Nanoparticulate Assembly of Mannuronic Acid-and Guluronic Acid-Rich Alginate: Oral Insulin Carrier and Glucose Binder

2013 ◽  
Vol 102 (12) ◽  
pp. 4353-4363 ◽  
Author(s):  
Aminah Kadir ◽  
Mohammad Tarmizi Mohd Mokhtar ◽  
Tin Wui Wong
Keyword(s):  
Oral Insulin ◽  
Mannuronic Acid ◽  
Guluronic Acid

In situ studies on alginic acid synthesis and other aspects of the metabolism of Laminaria digitata

1972 ◽  
Vol 50 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Johan A. Hellebust ◽  
Arne Haug
Keyword(s):  
Amino Acids ◽  
Time Course ◽  
Alginic Acid ◽  
Acid Synthesis ◽  
Short Term ◽  
Fresh Weight Basis ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Rate Of Photosynthesis

Amino acids, particularly alanine and aspartate, become more strongly labeled than mannitol in short-term 14C-photoassimilation experiments. The amino acids are the most likely sources of carbon for alginic acid synthesis and respiration in the dark, in contrast to mannitol, which appears to be relatively unavailable. Temperature is very important in determining the rate of loss of recent photoassimilate in L. digitata. The rate of photosynthesis, on a fresh weight basis, is much higher for blades than for stipes.The time course for incorporation of photoassimilated carbon into alginate differs for the stipe and blade both in light and dark periods. Very little 14C enters alginate in blades in the dark, while alginate in stipes acquires considerable amounts of activity during dark periods. Alginate in both blade and stipe acquires 14C predominantly in mannuronic acid residues of their alginate during short-term photoassimilation periods, while guluronic acid residues become relatively more rapidly labeled during dark periods.

Photosynthesis, translocation, and alginic acid synthesis in Laminaria digitata and Laminaria hyperborea

1972 ◽  
Vol 50 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Johan A. Hellebust ◽  
Arne Haug
Keyword(s):  
Time Course ◽  
Alginic Acid ◽  
Acid Synthesis ◽  
Laminaria Hyperborea ◽  
Short Term ◽  
Fresh Weight Basis ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Isolated Cortex ◽  
Photosynthetic Capacities

New and old tissues of L. digitata blades have very similar photosynthetic capacities on a fresh weight basis. Very little of the photoassimilate goes into alginic acid, or other macromolecular substances in old blade tissues. Less than 1% of the photoassimilated 14C in the old blade portion of a L. digitata blade was translocated to the new blade tissues in a 5-h experiment. In contrast, there is rapid transport of photoassimilate from bark cells to cells of the underlying tissues of L. digitata and L. hyperborea stipe sections. Isolated cortex and medulla tissues of L. digitata stipes have significant photosynthetic capacities, but are probably so strongly shaded by the darkly pigmented bark cells that little photosynthesis can normally occur in these tissues.A larger proportion of the photoassimilated carbon enters alginate in the cortex and medulla than in the bark of L. digitata and L. hyperborea stipes in short-term experiments. The time course for incorporation of photosynthate into alginate in continuous and pulse-labeling experiments indicates the presence of relatively large pools of alginate precursors. A large proportion of the total 14C incorporated into alginate in short-term experiments is found in the "M–M" (mannuronic acid) and "M–G" (alternating mannuronic and guluronic acid) block components.

Effect of sodium alginate and its guluronic acid/mannuronic acid ratio on the physicochemical properties of high-amylose cornstarch

2016 ◽  
Vol 68 (11-12) ◽  
pp. 1215-1223 ◽  
Author(s):  
Yang Zhao ◽  
HaiHua Chen ◽  
YuSheng Wang ◽  
QianQian Li
Keyword(s):  
Physicochemical Properties ◽  
Sodium Alginate ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Acid Ratio ◽  
High Amylose

scholarly journals The biosynthesis of alginic acid by Azotobacter vinelandii

1975 ◽  
Vol 152 (3) ◽  
pp. 617-622 ◽  
Author(s):  
D F Pindar ◽  
C Bucke
Keyword(s):  
Alginic Acid ◽  
Azotobacter Vinelandii ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Polymeric Substance

The sequence of reactions by which alginic acid is biosynthesized from sucrose in Azotobacter vinelandii was determined both by feeding radioactive individual enzymes involved. Results indicate that the first polymeric substance formed in the synthesis is polymannuronic acid and that mannuronic acid units are epimerized to guluronic acid at the polymer level. Guluronic acid does not appear to be formed at the monomer level, either free or in combination with GDP.

Acceptor Reactivity in the Total Synthesis of Alginate Fragments Containing α-L-Guluronic Acid and β-D-Mannuronic Acid

2015 ◽  
Vol 54 (26) ◽  
pp. 7670-7673 ◽  
Author(s):  
Qingju Zhang ◽  
Erwin R. van Rijssel ◽  
Marthe T. C. Walvoort ◽  
Herman S. Overkleeft ◽  
Gijsbert A. van der Marel ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Mannuronic Acid ◽  
Guluronic Acid

scholarly journals Structural characterization of cocktail-like targeting polysaccharides from Ecklonia kurome Okam and their anti-SARS-CoV-2 activities invitro

2021 ◽  
Author(s):  
Shihai Zhang ◽  
Rongjuan Pei ◽  
Meixia Li ◽  
Hao Sun ◽  
Minbo Su ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Monosaccharide Composition ◽  
Structure Study ◽  
Exchange Chromatography ◽  
Spike Protein ◽  
Drug Candidate ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
The Impact

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent responsible for the worldwide coronavirus disease 2019 (COVID-19) outbreak. Investigation has confirmed that polysaccharide heparan sulfate can bind to the spike protein and block SARS-CoV-2 infection. Theoretically, similar structure of nature polysaccharides may also have the impact on the virus. Indeed, some marine polysaccharide has been reported to inhibit SARS-Cov-2 infection in vitro, however the convinced targets and mechanism are still vague. By high throughput screening to target 3CLpro enzyme, a key enzyme that plays a pivotal role in the viral replication and transcription using nature polysaccharides library, we discover the mixture polysaccharide 375 from seaweed Ecklonia kurome Okam completely block 3Clpro enzymatic activity (IC50, 0.48 µM). Further, the homogeneous polysaccharide 37502 from the 375 may bind to 3CLpro molecule well (kD value : 4.23 × 10−6). Very interestingly, 37502 also can potently disturb spike protein binding to ACE2 receptor (EC50, 2.01 µM). Importantly, polysaccharide 375 shows good anti-SARS-CoV-2 infection activity in cell culture with EC50 values of 27 nM (99.9% inhibiting rate at the concentration of 20 µg/mL), low toxicity (LD50: 136 mg/Kg on mice). By DEAE ion-exchange chromatography, 37501, 37502 and 37503 polysaccharides are purified from native 375. Bioactivity test show that 37501 and 37503 may impede SARS-Cov-2 infection and virus replication, however their individual impact on the virus is significantly less that of 375. Surprisingly, polysaccharide 37502 has no inhibition effect on SARS-Cov-2. The structure study based on monosaccharide composition, methylation, NMR spectrum analysis suggest that 375 contains guluronic acid, mannuronic acid, mannose, rhamnose, glucouronic acid, galacturonic acid, glucose, galactose, xylose and fucose with ratio of 1.86 : 9.56 : 6.81 : 1.69 : 1.00 : 1.75 : 1.19 : 11.06 : 4.31 : 23.06. However, polysaccharide 37502 is an aginate which composed of mannuronic acid (89.3 %) and guluronic acid (10.7 %), with the molecular weight (Mw) of 27.9 kDa. These results imply that mixture polysaccharides 375 works better than the individual polysaccharide on SARS-Cov-2 may be the cocktail-like polysaccharide synergistic function through targeting multiple key molecules implicated in the virus infection and replication. The results also suggest that 375 may be a potential drug candidate against SARS-CoV-2.

scholarly journals Sodium Alginate as a Potential Therapeutic Filler: An In Vivo Study in Rats

Marine Drugs ◽  
2020 ◽  
Vol 18 (10) ◽  
pp. 520
Author(s):  
Masanori Mori ◽  
Rintaro Asahi ◽  
Yoshihiro Yamamoto ◽  
Takanobu Mashiko ◽  
Kayo Yoshizumi ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Sodium Hyaluronate ◽  
Capsule Formation ◽  
Filler Injection ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Therapeutic Value ◽  
G Ratio

Filler injection demand is increasing worldwide, but no ideal filler with safety and longevity currently exists. Sodium alginate (SA) is the sodium salt of alginic acid, which is a polymeric polysaccharide obtained by linear polymerization of two types of uronic acid, d-mannuronic acid (M) and l-guluronic acid (G). This study aimed to evaluate the therapeutic value of SA. Nine SA types with different M/G ratios and viscosities were tested and compared with a commercially available sodium hyaluronate (SH) filler. Three injection modes (onto the periosteum, intradermally, or subcutaneously) were used in six rats for each substance, and the animals were sacrificed at 4 or 24 weeks. Changes in the diameter and volume were measured macroscopically and by computed tomography, and histopathological evaluations were performed. SA with a low M/G ratio generally maintained skin uplift. The bulge gradually decreased over time but slightly increased at 4 weeks in some samples. No capsule formation was observed around SA. However, granulomatous reactions, including macrophage recruitment, were observed 4 weeks after SA implantation, although fewer macrophages and granulomatous reactions were observed at 24 weeks. The long-term volumizing effects and degree of granulomatous reactions differed depending on the M/G ratio and viscosity. By contrast, SH showed capsule formation but with minimal granulomatous reactions. The beneficial and adverse effects of SA as a filler differed according to the viscosity or M/G ratio, suggesting a better long-term volumizing effect than SH with relatively low immunogenicity

scholarly journals The A Modules of the Azotobacter vinelandii Mannuronan-C-5-Epimerase AlgE1 Are Sufficient for both Epimerization and Binding of Ca2+

1999 ◽  
Vol 181 (10) ◽  
pp. 3033-3038 ◽  
Author(s):  
Helga Ertesvåg ◽  
Svein Valla
Keyword(s):  
Amino Acids ◽  
Reaction Rate ◽  
Azotobacter Vinelandii ◽  
Binding Studies ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Catalytic Sites ◽  
Direct Binding ◽  
Protein Modules ◽  
Secreted Enzymes

ABSTRACT The industrially important polysaccharide alginate is composed of the two sugar monomers β-d-mannuronic acid (M) and its epimer α-l-guluronic acid (G). In the bacteriumAzotobacter vinelandii, the G residues originate from a polymer-level reaction catalyzed by one periplasmic and at least five secreted mannuronan C-5-epimerases. The secreted enzymes are composed of repeats of two protein modules designated A (385 amino acids) and R (153 amino acids). The modular structure of one of the epimerases, AlgE1, is A1R1R2R3A2R4. This enzyme has two catalytic sites for epimerization, each site introducing a different G distribution pattern, and in this article we report the DNA-level construction of a variety of truncated forms of the enzyme. Analyses of the properties of the corresponding proteins showed that an A module alone is sufficient for epimerization and that A1 catalyzed the formation of contiguous stretches of G residues in the polymer, while A2 introduces single G residues. These differences are predicted to strongly affect the physical and immunological properties of the reaction product. The epimerization reaction is Ca2+ dependent, and direct binding studies showed that both the A and R modules bind this cation. The R modules appeared to reduce the Ca2+ concentration needed for full activity and also stimulated the reaction rate when positioned both N and C terminally.

Acceptor Reactivity in the Total Synthesis of Alginate Fragments Containing α-L-Guluronic Acid and β-D-Mannuronic Acid

2015 ◽  
Vol 127 (26) ◽  
pp. 7780-7783 ◽  
Author(s):  
Qingju Zhang ◽  
Erwin R. van Rijssel ◽  
Marthe T. C. Walvoort ◽  
Herman S. Overkleeft ◽  
Gijsbert A. van der Marel ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Mannuronic Acid ◽  
Guluronic Acid
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