Oligosaccharides bioactive

The first paper on the bioactive polysaccharides from Glycyrrhiza uralensis roots was published in 1996 by Kiyohara et al. [57]. They isolated a pectic type polymer with anti-complementary and mitogenic activity that was an acidic pectin, possibly containing rhamnogalacturonan type I as part of the total structure. Degradation of the uronic acid part of the molecule decreased both types of bio activities. The neutral oligosaccharide chains were shown to retain some of the activities of the native polymer, but it was suggested that they should be attached to the acidic core to retain maximum activity. 

Bioactive peptides can be extracted and purified with these technologies, which vary from simple to complex. Following this, the isolation of bioactive peptides, oligosaccharides, fatty acids, enzymes, water-soluble minerals, and biopolymers for biotechnological and pharmaceutical applications is possible. Further, some of these bioactive peptides have been identified to possess nutraceutical potentials that are beneficial for human health. 

Besides the PMB and TBS moieties, other acid-labile protecting groups have been utilized in the one-pot assembly of oligosaccharides. These include benzylidene by Boons [111] and the trityl group by Li and coworkers in the synthesis of flaccidoside II, a bioactive component of Chinese traditional medicine [57],... 

Abstract Lipopolysaccharides are the major components on the surface of most Gram-negative bacteria, and recognized by immune cells as a pathogen-associated molecule. They can cause severe diseases like sepsis and therefore known as endotoxins. Lipopolysaccharide consists of lipid A, core oligosaccharide and O-antigen repeats. Lipid A is responsible for the major bioactivity of endotoxin. Because of their specific structure and amphipathic property, purification and analysis of lipopolysaccharides are difficult. In this chapter, we summarize the available approaches for extraction, purification and analysis of lipopolysaccharides. 

BSA + glucose/silica containing nanocomposites demonstrated much higher bioactivity than BSA + fructose/silica nanocomposites. It is interesting to note that glucose was chosen by evolution as a terminal carbohydrate in oligosaccharide chains used in animal cell membranes receptors, while fructose was not. 

Imberty A, S Perez (2000) Structure, conformation, and dynamics of bioactive oligosaccharides Theoretical approaches and experimental validations. Chem. Rev. 100 (12) 4567 1588... 

The first structure of human renin was obtained from prorenin produced by expression of its cDNA in transfected mammalian cells. Prorenin was cleaved in the laboratory to renin using the protease trypsin. Because the carbohydrates in renin are not required for bioactivity, oligosaccharides were removed enzymatically. This process facilitates crystallization in some cases and also removes the contribution of the heterogeneous sugar chains to the diffraction pattern. The structure was determined without the use of heavy-atom derivatives, by application of molecular replacement techniques based on the atomic coordinates of porcine pepsinogen as the model. The molecular dynamic method of refinement was used extensively to arrive at a 2.5 A resolution structure. However, some of the loop regions were not well resolved in this structure (Sielecki et al, 1989 Sail et al, 1990). 

Presented below is an overview of known genes and gene clusters involved in the biosynthesis of deoxysugars and deoxysugar-containing oligosaccharide moieties of bioactive natural products. The discussion is based on literature available up until mid-1996. 

Catalytic aldol reactions are among the most useful synthetic methods for highly stereo-controlled asymmetric synthesis. In this account we discuss the recent development of a novel synthetic technique which uses tandem enzyme catalysis for the bi-directional chain elongation of simple dialdehydes and related multi-step procedures. The scope and the limitations of multiple one-pot enzymatic C-C bond formations is evaluated for the synthesis of unique and structurally complex carbohydrate-related compounds that may be regarded as metabolically stable mimetics of oligosaccharides and that are thus of interest because of their potential bioactivity. 

Deoxy-sugars are very common monosaccharides and are frequently found as components of oligosaccharides in antibiotics. A large number of the so-called bioactive lipopolysaccharides as well as several antibiotics are deoxy-sugars [41]. 

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