China
Africa
Explore chapters and articles related to this topic
Marine-Based Carbohydrates as a Valuable Resource for Nutraceuticals and Biotechnological Application
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Rajni Kumari, V. Vivekanand, Nidhi Pareek
It is classified on the basis of molecular size and degree of polymerization into monosaccharides, disaccharides, oligosaccharides, and polysaccharides (Knudsen et al., 2013). Monosaccharides are the simplest sugar and have the chemical formula (CH2O)n, where n is the number of carbon atoms in a molecule (Vaclavik et al., 2008), that cannot be further hydrolyzed. The rest of the other saccharides are linked by glycosidic bonds and hydrolyzed into simpler units. For example, fructose, galactose, and glucose are the main source of energy preferentially utilized by the brain and red blood cells (Ferrier, 2014). Disaccharides comprise two monomer sugar units linked by glycosidic bonds. Sucrose, lactose, trehalose, and maltose belong to disaccharides. Oligosaccharides are composed of a few monosaccharide units (2 to 20 units) (Roberfroid and Slavin, 2000) which are soluble in 80% ethanol, but intestinal enzymes are unable to digest them. Fructo-oligosaccharides, galacto-oligosaccharides, and mannan-oligosaccharides are examples of oligosaccharides (Englyst et al., 2007). Polysaccharides belong to high-molecular-weight polymeric monosaccharide units, and the degree of polymerization ranges from 70,000 to 90,000, depending on the type of polysaccharide (BeMiller, 2018). They are neither sweet in taste nor utilized directly like other carbohydrates. They may be linear (starch, cellulose) or branched (amylopectin, glycogen), homopolysaccharides (cellulose, glycogen) or heteropolysaccharides (hyaluronic acid, arabinoxylans) (Slavin, 2012).
Macronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
The principal disaccharides are sucrose, lactose and maltose. Sucrose is composed of one molecule each of glucose and fructose, while lactose is a combination of glucose and galactose. Sucrose is found widely in fruits, berries and vegetables, and can be extracted from sugar cane or beet sugar for human consumption. Lactose is the main sugar in milk. Maltose is the less abundant of disaccharides; formed by two glucose units, and derived from starch, it occurs in sprouted wheat and barley. Trehalose or mycose, a disaccharide also formed by two glucose units, is found in yeast, mushrooms, bread and honey (8).
The patient with acute endocrine problems
Published in Peate Ian, Dutton Helen, Acute Nursing Care, 2020
Plasma glucose levels increase with meals, rising slightly and then returning to basal levels after around two hours; therefore, both of these mechanisms are necessary for normal daily functioning. The most direct pathway for the formation of glucose is as a result of carbohydrate metabolism. As there is very little pure glucose in the diet, this results predominantly from the breakdown of the larger molecules, disaccharides and polysaccharides. The former are hydrolysed (broken down, using water to split the molecule) and absorbed rapidly, causing a prompt increase in plasma glucose concentration.
Subcutaneous immunoglobulin 16.5% for the treatment of pediatric patients with primary antibody immunodeficiency
Published in Expert Review of Clinical Immunology, 2023
Sudhir Gupta, Roger H. Kobayashi, Jiří Litzman, Laurel Cherwin, Sonja Hoeller, Huub Kreuwel
The excipient maltose is used as the stabilizer for SCIG 16.5% at a target concentration of 7.4% to achieve osmolality and assure IgG stability [57]. Maltose is a water-soluble disaccharide. Unlike sucrose, maltose is metabolized by kidney cells [71–73]. The SCIG and IVIG products stabilized with maltose are well tolerated [74]. This is believed to occur as because maltase, the enzyme responsible for catalyzing the hydrolysis of the disaccharide maltose to glucose, is present in the brush border of proximal convoluted renal tubules [74]. Nonclinical research has demonstrated that maltose is mostly metabolized with <5% excreted unchanged, unlike sucrose in which >60% may be excreted unchanged in the urine [75]. The conversion of maltose to glucose occurs intracellularly in the kidney; thus, maltose does not increase glucose levels in the blood, even in diabetic patients [76]. Falsely elevated blood glucose readings may occur during and after the infusion of SCIG 16.5% stabilized with maltose with some glucometer and test strip systems. When administering SCIG 16.5%, measure blood glucose with a glucose-specific method.
In silico prediction of post-translational modifications in therapeutic antibodies
Published in mAbs, 2022
Glycation is a non-enzymatic modification, where amino groups at lysine (Lys) and arginine residues or the N-terminal are glycated by reducing sugars such as glucose.89 The Schiff base is formed after a condensation reaction between the aldehydes of the reducing sugars and the amine groups of Lys residues (Figure 3(a)). Schiff base formation is reversible; however, the multistep Amadori rearrangement can generate more stable ketoamines (Figure 3(b)).90 Glycated Lys residues can further degrade to form advanced glycation end products,91 which can cause an immunogenic response. Lys glycation typically occurs during long-term storage in formulations, cell culture, and in vivo.92 Disaccharides in formulations can degrade to form reducing sugars, leading to glycation during storage.92 During cell culture, a high glucose concentration can accelerate Lys glycation and reduce protein yield.89 The effects of Lys glycation on antigen binding varies from decreased binding affinity93 to minimal change in binding affinity.94 Lys glycation can increase protein aggregation by affecting the net surface charge, reducing the electrostatic repulsion between antibodies.95 Forced glycation is used to identify liable Lys residues by incubating the IgG with high concentrations of reducing sugars (e.g., glucose) at high temperatures.92 Forced glycation in citrate buffers correlates well with glycation during cell culture.96
Biofilm-based delivery approaches and specific enrichment strategies of probiotics in the human gut
Published in Gut Microbes, 2022
Jie Gao, Faizan Ahmed Sadiq, Yixin Zheng, Jinrong Zhao, Guoqing He, Yaxin Sang
DM is a porous material and thus many nutritious prebiotic substances can be loaded within the microsphere lumen, which may remain metabolically available only to probiotics and can successfully pass through the gastrointestinal tract. For instance, disaccharide (sucrose and maltose) may be metabolized and absorbed during the gastrointestinal transit if they are not protected by a suitable material. Lumen of DM cab be load with growth promoting disaccharides that are discriminatively available for the probiotics adhered to the surface of DM and the presence of these growth-promoting factors reportedly enhances adherence of probiotics on the surface of DM (Figure 5A).106 Probiotic strains on the surface of DM produce EPS which can help to stick two different DM particles together (Figure 5A and 5B). Interestingly, DM containing biofilms of L. reuteri can be loaded with L. histidine which serves as a unique method for the delivery of L-histidine to L. reuteri in the form of biofilms.106 Probiotic-biofilm containing DM particles assure a high density of probiotics on the surface of epithelial cells in a single dose – the density which could only be achieved by frequent repetition of planktonic doses.93 DM-based probiotic biofilm delivery system has also been reported to increase the probiotic potential of bacterial strains and maximize associated health benefits.