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Macronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Glycolipids are glycosyl derivatives of lipids. Glycolipid is any compound containing one or more monosaccharide residues (glucose or galactose) bound by a glycosidic linkage to a hydrophobic moiety such as an acylglycerol, a sphingoid, a ceramide (N-acylsphingoid) or a prenyl phosphate (66, 119, 137–138). Cellular membranes contain several types of glycoproteins, glycolipids, and other lipids, including cholesterol, glycerophospholipids, and sphingomyelin. Glycolipids are essential for biological activities of the cell membrane (137). In addition, the roles of glycolipids are to facilitate cellular recognition, which is crucial to the immune response and the cell connections in tissues.
Medicinal Mushrooms
Published in Anil K. Sharma, Raj K. Keservani, Surya Prakash Gautam, Herbal Product Development, 2020
Temitope A. Oyedepo, Adetoun E. Morakinyo
β-D-glucans are a naturally occurring structural constituent of the cell walls of mushrooms, mycelium, yeast, and certain bacteria. About 50% of the mass for the cell wall in a fungus is made up of β-glucans (Rop et al., 2009; Wasser, 2002; Wasser and Weis, 1999a). Research into the active polysaccharides in basidiomycetes has identified them as β-D-glucans (Rop et al., 2009; Vetvicka et al., 2008). β-glucans contain a glucose polymer-chain core which are held together by a linear linkage. The glycosidic linkage can present as (β-1 → 3), (β-1 → 4), (β-1 → 6), or a mixture of these (Volman et al., 2010a). However, the designation of the branching depends on the species of the mushroom (Rop et al., 2009). This is the reason why β-glucans from different sources have different structures. For instance, the structure for the β-glucans of mushrooms which have β-1 → 3 and β-1 → 6 side branches is different from those of bacteria that have β-1 → 4 side branches (Sakagami and Aoki, 1991).
The Development of Improved Therapeutics through a Glycan- “Designer” Approach
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
There are four known types of glycosylation based on the type of carbohydrate-peptide linkage: N-linked (Asparagine), O-linked (Threonine, Serine) C-linked (via Carbon atom) and S-glycosylation (Cysteine). Glycosylation can be further diversified on the base of glycosidic linkage, glycan composition, structure, and length. The N-type glycosylation in which glycan is attached to the amine group of asparagine residue resulting in formation of amide bond, is the most prevalent naturally occurring glycosylation type. The most common glycan linkage in human body among N-glycans is N-acetylglucosamine (GlcNAcβ1-Asn) found abundant in human serum. Overall different N-glycans are prevalent structures in prokaryotic surface proteins with a unique species-specific oligosaccharide structure; for that reason the glycoproteins derived from pathogens are excellent immunogens. The synthesis of N-glycans is well described for both prokaryotes and eukaryotes. While glycosylation in prokaryotes can be easily predicted and controlled the synthesis of all eukaryotic N-glycans is more complexed.
Linear and branched β-Glucans degrading enzymes from versatile Bacteroides uniformis JCM 13288T and their roles in cooperation with gut bacteria
Published in Gut Microbes, 2020
Ravindra Pal Singh, Sivasubramanian Rajarammohan, Raksha Thakur, Mohsin Hassan
The β- glucans have gained strong attention as an imperative in food supplements, wherein they can act as either immunostimulants in cancer treatments and inflammation10,11 or microbiome modulatory agents.12 The β- glucans are predominantly present in the daily human diet in soluble and insoluble fiber states. These are structurally diverse with a variety of glycosidic linkages. For instance, β-glucans extracted from Euglena (known as paramylon) and bacterial polysaccharides (known as curdlan) are linear in chain with β-1-3 linked,13 while marine macroalgal-extracted glucan (known as laminarin) is branched with β-1-3 and β-1-6 linkages.14 Furthermore, frequency and length of β-1-6 linked glucans depend on the type of sources, i.e. yeast, Laminarin digitata, Lasallia pustulata, and Lentinus edodes.15–18 Curdlan is one of the abundant bio-resources that can be synthesized by several bacteria, including Agrobacterium,19Rhizobium,20 and Cellulomonas species.21,22 In addition, huge quantities of laminarin can accumulate in marine environment upon degradation of macroalgae, and plays a major role in marine carbon cycle.23,24 Therefore, extraction of curdlan and laminarin is much simpler as compared to other natural glycans and can be easily exploited for nutraceutical perspectives.25–27 However, laminarin and curdlan utilizing capability of gut bacteria is still poorly understood.
Extraction and chemical characterization of novel water-soluble polysaccharides from two palm species and their antioxidant and antitumor activities
Published in Egyptian Journal of Basic and Applied Sciences, 2020
Dawood H. Dawood, Mohamed S. Elmongy, Amr Negm, Mohamed A. Taher
It could be divided the linkages in the structure of glycoproteins into two categories on the basis of their stability to alkali: O- glycosidic linkages and N-glycosidic linkages [53]. The alkali-sensitive O-glycosidic linkages (involving Xyl, GlcNAc, Gal or Man and Ser or Thr) were readily split in relatively mild conditions by a β-elimination mechanism resulting in the release of the carbohydrate moiety. This method has been widely employed to analyze the type of linkages in glycoproteins [51]. In this study, the distinct absorbance at 240 nm in the presence of alkali treatment exhibiting that the β-elimination reaction had taken place. Thus, the sugars were linked to the polypeptide backbone via an O-linkage in CM and CH polysaccharides, similar findings have been reported by Dawood et al. [44] and Tsai et al. [54].
Dietary polydextrose and galactooligosaccharide increase exploratory behavior, improve recognition memory, and alter neurochemistry in the young pig
Published in Nutritional Neuroscience, 2019
Stephen A. Fleming, Supida Monaikul, Alexander J. Patsavas, Rosaline V. Waworuntu, Brian M. Berg, Ryan N. Dilger
PDX is a non-digestible polysaccharide composed of a highly branched glucose polymer. It is fermented in the large intestine by host microbiota, with approximately 60% excreted in feces.4 Consumption of PDX in adults has been shown to increase absorption of calcium, magnesium, and iron,5–7 improve glucose and lipid metabolism,8,9 and increase the presence of beneficial bacteria.10,11 Infant consumption of formula containing both PDX and GOS brought stool consistency and fecal counts of Bifidobacterium longum and total bifidobacterial counts closer to that of breastfed infants when compared to infants consuming formula without PDX and GOS.12 Galactooligosaccharides are found in numerous structural configurations, and are typically composed of galactose monomers linked together by β-glycosidic linkages with a terminal glucopyranosyl residue linked via an α-glycosydic bond.13 Supplementation of infant formula with GOS supports the selective growth of bifidobacteria and lactobacilli species,14,15 and provision of formula containing GOS has also been shown to reduce intestinal infection16 and incidence of allergy17 in infants.