RESUMEN
We propose a closed-loop pretreatment process, wherein volatiles produced during steam explosion pretreatment were recovered and reintroduced as acid catalysts into the pretreatment system. The volatiles were separated through a drastic decompression process followed by a steam explosion process and recovered as a liquified catalyst (LFC) through a heat exchanger. The LFC effectively served as an acid catalyst for hemicellulose hydrolysis, significantly decreasing residence time from 90 min to 30 min to achieve 80 % conversion yield at 170 °C. Hydrolysates with high content of lower molecular weight oligomeric sugars were obtained using LFC, and were considered advantageous for application as prebiotics. These results are attributed to the complementary features of acetic acid and furfural contained within the LFC. Computational simulation using Aspen Plus was used to investigate the effects of recycling on LFC, and it demonstrated the feasibility of the catalyst-recirculating system. A validation study was conducted based on simulation results to predict the actual performance of the proposed pretreatment system. Based on these results, the recirculating system was predicted to improve the conversion yield and low-molecular weight oligomers yield by 1.5-fold and 1.6-fold, respectively.
Asunto(s)
Avena , Glucuronatos , Oligosacáridos , Vapor , Catálisis , Hidrólisis , Oligosacáridos/química , Avena/química , Glucuronatos/química , Polisacáridos/químicaRESUMEN
Xylooligosaccharides (XOs) have shown high potential as prebiotics with nutritional and health benefits. In this work, XOs were obtained from highly purified, carboxy-reduced glucuronoarabinoxylans by treatment with Driselase®. The mixtures were fractionated, and the structures were elucidated by methylation analysis and NMR spectroscopy. Antioxidant activity was determined by the methods of DPPH and ß-carotene/linoleic acid. It was found that the most active oligosaccharides (P3 and G3) comprised 4 or 5 xylose units, plus two arabinoses and one 4-O-methylglucose as side chains, their sequence of units was determined. The optimal concentration for their use as antioxidants was 2 mg/mL. The synthetic antioxidant butylated hydroxytoluene (BHT, 0.2 mg/mL) showed a percentage of inhibition 15% higher than P3. Although its concentration was â¼10 times higher, P3 is non-toxic, and could have great advantages as food additive. These results show that pure XOs exert significant antioxidant activity, only due to their carbohydrate nature.
Asunto(s)
Antioxidantes , Oligosacáridos , Antioxidantes/química , Antioxidantes/farmacología , Oligosacáridos/química , Xilanos/química , Glucuronatos/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Relación Estructura-Actividad , Brotes de la Planta/químicaRESUMEN
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.
Asunto(s)
Bifidobacterium longum , Celulosa , Endo-1,4-beta Xilanasas , Glucuronatos , Glicósido Hidrolasas , Oligosacáridos , Saccharum , Xilanos , Oligosacáridos/química , Oligosacáridos/metabolismo , Glicósido Hidrolasas/metabolismo , Glicósido Hidrolasas/química , Glucuronatos/metabolismo , Glucuronatos/química , Endo-1,4-beta Xilanasas/metabolismo , Endo-1,4-beta Xilanasas/química , Xilanos/metabolismo , Xilanos/química , Saccharum/química , Saccharum/metabolismo , Celulosa/química , Celulosa/metabolismo , Bifidobacterium longum/enzimología , Bifidobacterium longum/metabolismo , Hidrólisis , Especificidad por Sustrato , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/química , DisacáridosRESUMEN
Lignocellulose is an abundant renewable bio-macromolecular complex, which can be used to produce biomethane and other high-value products. The lignin, presents in lignocellulose is typically regarded as an inhibitor of anaerobic digestion. Therefore, it is crucial to develop a novel selective separation strategy to achieve efficient biomethane production and all-component utilization of biomass. Hence, a combination of two-step pretreatment and solid-state anaerobic digestion was employed to enhance the production of biomethane and to generate valuable chemicals from poplar waste. Optimal conditions (4 % acetic acid, 170 °C, and 40 min) resulted in 70.85 % xylan removal, yielding 50.28 % xylo-oligosaccharides. The effect of a strong acid 4-CSA-based novel three-constituent DES on delignification was investigated from 80 °C to 100 °C; the cellulose content of DES pretreated poplar increased from 64.11 % to 80.92 %, and the delignification rate increased from 49.0 % to 90.4 %. However, high delignification of the pretreated poplar (DES-100 and DES-110) led to a rapid accumulation of volatile organic acids during the hydrolysis and acidogenesis stages, resulting in methanogenesis inhibition. The highest biomethane yield of 208 L/kg VS was achieved with DES-80 (49.0 % delignification), representing a 148 % improvement compared over untreated poplar. This approach demonstrates the potential for comprehensive utilization of all components of biomass waste.
Asunto(s)
Lignina , Metano , Populus , Lignina/química , Populus/química , Populus/metabolismo , Metano/química , Metano/metabolismo , Anaerobiosis , Hidrólisis , Oligosacáridos/química , Biomasa , Glucuronatos/química , ResiduosRESUMEN
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.
Asunto(s)
Endo-1,4-beta Xilanasas , Microbioma Gastrointestinal , Glucuronatos , Oligosacáridos , Xilosidasas , Glucuronatos/metabolismo , Glucuronatos/química , Oligosacáridos/química , Oligosacáridos/metabolismo , Endo-1,4-beta Xilanasas/metabolismo , Endo-1,4-beta Xilanasas/química , Xilosidasas/metabolismo , Xilosidasas/química , Humanos , Cristalografía por Rayos X , Xilanos/química , Xilanos/metabolismo , Dominio Catalítico , Modelos Moleculares , Especificidad por SustratoRESUMEN
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.
Asunto(s)
Apigenina , Ciclodextrinas , Portadores de Fármacos , Glucuronatos , Peróxido de Hidrógeno , Silicio , Animales , Humanos , Ciclodextrinas/química , Ratones , Peróxido de Hidrógeno/química , Apigenina/química , Apigenina/farmacología , Portadores de Fármacos/química , Concentración de Iones de Hidrógeno , Glucuronatos/química , Glucuronatos/farmacología , Silicio/química , Porosidad , Antineoplásicos/farmacología , Antineoplásicos/química , Línea Celular Tumoral , Ensayos Antitumor por Modelo de Xenoinjerto , Liberación de Fármacos , Neoplasias/tratamiento farmacológico , Nanopartículas/química , CelulosaRESUMEN
Rice husks are rich in xylan, which can be hydrolyzed by xylanase to form xylooligosaccharides (XOS). XOS are a functional oligosaccharide such as improving gut microbiota and antioxidant properties. In this study, the structure and functional characteristics of XOS were studied. The optimal xylanase hydrolysis conditions through response surface methodology (RSM) were: xylanase dosage of 3000â¯U/g, hydrolysis time of 3â¯h, hydrolysis temperature of 50⯰C. Under this condition, the yield of XOS was 150.9â¯mg/g. The TG-DTG curve showed that XOS began to decompose at around 200⯰C. When the concentration of XOS reached 1.0â¯g/L, the clearance rate of DPPH reached 65.76â¯%, and the scavenging rate of OH reached 62.10â¯%, while the clearance rate of ABTS free radicals reached 97.70â¯%, which was equivalent to the clearance rate of VC. XOS had a proliferative effect on four probiotics: Lactobacillus plantarum, Lactobacillus brucelli, Lactobacillus acidophilus, and Lactobacillus rhamnosus. However, the further experiments are needed to explore the improvement effect of XOS on human gut microbiota, laying a foundation for the effective utilization of XOS. XOS have a wide range of sources, low price, and broad development prospects. The reasonable utilization of XOS can bring greater economic benefits.
Asunto(s)
Antioxidantes , Glucuronatos , Oligosacáridos , Oryza , Probióticos , Oligosacáridos/farmacología , Oligosacáridos/química , Oryza/química , Glucuronatos/farmacología , Glucuronatos/química , Antioxidantes/farmacología , Antioxidantes/química , Hidrólisis , Endo-1,4-beta Xilanasas/metabolismo , LactobacillusRESUMEN
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 55â¯% to 80â¯%. Products with different degrees of polymerization were also noticed: while XOSâ¯≤â¯X6 where the main products at 40⯰C, a mixture of long arabinoxylan derived polymers (ADPo) and XOSâ¯≤â¯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 XOSâ¯≤â¯X6 produced, X2-X3 were the main products, and X4 was the minor one. At the end of the hydrolysis, 146.7â¯mg XOS per gram of pre-treated wheat straw were obtained.
Asunto(s)
Endo-1,4-beta Xilanasas , Oligosacáridos , Polisacáridos , Temperatura , Triticum , Triticum/química , Hidrólisis , Polisacáridos/química , Endo-1,4-beta Xilanasas/metabolismo , Oligosacáridos/química , Glucuronatos/química , Xilanos/química , Xilanos/metabolismoRESUMEN
In this study, the family GH10 xylanase AnXylA10 derived from Aspergillus niger JL15 strain was expressed in Pichia pastoris X33. The recombinant xylanase, reAnXylA10 exhibited optimal activity at 40 â and pH 5.0. The hydrolysates generated from beechwood xylan using reAnXylA10 primarily consisted of xylobiose (X2) to xylohexaose (X6) and demonstrated remarkable antioxidant capacity. Furthermore, the rice xylanase inhibitory protein (riceXIP) was observed to competitively inhibit reAnXylA10, exhibiting an inhibition constant (Ki) of 140.6â¯nM. Molecular dynamics (MD) simulations of AnXylA10-riceXIP complex revealed that the α-7 helix (Q225-S238) of riceXIP intruded into the catalytic pocket of AnXylA10, thereby obstructing substrate access to the active site. Specifically, residue K226 of riceXIP formed robust interactions with E136 and E242, the two catalytic sites of AnXylA10, predominantly through high-occupied hydrogen bonds. Based on QTAIM, electron densities for the atom pairs K226riceXIP@HZ1-E136AnXylA10@OE2 and K226riceXIP@HZ3-E242AnXylA10@OE1 were determined to be 0.04628 and 0.02914â¯a.u., respectively. Binding free energy of AnXylA10-riceXIP complex was -59.0±7.6â¯kcal/mol, significantly driven by electrostatic and van der Waals forces. Gaining insights into the interaction between xylanase and its inhibitors, and mining the inhibition mechanism in depth, will facilitate the design of innovative GH10 family xylanases that are both highly efficient and resistant to inhibitors.
Asunto(s)
Antioxidantes , Aspergillus niger , Endo-1,4-beta Xilanasas , Proteínas Fúngicas , Glucuronatos , Oligosacáridos , Proteínas Recombinantes , Xilanos , Glucuronatos/metabolismo , Glucuronatos/química , Xilanos/metabolismo , Endo-1,4-beta Xilanasas/metabolismo , Endo-1,4-beta Xilanasas/genética , Endo-1,4-beta Xilanasas/química , Aspergillus niger/enzimología , Aspergillus niger/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Oligosacáridos/metabolismo , Antioxidantes/metabolismo , Antioxidantes/química , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/química , Simulación de Dinámica Molecular , Oryza , Fagus , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/química , Madera , Pichia/genética , Pichia/metabolismo , Hidrólisis , Dominio CatalíticoRESUMEN
Phenolics produced during xylooligosaccharide production might inhibit xylanases and enhance the antioxidant and antimicrobial activities of XOS. The effects of phenolic compounds on xylanases may depend on the type and concentration of the compound, the plant biomass used, and the enzyme used. Understanding the effects of phenolic compounds on xylanases and their impact on XOS is critical for developing viable bioconversion of lignocellulosic biomass to XOS. Understanding the complex relationship between phenolic compounds and xylanases can lead to the development of strategies that improve the efficiency and cost-effectiveness of XOS manufacturing processes and optimise enzyme performance.
Asunto(s)
Glucuronatos , Oligosacáridos , Fenoles , Prebióticos , Oligosacáridos/química , Oligosacáridos/farmacología , Glucuronatos/farmacología , Glucuronatos/química , Fenoles/química , Fenoles/farmacología , Estructura Molecular , Antioxidantes/farmacología , Antioxidantes/química , Endo-1,4-beta Xilanasas/metabolismoRESUMEN
We presented a strategy utilizing 2D NMR-based metabolomic analysis of crude extracts, categorized by different pharmacological activities, to rapidly identify the primary bioactive components of TCM. It was applied to identify the potential bioactive components from Scutellaria crude extracts that exhibit anti-non-small cell lung cancer (anti-NSCLC) activity. Four Scutellaria species were chosen as the study subjects because of their close phylogenetic relationship, but their crude extracts exhibit significantly different anti-NSCLC activity. Cell proliferation assay was used to assess the anti-NSCLC activity of four species of Scutellaria. 1H-13C HSQC spectra were acquired for the chemical profiling of these crude extracts. Based on the pharmacological classification (PCA, OPLS-DA and univariate hypothesis test) were performed to identify the bioactive constituents in Scutellaria associated with the anti-NSCLC activity. As a result, three compounds, baicalein, wogonin and scutellarin were identified as bioactive compounds. The anti-NSCLC activity of the three potential active compounds were further confirmed via cell proliferation assay. The mechanism of the anti-NSCLC activity by these active constituents was further explored via flow cytometry and western blot analyses. This study demonstrated 2D NMR-based metabolomic analysis of pharmacologically classified crude extracts to be an efficient approach to the identification of active components of herbal medicine.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Proliferación Celular , Espectroscopía de Resonancia Magnética , Metabolómica , Extractos Vegetales , Scutellaria , Scutellaria/química , Humanos , Proliferación Celular/efectos de los fármacos , Extractos Vegetales/farmacología , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Apigenina/farmacología , Apigenina/química , Apigenina/aislamiento & purificación , Apigenina/análisis , Flavanonas/farmacología , Flavanonas/química , Flavanonas/aislamiento & purificación , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Glucuronatos/farmacología , Glucuronatos/aislamiento & purificación , Glucuronatos/química , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Línea Celular Tumoral , Ensayos de Selección de Medicamentos AntitumoralesRESUMEN
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.
Asunto(s)
Camellia , Ácido Pirúvico , Temperatura , Hidrólisis , Oligosacáridos/química , Glucuronatos/química , ÁcidosRESUMEN
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.
Asunto(s)
Celulosa , Endo-1,4-beta Xilanasas , Endo-1,4-beta Xilanasas/química , Xilanos/química , Hidrólisis , Oligosacáridos/química , Glucuronatos/químicaRESUMEN
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.
Asunto(s)
Saccharum , Celulosa/química , Endo-1,4-beta Xilanasas/química , Glucuronatos/química , Hidrólisis , Imidazoles , Oligosacáridos , Saccharum/químicaRESUMEN
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 (0.1â¯M of MA and 0.5â¯M of CA at 150⯰C for 40â¯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.
Asunto(s)
Glucuronatos/análisis , Oligosacáridos/análisis , Prebióticos , Xilanos , Ácidos/química , Ácidos Grasos Volátiles/química , Glucuronatos/química , Hidrólisis , Oligosacáridos/químicaRESUMEN
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.
Asunto(s)
Antioxidantes , Prebióticos , Endo-1,4-beta Xilanasas/química , Glucuronatos/química , Hidrólisis , Oligosacáridos/química , Xilanos/químicaRESUMEN
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.
Asunto(s)
Quimiometría , Xilanos , Cromatografía , Endo-1,4-beta Xilanasas/química , Glucuronatos/química , Hidrólisis , Oligosacáridos/química , Xilanos/químicaRESUMEN
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.
Asunto(s)
Espectrometría de Masas en Tándem , Xilanos , Aniones , Cromatografía , Glucuronatos/química , Hidrólisis , Oligosacáridos/química , Xilanos/químicaRESUMEN
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.
Asunto(s)
Endo-1,4-beta Xilanasas/química , Glucuronatos/química , Oligosacáridos/química , Oryza/química , Xilanos/química , Álcalis/química , Disacáridos/análisis , Hidrólisis , Microondas , Oryza/efectos de la radiación , Prebióticos/análisis , Semillas/química , Trisacáridos/análisisRESUMEN
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.