Isolation and characterization of water-soluble hemicelluloses from flax shive.
Partially depolymerized, water-soluble hemicelluloses were solubilized from flax shive employing hydrothermal microwave treatment and thereafter subjected to ion-exchange chromatography, enzymatic purification and/or size-exclusion chromatography (SEC). The oligo- and polysaccharide fractions thus obtained were characterized with respect to molar mass, molar mass distribution, degree of polymerization (DP) and degree of substitution with acetyl moieties (DSAc) by employing SEC in combination with MALDI-TOF mass spectrometry. The major portion of the water-soluble flax hemicellulose consisted of an O-acetyl-4-O-methylglucuronoxylan exhibiting a DPp value (i.e., peak-average DP) of 28. When the DSAc for this O-acetyl-4-O-methylglucuronoxylan was calculated on the basis of the MALDI-MS spectra obtained without and following deacetylation, a value of 0.7 was obtained. In addition, an O-acetyl-glucomannan (DPp=9, DS=0.4) and minor quantities of small neutral O-acetyl-xylooligosaccharides were also isolated from the mixture of water-soluble hemicelluloses released from the flax shive by microwave treatment.
Jacobs
Anna
A
STFI, Swedish Pulp and Paper Research Institute, PO Box 5604, SE-114 86 Stockholm, Sweden. anna.jacobs@stfi.se
Palm
Magnus
M
Zacchi
Guido
G
Dahlman
Olof
O
D000085:Acetates / Q000737:chemistry; D001089:Arabinose / Q000032:analysis; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism; D019597:Flax / Q000737:chemistry*; D005690:Galactose / Q000032:analysis; D005936:Glucans / Q000032:analysis; D005947:Glucose / Q000032:analysis; D005965:Glucuronates / Q000032:analysis; D020723:Glucuronic Acid / Q000032:analysis; D006603:Hexuronic Acids / Q000032:analysis; D006868:Hydrolysis; D008351:Mannans / Q000737:chemistry* / Q000302:isolation & purification; D008358:Mannose / Q000032:analysis; D008872:Microwaves; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D012995:Solubility; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014990:Xylans / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D014994:Xylose / Q000032:analysis
D000085:Acetates; D005936:Glucans; D005965:Glucuronates; D006603:Hexuronic Acids; D008351:Mannans; C456725:O-acetyl-(4-O-methylglucurono)xylan; D011134:Polysaccharides; D014990:Xylans; C036035:4-O-methylglucuronic acid; C022901:(1-6)-alpha-glucomannan; C029353:xyloglucan; C038910:glucuronoxylan; C007819:galacturonic acid; C007916:hemicellulose; D020723:Glucuronic Acid; D014994:Xylose; D001089:Arabinose; D043364:Endo-1,4-beta Xylanases; D005947:Glucose; D008358:Mannose; D005690:Galactose