Analysis of the hydrolysis of inulin using real time 1H NMR spectroscopy

Barclay, Thomas G.; Ginic‐Markovic, Milena; Johnston, Martin R.; Cooper, Penny; Petrovsky, Nikolai

doi:10.1016/j.carres.2012.03.001

Cited by 75 publications

(45 citation statements)

References 66 publications

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“…The integral of the glucose anomeric peak at 5.44 ppm was set to 1 to calibrate a spectrum and the combined integral of all other resonances of inulin (= X) provided a measure of the average number of units in the chain using the formula: DPn = ((X − 6)/7) + 1 (Barclay et al 2012). The 1 H NMR data were obtained over 64 scans with a 30°flip angle (90°pulse = 8.4 µs), an acquisition time of 2.7 s, a relaxation delay of 2 s and 65K data points.…”

mentioning

confidence: 99%

The polysaccharide inulin is characterized by an extensive series of periodic isoforms with varying biological actions

2013

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In studying the molecular basis for the potent immune activity of previously described gamma and delta inulin particles and to assist in production of inulin adjuvants under Good Manufacturing Practice, we identified five new inulin isoforms, bringing the total to seven plus the amorphous form. These isoforms comprise the step-wise inulin developmental series amorphous → alpha-1 (AI-1) → alpha-2 (AI-2) → gamma (GI) → delta (DI) → zeta (ZI) → epsilon (EI) → omega (OI) in which each higher isoform can be made either by precipitating dissolved inulin or by direct conversion from its precursor, both cases using regularly increasing temperatures. At higher temperatures, the shorter inulin polymer chains are released from the particle and so the key difference between isoforms is that each higher isoform comprises longer polymer chains than its precursor. An increasing trend of degree of polymerization is confirmed by end-group analysis using 1 H nuclear magnetic resonance spectroscopy. Inulin isoforms were characterized by the critical temperatures of abrupt phase-shifts (solubilizations or precipitations) in water suspensions. Such (aqueous) "melting" or "freezing" points are diagnostic and occur in strikingly periodic steps reflecting quantal increases in noncovalent bonding strength and increments in average polymer lengths. The (dry) melting points as measured by modulated differential scanning calorimetry similarly increase in regular steps. We conclude that the isoforms differ in repeated increments of a precisely repeating structural element. Each isoform has a different spectrum of biological activities and we show the higher inulin isoforms to be more potent alternative complement pathway activators.

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confidence: 99%

The polysaccharide inulin is characterized by an extensive series of periodic isoforms with varying biological actions

2013

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“…Recently, 1 H NMR signals of D-fructose were assigned. 12 The designated signals broaden when THGPNa forms complexes with both glucose and fructose ( Fig. 3A and B); and novel signals appeared.…”

Section: Discussionmentioning

confidence: 97%

“…4). 12 The possible complex formation between THGPNa and the four conformations was considered relative to their structures. The bfuranosyl conformation has a cis-diol structure that can interact with THGPNa.…”

Section: Discussionmentioning

confidence: 99%

Nuclear magnetic resonance studies of the interactions between the organic germanium compound Ge-132 and saccharides

Shimada

Sato

Tokuji

et al. 2015

Carbohydrate Research

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“…2. The prominent peak at 4.70 ppm is from the solvent (Barclay, Ginic-Markovic, Johnston, Cooper, & Petrovsky, 2012). The peaks from 3.30 ppm to 4.23 ppm and the peak at 5.35 ppm are from the inulin itself (Kulminskaya et al, 2003).…”

Section: Characterizationmentioning

confidence: 97%

Synthesis, characterisation and physicochemical properties of hydrophobically modified inulin using long-chain fatty acyl chlorides

Han

Ratcliffe

Williams

2017

Carbohydrate Polymers

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A B S T R A C TA series of inulin derivatives were synthesized in aqueous solution using acyl chlorides with varying alkyl chain length (C10-C16). They were characterised using a number of techniques including MALDI TOF-MS, 1 H NMR and FTIR and their degree of substitution determined. The solution properties of the hydrophobically modified inulins were investigated using dye solubilisation and surface tension and it was confirmed that the molecules aggregated in solution above a critical concentration (critical aggregation concentration, CAC). The value of the CAC was found to be reasonably consistent between the different techniques and was shown to decrease with increasing hydrophobe chain length. It was found that the C10, C12 and C14 derivatives formed stable oil-inwater emulsions and the emulsion droplet size decreased with increasing alkyl chain length. The C16 derivative was not able to produce stable oil-in-water emulsions; however, it was able to form stable water-in-oil emulsions. The fact that the derivatives are able to form micellar-like aggregates and stabilise emulsions makes them suitable candidates for the encapsulation and delivery of active compounds with potential application in food, cosmetic, personal care and pharmaceutical formulations.

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Analysis of the hydrolysis of inulin using real time 1H NMR spectroscopy

Cited by 75 publications

References 66 publications

The polysaccharide inulin is characterized by an extensive series of periodic isoforms with varying biological actions

The polysaccharide inulin is characterized by an extensive series of periodic isoforms with varying biological actions

Nuclear magnetic resonance studies of the interactions between the organic germanium compound Ge-132 and saccharides

Synthesis, characterisation and physicochemical properties of hydrophobically modified inulin using long-chain fatty acyl chlorides

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