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1.
Carbohydr Polym ; 339: 122248, 2024 Sep 01.
Article in English | MEDLINE | ID: mdl-38823916

ABSTRACT

Arabinoxylan is a major hemicellulose in the sugarcane plant cell wall with arabinose decorations that impose steric restrictions on the activity of xylanases against this substrate. Enzymatic removal of the decorations by arabinofuranosidases can allow a more efficient arabinoxylan degradation by xylanases. Here we produced and characterized a recombinant Bifidobacterium longum arabinofuranosidase from glycoside hydrolase family 43 (BlAbf43) and applied it, together with GH10 and GH11 xylanases, to produce xylooligosaccharides (XOS) from wheat arabinoxylan and alkali pretreated sugarcane bagasse. The enzyme synergistically enhanced XOS production by GH10 and GH11 xylanases, being particularly efficient in combination with the latter family of enzymes, with a degree of synergism of 1.7. We also demonstrated that the enzyme is capable of not only removing arabinose decorations from the arabinoxylan and from the non-reducing end of the oligomeric substrates, but also hydrolyzing the xylan backbone yielding mostly xylobiose and xylose in particular cases. Structural studies of BlAbf43 shed light on the molecular basis of the substrate recognition and allowed hypothesizing on the structural reasons of its multifunctionality.


Subject(s)
Bifidobacterium longum , Cellulose , Endo-1,4-beta Xylanases , Glucuronates , Glycoside Hydrolases , Oligosaccharides , Saccharum , Xylans , Oligosaccharides/chemistry , Oligosaccharides/metabolism , Glycoside Hydrolases/metabolism , Glycoside Hydrolases/chemistry , Glucuronates/metabolism , Glucuronates/chemistry , Endo-1,4-beta Xylanases/metabolism , Endo-1,4-beta Xylanases/chemistry , Xylans/metabolism , Xylans/chemistry , Saccharum/chemistry , Saccharum/metabolism , Cellulose/chemistry , Cellulose/metabolism , Bifidobacterium longum/enzymology , Bifidobacterium longum/metabolism , Hydrolysis , Substrate Specificity , Recombinant Proteins/metabolism , Recombinant Proteins/chemistry , Disaccharides
2.
Int J Biol Macromol ; 269(Pt 1): 132134, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38719013

ABSTRACT

Stimulus-responsive nanomaterials, particularly with targeting capabilities, have garnered significant attention in the cancer therapy. However, the biological safety of these innovative materials in vivo remains unknown, posing a hurdle to their clinical application. Here, a pH/H2O2 dual-responsive and targeting nano carrier system (NCS) was developed using core shell structure of Fe3O4 mesoporous silicon (MSN@Fe3O4) as main body, scutellarin (SCU) as antitumor drug and polymer cyclodextrin (PCD) as molecular switch (denoted as PCD@SCU@MSN@Fe3O4, abbreviated as NCS). The NCS, with an average particle size of 100 nm, displayed exceptional SCU loading capacity, a result of its uniform radial channel structure. The in vitro investigation under condition of pH and H2O2 indicated that NCS performed excellent pH/H2O2-triggered SCU release behavior. The NCS displayed a higher cytotoxicity against tumor cells (Huh7 and HCT116) due to its pH/H2O2 dual-triggered responsiveness, while the PCD@MSN@Fe3O4 demonstrated lower cytotoxicity for both Huh7 and HCT116 cells. In vivo therapeutic evaluation of NCS indicates significant inhibition of tumor growth in mouse subcutaneous tumor models, with no apparent side-effects detected. The NCS not only enhances the bioavailability of SCU, but also utilizes magnetic targeting technology to deliver SCU accurately to tumor sites. These findings underscore the substantial clinical application potential of NCS.


Subject(s)
Apigenin , Cyclodextrins , Drug Carriers , Glucuronates , Hydrogen Peroxide , Silicon , Animals , Humans , Cyclodextrins/chemistry , Mice , Hydrogen Peroxide/chemistry , Apigenin/chemistry , Apigenin/pharmacology , Drug Carriers/chemistry , Hydrogen-Ion Concentration , Glucuronates/chemistry , Glucuronates/pharmacology , Silicon/chemistry , Porosity , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Cell Line, Tumor , Xenograft Model Antitumor Assays , Drug Liberation , Neoplasms/drug therapy , Nanoparticles/chemistry , Cellulose
3.
Int J Biol Macromol ; 270(Pt 2): 132211, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38723833

ABSTRACT

Prebiotics are non-digestible compounds that promote intestinal microbiota growth and/or activity. Xylooligosaccharides (XOS) are new prebiotics derived from the hemicellulose fraction of lignocellulosic materials. Challenges in using those materials as sources for prebiotic compounds lie in the hemicellulose extraction efficiency and the safety of those ingredients. In this sense, this work aims to optimize hemicellulose extraction and XOS production through direct enzymatic hydrolysis of alkali pre-treated wheat straw without undesired byproducts. By increasing the temperature of the enzymatic step from 40 °C to 65 °C we achieved an improvement in the extraction yield from 55 % to 80 %. Products with different degrees of polymerization were also noticed: while XOS ≤ X6 where the main products at 40 °C, a mixture of long arabinoxylan derived polymers (ADPo) and XOS ≤ X6 was obtained at 65 °C, irrespective of the extraction yield. Thus, a modulatory effect of temperature on the product profile is suggested here. Among the XOS ≤ X6 produced, X2-X3 were the main products, and X4 was the minor one. At the end of the hydrolysis, 146.7 mg XOS per gram of pre-treated wheat straw were obtained.


Subject(s)
Endo-1,4-beta Xylanases , Oligosaccharides , Polysaccharides , Temperature , Triticum , Triticum/chemistry , Hydrolysis , Polysaccharides/chemistry , Endo-1,4-beta Xylanases/metabolism , Oligosaccharides/chemistry , Glucuronates/chemistry , Xylans/chemistry , Xylans/metabolism
4.
Carbohydr Polym ; 337: 122141, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38710568

ABSTRACT

Production of value-added compounds and sustainable materials from agro-industrial residues is essential for better waste management and building of circular economy. This includes valorization of hemicellulosic fraction of plant biomass, the second most abundant biopolymer from plant cell walls, aiming to produce prebiotic oligosaccharides, widely explored in food and feed industries. In this work, we conducted biochemical and biophysical characterization of a prokaryotic two-domain R. champanellensis xylanase from glycoside hydrolase (GH) family 30 (RcXyn30A), and evaluated its applicability for XOS production from glucuronoxylan in combination with two endo-xylanases from GH10 and GH11 families and a GH11 xylobiohydrolase. RcXyn30A liberates mainly long monoglucuronylated xylooligosaccharides and is inefficient in cleaving unbranched oligosaccharides. Crystallographic structure of RcXyn30A catalytic domain was solved and refined to 1.37 Å resolution. Structural analysis of the catalytic domain releveled that its high affinity for glucuronic acid substituted xylan is due to the coordination of the substrate decoration by several hydrogen bonds and ionic interactions in the subsite -2. Furthermore, the protein has a larger ß5-α5 loop as compared to other GH30 xylanases, which might be crucial for creating an additional aglycone subsite (+3) of the catalytic site. Finally, RcXyn30A activity is synergic to that of GH11 xylobiohydrolase.


Subject(s)
Endo-1,4-beta Xylanases , Gastrointestinal Microbiome , Glucuronates , Oligosaccharides , Xylosidases , Glucuronates/metabolism , Glucuronates/chemistry , Oligosaccharides/chemistry , Oligosaccharides/metabolism , Endo-1,4-beta Xylanases/metabolism , Endo-1,4-beta Xylanases/chemistry , Xylosidases/metabolism , Xylosidases/chemistry , Humans , Crystallography, X-Ray , Xylans/chemistry , Xylans/metabolism , Catalytic Domain , Models, Molecular , Substrate Specificity
5.
Int J Biol Macromol ; 259(Pt 2): 129262, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38199559

ABSTRACT

XOS production from lignocellulose using organic carboxylic acids and alkyd acids has been widely reported. However, it still faces harsh challenges such as high energy consumption, high cost, and low purity. Pyruvic acid (PYA), a carbonyl acid with carbonyl and carboxyl groups, was used to produce XOS due to its stronger catalytic activity. In this work, XOS was efficiently prepared from COS in an autoclave under the condition of 0.21 M PYA-121 °C-35 min. The total yield of XOS reached 68.72 % without producing any toxic by-products, including furfural (FF) and 5-hydroxymethylfurfural (5-HMF). The yield of xylobiose (X2), xylotriose (X3), xylotetraose (X4), and xylopentaose (X5) were 20.58 %, 12.47 %, 15.74 %, and 10.05 %, respectively. Meanwhile, 89.05 % of lignin was retained in the solid residue, which provides a crucial functional group for synthesizing layered carbon materials (SRG-a). It achieves excellent electromagnetic shielding (EMS) performance through graphitization, reaching -30 dB at a thickness of 2.0 mm. The use of a PYA catalyst in the production of XOS has proven to be an efficient method due to lower temperature, lower acid consumption, and straightforward operation.


Subject(s)
Camellia , Pyruvic Acid , Temperature , Hydrolysis , Oligosaccharides/chemistry , Glucuronates/chemistry , Acids
6.
Biomacromolecules ; 24(1): 132-140, 2023 01 09.
Article in English | MEDLINE | ID: mdl-36542490

ABSTRACT

Xylooligosaccharides (XOSs) gained much attention for their use in food and animal feed, attributed to their prebiotic function. These short-chained carbohydrates can be enzymatically produced from xylan, one of the most prevalent forms of hemicellulose. In this work, endo-1,4-ß-xylanase from Thermotoga maritima was immobilized on cellulose-based beads with the goal of producing xylooligosaccharides with degrees of polymerization (DPs) in the range of 4-6 monomeric units. More specifically, the impact of different spacer arms, tethers connecting the enzyme with the particle, on the expressed enzymatic activity and oligosaccharide yield was investigated. After surface functionalization of the cellulose beads, the presence of amines was confirmed with time of flight secondary ion mass spectrometry (TOF-SIMS), and the influence of different spacer arms on xylanase activity was established. Furthermore, XOSs (DPs 2-6) with up to 58.27 mg/g xylan were obtained, which were greatly enriched in longer oligosaccharides. Approximately 80% of these XOSs displayed DPs between 4 and 6. These findings highlight the importance of topochemical engineering of carriers to influence enzyme activity, and the work puts forward an enzymatic system focusing on the production of longer xylooligosaccharides.


Subject(s)
Cellulose , Endo-1,4-beta Xylanases , Endo-1,4-beta Xylanases/chemistry , Xylans/chemistry , Hydrolysis , Oligosaccharides/chemistry , Glucuronates/chemistry
7.
Bioresour Technol ; 362: 127800, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36007765

ABSTRACT

The application of biorefinery concepts to produce different value-added biomolecules such as xylooligosaccharides (XOs) generates economical competitive, sustainable and environmentally friendly processes. The objective of this work was to develop an efficient imidazole-pretreatment process of sugarcane bagasse (SB) and the use of the obtained hemicellulose fraction in the production of XOs with the application of in house produced xylanolytic enzymes using SB as substrate, under a biorefinery approach. SB imidazole pretreatment allowed the recovery of a hemicellulose rich fraction (34%) with 91.2% of delignification. Xylanase production by Aspergillus niger reached 53.1 U·mL-1 at 120 h. The application of produced xylanases in the enzymatic hydrolysis of extracted xylan, allowed the production of 6.06 g·L-1 of XOs, where xylotriose represented >70%. Great perspectives are viewed for the implementation of mixed processes in a sustainable closed cycle to produce biomolecules with concomitant valorization of subproducts from SB chain.


Subject(s)
Saccharum , Cellulose/chemistry , Endo-1,4-beta Xylanases/chemistry , Glucuronates/chemistry , Hydrolysis , Imidazoles , Oligosaccharides , Saccharum/chemistry
8.
Carbohydr Polym ; 292: 119641, 2022 Sep 15.
Article in English | MEDLINE | ID: mdl-35725201

ABSTRACT

In order to produce xylooligosaccharides (XOS) with excellent prebiotics properties from industrial-derived xylan residue (IDXR), maleic acid (MA) and citric acid (CA) were used as catalysts under different treatment conditions. Under the identified optimum conditions (0.1 M of MA and 0.5 M of CA at 150 °C for 40 min), CA showed a better ability than MA to maximumly produce XOS. The yields of XOS from MA and CA treatments were 48.9% and 52.3%, which were comprised of X2-X6 proportions of 69.47% and 66.70%, respectively. Anaerobic fermentation results demonstrated that both XOS-CA and XOS-MA exhibited pronounced prebiotic activity for proliferating Bifidobacterium adolescentis (B. adolescentis) and Lactobacillus acidophilus (L. acidophilus). XOS-CA possessed the better ability for B. adolescentis to produce the short-chain fatty acid (SCFA), while XOS-MA outperformed XOS-CA for L. acidophilus to produce SCFA. These results imply organic acid treatments can be applied to produce XOS with excellent prebiotic properties from IDXR.


Subject(s)
Glucuronates/analysis , Oligosaccharides/analysis , Prebiotics , Xylans , Acids/chemistry , Fatty Acids, Volatile/chemistry , Glucuronates/chemistry , Hydrolysis , Oligosaccharides/chemistry
9.
Food Chem ; 391: 133231, 2022 Oct 15.
Article in English | MEDLINE | ID: mdl-35613528

ABSTRACT

This study explores the structural characterization, antioxidant and prebiotic activities of hydrolysates containing xylooligosaccharides (XOS) produced by different strategies: direct fermentation of beechwood xylan (FermBX) and enzymatic treatment of beechwood (EnzBX) and rice husk (EnzRH) xylans. EnzBX and EnzRH showed XOS with a backbone of (1 â†’ 4)-linked-xylopyranosyl residues and branches of arabinose, galactose, and uronic acids. FermBX presented the highest content of total phenolic compounds (14 mg GAE/g) and flavonoids (0.6 mg QE/g), which may contribute to its antioxidant capacity -39.1 µmol TE/g (DPPH), 45.7 µmol TE/g (ABTS), and 79.9 µmol Fe II/g (FRAP). The fermentation of hydrolysates decreased the abundance of microorganisms associated with intestinal diseases from Eubacteriales, Desulfovibrionales and Methanobacteriales orders, while stimulating the growth of organisms belonging to Bacteroides, Megamonas and Limosilactobacillus genera. The production of short-chain fatty acids, ammonia, and CO2 suggested the prebiotic potential. In conclusion, hydrolysates without previous purification and obtained from non-chemical approaches demonstrated promising biological activities for further food applications.


Subject(s)
Antioxidants , Prebiotics , Endo-1,4-beta Xylanases/chemistry , Glucuronates/chemistry , Hydrolysis , Oligosaccharides/chemistry , Xylans/chemistry
10.
Bioresour Technol ; 352: 127041, 2022 May.
Article in English | MEDLINE | ID: mdl-35318144

ABSTRACT

Generation of specific xylooligosaccharides (XOS) is attractive to the pharmaceutical and food industries due to the importance of their structure upon their application. This study used chemometrics to develop a comprehensive computational modelling set to predict the parameters maximising the generation of the desired XOS during enzymatic hydrolysis. The evaluated parameters included pH, temperature, substrate concentration, enzyme dosage and reaction time. A Box-Behnken design was combined with response surface methodology to develop the models. High-performance anion-exchange chromatography coupled with triple-quadrupole mass spectrometry (HPAEC-QqQ-MS) allowed the identification of 22 XOS within beechwood xylan hydrolysates. These data were used to validate the developed models and demonstrated their accuracy in predicting the parameters maximising the generation of the desired XOS. The maximum yields for X2-X6 were 314.2 ± 1.2, 76.6 ± 4.5, 38.4 ± 0.4, 17.8 ± 0.7, and 5.3 ± 0.2 mg/g xylan, respectively. These values map closely to the model predicted values 311.7, 92.6, 43.0, 16.3, and 4.9 mg/g xylan, respectively.


Subject(s)
Chemometrics , Xylans , Chromatography , Endo-1,4-beta Xylanases/chemistry , Glucuronates/chemistry , Hydrolysis , Oligosaccharides/chemistry , Xylans/chemistry
11.
J Chromatogr A ; 1666: 462836, 2022 Mar 15.
Article in English | MEDLINE | ID: mdl-35108629

ABSTRACT

High-performance anion-exchange chromatography (HPAEC) coupled with triple quadrupole mass spectrometry (HPAEC-QqQ-MS) was applied to the determination of xylooligosaccharides (XOS) derived from enzymatically hydrolysed commercial xylan from beechwood and the analytical performance and advantages of the method explored. Separation, eluent suppression, electrospray ionisation, and detection options to enhance XOS sensitivity and selectivity were evaluated, delivering a new simple, fast, selective, and sensitive solution for the characterisation of these complex compounds. The method was fully validated in terms of its analytical performance for those XOS for which standards were available, i.e., degree of polymerisation from 1 to 6. The new method was applied to the analysis of xylan hydrolysates obtained by different enzymatic hydrolysis treatments using endo-xylanase from Thermomyces lanuginosus, characterising 25 different XOS and demonstrating the method's utility for future tailoring of enzymatic hydrolysis conditions to obtain desired XOS profiles in such hydrolysates. Linear XOS and 4-O-methyl glucuronic acid (MeGluA) branched XOS were detected by direct injection of the xylan hydrolysates after a simple 10-fold sample dilution and filtration. Identification of XOS detected by HPAEC-QqQ-MS was additionally confirmed using high-resolution orbitrap mass spectrometry (HR-orbitrap-MS). Further, an ultra-sensitive and -selective method was developed by using selected reaction monitoring acquisition mode (SRM), increasing signal-to noise ratio and decreasing the limits of detection, opening future applications to low concentrated sample analysis.


Subject(s)
Tandem Mass Spectrometry , Xylans , Anions , Chromatography , Glucuronates/chemistry , Hydrolysis , Oligosaccharides/chemistry , Xylans/chemistry
12.
Bioengineered ; 13(1): 1013-1024, 2022 01.
Article in English | MEDLINE | ID: mdl-34974800

ABSTRACT

The present research aimed to elucidate a convenient, safe and economic approach to induce the growth of endogenous bone tissue and bone regeneration. S-UNL-E was prepared using reverse-phase evaporation, and scutellarin encapsulation was subsequently compared. Meanwhile, the optimal preparation scheme was developed using an orthogonal method, and the particle size was determined using laser light scattering. In osteoblasts cultured in vitro, methyl thiazolyl tetrazolium (MTT), alkaline phosphatase (ALP) staining and alizarin red staining were used to detect the osteogenic effects of S-UNL-E. The results indicated that the optimal process conditions for S-UNL-E included mass ratios of phospholipid-cholesterol, phospholipid-breviscapine, phospholipid-sodium cholate, and phospholipid-stearamide were 2:1, 15:1, 7:1 and 7:1, respectively, and the mass of ethylenediamine tetramethylphosphonic acid (EDTMP) was 30 mg. The average particle size of S-UNL-E was 156.67 ± 1.76 nm, and Zeta potential was -28.77 ± 0.66 mv. S-UNL-E substantially increased the expression of ALP osteoblasts, elevated the content of osteocalcin protein and promoted the formation of mineralized nodules. Cells in the S-UNL-E group were densely distributed with integrated cell structure, and the actin filaments were clear and obvious. The findings demonstrated that S-UNL-E greatly promoted the differentiation and maturation of osteoblasts, and S-UNL-E (2.5 × 108) produced the most favorable effect in differentiation promotion. In conclusion, the present study successfully constructed an S-UNL-E material characterized by high encapsulation and high stability, which could effectively promote osteogenic differentiation and bone formation.


Subject(s)
Actin Cytoskeleton/metabolism , Alkaline Phosphatase/metabolism , Apigenin/pharmacology , Glucuronates/pharmacology , Osteoblasts/cytology , Osteocalcin/metabolism , Animals , Apigenin/chemistry , Cell Differentiation/drug effects , Cells, Cultured , Drug Compounding , Glucuronates/chemistry , Liposomes , Nanoparticles , Osteoblasts/drug effects , Osteoblasts/metabolism , Osteogenesis , Particle Size , Primary Cell Culture , Rats
13.
Sci Rep ; 12(1): 11, 2022 01 07.
Article in English | MEDLINE | ID: mdl-34996923

ABSTRACT

The prebiotic properties of xylooligosaccharides (XOS) and arabino-xylooligosaccharides (AXOS) produced from rice husk (RH) using microwave treatment combined with enzymatic hydrolysis were evaluated. The RH was subjected to microwave pretreatment at 140, 160 and 180 °C for 5, 10 and 15 min to obtain crude arabinoxylan (AX). Increasing microwave pretreatment time increased sugar content. Crude AX was extracted with 2% (w/v) sodium hydroxide at 25 °C for 24 h and used as a substrate for XOS production by commercial xylanases. Results showed that oligosaccharides produced by Pentopan Mono BG and Ultraflo Max provided xylobiose and xylotriose as the main products. AXOS was also present in the oligosaccharides that promoted growth of Lactobacillus spp. and resisted degradation by over 70% after exposure to simulated human digestion.


Subject(s)
Endo-1,4-beta Xylanases/chemistry , Glucuronates/chemistry , Oligosaccharides/chemistry , Oryza/chemistry , Xylans/chemistry , Alkalies/chemistry , Disaccharides/analysis , Hydrolysis , Microwaves , Oryza/radiation effects , Prebiotics/analysis , Seeds/chemistry , Trisaccharides/analysis
14.
Mol Biotechnol ; 64(1): 75-89, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34542815

ABSTRACT

Xylooligosaccharides having various degrees of polymerization such as xylobiose, xylotriose, and xylotetraose positively affect human health by interacting with gut proteins. The present study aimed to identify proteins present in gut microflora, such as xylosidase, xylulokinase, etc., with the help of retrieved whole-genome annotations and find out the mechanistic interactions of those with the above substrates. The 3D structures of proteins, namely Endo-1,4-beta-xylanase B (XynB) from Lactobacillus brevis and beta-D-xylosidase (Xyl3) from Bifidobacterium adolescentis, were computationally predicted and validated with the help of various bioinformatics tools. Molecular docking studies identified the effectual binding of these proteins to the xylooligosaccharides, and the stabilities of the best-docked complexes were analyzed by molecular dynamic simulation. The present study demonstrated that XynB and Xyl3 showed better effectual binding toward Xylobiose with the binding energies of - 5.96 kcal/mol and - 4.2 kcal/mol, respectively. The interactions were stabilized by several hydrogen bonding having desolvation energy (- 6.59 and - 7.91). The conformational stabilities of the docked complexes were observed in the four selected complexes of XynB-xylotriose, XynB-xylotetraose, Xyl3-xylobiose, and Xyn3-xylotriose by MD simulations. This study showed that the interactions of these four complexes are stable, which means they have complex metabolic activities among each other. Extending these studies of understanding, the interaction between specific probiotics enzymes and their ligands can explore the detailed design of synbiotics in the future.


Subject(s)
Bifidobacterium adolescentis/metabolism , Glucuronates/metabolism , Levilactobacillus brevis/metabolism , Oligosaccharides/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Bifidobacterium adolescentis/genetics , Computational Biology , Disaccharides/chemistry , Disaccharides/metabolism , Endo-1,4-beta Xylanases/chemistry , Endo-1,4-beta Xylanases/genetics , Genome, Bacterial/genetics , Glucuronates/chemistry , Humans , Levilactobacillus brevis/genetics , Molecular Docking Simulation , Molecular Dynamics Simulation , Oligosaccharides/chemistry , Probiotics/metabolism , Trisaccharides/chemistry , Trisaccharides/metabolism , Xylosidases/chemistry , Xylosidases/genetics
15.
Carbohydr Polym ; 275: 118684, 2022 Jan 01.
Article in English | MEDLINE | ID: mdl-34742414

ABSTRACT

Bioconversion of lignocellulosic biomass into value-added products relies on polysaccharides depolymerization by carbohydrate active enzymes. This work reports biochemical characterization of Paludibacter propionicigenes xylanase from GH10 (PpXyn10A) and its application for enzymatic xylooligosaccharides (XOS) production from commercial heteroxylans and liquor of hydrothermally pretreated corn cobs (PCC). PpXyn10A is tolerant to ethanol and NaCl, and releases xylobiose (X2) and xylotriose (X3) as the main hydrolytic products. The conversion rate of complex substrates into short XOS was approximately 30% for glucuronoxylan and 8.8% for rye arabinoxylan, after only 4 h; while for PCC, PpXyn10A greatly increased unbranched XOS yields. B. adolescentis fermentation with XOS from beechwood glucuronoxylan produced mainly acetic and lactic acids. Structural analysis shows that while the glycone region of PpXyn10A active site is well preserved, the aglycone region has aromatic interactions in the +2 subsite that may explain why PpXyn10A does not release xylose.


Subject(s)
Bacteroidetes , Endo-1,4-beta Xylanases/metabolism , Glucuronates/chemistry , Oligosaccharides/chemistry , Xylans/chemistry , Animals , Bifidobacterium adolescentis/drug effects , Disaccharides/chemistry , Fermentation , Glucuronates/pharmacology , Humans , Hydrolysis , Oligosaccharides/pharmacology , Prebiotics , Trisaccharides/chemistry , Xylose/chemistry , Zea mays/chemistry
16.
Biotechnol Lett ; 43(12): 2299-2310, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34718907

ABSTRACT

OBJECTIVE: To develop an endo-ß-1,4-xylanase with high specificity for production of prebiotic xylooligosaccharides that optimally works at moderate temperature desirable to reduce the energy cost in the production process. RESULTS: The xylB gene, encoding for a glycosyl hydrolase family 11 xylanase from a thermoresistant fungus, Aspergillus niger BCC14405 was expressed in a methylotrophic yeast P. pastoris KM71 in a secreted form. The recombinant XylB showed a high specific activity of 3852 and 169 U mg-1 protein on beechwood xylan and arabinoxylan, respectively with no detectable side activities against different forms of cellulose (Avicel Ò PH101 microcrystalline cellulose, phosphoric acid swollen cellulose and carboxymethylcellulose). The enzyme worked optimally at 45 °C, pH 6.0. It showed a specific cleavage pattern by releasing xylobiose (X2) as the major product from xylooligosaccharides (X3 to X6) substrates. The highest XOS yield of 708 mg g-1 substrate comprising X2, X3 and X6 was obtained from beechwood xylan hydrolysis. CONCLUSION: The enzyme is potent for XOS production and for saccharification of lignocellulosic biomass.


Subject(s)
Aspergillus niger/chemistry , Endo-1,4-beta Xylanases/genetics , Glucuronates/biosynthesis , Oligosaccharides/biosynthesis , Xylans/metabolism , Aspergillus niger/enzymology , Endo-1,4-beta Xylanases/isolation & purification , Enzyme Stability/genetics , Glucuronates/chemistry , Hydrogen-Ion Concentration , Hydrolysis , Oligosaccharides/chemistry , Substrate Specificity , Temperature , Xylans/genetics
17.
World J Microbiol Biotechnol ; 37(10): 169, 2021 Sep 06.
Article in English | MEDLINE | ID: mdl-34487266

ABSTRACT

The majority of lignocellulosic biomass on the planet originates from plant cell walls, which are complex structures build up mainly by cellulose, hemicellulose and lignin. The largest part of hemicellulose, xylan, is a polymer with a ß-(1→4)-linked xylose residues backbone decorated with α-D-glucopyranosyl uronic acids and/or L-arabinofuranose residues. Xylan is the second most abundant biopolymer in nature, which can be sustainably and efficiently degraded into decorated and undecorated xylooligosaccharides (XOS) using combinations of thermochemical pretreatments and enzymatic hydrolyses, that have broad applications in the food, feed, pharmaceutical and cosmetic industries. Endo-xylanases from different complex carbohydrate-active enzyme (CAZyme) families can be used to cleave the backbone of arabino(glucurono)xylans and xylooligosaccharides and degrade them into short XOS. It has been shown that XOS with a low degree of polymerization have enhanced prebiotic effects conferring health benefits to humans and animals. In this review we describe recent advances in the enzymatic production of XOS from lignocellulosic biomass arabino- and glucuronoxylans and their applications as food and feed additives and health-promoting ingredients. Comparative advantages of xylanases from different CAZy families in XOS production are discussed and potential health benefits of different XOS are presented.


Subject(s)
Biotechnology/trends , Endo-1,4-beta Xylanases/chemistry , Glucuronates/chemistry , Oligosaccharides/chemistry , Xylans/chemistry , Biocatalysis , Hydrolysis
18.
Carbohydr Polym ; 273: 118510, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34560939

ABSTRACT

Human cytomegalovirus (HCMV) remains a major public health burden worldwide. The anti-HCMV activity of glucuronomannan oligosaccharides (Gs) and sulphated glucuronomannan oligosaccharides (SGs) was investigated. Among these Gs and SGs, G4S1 and G6S1 (higher sulphated glucuronomannan tetramer and hexamer) showed satisfactory anti-HCMV activity starting at 50 µg/mL and 10 µg/mL, respectively. The results of the morphology, western blotting, qPCR and TCID50 assay showed that they prevented lytic cytopathic changes, inhibited the expression of IE1/2 and UL44, and reduced the UL123 copy number and virus titre significantly. It was interesting to note that degree of sulphation and polymerization was more important for anti-HCMV activity. Moreover, the anti-HCMV activities of G4S1 and G6S1 were stable when stored at 4 °C, -20 °C, and -80 °C for at least three months and mainly occurred in the early stage of HCMV infection through the negative charge of the sulphate groups and the interaction between SGs and the host cells.


Subject(s)
Antiviral Agents/pharmacology , Cytomegalovirus/drug effects , Glucuronates/pharmacology , Mannose/analogs & derivatives , Sargassum/chemistry , Sulfates/chemistry , Virus Internalization/drug effects , Cell Line , Cell Survival/drug effects , Cytomegalovirus Infections/virology , Glucuronates/chemistry , Humans , Mannose/chemistry , Mannose/pharmacology , Virus Replication/drug effects
19.
Molecules ; 26(15)2021 Jul 30.
Article in English | MEDLINE | ID: mdl-34361767

ABSTRACT

This study describes the catalytic properties of a GH30_7 xylanase produced by the fungus Talaromyces leycettanus. The enzyme is an ando-ß-1,4-xylanase, showing similar specific activity towards glucuronoxylan, arabinoxylan, and rhodymenan (linear ß-1,3-ß-1,4-xylan). The heteroxylans are hydrolyzed to a mixture of linear as well as branched ß-1,4-xylooligosaccharides that are shorter than the products generated by GH10 and GH11 xylanases. In the rhodymenan hydrolyzate, the linear ß-1,4-xylooligosaccharides are accompanied with a series of mixed linkage homologues. Initial hydrolysis of glucuronoxylan resembles the action of other GH30_7 and GH30_8 glucuronoxylanases, resulting in a series of aldouronic acids of a general formula MeGlcA2Xyln. Due to the significant non-specific endoxylanase activity of the enzyme, these acidic products are further attacked in the unbranched regions, finally yielding MeGlcA2Xyl2-3. The accommodation of a substituted xylosyl residue in the -2 subsite also applies in arabinoxylan depolymerization. Moreover, the xylose residue may be arabinosylated at both positions 2 and 3, without negatively affecting the main chain cleavage. The catalytic properties of the enzyme, particularly the great tolerance of the side-chain substituents, make the enzyme attractive for biotechnological applications. The enzyme is also another example of extraordinarily great catalytic diversity among eukaryotic GH30_7 xylanases.


Subject(s)
Endo-1,4-beta Xylanases/metabolism , Fungal Proteins/metabolism , Talaromyces/enzymology , Xylans/metabolism , Amino Acid Sequence , Arabinose/chemistry , Arabinose/metabolism , Carbohydrate Sequence , Endo-1,4-beta Xylanases/genetics , Fungal Proteins/genetics , Gene Expression , Glucuronates/chemistry , Glucuronates/metabolism , Hydrolysis , Oligosaccharides/chemistry , Oligosaccharides/metabolism , Sequence Alignment , Sequence Homology, Amino Acid , Substrate Specificity , Talaromyces/chemistry , Talaromyces/genetics , Xylans/chemistry
20.
Am J Chin Med ; 49(6): 1369-1397, 2021.
Article in English | MEDLINE | ID: mdl-34263720

ABSTRACT

Breviscapine is one of the extracts of several flavonoids of Erigeron breviscapus. Scutellarin is the main active component of breviscapine, and the qualitative or quantitative criteria as well. Scutellarin and its analogs share a similar skeleton of the flavonoids. Breviscapine has been widely used in the treatment of cerebral infarction and its sequelae, cerebral thrombus, coronary heart disease (CHD), and angina pectoris. Breviscapine has a broad spectrum of pharmacological activities, such as increasing blood flow, improving microcirculation, dilating blood vessels, decreasing blood viscosity, promoting fibrinolysis, inhibiting platelet aggregation, and thrombosis formation, etc. In addition, breviscapine and its analogs have significant value for drug research and development because of the superiority of those significant bioactivities. Furthermore, an increasing number of pharmacokinetic studies have explored the mechanism of scutellarin and its analogs. To provide a comprehensive understanding of the current research on breviscapine, scutellarin, and the analogs, the structural features, distribution situation, preparation method, content determination method, clinical applications, pharmacological action as well as pharmacokinetics are summarized in the present review.


Subject(s)
Apigenin , Flavonoids , Glucuronates , Plant Extracts , Apigenin/chemistry , Apigenin/pharmacokinetics , Apigenin/pharmacology , Flavonoids/chemistry , Flavonoids/pharmacokinetics , Flavonoids/pharmacology , Glucuronates/chemistry , Glucuronates/pharmacokinetics , Glucuronates/pharmacology , Humans , Molecular Structure , Plant Extracts/chemistry , Plant Extracts/pharmacokinetics , Plant Extracts/pharmacology
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