Structural analysis by 13C- nuclear magnetic resonance spectroscopy of glucan extracted from natural palm wine

Uzochukwu, Sylvia; Balogh, Esther A.; Loefler, R.T; Ngoddy, P.O.

doi:10.1016/s0308-8146(01)00274-6

Cited by 42 publications

(23 citation statements)

References 12 publications

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“…No additional peaks were observed in the region of δ 77 -85 ppm, indicating that the absence of branched linkages and confirming that the dextran synthesized by Leuconostoc pseudomesenteroides R2 is a highly linear dextran with α(1→6) glycosidic bonds (Seymour 1979, Uzochukwu et al 2002.…”

Section: Identification Of Exopolysaccharidesmentioning

confidence: 52%

Production, extraction and characterization of exopolysaccharides produced by the native Leuconostoc pseudomesenteroides R2 strain

Paulo

Boffo

Branco

et al. 2012

An. Acad. Bras. Ciênc.

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The genus Leuconostoc belongs to a group of lactic acid bacteria usually isolated from fermented vegetables, which includes species involved in the production of exopolysaccharides (EPS). These biopolymers possess considerable commercial potential. Because of the wide variety of industrial applications of EPS, this study aimed to produce and characterize the native exopolysaccharide strain Leuconostoc pseudomesenteroides R2, which was isolated from cabbage collected in a semi-arid region of Bahia. We employed the following conditions for the production of EPS: 10.7% sucrose, pH 8.2, without agitation and incubation at 28°C for 30 hours. The fermentation broth was treated with ethanol and generated two types of polysaccharide substances (EPS I and EPS II). The identification of EPS I and EPS II was conducted using FT-IR, 1 H, 13 C and DEPT-135 NMR spectra. The two substances were identified as linear dextran α polysaccharides (1 → 6) which indicated different characteristics with respect to thermal analysis and density of free packaging, viscosity and time of solubilization. Both dextrans are of low density, possess high thermal stability and exhibited the behavior characteristic of pseudoplastic polymers.

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Section: Identification Of Exopolysaccharidesmentioning

confidence: 52%

Production, extraction and characterization of exopolysaccharides produced by the native Leuconostoc pseudomesenteroides R2 strain

Paulo

Boffo

Branco

et al. 2012

An. Acad. Bras. Ciênc.

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“…On the hand, the presence of glycerol but no d-glucose in WIPS suggests the existence of 1,6-linkage, and the 1.0:5.86 molar ratio of glycerol to erythritol suggests that the molar ratio of (1 → 6)-glycosyl and (1 → 4)-glycosyl residues was about 1: 6 in the repeating unit of WIPS. Table 2 shows the chemical shifts of the major carbon atom signals on the 13 C NMR spectra of WIPS and AIPS, corresponding to the relevant sugar residues according to reference data (Agrawal, 1992;Funane et al, 2001;Uzochukwu, Balogh, Loefler, & Ngoddy, 2002). On the 13 C spectrum of AIPS, the anomeric carbon signal at ı 99.28 ppm is ascribed to the C-1 in (1 → 4)-d-glucan, which was another proof for a glucan with an ␣-glycosidic linkage (Chakraborty, Mondal, Pramanik, Rout, & Islam, 2004).…”

Section: Purification and Chemical Properties Of Ipsmentioning

confidence: 99%

Physiochemical properties and antitumor activities of two α-glucans isolated from hot water and alkaline extracts of Cordyceps (Cs-HK1) fungal mycelia

Yan

Wang

Lin

et al. 2011

Carbohydrate Polymers

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“…The Ca 2+ , Mg 2+ , Co 2+ ions and stabilizers such as Triton X-100, Tween 80, glycerol, polyethylene glycols, dextran, glutaraldehyde and polyvinyl alcohols have been used for these enzyme systems [9,10]. Leuconostoc mesenteroides NRRL B-640 was shown to produce dextransucrase that gives highly linear and soluble dextran [11]. Dextransucrase from Leuconostoc mesenteroides NRRL B-640 was purifi ed [12] and the conditions for its assay were optimized [13].…”

Section: Introductionmentioning

confidence: 99%

Stabilization of dextransucrase from Leuconostoc mesenteroides NRRL B-640

2010

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Stabilization of dextransucrase from Leuconostoc mesenteroides NRRL B-640 with various stabilizers at different temperatures was studied. Dextransucrase was stable at lower temperatures (10-30°C) and lost the activity at above 30°C. The salts such as CaCl 2 , CoCl 2 and MgCl 2 enhanced the dextransucrase activity. A 22% higher dextransucrase activity was obtained by 4 mM CoCl 2 . The dextransucrase activity was lost by 50% at 1 mM EDTA. Urea denatured the enzyme and caused 45%, 90% and 98% loss of activity in 30 min when treated with 1 M, 3 M, and 5 M urea concentrations, respectively. Amongst the stabilizers Tween 80, glycerol, PEG-8000, dextran (500 kDa) and glutaraldehyde, Tween 80 provided the maximum stability at 30°C. In the presence of Tween 80 the enzyme lost only 8% activity at 30°C in 20 h but, it lost 65% of activity with out any stabilizer. The enzyme lost 92% of activity with in 4 days at 30°C and lost only 25% of activity at -20°C after 14 days.

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Structural analysis by 13C- nuclear magnetic resonance spectroscopy of glucan extracted from natural palm wine

Cited by 42 publications

References 12 publications

Production, extraction and characterization of exopolysaccharides produced by the native Leuconostoc pseudomesenteroides R2 strain

Production, extraction and characterization of exopolysaccharides produced by the native Leuconostoc pseudomesenteroides R2 strain

Physiochemical properties and antitumor activities of two α-glucans isolated from hot water and alkaline extracts of Cordyceps (Cs-HK1) fungal mycelia

Stabilization of dextransucrase from Leuconostoc mesenteroides NRRL B-640

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