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Biocatalyzed Synthesis of Antidiabetic Drugs
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
It is well known that inhibitors of intestinal α-glucosidase enzymes promote a delay in the absorption of sugars because of the retard in the final steps of carbohydrate digestion, so that they are useful for reducing postprandial hyperglycemia in diabetes (Derosa and Maffioli, 2012; Campo et al., 2013). These α-glucosidase inhibitors act as glycomimetics, because they bear a certain grade of resemblance to the natural carbohydrates, but the differential part of their structure promotes a blockade of enzymatic action (Ernst and Magnani, 2009). The use of iminosugars (N atom replacing O) (Winchester, 2009; Horne et al., 2011), thiosugars (S instead of O) (Witczak and Culhane, 2005) or carbasugars (ethereal bridge substituted by a methylene) (Mayato et al., 2012) as glycomimetics is a well-developed strategy. More specifically, iminosugars mimics transition state (oxocarbenium) of glycosidases mechanism, due to the nitrogen protonation at physiological pH values (Caines et al., 2007; Winchester, 2009), and we will show some examples of biocatalyzed synthesis of this type of α-glucosidase inhibitors.
Biological Process for Ethanol Production
Published in Jay J. Cheng, Biomass to Renewable Energy Processes, 2017
β-Glucosidase: β-Glucosidases degrade cellobiose into glucose that provides the source of energy and C to the host microorganisms during the enzyme production. They have very broad specificity to both glycon and aglycon substrates (such as steroid β-glucosides and β-glucosylceramides of mammals) compared to endoglucanases and exoglucanases. β-Glucosidase can greatly improve the hydrolysis efficiency of cellulose by degrading cellobiose, the end-product and competitive inhibitor of endoglucanases and exoglucanases. β-Glucosidase can be produced from both fungi and bacteria. The commonly used fungi for β-glucosidase production include the species of Aspergillus, Candida, Humicola, Penicillium, Saccharomyces, and Trichoderma. The optimum conditions for the β-glucosidases from some of the above fungi are listed in Table 7.9. Bacteria that are commonly used for β-glucosidase production include Clostridium sp., Ruminococcus sp., and Streptomyces sp. The optimum conditions for the β-glucosidases from the bacteria are listed in Table 7.10.
Hydrolysis and Fermentation Technologies for Alcohols
Published in Yatish T. Shah, Water for Energy and Fuel Production, 2014
Beta-glucosidase converts cellobiose to glucose by hydrolysis. In general, glucosidase is any enzyme that catalyzes the hydrolysis of glucoside. Beta-glucosidase catalyzes the hydrolysis of terminal, nonreducing beta-D-glucose residues with the release of beta-D-glucose. Kadam and Demain [48] determined the substrate specificity of the beta-glucosidase and demonstrated that its addition to the cellulase complex enhances the hydrolysis of Avicel, specifically by removing the accumulated cellobiose. They used C. thermocellum that is expressed in Escherichia coli to determine the surface specificity of the enzyme. The hydrolysis of cellobiose to glucose is a liquid-phase reaction. The action of beta-glucosidase on this reaction can be slowed or halted by the inhibitive action of glucose accumulated in the solution. The accumulation may also induce the entire hydrolysis to a halt as inhibition of the beta-glucosidase results in the buildup of cellobiose, which in turn inhibits the action of exogluconases. Thus, the hydrolysis of the cellulosic materials depends on the presence of all three enzymes in proper amounts. If any of these enzymes is present in the amount less than the required amount, the other enzymes will be inhibited or lack the necessary substrates upon which to act.
Some of the organic ligand transition metal complexes can serve as potent α-glucosidase inhibitors: in-vitro, kinetics and in-silico studies
Published in Inorganic and Nano-Metal Chemistry, 2023
Syed Majid Bukhari, Rizwana Sarwar, Asma Zaidi, Majid Ali, Farhan A. Khan, Umar Farooq, Jalal Uddin, Aliya Ibrar, Ajmal Khan, Ahmed Al-Harrasi
The α-glucosidase is a membrane bound enzyme which is located in epithelium of the small intestine. It has vital importance in the functioning of carbohydrase and in digestion process of glycolipids, lyco-proteins and is involved in several other metabolic pathways.[1] It releases α-D-glucose (monosaccharide unit) by hydrolyzing non-reducing, terminal 1, 4-linked α-D-glucose (oligosaccharides and polysaccharides) to maintain postprandial blood glucose level.[2,3] The α-glucosidase inhibitors have been shown to possess therapeutic potential against type-2 diabetes mellitus, human immunodeficiency virus infection, obesity and metastatic cancer.[3–5] There are only three α-glucosidase inhibitors (acarbose, miglitol and voglibose) which are clinically used today for the treatment of type-2 diabetes. These inhibitors lower the rate of carbohydrase absorption and suppress postprandial hyperglycemia.[4]
Valorization of waste Syzygium cumini seed kernels by three-phase partitioning extraction and evaluation of in vitro antioxidant and hypoglycemic potential
Published in Preparative Biochemistry & Biotechnology, 2021
Komal V. Mahindrakar, Virendra K. Rathod
In the small intestine’s brush border, the catalyzing action of enzyme α-glucosidase occurred, causing the breakdown of oligosaccharides into simple sugars that result in hyperglycemia in diabetic patients. Hence, α-glucosidase inhibitors prevent the uptake of carbohydrates and, in turn, controls the blood glucose level.[45] The basis of this assay is the conversion of PNPG to p-nitrophenol (yellow colored) by enzyme α-glucosidase, which could be measured at λmax 405 nm. An increase in concentration (10–100 µg/mL) of positive control, acarbose and extract, % inhibition of enzyme also increases (Figure 11). IC50 values for acarbose and extract were obtained as 58.22 and 7.55 µg/mL, respectively (Table 2). In literature, methanolic (70%) Syzygium cumini kernel’s extract and acarbose showed 1.9 and 45.2 µg/mL IC50 value for α-glucosidase inhibition, respectively.[44] 1-Butanol extract of Syzygium cumini kernel obtained by the soxhlet technique showed 8.3 µg/mL of IC50, while no inhibition of α-glucosidase was observed by acarbose.[45]
Carboxymethyl cellulase production optimization from Glutamicibacter arilaitensis strain ALA4 and its application in lignocellulosic waste biomass saccharification
Published in Preparative Biochemistry and Biotechnology, 2018
Chirom Aarti, Ameer Khusro, Paul Agastian
Lignocellulose is a pivotal source of renewable energy consisting of cellulose, which is in fact structurally, and compositionally complex hemicellulose and recalcitrant lignin.[1] Cellulose is the most copious renewable natural homopolysaccharide in the biosphere.[2] The cellulolytic enzymes synergistically act on cellulosic biomass and hydrolyze them into fermentable sugars in order to produce bioethanol. Cellulase is a multi-enzyme system comprised of endo-1,4-β-D-glucanase (EC 3.2.1.4), exo-1,4-β-D-glucanase (EC 3.2.1.91), and β-glucosidase (EC 3.2.1.21). The endoglucanase (carboxymethyl cellulase) randomly attacks β-1,4 bonds in cellulose, producing glucan chains of different lengths, whereas exoglucanase acts on the ends of the cellulose chain and releases β-cellobiose as the end product. β-glucosidase catalyzes the hydrolysis of glycosidic bonds to non-reducing residues in β-D-glucosides and oligosaccharides, thereby releasing glucose.[3] Despite the substantial necessity of cellulase in bioresource technologies, they are also enormously utilized in diversiform bioprocess industries viz. food, wine, brewery, pulp and paper, textile, pharmaceutical, detergent, livestock, and agriculture.[4]