Xylopentaose, also known as 1,4-β-D-xylopentaose, consists of five β-1,4-linked D-xylose units, with the formula C₂₅H₄₂O₂₁ and a molecular weight of 678.6 g/mol. This hemicellulose-derived oligosaccharide exhibits a predicted density of 1.75 g/cm³ and serves as a high-purity (>95%) substrate for endo-1,4-β-xylanases in enzymatic assays. Its linear structure facilitates studies on xylan degradation and biomass processing.
Structural Features
The repeating β-D-Xylp-(1→4) backbone defines its composition, distinguishing it from glucose-based cellopentaose by lacking hydroxymethyl groups on C5. Commercial forms appear as white powders supporting solubility in aqueous buffers for biochemical applications. Exact mass calculations confirm 678.222 Da, aiding NMR and HPLC characterization.
Biological and Enzymatic Roles
Xylopentaose acts as a model substrate for xylanases, glucuronidases, and carbohydrate-binding modules, enabling evaluation of hydrolysis to xylobiose (X2) and xylotriose (X3) with up to 61% conversion. It enhances xylooligosaccharide (XOS) production from lignocelluloses like moso bamboo via acid hydrolysis followed by xylanase treatment, yielding up to 65.7% XOS. Applications include profiling arabinofuranosidases on arabinoxylans and improving bioethanol production from invasive species like Acacia dealbata.
Research Applications
High-throughput screening uses xylopentaose for halotolerant glycoside hydrolases, with Km values around 3.5 mg/mL for enzymes like Xyl-L from Pichia pastoris. It supports neoglycoconjugate microarrays for monoclonal antibody recognition and nutraceutical XOS generation from flours, producing DP 2-4 oligomers. Purity standards from suppliers like Megazyme ensure reliability in biofuel saccharification and food industry enzyme optimization.
