RESUMO
Sea urchin possesses both high nutritional and medicinal value. It contains diverse biological active polysaccharides. But there are few studies on its glycogen. In the current study, a glucan (MSGA) was separated from Strongylocentyotus internedius and purified by ion exchange and gel filtration column. Chemical analysis revealed that MSGA with 2.65 × 107 Da is made up entirely of glucose. The analysis of methylation, NMR and mass spectrum demonstrated that MSGA is a highly branched glycogen with α-(1â4) linked gluconic backbone and branched at C-6 (one branch per five residues). In addition, MSGA showed good in vitro immunostimulatory activity via NF-κB and MAPKs pathways. It is considered that high degree of branching is necessary for its activity. However, the relationship between structure and immunostimulatory activity of natural glycogens is difficult to elucidate because the difference in their structural properties. Therefore, much more research is needed in this area.
Assuntos
Glicogênio/química , Ouriços-do-Mar/metabolismo , Animais , Ciclo-Oxigenase 2/metabolismo , Endotoxinas/química , Técnicas In Vitro , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Sistema de Sinalização das MAP Quinases , Espectroscopia de Ressonância Magnética , Metilação , Camundongos , NF-kappa B/metabolismo , Óxido Nítrico/química , Oligossacarídeos/química , Células RAW 264.7 , Espectrometria de Massas por Ionização por Electrospray , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Monosaccharide composition analysis is important for structural characterization of polysaccharides. To investigate the influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of polysaccharides, we chose alginate, starch, chitosan and chondroitin sulfate as representative of acidic, neutral, basic and complex polysaccharides to compare the release degree of monosaccharides under different hydrolytic conditions. The hydrolysis stability of 10 monosaccharide standards was also explored. Results showed that the basic sugars were hard to release but stable, the acidic sugars (uronic acids) were easy to release but unstable, and the release and stability of neutral sugars were in between acidic and basic sugars. In addition, the hydrolysis process was applied to monosaccharide composition analysis of Hippocampus trimaculatus polysaccharide and the appropriate hydrolytic condition was accorded with that of the above four polysaccharides. Thus, different hydrolytic conditions should be used for the monosaccharide composition analysis of polysaccharides based on their structural characteristics.
Assuntos
Alginatos/química , Quitosana/química , Sulfatos de Condroitina/química , Monossacarídeos/análise , Amido/química , Animais , Antipirina/análogos & derivados , Antipirina/química , Cromatografia Líquida de Alta Pressão , Edaravone , Hidrólise , SmegmamorphaRESUMO
In recent years, antibiotic resistance of bacteria has become a global health crisis. Especially, the new class of "superbug" was found in South Asia, which is resistant to almost known antibiotics and causes worldwide alarm. Through the underlying mechanisms of bacterial pathogenecity, the expression of many pathogen virulence factors is regulated by the process of quorum sensing. Screening efficient quorum sensing inhibitors is an especially compelling approach to the future treatment of bacterial infections and antibiotic resistance. This article focuses on bacterial quorum sensing system, quorum sensing screening model for in vitro and evaluation of animal models in vivo, recent research of quorum sensing inhibitors and so on.
