Synthesis, characterisation and microbial utilisation of amorphous polysugars from lactose

2020 ◽  
Author(s):  
Alison Daines ◽  
Z Smart ◽  
Ian Sims ◽  
GW Tannock ◽  
Simon Hinkley
Keyword(s):  
Molecular Weight ◽  
Citric Acid ◽  
Microwave Radiation ◽  
Reaction Products ◽  
Preliminary Assessment ◽  
Growth Profile ◽  
Catalysed Reaction ◽  
Melt Condensation

© 2014 Elsevier Ltd. All rights reserved. The melt polymerisations of glucose, galactose, xylose and fucose with citric acid, and mixtures of sugars therein are reported. Characterisation of the citric-acid catalysed reaction products indicated similar degrees of branched polymerisation but differences in the overall molecular weight of the polymers produced. The dairy by-product lactose could not be polymerised in a similar fashion but was shown tobe readily hydrolysed using microwave radiation and a polymer generated from the melt condensation of the resultant glucose and galactose monosaccharides. A preliminary assessment of the bifido-bacterialutilisation of the lactose-derived polymerised products demonstrated a significantly different growth profile compared to commercially utilised galactooligosaccharides (GOS).

Synthesis, characterisation and microbial utilisation of amorphous polysugars from lactose

2020 ◽  
Author(s):  
Alison Daines ◽  
Z Smart ◽  
Ian Sims ◽  
GW Tannock ◽  
Simon Hinkley
Keyword(s):  
Molecular Weight ◽  
Citric Acid ◽  
Microwave Radiation ◽  
Reaction Products ◽  
Preliminary Assessment ◽  
Growth Profile ◽  
Catalysed Reaction ◽  
Melt Condensation

© 2014 Elsevier Ltd. All rights reserved. The melt polymerisations of glucose, galactose, xylose and fucose with citric acid, and mixtures of sugars therein are reported. Characterisation of the citric-acid catalysed reaction products indicated similar degrees of branched polymerisation but differences in the overall molecular weight of the polymers produced. The dairy by-product lactose could not be polymerised in a similar fashion but was shown tobe readily hydrolysed using microwave radiation and a polymer generated from the melt condensation of the resultant glucose and galactose monosaccharides. A preliminary assessment of the bifido-bacterialutilisation of the lactose-derived polymerised products demonstrated a significantly different growth profile compared to commercially utilised galactooligosaccharides (GOS).

scholarly journals Structural Characterization of a Polysaccharide from Gastrodia elata and Its Bioactivity on Gut Microbiota

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4443
Author(s):  
Jiangyan Huo ◽  
Min Lei ◽  
Feifei Li ◽  
Jinjun Hou ◽  
Zijia Zhang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Citric Acid ◽  
Gut Microbiota ◽  
Structural Characterization ◽  
Hot Water ◽  
Nmr Analysis ◽  
Gastrodia Elata ◽  
Hot Water Extraction ◽  
Hydroxybenzyl Alcohol

A novel homogeneous polysaccharide named GEP-1 was isolated and purified from Gastrodia elata (G. elata) by hot-water extraction, ethanol precipitation, and membrane separator. GEP-1, which has a molecular weight of 20.1 kDa, contains a polysaccharide framework comprised of only glucose. Methylation and NMR analysis showed that GEP-1 contained 1,3,6-linked-α-Glcp, 1,4-linked-α-Glcp, 1,4-linked-β-Glcp and 1,4,6-linked-α-Glcp. Interestingly, GEP-1 contained citric acid and repeating p-hydroxybenzyl alcohol as one branch. Furthermore, a bioactivity test showed that GEP-1 could significantly promote the growth of Akkermansia muciniphila (A. muciniphila) and Lacticaseibacillus paracasei (L.paracasei) strains. These results implied that GEP-1 might be useful for human by modulating gut microbiota.

The Reactions of Substituted Germyl- and Silylhydrazines with BX3 and CY2 Acceptor Species

1972 ◽  
Vol 50 (4) ◽  
pp. 562-566 ◽  
Author(s):  
L. K. Peterson ◽  
K. I. Thé
Keyword(s):  
Molecular Weight ◽  
Nitrogen Atom ◽  
Low Temperatures ◽  
Adduct Formation ◽  
Steric Effects ◽  
Reaction Products ◽  
Hydrazine Derivatives ◽  
Basic Catalysts ◽  
Series Of Experiments ◽  
Electronic And Steric Effects

Boron trimethyl reacts with each of the organometalloid-hydrazine derivatives Me2NN(R)GeMe3 (R = H, Me, SiMe3) except Me2NN(SiMe3)GeMe3, and with Me2NNHSiMe3, forming 1:1 adducts. With Me2NN(SiMe3)GeMe3 and BMe3, no adduct was formed even at low temperatures. On the basis of p.m.r. spectra, the metalloid-substituted nitrogen atom rather than the terminal nitrogen, is indicated as the basic center at which adduct formation occurs. With BF3, the Si—N and Ge—N bonds of the hydrazine derivatives were cleaved, again indicating attack at the central nitrogen atom. In a series of experiments involving CY2 (Y = O, S) and Me2NN(R)MMe3 (R = H, Me, SiMe3; M = Si, Ge), reaction occurred readily for R = H, but less readily for R = Me and for the compound Me2NN(GeMe3)2, while no reaction was observed for the compounds Me2NN(SiMe3)2 and Me2NN(SiMe3)GeMe3, even when heat or basic catalysts were employed. Reaction products, carbamate and thiocarbamate derivatives, Me2NN(R)C(Y)YMMe3, were characterized on the basis molecular weight, i.r., p.m.r., and mass spectroscopy, and m.p. data. Ease of formation is discussed in terms of electronic and steric effects.

Citric Acid Mediates the Iron Absorption from Low Molecular Weight Human Milk Fractions

2013 ◽  
Vol 61 (46) ◽  
pp. 11151-11157 ◽  
Author(s):  
Ravindranadh Palika ◽  
Purna Chandra Mashurabad ◽  
Sreenivasulu Kilari ◽  
Sunanda Kasula ◽  
Krishnapillai Madhavan Nair ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Citric Acid ◽  
Human Milk ◽  
Iron Absorption ◽  
Low Molecular Weight

scholarly journals Analysis of Allelic Variation in Hmw-Glu-1 Gene Blocks in Iranian Wheat Cultivars using Alp Molecular Marker

2015 ◽  
Vol 48 (2) ◽  
pp. 51-60 ◽  
Author(s):  
Y. Shiri ◽  
M. Solouki ◽  
M. Forootan
Keyword(s):  
Molecular Weight ◽  
Cluster Analysis ◽  
Relative Frequency ◽  
Geographical Variation ◽  
Allelic Variation ◽  
Agarose Gel ◽  
Wheat Cultivars ◽  
Reaction Products ◽  
Specific Primer ◽  
The Relationship

AbstractIn order to study the allelic variation of Glu-1 gene (High molecular weight glutenin), 100 Iranian wheat cultivars including imported and domestic genotypes were analyzed using ALP-PCR technique. Four specific primer pairs were used based on the genetic loci of Glu-A1, Glu-B1, and Glu-D1 to perform the chain polymerase reactions. PCR reaction products were resolved on 2% agarose gel. Since allele “a” had the largest relative frequency (0.707), two alleles (a 344bp; b 362bp) were identified by P1-P2 primer for Glu-A1 locus. Three alleles (a 800bp; b 500bp; c 300bp) were detected for Glu-B1 locus by P5-P6 primer, and allele “b” was assumed as the highest relative frequency (0.618). Two primer pairs were applied for Glu-D1 locus. Ultimately, four alleles were identified, where allele “c” had the highest relative frequency (0.525). The observed genetic variation value for Glu-D1 locus (H=0.648) exhibits the maximal polymorphism. Using cluster analysis, the relationship between the observed polymorphism and geographical variation was investigated. The results indicated that there exists a remarkable variation in Glu- A1 locus between the Iranian wheat cultivars.

Polyelectrolyte Complexes of Low Molecular Weight PEI and Citric Acid as Efficient and Nontoxic Vectors for in Vitro and in Vivo Gene Delivery

2016 ◽  
Vol 27 (3) ◽  
pp. 549-561 ◽  
Author(s):  
M. Dolores Giron-Gonzalez ◽  
Rafael Salto-Gonzalez ◽  
F. Javier Lopez-Jaramillo ◽  
Alfonso Salinas-Castillo ◽  
Ana Belen Jodar-Reyes ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Citric Acid ◽  
Gene Delivery ◽  
Low Molecular Weight ◽  
Polyelectrolyte Complexes ◽  
In Vivo Gene Delivery

The Chemistry of Phenol-Formaldehyde Resin Vulcanization of EPDM: Part I. Evidence for Methylene Crosslinks

1995 ◽  
Vol 68 (5) ◽  
pp. 717-727 ◽  
Author(s):  
Martin van Duin ◽  
Aniko Souphanthong
Keyword(s):  
Molecular Weight ◽  
Phenol Formaldehyde ◽  
Polymer System ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Low Molecular Weight ◽  
Hydroxyl Groups ◽  
Reaction Products ◽  
Cure Reaction ◽  
Weight Model

Abstract The application of phenol-formaldehyde resins as crosslinking agents is increasing in importance due to the good high temperature properties of the corresponding vulcanizate and the use in thermoplastic vulcanizates. With respect to the chemistry of phenol-formaldehyde cure (reaction mechanism and structure of crosslink) there are still problems that have to be resolved. The reaction products of the phenol-formaldehyde resin curing of EPDM, contain 2-ethylidene norbornene (ENB) as the third monomer, have been studied. Since such an investigation is rather difficult to perform for the polymer system, a low molecular weight model for EPDM was used: 2-ethylidene norbornane (ENBH). Reaction of ENBH and a resole results in scission of the dimethylene ether bridges, i.e. in degradation of the resole into mono-, bis- and terisooctylphenol units. These are consequently converted into products, consisting of two ENBH molecules linked by mono-, bis- and terisooctylphenol units. The solid resole seems to be a technological solution for storing phenol in combination with formaldehyde. These results support the use of 2-hydroxymethylphenol (HMP) as a low molecular weight model for the resole. At low temperatures and/or short reaction times HMP oligomers (= resoles) and HMP oligomers linked to one ENBH molecule are formed, which are converted into ENBH/HMP (1:1) condensation products. The reaction products of ENBH with both the resole and HMP are shown to contain methylene linked structures, as demonstrated by the formation of monisooctylphenol crosslinks and the presence of residual unsaturation and hydroxyl groups, besides chroman linked structures. This is the first experimental evidence that during phenol-formaldehyde resin cure of rubber, formation of methylene bridges occurs.

The photochemical decomposition of the citrate-ferric iron comples: A study of the reaction products by paper ionoporesis

1958 ◽  
Vol 11 (4) ◽  
pp. 399 ◽  
Author(s):  
JL Frahn
Keyword(s):  
Citric Acid ◽  
Ferric Chloride ◽  
Ferrous Iron ◽  
Photochemical Reaction ◽  
Ferric Iron ◽  
Iron Complex ◽  
Reaction Products ◽  
Acetoacetic Acid ◽  
Photochemical Decomposition ◽  
Bright Sunlight

A solution containing citric acid (0.lM) and ferric chloride (0.1M) was irradiated by bright sunlight for 3 hr. The products of the photochemical reaction were examined by means of paper ionophoresis using 0.05M sodium chloride as the electrolyte. Acetone-dicarboxylic acid and acetoacetic acid separated readily and were identified by their positions on the paper and by their red-violet reactions on contact with a solution of ferric chloride sprayed onto the paper. The ferrous iron simultaneously produced during the photochemical reaction also separated during ionophoresis and was identified on the paper. The existence of an anionic citrate-ferric iron complex was demonstrated by paper ionophoresis.

scholarly journals Organic acids effects on desorption of heavy metals from a contaminated soil

2006 ◽  
Vol 63 (3) ◽  
pp. 276-280 ◽  
Author(s):  
Clístenes Williams Araújo do Nascimento
Keyword(s):  
Heavy Metals ◽  
Molecular Weight ◽  
Citric Acid ◽  
Organic Acids ◽  
Low Molecular Weight ◽  
High Biomass ◽  
High Concentration ◽  
Accumulation Of Metals ◽  
Pb Concentration ◽  
Oxalic Acids

Phytoremediation of heavy metals is a biotechnology that extracts metals from soils and transfer them to plant. As hyperaccumulator species have demonstrated low potential for commercial phytoextraction, synthetic chelates have been successfully used to induce accumulation of metals by high-biomass plants. However, they pose serious environmental drawbacks regarding excessive amount of metals solubilized. In search for synthetic chelate-alternatives, this paper evaluate the performance of DTPA, EDTA, citric acid, oxalic acid, vanillic acid, and gallic acid in desorbing Cd, Pb, Zn, Cu, and Ni from soil. DTPA and EDTA were highly effective in desorbing Cd, Pb, Zn, Cu, and Ni from soil. However, the excessively high concentration of metals brought in solution by such chelates limits their application in the field. Citric and oxalic acids desorbed substantial quantities of Zn, Cu, and Ni if applied at 10 or 20 mmol kg-1. At the 20 mmol kg-1 dose, vanillic and gallic acids solubilized significant amounts of Zn, Ni, and Cd from soil. None of the tested low molecular weight organic acids substantially increased the Pb concentration in soil solution.

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