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Exopolysaccharide Production from Marine Bacteria and Its Applications
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Prashakha J. Shukla, Shivang B. Vhora, Ankita G. Murnal, Unnati B. Yagnik, Maheshwari Patadiya
The biosynthesis of EPSs occurs in four steps: (1) transport of sugar into the cell, (2) phosphorylation of sugar, (3) polymerization of sugar units and (4) export of EPSs to the cell surface (Madhuri and Prabhakar, 2014). The biosynthesis of EPSs is initiated when carbon substrate is available as the precursor to the cell. Synthesis is initiated by the transport of monosaccharides into the cell by diffusion, active transport or group translocation. In the cell, the sugar molecule is phosphorylated and converted into sugar-6-phosphate, which is further converted to sugar-1-phosphate using the enzyme phosphoglucomutase (Jolly et al., 2002). Sugar nucleotides (UDP-glu) are then formed from the sugar-1-phosphate with the help of enzyme pyrophosphorylase (Lieberman and Markovitz, 1970; Jolly et al., 2002). UDP-glu serves as an intermediate for other sugar moieties involved in polysaccharide assembly and synthesis. Bacterial polysaccharides consist of repeating units of sugars that are synthesized by glycosyltransferases (GTs) that transfer sugar to a glycosyl carrier lipid in the cytoplasmic membrane. In the last step, monosaccharide units of assembled polysaccharides are further modified by different enzymatic activities like acylation, acetylation, methylation and sulfation. They are then exuded from the cell in the form of loose slime or a capsule with the help of flippase, permease or ABC transporters (energy-dependent efflux transporter protein).
Allopathic Medicines
Published in Varma H. Rambaran, Nalini K. Singh, Alternative Medicines for Diabetes Management, 2023
Varma H. Rambaran, Nalini K. Singh
As research progresses under this particular class of compounds, there have been recent reports on nitrogen-containing heterocyclic compounds (without glycosyl moieties), that exhibit potent α-glucosidase inhibiting activity. Some of these drugs, classified as triazoloquinazolines, have already undergone in vitro studies and have shown comparable inhibitory activity to that of acarbose (Abuelizz et al. 2019). These findings have given support to the drugs being further studied in clinical trials, for their potential use as novel AGIs.
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.
Research progress of coumarins and their derivatives in the treatment of diabetes
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Yinbo Pan, Teng Liu, Xiaojing Wang, Jie Sun
α-glucosidase is widely distributed in the brush border of the small intestinal mucosa, which has an important influence on the structure of glycosyl groups. They can degrade polysaccharides such as starch, maltose and sucrose into monosaccharides48. It hydrolyses the glycosidic bonds in various sugar compounds by endo or exo cleavage, causing the increase of blood glucose. After hydrolysis, the sugary compounds mainly exist in the following three forms: monosaccharide, oligosaccharide and carbohydrate complex. The existing traditional α-glucosidase inhibitors, such as acarbose and voglibose, have more or less gastrointestinal adverse reactions such as nausea and vomiting. Hu et al.49,50 studied 3–(4′-benzoyl amino-phenyl) coumarin derivatives (Figure 5, Table 2), and found that their inhibitory activities on α-glucosidase were different from those of positive control drugs, but their inhibitory activities were all lower than 65 μmol/L, and compound 27 had stronger inhibitory activities through screening.
Abundant production of exopolysaccharide by EAEC strains enhances the formation of bacterial biofilms in contaminated sprouts
Published in Gut Microbes, 2018
Quintin Borgersen, David T. Bolick, Glynis L. Kolling, Matthew Aijuka, Fernando Ruiz-Perez, Richard L. Guerrant, James P. Nataro, Araceli E. Santiago
Glycosyl composition analysis was performed by combined gas chromatography/mass spectrometry (GC/MS) of the per-O-trimethylsilyl (TMS) derivatives of the monosaccharide methyl glycosides produced from the sample by acidic methanolysis.55 Briefly, an aliquot was taken from the sample and added to separate tubes with 20ug of Inositol as internal standard. Methyl glycosides were then prepared from the dry sample following the mild acid treatment by methanolysis in 1 M HCl in methanol at 80°C (16 hours), followed by re-N-acetylation with pyridine and acetic anhydride in methanol (for detection of amino sugars). The sample was then per-O-trimethylsilylated by treatment with Tri-Sil (Pierce) at 80°C (0.5 hours). GC/MS analysis of the TMS methyl glycosides was performed on an Agilent 7890A GC interfaced to a 5975C MSD, using a Supelco EC-1 fused silica capillary column (30m × 0.25 mm ID).
TiO2 nanotube immobilised 5-lipoxygenase-mediated screening and isolation of anti-inflammatory active compounds from the leaves of lonicera japonica thunb
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Jinhua Zhu, Danyang Zhou, Dandan Wu, Wei Liu, Xiuhua Liu
The 1H-NMR data and the H assignation of compound 1′ were as follows: δ(600 MHZ, DMSO-d6): 13.09 (1H, s, 5-OH), 9.71 (2H, s, 3′, 4′-H), 7.53 (1H, dd, 6′-H), 7.27 (1H, d, 2′-H), 6.97 (1H, d, 5′-H), 6.87 (1H, s, 3-H), 6.80 (1H, d, 8-H), 6.51 (1H, d, 6-H), 5.38 (1H, d, H-1′’), 5.15 (1H, s, H-1′’’), 3.10–4.20 (m, sugar). As shown in Figure 7, when δ was between 5.15 and 13.09, it was consistent with the chemical shift of aglycone luteolin, but when δ was between 3.10 and 4.20, the sugar group was a group peak, and the type of sugar group attached to the aglycone was unknown. Further 13 C-NMR analysis was required to obtain its glycosyl information.