Acid Hydrolysis Research Articles

Ultra-inert lanthanide chelates as mass tags for multiplexed bioanalysis.

Coordination compounds of lanthanides are indispensable in biomedical applications as MRI contrast agents and radiotherapeutics. However, since the introduction of the chelator DOTA four decades ago, there has been only limited progress on improving their thermodynamic stability and kinetic inertness, which are essential for safe in vivo use. Here, we present ClickZip, an innovative synthetic strategy employing a coordination-templated formation of a 1,5-triazole bridge that improves kinetic inertness up to a million-fold relative to DOTA, expanding utility of lanthanide chelates beyond traditional uses. Acting as unique mass tags, the ClickZip chelates can be released from (biological) samples by acidic hydrolysis, chromatographically distinguished from interfering lanthanide species, and sensitively detected by mass spectrometry. Lanthanides enclosed in ClickZip chelates are chemically almost indistinguishable, providing a more versatile alternative to chemically identical isotopic labels for multiplexed analysis. The bioanalytical potential is demonstrated on tagged cell-penetrating peptides in vitro, and anti-obesity prolactin-releasing peptides in vivo.

Surface Modification of Cellulose Nanofiber (CNF) from Banana (<i>Musa paradisiaca</i>) Pseudo-Stem with Cetyltrimethylammonium Bromide (CTAB)

Modifying cellulose nanofiber (CNF) is necessary to improve its hydrophobic properties for broader applications. The surface of CNF from the banana pseudo-stem (Musa paradisiaca) was modified using a cationic surfactant, Cetyltrimethylammonium Bromide (CTAB). Principally, CNF surface sulfate ester group counterions are substituted for cetyltrimethylammonium (CTA+), which acts as a bulky, amphiphilic cation. Three steps produce CNF from banana pseudo-stem: delignification, bleaching, and acid hydrolysis. The acid hydrolysis process was optimized by adjusting the concentration of sulfuric acid. A 50% sulfuric acid concentration produced CNF with a size of 118 nm and the highest stability of its zeta potential value of -28.4 mV. The hydrophobicity of CNF increased after CTAB modification, as demonstrated by a change in surface charge from -28.4 mV to +3.63 mV. The modified CNF50-CTAB had a contact angle of 45.5º. In addition, CNF50-CTAB was unstable in water and formed stable colloidal suspensions in chloroform.

Electrochemical Upgrading of Waste Polylactic Acid Plastic for the Coproduction of C2 Chemicals and Green Hydrogen

Tandem alkali-catalyzed hydrolysis and alkaline electrolysis have gradually become appealing avenues for the reformation of polyester plastics into high-value-added chemicals and green hydrogen with remarkable environmental and economic benefits. In this study, an electrochemical upcycling strategy was developed for the electrocatalytic oxidation of polylactic acid (PLA) hydrolysate into valued C2 chemicals (i.e., acetate) and hydrogen fuel using N, P-doped CuOx nanowires (NW) supported on nickel foam (NF) as the electrocatalyst. This 3D well-integrated catalyst was easily prepared from a Cu(OH)2 NW/NF precursor with Saccharomycetes as a green and safe P and N source. The electrocatalyst can efficiently catalyze the lactate monomer derived from the hydrolysis of PLA waste to acetate with high selectivity and exhibits a lower onset potential for the lactate oxidation reaction (LOR) than for water oxidation, saving 224 mV to deliver a current density of 30 mA/cm2. The experimental results reveal that the plausible pathway of the LOR on these CuOx NW involves oxidation and subsequent decarboxylation. Divalent copper species have been verified to be active sites for LOR via in situ Raman spectroscopy.

Low-cost bacterial cellulose production from agricultural waste for antibacterial applications

Various carbon sources can be utilized for the biosynthesis of bacterial cellulose (BC), with agricultural wastes being explored as sustainable options. In this study, glucose was extracted from bamboo dust via mild acid hydrolysis to prepare a modified medium combining extracted glucose with Hestrin-Schramm (HS) medium for BC biosynthesis using Acetobacter xylinus NCIM 2526. Chitosan, a biopolymer, was incorporated into the BC synthesis medium at concentrations of 0.2%, 0.6%, and 1% (w/v) after 2 days of shaking incubation, producing chitosan-incorporated BC membranes through in situ synthesis. Fourier transform infrared (FTIR) spectroscopy confirmed cellulose in the BC produced from the modified medium and chitosan in BC membranes with 0.2% and 0.6% (w/v) chitosan. Changes in physical and crystalline morphology were further characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The purity of cellulose was validated through chemical solubility tests, while energy-dispersive X-ray (EDX) analysis confirmed the presence of chitosan in the BC membranes. The average yields were 5.8 ± 0.21 g/l for pure BC, 5.2 ± 0.21 g/l for BC with 0.2% (w/v) chitosan, and 4.6 ± 0.21 g/l for BC with 0.6% (w/v) chitosan after 7 days. The medium with 1% (w/v) chitosan did not produce BC membranes. BC synthesized with 0.2% chitosan exhibited similar physical and chemical properties to pure BC and demonstrated good antimicrobial properties, suggesting its potential use in bandages and wound dressings.

The Potential of Acid Hydrolysis as Pre-Treatment for Improved Nutrient Recovery from Domestic Wastewater

The Potential of Acid Hydrolysis as Pre-Treatment for Improved Nutrient Recovery from Domestic Wastewater

Optimization of Microcrystalline Cellulose Production from Brewer’s Spent Grain by Acid Hydrolysis

Brewer’s spent grain (BSG) is the main insoluble solid by-product of the brewing industry. To add value to this non-wood material, microcrystalline cellulose (MCC) was prepared from BSG by alkaline pretreatment, bleaching, and subsequent acid hydrolysis to produce non-wood MCC. This study aimed to optimize MCC production using a statistical design (Box-Behnken) with three factors at three levels: acid concentration (0.5–1.5 M), hydrolysis time (70–90 min) and hydrolysis temperature (55–65 °C), to achieve the maximum yield and crystallinity of MCC derived from BSG. Results from 17 experimental runs revealed that the hydrolysis condition of 0.63 M HCl for 70 min at 61 °C yielded the highest output of 15% with a crystallinity index of 60%. The chemical structures and characteristics of MCC derived from BSG were verified by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction analysis (XRD). FT-IR analysis showed that the major wavenumbers of lignin and hemicellulose after the chemical processes (1500 cm–1 and 1735 cm–1) decreased by 21.40% and 4.60%, respectively. The XRD chromatogram revealed that the XRD characteristic peaks were sharper after the chemical treatments, indicating an increase in cellulose crystallinity due to removing lignin and hemicellulose. The crystallinity index of MCC derived from BSG ranged from 55–64%, which is comparable in quality to commercial pharmaceutical MCC, Avicel® PH-101 (67.37%). These results demonstrated that MCC from BSG was successfully prepared by acid hydrolysis under optimized conditions. BSG proved a viable non-wood source for preparing MCC for application in the pharmaceutical and nutraceutical industries.

Antioxidant Potential Evaluation at Various Stages of Black Cumin Oil Production.

Nigella sativa L. seeds and their industrial process products, oils, cake, and meal, are valuable sources of bioactive compounds with antioxidant properties. In this work, the effect of technological processes on the antioxidant capacity (AC) and total phenolic content (TPC) in the black cumin oils obtained by cold pressing and solvent extraction, as well as the by-products, were evaluated. The AC values of black cumin seeds (BCS), cold-pressed black cumin oil (BCCPO), black cumin oil extracted from seeds (BCEO-S), black cumin oil extracted from cake (BCEO-C), black cumin cake (BCC), and black cumin meal (BCM) were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and cupric reducing antioxidant capacity (CUPRAC) assays, whereas TPC in these samples was analyzed by the Folin-Ciocalteu (FC) method. Two applied conventional oil extraction methods, screw pressing and solvent extraction, significantly affected the AC and TPC in the obtained black cumin oils and by-products. The solvent-extracted black cumin oils revealed higher antioxidant properties (DPPH = 4041-16,500 μmol TE/100 g, CUPRAC = 1275-4827 μmol TE/100 g) than the cold-pressed black cumin oil (DPPH = 3451 μmol TE/100 g and CUPRAC = 3475 μmol TE/100 g). In addition, the oil yield (20.92-48.86%) and antioxidant properties of BCCPO (DPPH = 2933-5894 μmol TE/100 g and TPC = 135-199 mg GAE/100 g) and BCC (DPPH = 1890-2265 μmol TE/100 g and TPC = 284-341 mg GAE/100 g) closely depended on the nozzle diameters (5, 8, and 10 mm) mounted in a screw press. Although both by-products were a rich source of antioxidants, BCM had significantly lower CUPRAC (1514 μmol TE/100 g) and TPC (92 mg GAE/100 g) values than BCC (CUPRAC = 3397 μmol TE/100 g and TPC = 426 mg GAE/100 g). Nevertheless, acid hydrolysis and alkaline hydrolysis of BCM extracts significantly increased their antioxidant potential. However, the DPPH (35,629 μmol TE/100 g), CUPRAC (12,601 μmol TE/100 g), and TPC (691 mg GAE/100 g) results were higher for the BCM extract after acid hydrolysis than those for alkaline hydrolysate (DPPH = 2539 μmol TE/100 g, CUPRAC = 5959 μmol TE/100 g, and TPC = 613 mg GAE/100 g). Finally, the generated AGREEprep metrics highlighted the sustainability and the greenness of the cold pressing of oil from BCS.

Reactivity of the 2-Methylfuran Phase I Metabolite 3-Acetylacrolein Toward DNA.

2-Methylfuran (2-MF) is a well-known industrial chemical and also formed via thermal treatment of food. One main source of 2-MF in the human diet is coffee. 2-MF is known to form 3-acetylacrolein (AcA, 4-oxopent-2-enal) via cytochrome P 450 metabolism and further reacts with amino acids in vivo. Still the reactivity toward other biomolecules is rather scarce. Therefore, AcA was synthesized, and its reaction with 2'-deoxyadenosine (dA), 2'deoxyguanosine (dG), 2'deoxycytosine (dC), and 2'-deoxythymidine (dT) was tested. For this purpose, adduct formation was performed by acid hydrolysis of 2,5-dihydro-2,5-dimethoxy-2-methylfuran (DHDMMF) as well as pure AcA. The structures of these adducts were confirmed by UPLC-ESI+-MS/MS fragmentation patterns and 1H-/13CNMR spectra. Except for dT, which showed no reactivity, all adducts of AcA were characterized, which enabled the development of sensitive quantification methods via (U)HPLC-ESI±-MS/MS. Pure AcA was synthesized by oxidation of 2-MF using dimethyldioxirane (DMDO), and its behavior in aqueous medium was studied. Incubations of AcA and isolated DNA of primary rat hepatocytes (pRH) showed time- and dose-dependent formation of the identified DNA adducts dA-AcA, dG-AcA, or dC-AcA. In contrast, the DNA adducts dA-AcA, dG-AcA, or dC-AcA were not detected on a cellular level when pRH were incubated with 2-MF or AcA. This indicates an efficient detoxification or reaction with biomolecules in the cell, although the induction of other DNA damage, possibly also by other metabolites, cannot be ruled out in principle.

The simultaneous application of fulvic acid and protein hydrolysate biostimulants enhances cucumber responses to Fe deficiency

Iron (Fe) is widely recognized as a critical factor in limiting crop production; however, eco-friendly strategies to address its deficiency are still required. The use of biostimulants has displayed promising results in mitigating Fe deficiency. Our hypothesis was that the combined application of two biostimulants with distinct molecular structures - fulvic acid (FA) and protein hydrolysate (PH) - could be more effective than the use of a single compound. The simultaneous presence of FA and PH (MIX) in a Fe-free nutrient solution led to a redistribution of endogenous Fe, resulting in a higher leaf SPAD index. Furthermore, the addition of FeCl3 as a Fe source (resupply) in MIX-treated plants enhanced the biostimulant effect, as evidenced by increased dry root and shoot weight and a more developed root system. In addition, the expression of Strategy-I-related genes, CsFRO1 and CsIRT1, remained elevated. These effects can be attributed to improved interaction between the roots and biostimulants through the formation of the FA-PH complex, as demonstrated by circular dichroism and isothermal titration calorimetry analyses.

Preparation of cellulose nano crystals from cinnamon stick, curcumin delivery and interaction with human hemoglobin protein: A novel view of the oxygenation hemoglobin

Curcumin (Cur), a natural phenolic compound, exhibits promising therapeutic properties including anti-cancer and anti-inflammatory effects. However, its limited bioavailability hinders its efficacy when administered alone. To address this challenge, this study explores the use of cellulose nano crystals (CNCs) derived from cinnamon stick via acid hydrolysis as carriers for Cur. The CNCs were thoroughly characterized, and Cur was successfully bound to them. Structural and morphological analyses of the CNCs-Cur complex were investigated applying Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Interaction studies between hemoglobin and the CNCs-Cur complex were carried out using various fluorescence spectroscopic techniques. Fluorescence spectroscopy revealed hemoglobin fluorescence quenching by the CNCs-Cur complex, with Stern-Volmer constants determined at different temperatures indicating static mechanism for the quenching. Synchronous fluorescence spectroscopy provided insights into the molecular micro-environment surrounding chromophores, and the distance between the CNCs-Cur complex and hemoglobin fluorophores was calculated using Forster's non-radioactive energy transfer theory (FRET), yielding a distance of less than 7 nm. Circular dichroism (CD) analysis indicated structural changes in hemoglobin upon the interaction with CNCs-Cur, while oxygenation techniques were employed to investigate oxygen binding, release, and transfer in hemoglobin. This comprehensive investigation sheds light on the potential of CNCs as effective carriers for curcumin, offering valuable insights into their interaction with biological molecules.

Production of cellulose nanocrystals from the waste banana (M. Oranta) tree rachis fiber as a reinforcement to fabricate useful bionanocomposite

It is crucial to produce CNCs from the waste biomass of secondary plants to reduce the extra pressure on primary plants which have other advantageous applications in many sectors. Whereas the useless banana (M. oranta) rachis after harvesting its edible part could be a very new and beneficial one. Meanwhile, several well-known methods could be conducted, namely water retting, scouring, alkali treatment, chlorite bleaching, and acid hydrolysis, to yield high-quality CNCs. The samples of all stages were characterized by several state-of-the-art techniques, namely FTIR-ATR, TGA, FESEM, XRD, UV-vis-NIR, DLS, and zeta potential analysis, for a better understanding of their structural properties/purity. However, obtained results recommended that the CNCs have shown extensive active edges, greater thermal improvement up to 700°C, high crystallinity around 81.07±0.15% with JCPDS-ICDD card number (00-056-1718), a honeycomb-like porous microstructure, and promising spherical shapes along with an average size around 50nm. Additionally, the newly produced CNCs were free from all impurities and coloring materials and revealed a higher negatively charged surface around -45mV. Therefore, due to these outstanding features, banana rachis CNCs with a high yield (around 82.05±0.06%) would be beneficially used as promising reinforcement to fabricate useful bionanocomposite for various applications to replace fossil-based hazardous synthetic materials.

Chitin nanocrystal Pickering emulsions for sustainable release pesticide microencapsulation with superior leaf adhesion and enhanced safety

Traditional pesticides often exhibit high non-target toxicity, poor stability, short persistence, and susceptibility to wash-off by rain. Pesticide microencapsulation represents a significant advancement in formulation strategies, addressing safety and sustainability concerns associated with conventional pesticides. This study explores the utilization of biodegradable chitin nanocrystals (ChNCs), prepared via acid hydrolysis, for the development of pesticide microcapsules. Specifically, ChNCs were employed to emulsify molten pesticides, followed by interfacial polymerization to fabricate pesticide-loaded microcapsules. Using molten emulsification and Pickering emulsion templates offer a simple and solvent-free approach for microcapsule preparation, eliminating the need for conventional surfactants. The microcapsules displayed a size distribution ranging from hundreds of nanometers to several micrometers, which could be tuned by adjusting the ChNCs content. These microcapsules demonstrated remarkable properties, including a high pesticide loading capacity (reaching 78.7% for lambda-cyhalothrin), excellent storage stability, and enzyme-responsive release behavior. Furthermore, the abundant positive charges enhanced the interaction between the microcapsules and leaf surfaces, leading to improved pesticide retention. Microencapsulation reduces acute insecticidal activity of pesticides due to the slow-release effect; however, field experiments provide compelling evidence that microcapsule formulations significantly prolong pesticide efficacy compared to conventional formulations. Additionally, microencapsulation significantly improved the safety of pesticides, with the LC50 increasing from 0.0116 mg/L to 3.75 mg/L. Overall, this study introduces a promising method for pesticide microencapsulation using ChNCs Pickering emulsion, highlighting its potential advantages and providing valuable insights for the development of environmentally friendly and novel pesticide formulations.

A new strategy to prepare bio-based polylactic acid modifier for multi-functionality: Dopamine-grafted modified lignin

Currently, to address the performance deficiencies associated with high brittleness, inadequate thermal stability, and susceptibility to hydrolysis in polylactic acid (PLA), it is common practice to incorporate multiple or high proportions of additives. However, this approach raises concerns regarding interface compatibility, energy consumption, and environmental impact. In this context, we introduce an environmentally friendly, bio-based PLA modifier that is facile to prepare and facilitates multi-functional applications at a minimal dosage. The presence of a benzene ring structure in lignin endows the material with ultraviolet (UV) resistance, thermal stability, and hydrophobic characteristics, while the exceptional adhesion properties of polydopamine (PDA) enhance interfacial compatibility. A novel biomass polylactic acid modifier, designated as OL@PDA, has been synthesized by modifying low-molecular-weight lignin (OL) with PDA. Comparative analysis of OL@PDA/PLA composite materials reveals a 14.08 % increase in tensile strength and a 42.00 % enhancement in elongation at break relative to pure PLA. The incorporation of the lignin-derived benzene ring structure effectively transforms PLA from a hydrophilic to a hydrophobic material. Furthermore, the UV transmittance at 400 nm (T400 nm%) is recorded at 65.8 % for pure PLA, which significantly decreases to below 5 % for OL@PDA/PLA composites. The integration of OL@PDA as a modifier in PLA materials yields comprehensively performance enhancements while maintaining a low additive concentration.

Silicified microcrystalline cellulose from renewable banana pseudostem: Physicochemical and functional analysis.

Microcrystalline cellulose (MCC) has been isolated from numerous sources through acid hydrolysis of mercerized cellulose. Due to the fibrous shape, its poor flow ability and lower compactibility, MCC is often co-processed with other excipients to improve its functional properties. Musa MCC was isolated from the pseudostem of Musa balbisiana and silicified with 2 % silicon dioxide (SMCC) through homogenization followed by filtration and oven drying. Both Musa MCC and SMCC were thoroughly characterized through FTIR, SEM- EDS, XRD, and TGA-DTG analysis. Detailed pharmaceutical functional properties including packing and rearrangement, consolidation, compressibility, compactibility and tabletability were also investigated and compared against the standard commercial grade MCC. While the percent crystallinity was reduced by silicification, there was enhanced resistance to thermal degradation. By reducing the internal friction, silicification was able to decrease the cohesiveness and improve the flow property of MCC. From Heckel plot and the yield pressure obtained, silicification reduces the extent of plastic deformation of MCC. However, silicification successfully improved the compactibity, tabletability and manufacturability of the Musa MCC. Results from these analyses show that the pseudostem of M balbisiana is a potential sustainable source of highly functional MCC and the silicification process improved the compactibility and tabletability of the MCC.

Continuous bioethanol production from glucose-rich hydrolysate derived from wheat straw using a unique fed-batch cultivation method in a bioreactor

The present study provides solutions to the bioethanol industry’s main issues of the absence of production of maximum fermentable sugars from lignocellulosic biomass, the unsuitability of a single microorganism to convert the fermentable sugars (xylose and glucose) together to bioethanol, and the unavailability of fermentation technique to run the process unlimitedly with consistent yield and productivity. A novel fractional acid hydrolysis technology was demonstrated in this study, which produced more than 90% (w/w) of available glucose in wheat straw as glucose-rich hydrolysate (GRH). This hydrolysate was then made acid-free using a membrane-based acid separation unit to reuse the separated acid to make the hydrolysis process environmentally safe and chemically inexpensive. Thereafter, this acid-free GRH was fermented to bioethanol using a unique constant volume fed-batch fermentation technique under an optimum glucose-feeding strategy. Remarkably, this fermentation technique yielded optimal average bioethanol productivity (g/Lh), yield (g/g), and titer (g/L) of 7.147±0.533, 0.508±0.002, and 58.835±0.766; 5.722±0.529, 0.501±0.006, and 33.748±0.322, respectively, with more than 99% glucose utilization during ten fed-batch cycles of synthetic and GRH glucose. Notably, the high production of GRH from lignocellulosic biomass, acid separation and reuse, and continuous and consistent bioethanol production sets this study apart as a pioneering endeavor. Furthermore, the bioethanol profit of USD 0.019/kg biomass from the second batch onwards at a bioethanol selling price of USD 0.745/L suggests the feasibility of the current study for industrial-scale bioethanol production from lignocellulosic biomass.

Preparation of carboxylated-silk nanofibers by the one-pot method of maleic acid hydrolysis

Preparation of carboxylated-silk nanofibers by the one-pot method of maleic acid hydrolysis

Nanocrystalline cellulose from Calophyllum inophyllum shells waste by adjusting organic acid hydrolysis and optimization of reaction parameters using response surface methodology

Biodiesel production from Calophyllum inophyllum oil in Indonesia produces significant biomass waste, including seed shells. This study explores the conversion of the seed shell of Calophyllum inophyllum into nanocrystalline cellulose (NCC) via consecutive alkalization, bleaching and hydrolysis using various organic acids. Scanning electron microscopy (SEM) analysis showed a reduction in the diameter of cellulose fibers from 21.7 μm to 9.6 μm after alkalinization and bleaching. The hydrolysis process using several organic acids was optimized to produce thermally stable nanocellulose while maintaining its crystallinity. The diameter of the resulting nanofibrous cellulose was 20.53 nm for citric acid, 21.69 nm for maleic acid, and 22.06 nm for formic acid hydrolysis. In particular, lactic acid-derived NCC (NCC-LA) showed the highest crystallinity of 64.22 % with an average diameter of ~13.69 nm. Optimization of hydrolysis parameters using Response Surface Methodology (RSM) suggested 74.79 % crystallinity could be achieved with 6.01 M lactic acid following 3.46 h of hydrolysis at 91.12 °C.

Screening and Selection of a New Medium and Culture Conditions for Diosgenin Production via Microbial Biocatalysis of SYt1

Diosgenin (DSG) is a phytosterol saponin mainly found in Dioscorea zingiberensis C.H. Wright. It has shown promising results in treating various diseases such as cancer, diabetes, arthritis, asthma, and cardiovascular diseases. Diosgenin is also an important medicinal chemical for synthesizing various steroid medicines. The production of diosgenin by acid hydrolysis generates a large amount of wastewater, leading to severe environmental pollution. However, producing diosgenin through microbial fermentation can effectively reduce environmental pollution. Numerous studies have demonstrated that various microorganisms can produce diosgenin via solid-state fermentation. Nevertheless, due to the complexity, high maintenance costs, uneven heat production, and other characteristics of solid-state fermentation, it is not commonly used in the industrial production of diosgenin. In contrast, liquid fermentation offers advantages such as simple operation, easy maintenance, and stable fermentation, making it more suitable for the industrial production of diosgenin. However, few studies have focused on producing diosgenin using liquid fermentation. In this study, endophytic Bacillus licheniformis SYt1 was used to produce diosgenin via liquid fermentation, with Dioscorea tuber powder as a substrate. Soxhlet extraction and silica gel column chromatography were employed to identify the diosgenin from the liquid fermentation products. Suitable fermentation conditions were screened and identified. The environmental variables that significantly affect the diosgenin yield were determined by the Plackett–Burman design (P-BD) with eight factors. The three factors (peptone, yeast extract powder and inorganic salt) with the greatest influence on the diosgenin yield were selected and further optimized using a response surface methodology (RSM). The final culture conditions were determined to be 35.79 g/L of peptone, 14.56 g/L of yeast extract powder, and 1.44 g/L of inorganic salt. The yield of diosgenin under these conditions was 132.57 mg/L, which was 1.8 times greater than the yield under pre-optimization conditions. This effective, clean, and promising liquid fermentation method possesses the potential to replace the traditional acid hydrolysis method for the industrial production of diosgenin.

New Insights into the Antibacterial Activity of Hydroxytyrosol Extracted from Olive Leaves: Molecular Docking Simulations of its Antibacterial Mechanisms.

This study investigated the biological activities of a hydroxytyrosol-rich extract from Olea europaea leaves, particularly its ability to eradicate severe pathogenic bacteria producing Extended-Spectrum Beta-Lactamases (ESBLs). The latter bacteria are emerging microorganisms that pose significant challenges due to their resistance to a broad range of potent therapeutic drugs. The extract was prepared through an accessible acid hydrolysis method. In vitro and In silico analyses through MIC, MBC analysis and molecular docking were conducted to evaluate the antibacterial properties. The extract showed remarkable antioxidant activity and significant antibacterial potential against reference species and ESBL bacteria. MIC and MBC calculations confirmed the extract's capacity to kill bacteria rather than just inhibit their growth. Further in silico analyzes demonstrated the high binding affinity of HT to the active sites of the gyrase B subunit and the peptidoglycan DD-transpeptidase domain from proteins located in the cytoplasm and the cell wall of the bacteria, respectively. Results confirmed the structure-activity relationship and the ability of HT to disrupt essential bacterial functions. This study validates the debated antimicrobial potential of HT and highlights its importance as a potential therapeutic agent against resistant bacteria, which is a critical area of research given the global challenge of antibiotic resistance.

Unlocking full potential of bamboo waster: Efficient co-production of xylooligosaccharides, lignin, and glucose through low-dosage mandelic acid hydrolysis with alkaline processing

Mandelic acid (MA), a natural and environmentally friendly organic acid, demonstrates high selectivity and efficiency in hydrolyzing hemicellulose, making it an excellent candidate for xylooligosaccharides (XOS) production at low acid dosages. Despite its potential, the application of MA for XOS production has not been evaluated. The study first investigated the effectiveness of MA in hydrolyzing hemicellulose in bamboo into XOS. Under optimized conditions (50 mM MA, 180 °C, 45 min), a high XOS yield of 65.9 % was achieved, with a total xylobiose and xylotriose yield of 43.5 %. Subsequent alkaline pretreatment enabled 92.1 % lignin removal from MA-pretreated bamboo. The recovered lignin exhibited a high purity of 95.2 % and retained fundamental structure and functional groups of native lignin. The resulting residue displayed enhanced crystallinity and accessibility, with reduced hydrophobicity and surface area lignin compared to untreated bamboo. At high substrate concentration of 20 %, cellulase hydrolysis resulted in a glucose conversion efficiency of 83.9 %. Overall, this integrated strategy offered an efficient approach for the co-production of valuable XOS, lignin, and glucose from bamboo. The efficient energy utilization and economic viability further highlight the potential of this method for large-scale industrial applications, making it an attractive option for biomass valorization.