6401-81-6Relevant articles and documents
Supercritical water treatment for cello-oligosaccharide production from microcrystalline cellulose
Tolonen, Lasse K.,Juvonen, Minna,Niemel?, Klaus,Mikkelson, Atte,Tenkanen, Maija,Sixta, Herbert
, p. 16 - 23 (2015/01/09)
Microcrystalline cellulose was treated in supercritical water at 380 °C and at a pressure of 250 bar for 0.2, 0.4, and 0.6 s. The yield of the ambient-water-insoluble precipitate and its average molar mass decreased with an extended treatment time. The highest yield of 42 wt % for DP2-9 cello-oligosaccharides was achieved after the 0.4 s treatment. The reaction products included also 11 wt % ambient-water-insoluble precipitate with a DPw of 16, and 6.1 wt % monomeric sugars, and 37 wt % unidentified degradation products. Oligo- and monosaccharide-derived dehydration and retro-aldol fragmentation products were analyzed via a combination of HPAEC-PAD-MS, ESI-MS/MS, and GC-MS techniques. The total amount of degradation products increased with treatment time, and fragmented (glucosyln-erythrose, glucosyln-glycolaldehyde), and dehydrated (glucosyln-levoglucosan) were identified as the main oligomeric degradation products from the cello-oligosaccharides.
Hydrolysis of konjac glucomannan by Trichoderma reesei mannanase and endoglucanases Cel7B and Cel5A for the production of glucomannooligosaccharides
Mikkelson, Atte,Maaheimo, Hannu,Hakala, Terhi K.
, p. 60 - 68 (2013/06/27)
In this paper we describe the enzymatic hydrolysis of konjac glucomannan for the production of glucomannooligosaccharides using purified Trichoderma reesei mannanase, endoglucanases EGI (Tr Cel7b) and EGII (Tr Cel5a). Hydrolysis with each of the three enzymes produced a different pattern of oligosaccharides. Mannanase was the most selective of the three enzymes in the hydrolysis of konjac mannan and over 99% of the formed oligosaccharides had mannose as their reducing end pyranosyl unit. Tr Cel5A hydrolysate shared similarities with mannanase and Tr Cel7B hydrolysates and the enzyme had the lowest substrate specificity of the studied enzymes. The hydrolysate of Tr Cel7B contained a series of oligosaccharides with non-reducing end mannose (M) and reducing end glucose (G) (MG, MMG, MMMG, and MMMMG). These oligosaccharides were isolated from the hydrolysate by size exclusion chromatography in relatively high purity (86-95%) and total yield (23% of substrate). The isolated oligosaccharides were characterized using acid hydrolysis and HPAEC-PAD (carbohydrate composition), HPLC-RI and HPAEC-MS (to determine the DP of purified oligosaccharides), enzymatic hydrolysis (determination of non-reducing end carbohydrate) and NMR (both 1D and 2D, to verify structure and purity of purified compounds). Hydrolysis of konjac mannan with a specific enzyme, such as T. reesei Cel7B or mannanase, followed by fractionation with SEC offers the possibility to produce glucomannooligosaccharides with defined structure. The isolated oligosaccharides can be utilised as analytical standards, for determination of bioactivity of oligosaccharides with defined structure or as substrates for defining substrate specificity of novel carbohydrate hydrolyzing enzymes.
GLYCOSIDE COMPOUND
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Paragraph 0319; 0320; 0383; 0384, (2013/11/06)
Compounds of formula (I″) wherein: R11, R12, R13, R14 and R15 are hydrogen, hydroxyl, C1-6 alkyl, C1-6 alkoxy, C1-6 alkyl-carbonyloxy, or a G-O— group, and at least one of R11, R12, R13, R14 and R15 is a G-O— group, wherein G is a saccharide residue,X1 is a single bond, or a methylene group, an ethylene group, a trimethylene group, a vinylene group or —CH═CH—CH2—,X2 is —CO—O— or —O—CO—,p and q are integer ofs 0 to 7, and p+q=0 to 8,Y1 is methylene, ethylene or an alkenylene group having a carbon number of 2 to 15 and 1 to 3 double bonds, andR16 and R17 are hydrogen, methyl or ethyl, or R16 and R17 form a C3-6 cycloalkyl group, are useful as GLP-1 secretion promoting agents.
