Glycogen storage diseases: introduction
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop in Atlas of Inherited Metabolic Diseases, 2020
Glycogen is a branched, polydisperse molecule that has been recognized since the time of Claude Bernard as the storage form for carbohydrates in animal tissues. This polysaccharide is composed entirely of units of α-D-glucose and the units are joined together in 1,4 and 1,6 linkages (Figure 58.1) to form molecules with molecular weights in the vicinity of 1 to 4 million. The branched, tree-like structure (Figure 58.2) was worked out through the elegant studies of Cori and Cori and their colleagues, using stepwise enzymatic degradation [5–7]. A free reducing group occurs at only one point. The straight chains of glucose residues are linked together by α-1,4 bonds; branching occurs through 1,6 linkages. In normal human glycogens, 6–8 percent of the glucose residues are joined to the rest of the molecule in α-1,6 linkage [8]. Glycogen contains seven tiers of branch points; the outer branches are terminated in nonreducing end groups [9].
An Introduction to Moles and Molar Mass
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk in Survival Guide to General Chemistry, 2019
Glucose has a formula of C6H12O6. How many moles of glucose are contained in a 1.75 liter bottle of a sports drink, if the drink is 5.50% glucose by mass?The density of the solution in the bottle is 1.10 g/mL.How many moles of carbon atoms from the glucose are in the bottle? Use your answer from part (a).How many hydrogen atoms from the glucose are in the bottle? Use your answer from part (a) then calculate the number of moles of hydrogen atoms.How many grams of pure glucose can be formed from 75.0 grams of oxygen? That is, how many grams of glucose contain 75.0 grams of oxygen atoms?
Exopolysaccharide Production from Marine Bacteria and Its Applications
Se-Kwon Kim in Marine Biochemistry, 2023
A marine bacterium Alteromonas infernus was reported to secrete branched acidic heteropolysaccharide EPS having an HMW. Its monosaccharide repeating units are composed of galacturonic, glucuronic acid, galactose and glucose substituted with a sulfate group (Roger et al., 2004). Alteromonas strain 1644 possessed the ability to produce two different kinds of EPSs that differ in their viscosity and concentration of ions, making their separation difficult due to their gelling nature (Poli et al., 2010). The tertiary structure and characteristics of EPSs mainly depend on the presence of hydroxyl and carboxyl groups. Microbial exopolymers are available either in dissolved form or as aggregates in a gel-like slime matrix. Figure 18.5 indicates the EPSs structure of psychrotolerant Pseudoalteromonas sp. SM9913 isolated from the deep sea of Antarctica at a depth of 1855 m. It contains a linear simple arrangement of α-1,6 glucose with an elevated degree of acetylation (Qin et al., 2007).
Solanaceae glycoalkaloids: α-solanine and α-chaconine modify the cardioinhibitory activity of verapamil
Published in Pharmaceutical Biology, 2022
Szymon Chowański, Magdalena Winkiel, Monika Szymczak-Cendlak, Paweł Marciniak, Dominika Mańczak, Karolina Walkowiak-Nowicka, Marta Spochacz, Sabino A. Bufo, Laura Scrano, Zbigniew Adamski
Steroidal glycoalkaloids are organic compounds with a ring structure, usually of plant origin. They are heterocyclic bases that contain a nitrogen atom and consist of a sugar moiety and an aglycone. The hydrophobic and nonpolar part of the aglycone is a steroidal structure to which carbohydrate moieties are attached at the 3-OH position. The polar, water-soluble sugar part contains three or four monosaccharide molecules of D-glucose, D-galactose, D-xylose, and L-rhamnose in various combinations (Friedman 2004, 2006; Nepal and Stine 2019). These compounds are produced by plants as secondary metabolites and used in protection against herbivores and as antipathogenic agents during fungal or bacterial infection (Roddick 1996; Chowański et al. 2016). They show properties such as analgesic, anti-inflammatory, antitumor, cardiovascular, and antioxidant effects, or activity that prevents muscle wasting. Thus, their high biological activity enables many of them to be used as pharmacological agents (Niño et al. 2009; Friedman 2013; Kolińska et al. 2016; Jan et al. 2017; Dey et al. 2019; Ebert et al. 2019; Morais et al. 2020).
Microencapsulation: a pragmatic approach towards delivery of probiotics in gut
Published in Journal of Microencapsulation, 2021
Rabia Iqbal, Atif Liaqat, Muhammad Farhan Jahangir Chughtai, Saira Tanweer, Saima Tehseen, Samreen Ahsan, Muhammad Nadeem, Tariq Mehmood, Syed Junaid Ur Rehman, Kanza Saeed, Nimra Sameed, Shoaib Aziz, Assam Bin Tahir, Adnan Khaliq
The starch granules consist almost entirely of two major polysaccharides, namely amylose and amylopectin. Both consist of chains of α-(1,4)-linked D-glucose residues, which are interconnected through α-(1,6)-glucosidic linkages, thus forming branches in the polymers (Figure 4) (Bertoft 2017). The use of starch has been reported in many studies. Starch is highly being used in food industries as a renewable material feedstock, corn starch, and high amylase corn starches (Ogunsona et al.2018) reported that resistant starch is not digested by amylases (pancreatic enzymes) in the small intestine of human. So, it reaches the colon in undigested form where it is fermented by probiotic bacteria being prebiotic in nature, to discharge the coated active agents (Ogunsona et al.2018, Albadran et al.2020).
Impact of biotin supplemented diet on mouse pancreatic islet β-cell mass expansion and glucose induced electrical activity
Published in Islets, 2022
Israel Morales-Reyes, Illani Atwater, Marcelino Esparza-Aguilar, E. Martha Pérez-Armendariz
So far, this is the first study to characterize a biotin effect on electrical activity. It is well known that the subthreshold Vm is mainly determined by KATP channels.27 In our study, we observed that the individual and median ΔVm values were larger in the BSD than in the CD group for [glucose] changes in the non-stimulatory range. Also, the clousure of these KATP channels by glucose mainly determines the threshold for glucose-induced electrical activity. We also observed a shift of 1.23 mM in the Ec50 of the APs-[glucose] threshold, toward higher glucose concentrations in ß-cells from the BSD compared with the CD group. In addition, at 11 mM glucose , a greater percentage of β cells reached the APs-[glucose] threshold in the BSD compared with the CD group. Due to the relatively reduced number of islet β-cells recorded in both groups, the double experimental condition (diet and glucose) and the non-parametric distribution of ΔVm values recorded, the statistical significance of these changes was not proved. Nonetheless, the consistency among results shown in Figure 3 strongly suggests that KATP conductance is increased in ß-cells from mice receiving a biotin supplement in the diet.