1,721,072 research outputs found
Heparin from marine mollusks: Occurrence, structure, and biological role
No full textSeveral invertebrate species contain variable amounts of one or more types of sulfated
glycosaminoglycans (GAGs). At present it is well known the existence of a species-specific sulfated
GAGs composition based on the relative amount and type of chondroitin sulfates, heparan sulfate
and heparin. Heparin is a sulfated polysaccharide belonging to the family of GAGs with numerous
important biological activities, such as anticoagulant and antithrombotic properties that derive from its
interaction with diverse proteins. Unusual heparin samples for molecular mass, fine structural
organization and anticoagulant activity, are isolated and characterized from molluscs. Variable
presence of the trisulfated disaccharide [DUA2S(1->4)-a-D-GlcN2S6S] and significant modifications of
the disaccharides bearing non-sulfated iduronic and glucuronic acids, [->4)-a-L-IdoA(1->4)-a-DGlcNAc6S(
1-> and ->4)-a-L-IdoA(1->4)-a-D-GlcN2S6S(1->] and [->4)-b-D-GlcA(1->4)-a-DGlcN2S6S(
1->], and oligosaccharide sequences bearing part of the ATIII-binding region,
[DUA2S(1->4)-a-D-GlcN2S6S(1->4)-b-D-GlcA(1->4)-a-D-GlcN2S3S6S] and [DUA2S (1->4) -a-DGlcN2S6S
(1->4)-a-L-IdoA (1->4)-a-D-GlcNAc6S (1->4)-b-D-GlcA (1->4)-a-D-GlcN2S3S6S], are
detected and measured in heparin samples derived from different clam species. This review more
specifically deals with structural and biologically important aspects of heparin in invertebrates with
special emphasis on the heparin from molluscs. Furthermore, the fine characterization of heparin
from Tapes phylippinarum and Callista chione is reported
Inseguire gli studenti: un modello compatto per l'analisi delle carriere scolastiche di coorte
No full textDipartimento di Studi Geoeconomici, Linguistici, Statistici e Storici per l’Analisi Regionale, Università degli Studi “La Sapienza”, Rom
Large Heterogeneous Earth Observation Constellations Exploitation: Architecture of a Pipeline for Automated Operations, from User Needs to Acquisitions Downlink
Full text linkANIME Asteroid CubeSat Mission Concept and Rendezvous Phase: Progressive Hyperbolic ARCS Design for Radio-Science and Close Observation
Full text link
Uronic acid carbazole assay and cetylpyridinium chloride titration depend on the chondroitin sulfate molecular weight
No full textChondroitin sulfate (CS) of various molecular weight (MW), up to ∼3 kDa, were produced and tested for uronic acid carbazole assay and cetylpyridinium chloride (CPC) titration showing an evident decrease in the assays depending on the CS MW. The described results for uronic acid assay by carbazole reaction and CPC titration of CS poses the problem to know the MW values before their application and to use comparable standards to obtain reliable results. Otherwise, the related quantitative data can be affected by a great error and fake certificate of analysis
Capillary electrophoresis analysis of intact and depolymerized complex heteropolysaccharides for quality assurance and purity
No full textComplex (hetero)polysaccharides, glycosaminoglycans (GAGs), are fundamental biomacromolecules for all living organisms having important biological and pathophysiological roles. Moreover, in the form of native or depolymerized biomolecules, they are active pharmaceutical and nutraceutical agents after extraction and purification from animal sources. Capillary electrophoresis (CE) is applied in many different biological, pharmacological, and nutraceutical fields, clearly showing evidence of the importance of this analytical method in glycosciences. Thanks to its versatility in separation and detection modes, CE may be applied for the analysis and quantification of intact high molecular mass heteropolysaccharides as well as their low molecular weight derivatives up to derived oligosaccharides, disaccharides, and monosaccharides, as single species but also in mixtures. As discussed in the present review and largely illustrated in the current scientific literature, CE may be one of the analytical techniques most useful in quality control laboratories of pharmaceutical and nutraceutical companies for the determination of GAGs’ purity and quality in raw material and finished products
Capillary Electrophoresis Separation of Artepillin C: Determination in Brazilian Green Propolis
No full textPropolis is important in complementary and alternative medicine having well-known therapeutic applications. Artepillin C, a main component of Brazilian (green) propolis, has attracted great attention for its anticancer action. Consequently, the synthesis of artepillin C has been reported but, due to the limited yield and elevated costs, this biomolecule is largely produced from Brazilian propolis. We report the capillary electrophoresis (CE) separation of artepillin C in Brazilian propolis also comparing the results with those of HPLC-UV-MS. Optimal separation was obtained with a simple buffer constituted of sodium tetraborate 30 mM pH 9.2 and detection at 210 nm. Artepillin C and the polyphenols of propolis were fully separated with a voltage gradient of 30 to 8 kV and a current of 300 μA for a total run of 50 min. The sensitivity of CE-UV was 22 times greater than HPLC-UV and 100 times more than HPLC-MS with also a stronger reduction in the run time and a greater robustness and reproducibility. The development of CE as an effective and reliable method for the analysis of artepillin C is desired as the standardized quality controls are essential before propolis or its biomolecules can be adopted routinely in nutraceuticals, food ingredients and therapeutic applications
Structural definition of terrestrial chondroitin sulfate of various origin and repeatability of the production process
No full textWe report results on the structure, physicochemical characteristics and purity of chondroitin sulfate (CS) samples derived from three largely available and common biological sources such as bovine and porcine trachea and chicken keel bones with the aim to define their structural signatures. Many lots of CS produced by a manufacturer at industrial scale were characterized with a view to assess the reproducibility of the process as not controlled extractive procedures may produce final products with variable structure and biological contaminants as well as not constant clinical efficacy and safety. By using standardized source animal tissues and manufacturing procedure, highly pure CS (∼92 %) products with constant structure and characteristics were obtained. Bovine CS showed a lower molecular weight (MWw of ∼21,500 Da) than porcine (MWw of ∼26,000 Da) and chicken (MWw of ∼35,900 Da) products with a CV% of ∼2.0–7.5 and a polydispersity variability of 0.7–2.7 %. The ratio between the sulfate groups main located in position 4 and 6 of N-acetyl-galactosamine (4/6 ratio) was ∼1.70 for bovine CS versus a value of 3.60 for porcine and ∼2.70 for chicken samples with a overall charge density of 0.92−0.93 and a CV% of 2.1−2.5. The final products also showed the presence of a very low and constant content of other co-purified bio(macro)molecules (hyaluronic acid, keratan sulfate, dermatan sulfate, heparan sulfate, nucleic acids and proteins), calcium and sodium, and the absence of versican. Finally, a high reproducibility of molecular weight values, disaccharide composition, specific optical rotation and particle dimension was observed. The observed parameters are structural signatures useful to specifically identify the origin of CS and obtained by a standardized and highly reproducible manufacturing process. The compositional profile determined from this study provides a measure of the norm and range of variation in CS samples of terrestrial origin produced under standardized production protocol to which future pharmaceutical/nutraceutical final products can be compared. Moreover, the physicochemical properties including molecular weight, disaccharide composition, presence of natural contaminants and particle dimension were characterized to provide the basis of CS of high quality for application as pharmaceutical/nutraceutical active agents
- …
