and nonasaccharides and dodecasaccharides from AjFG had potent anticoagulant activity by intrinsic FXase inhibition while avoiding side effects such as FXII activation and platelet aggregation.

1,3-Dimethyl-tetrakis(2-triphenylsilylethyl)dimethyldisiloxane: a new carbosilane for the preparation of high-refractive-index films

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sacha Legrand ◽  
Ari Kärkkäinen
Keyword(s):  
Refractive Index ◽  
Diffuse Reflectance ◽  
Gel Permeation Chromatography ◽  
2D Nmr ◽  
High Refractive Index ◽  
Diffuse Reflectance Infrared Spectroscopy ◽  
Gel Permeation ◽  
One Step ◽  
Diffuse Reflectance Infrared ◽  
Very High

Abstract A new carbosilane has been synthesised in one step by hydrosilylation of 1,3-dimethyl-tetravinyldisiloxane with triphenyl silane. The new carbosilane has been characterized by 1D and 2D NMR, MS, and Gel Permeation Chromatography (GPC). The new carbosilane has been spin-coated on silicon wafers to prepare a film with very high refractive index (μ = 1.520) and excellent hydrophobicity. The film has also been analysed by Diffuse Reflectance Infrared Spectroscopy (DRIFT). The preparation of the new carbosilane does not generate waste, and its application can be easily scaled-up. Consequently, the new precursor is likely to be very useful for industrial optoelectronic applications.

scholarly journals A deposit-feeder sea cucumber also ingests suspended particles through the mouth

2020 ◽  
pp. jeb.230508
Author(s):  
Mohamed Mohsen ◽  
Libin Zhang ◽  
Lina Sun ◽  
Chenggang Lin ◽  
Shilin Liu ◽  
...  
Keyword(s):  
Sea Cucumber ◽  
Apostichopus Japonicus ◽  
Pearson Correlation ◽  
Ingestion Rate ◽  
Video Recording ◽  
Suspended Particles ◽  
Deposit Feeder ◽  
Uptake Mechanism ◽  
Important Species ◽  
Particle Uptake

Although the sea cucumber Apostichopus japonicus has been characterised as a deposit feeder, nutrients sourced from the water column have been recorded in the intestines of this species. However, the mechanisms whereby nutrients in the water enter the intestinal tract of A. japonicus, and whether other suspended particles can be ingested via the mouth of A. japonicus adults, remain unknown. Here, we reveal how A. japonicus ingests suspended particles through the mouth. We used synthetic particles and video recording to confirm the suspension uptake by the sea cucumber. A. japonicus continued to ingest suspended particles (if present) over time, and the particle-ingestion rate was positively correlated with the concentration of suspended particles (Pearson correlation: r=0.808). Additionally, clearance rates of the suspended particles ranged from 0.3–0.9 L−1 h−1. The findings of this study thus provide evidence of a previously undescribed particle uptake mechanism in a commercially important species.

scholarly journals Psolusosides C1, C2, and D1, Novel Triterpene Hexaosides from the Sea CucumberPsolus fabricii (Psolidae, Dendrochirotida)

2018 ◽  
Vol 13 (12) ◽  
pp. 1934578X1801301 ◽  
Author(s):  
Alexandra S. Silchenko ◽  
Sergey A. Avilov ◽  
Anatoly I. Kalinovsky ◽  
Vladimir I. Kalinin ◽  
Pelageya V. Andrijaschenko ◽  
...  
Keyword(s):  
Sea Of Okhotsk ◽  
Sea Cucumber ◽  
Apostichopus Japonicus ◽  
2D Nmr ◽  
Shallow Waters ◽  
Monosaccharide Residue ◽  
2D Nmr Spectroscopy ◽  
The Third ◽  
Kurile Islands ◽  
Carbohydrate Chains

Three new triterpene glycosides, psolusosides C1 (1), C2 (2) and D1 (3) have been isolated from the sea cucumber Psolus fabricii collected in the Sea of Okhotsk in the shallow waters of Onekotan Island (Kurile Islands). Five known glycosides: cladolosides B, M1, P2, isolated earlier from the sea cucumbers of genus Cladolabes and holotoxin A1 with 27- nor-25-oxo-holotoxin A1, isolated earlier from Apostichopus japonicus have also been found. The glycoside structures were elucidated by 2D NMR spectroscopy and HR mass-spectrometry. Compounds 1–3 possess hexasaccharide carbohydrate chains, identical for 1 and 2 and different in the third monosaccharide residue for 3. All the glycosides comprise holostane type aglycones with a 9(11)-double bond and a 16-keto-group and differ from each other in the side chains structures.

Aggregated, Conformationally Changed Fibrinogen Exposes the Stimulating Sites for t-PA-Catalysed Plasminogen Activation

1996 ◽  
Vol 75 (02) ◽  
pp. 326-331 ◽  
Author(s):  
Unni Haddeland ◽  
Knut Sletten ◽  
Anne Bennick ◽  
Willem Nieuwenhuizen ◽  
Frank Brosstad
Keyword(s):  
Conformational Changes ◽  
Gel Permeation Chromatography ◽  
Tissue Type ◽  
Plasminogen Activation ◽  
Chromogenic Substrate ◽  
Type Plasminogen Activator ◽  
Gel Permeation ◽  
Self Association ◽  
Fibrin Monomers ◽  
Stimulation Of

SummaryThe present paper shows that conformationally changed fibrinogen can expose the sites Aα-(148-160) and γ-(312-324) involved in stimulation of the tissue-type plasminogen activator (t-PA)-catalysed plasminogen activation. The exposure of the stimulating sites was determined by ELISA using mABs directed to these sites, and was shown to coincide with stimulation of t-PA-catalysed plasminogen activation as assessed in an assay using a chromogenic substrate for plasmin. Gel permeation chromatography of fibrinogen conformationally changed by heat (46.5° C for 25 min) demonstrated the presence of both aggregated and monomeric fibrinogen. The aggregated fibrinogen, but not the monomeric fibrinogen, had exposed the epitopes Aα-(148-160) and γ-(312-324) involved in t-PA-stimulation. Fibrinogen subjected to heat in the presence of 3 mM of the tetrapeptide GPRP neither aggregates nor exposes the rate-enhancing sites. Thus, aggregation and exposure of t-PA-stimulating sites in fibrinogen seem to be related phenomena, and it is tempting to believe that the exposure of stimulating sites is a consequence of the conformational changes that occur during aggregation, or self-association. Fibrin monomers kept in a monomeric state by a final GPRP concentration of 3 mM do not expose the epitopes Aα-(148-160) and γ-(312-324) involved in t-PA-stimulation, whereas dilution of GPRP to a concentration that is no longer anti-polymerizing, results in exposure of these sites. Consequently, the exposure of t-PA-stimulating sites in fibrin as well is due to the conformational changes that occur during selfassociation.

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