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Anti-Inflammatory Compounds Derived from Marine Macroalgae
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Snezana Agatonovic-Kustrin, David W. Morton
In contrast to land polysaccharides, most marine polysaccharides are highly sulfated. Their biodegradation requires glycoside hydrolase enzymes to cleave the glycosidic bonds of the carbohydrate backbone, and polysaccharide sulfatases to cleave the sulfate ester groups. The introduction of sulfated groups improves the bioactivity of polysaccharides, especially their antioxidant and anti-inflammatory activities (Chen et al. 2015).
Host-Parasite Interactions With Macrophages In Culture
Published in Hans H. Gadebusch, Phagocytes and Cellular Immunity, 2020
Lee S. F. Soderberg, Morris Solotorovsky
The second major group of hydrolases found in macrophages comprises the glycoside hydrolases. These include β-glucuronidase, hyaluronidas, and muramidase, all of which act on glycosides and glycosyl linkages. The β-glucuronidase that characteristically appears in macrophage lysosomes has also been detected on the endoplasmic reticulum.24 This enzyme has been assayed with phenolphthalein glucuronic acid as a substrate.124 A higher β-glucuronidase content was reported in macrophages from immunized animals than from normal animals. Hyaluronidase activity is similar to that of β-glucuronidase, yet distinguishable enough to identify its presence in macrophages.24 Muramidase, also known as lysozyme, cleaves the glycan backbone of the peptidoglycan layer of certain bacterial cell walls. Very few unmodified microorganisms are susceptible to killing with lysozyme,24 but Micrococcus lysodeikticus has often been used to assay lysozyme activity. Muramidase has been found in high concentration in the lysosome of alveolar macrophages. Little, if any, muramidase was found in peritoneal macrophages. Fluorescein-labeled antibody specific for muramidase has also been used to detect the presence of this enzyme in macrophage-cell cultures123 established by Rebuck and Crowley’s skin window technique.128
Cyanogenic Glycosides
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Glycoside is a molecule composed of a sugar (known as glycone, either single [monosaccharide] or multiple [oligosaccharide]) and a functional, nonsugar group (known as aglycone or genin) connected via a glycosidic bond. The glycone and aglycone portions of a glycoside can be separated by hydrolysis in the presence of acid or alkali, or cleaved by specific enzymes (e.g., glycoside hydrolases, and glycosyltransferases).
Cellulolytic bacteria in the large intestine of mammals
Published in Gut Microbes, 2022
Alicia Froidurot, Véronique Julliand
Recently, several reviews have summarized the current knowledge on the enzymes involved in dietary fiber degradation, in particular cellulose degradation, notably in the gut microbiota.16,90–92 The enzymes responsible for carbohydrate degradation, modification, or creation are commonly named carbohydrate-active enzymes (CAZymes) and are indexed in the CAZy database (http://www.cazy.org/).93 This database classifies proteins into 6 families based on their mode of action: glycoside hydrolases (GHs), carbohydrate esterases, polysaccharide lyases, glycosyltransferases, and auxiliary activities. In turn, carbohydrate-binding modules (CBMs) are noncatalytic modules of CAZymes that help target enzymes to their substrates. The classification of CAZyme families is defined based on the significant similarity of amino acid sequences that do not necessarily correspond to one function. The presence of enzymes that act on different substrates within the same family is also possible.93
Benzonate derivatives of acetophenone as potent α-glucosidase inhibitors: synthesis, structure–activity relationship and mechanism
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Wen-Jia Dan, Qiang Zhang, Fan Zhang, Wei-Wei Wang, Jin-Ming Gao
Diabetes mellitus is one of the major chronic diseases1. The incidence and prevalence of diabetes have risen sharply in recent years, and 642 million people might be suffering from diabetes until 20402,3. α-Glucosidase is a type of glycoside hydrolase, which favors in absorption of carbohydrates. By inhibiting its activity, the absorption of small intestine carbohydrates could be delayed, which bring on the reduction of postprandial blood glucose4,5. Moreover, the inhibition of α-glucosidase also has positive effects to treat some diseases such as virosis, cancer, and chronic heart failure etc6,7. Nowadays, the α-glucosidase inhibitors have been recognised as an efficient therapy in the treatment of type-II diabetes (T2D)8. They inhibit membrane bound α-glucosidase in the cells lining the small intestine, which in turn decreases the digestion of starch and additional dietary sugars, helping to avoid hyperglycemia and maintain normal blood sugar levels9. Therefore, it is significant to discover new classes of α-glucosidase inhibitors and to investigate the action mechanism of these inhibitors.
Selection of fast and slow growing bacteria from fecal microbiota using continuous culture with changing dilution rate
Published in Microbial Ecology in Health and Disease, 2018
At low dilution rates, also Eubacterium coprostanoligenes, Eisenbergiella tayi, and Negativicoccus succinivorans were selected (Figure 5). Eisenbergiella is a lately described genus isolated from a sepsis sample [34,35]; however, occurrence of similar bacteria have been reported in stool samples [34,36]. According to our knowledge, data about cultivation of Eisenbergiella species in different environmental conditions are scarce. Amir et al. [34] showed that Eisenbergiella tayi was asaccharolytic and produced acids (about half was butyrate and the rest lactate, acetate, and succinate) only from glucose in tryptone peptone medium. However, this species showed positive reactions for several glycoside hydrolases showing potential for carbohydrate degradation. Negativicoccus succinicivorans is a novel little studied bacterium; however, succinate has been shown to support the growth of this bacterium [37]. Succinate can be produced by several gut bacteria such as Bacteroides species. Thus, high abundance of Bacteroides species (10–50%) in our experiments may explain the promoted growth of Negativicoccus at low dilution rates.