Mannobiose

Mannobiose, mannotriose, mannotetraose, mannopentaose and mannohexaose, xylobiose, xylotriose, xylotetraose, xylopentaose and xylohexaose were from Megazyme (Ireland). Mannose, xylose, 2-picoline borane, 2-aminobenzamide, ethyl acetate, methanol and ammonium formate were purchased from Sigma-Aldrich (Germany).
Acetylated galactoglucomannan (AcGGM) from Norway spruce (Picea abies) was produced in house from dried wood chips^{79 (link)}. A simplified (lower DP range) version of this substrate, named GH26-AcGGM was produced by treating the AcGGM with a β-mannanase (R. intestinalis β-mannanase RiGH26).
Acetylated (arabino)glucuronoxylan (AcAGX) was produced in house from birch (Betula pubescens) chips^{80 (link)}. A simplified (lower DP range and deacetylated) version of this substrate, named GH10-AGX was produced by treating the AcAGX with sodium hydroxide to remove all acetylations followed by subsequent treatment with the commercial xylanase Shearzyme (Novozymes, Denmark).

Phosphoric acid swollen cellulose (PASC) was prepared as follows. 5 g of Avicel^® PH-101 was moistened with water and treated with 150 mL ice cold 85% phosphoric acid, stirred on an ice bath for 1 h. Then 500 mL cold acetone was added while stirring. The swollen cellulose was filtered on a glass-filter funnel and washed 3 times with 100 mL ice cold acetone and subsequently twice with 500 mL water. PASC was then suspended in 500 mL water and blended to homogeneity.
High-purity pachyman (β-d-1,3-glucan), barley β-glucan (β-d-1,3-1,4-glucan), lichenan (from Icelandic moss, β-d-1,3-1,4-glucan), mannan (borohydride reduced), konjac glucomannan (β-d-1,4), carob galactomannan, larch arabinogalactan, wheat arabinoxylan, cellotriose, cellotetraose, cellopentaose, cellohexaose, mannobiose, and xylobiose were purchased from Megazyme. Locust bean gum, carboxymethyl cellulose (CMC), beechwood xylan, and cellobiose were purchased from Sigma. 5-bromo-4-chloro-3-indolyl-β-d-cellobioside was purchased from Santa Cruz Biotechnology.

Concentrations of OS in the OligoPKC were assessed using HPLC (2690, Waters, USA) with a COSMOSIL Sugar-Dcolumn (250 × 4.6 mm i.d., 5 μm) according to the method described by Jahromi et al. [9 ]. The mobile phase consisted of acetonitrile and water (65:35 v:v) with flow rate of 0.7 mL/min and column temperature of 35°C. Refractive index detector (2414, Waters, USA) was used for the detection of OS in the sensitivity of 1024 and temperature of 30°C. The sample injection volume was 20 μL, and the running time was 20 min. According to Jaafar and Jarvis [10 ], the cell wall component of PKC consisted of 580 g/kg mannan, and Zhang et al. [11 ] reported the extraction of up to 48.8% of D-mannose from PKC, suggesting that major part of OligoPKC is mannan-based. Therefore, five pure MOS, i.e. mannobiose, mannotriose, mannotetraose, mannopentaose and mannohexaose (Megazyme, Ireland) were used as standards for the assay of OS in this study.
Monosaccharides were detected using the same method described for OS, but the mobile phase was changed to 80% acetonitrile in water (instead of 65% for OS) and flow rate was changed to 1 mL/min. glucose, eructose, mannose and xylose (Sigma-Aldrich, St. Louis, MO, USA) were used as standards.