Major Functional Groups Research Articles

Optimization of microwave-assisted pectin extraction from walnut shells and evaluation of its physicochemical and biological attributes

Walnuts, known for their high nutritional value, generate significant waste in the form of husks and shells, the disposal of which contributes to environmental pollution. The utilization of this walnut waste for the production of beneficial compounds remains underexplored. In the current study, extraction time, temperature, microwave power, and solid-to-solvent ratio were optimized using response surface methodology. This technique significantly reduced the extraction time, yielding pectin at 34.13 ± 3.83 % under optimal conditions: temperature (74 °C), microwave power (400 W), irradiation time (16 min), and solid-solvent ratio (1:25). XRD characterization revealed the crystalline nature of the extracted pectin, while FTIR confirmed the presence of major functional groups. The extracted pectin exhibited an equivalent weight of 576.99 ± 7.63 g/mol with a degree of esterification of 59.88 ± 0.28 %, making it suitable for food, pharmaceutical, and cosmetic applications. Further, the extracted pectin demonstrated significant antioxidant activity with IC50 values of 5.08 ± 0.08 mg/ml for DPPH and 2.87 ± 0.023 mg/ml for ABTS assays. It also showed antibacterial activity against both gram-positive Staphylococcus aureus MTCC 96 and gram-negative Pseudomonas aeruginosa MTCC 424, with zones of inhibition measuring 25.33 ± 0.58 mm and 28.33 ± 0.58 mm, respectively. SEM analysis revealed changes in cell morphology of S. aureus and P. aeruginosa when treated with the extracted pectin. These findings suggest that microwave-assisted extraction offers a rapid, eco-friendly, and cost-effective method for pectin extraction from walnut shells, promoting sustainable utilization of this waste resource and providing a potential pectin source with enhanced biological activity.

Tunable Coassembly of Octaarginine with Thiazolyl Benzenesulfonamides Exerts Variable Antibacterial Activity.

The cationic peptide octaarginine (R8) is a prominent cell-penetrating peptide and has been extensively researched as a carrier of diverse cell-destined cargo. In this work, we describe the coassembly of R8 with small molecule thiazolyl benzenesulfonamide (TBS) derivatives. Physical complexation of R8 with three TBS derivatives across a range of weight ratios results in the formation of a distinctive set of nano- and microstructures. A detailed structural characterization of the R8:TBS-derivative coassemblies has been performed by a combination of FTIR, XRD, SEM, and DSC. The major functional groups that facilitate coassembly include sulfonamide SO2 and NH groups of the TBS derivatives, and the guanidinium of R8, via a combination of cation-π and hydrogen-bonding interactions. The R8:4F-TBS coassembly displays singular topological features compared to R8:4Br-TBS and R8:4CH3-TBS complexes. These differences are attributed to the changes in the preferred orientation of the guanidino groups of R8 with respect to the π-surface of TBS derivatives. The modulation of forces of interaction across the R8:TBS-derivative coassemblies aligns with their respective thermal stabilities. The single-crystal structure of bare 4F-TBS has been subjected to Hirshfeld and 2D fingerprinting analysis and indicates notable variations from the crystal packing of the R8:4F-TBS coassembly. The structural differences among the R8:TBS-derivative coassemblies correlate with distinctive profiles of antibacterial activity in each case. The coassembled structures exert a variable extent of bacterial membrane disruption and damage based on the unique disposition of R8 and the potency of small molecule in each case. The aqueous suspension of R8:4F-TBS displays significant outer membrane disruption and bacterial killing compared with the other complexes. This work successfully demonstrates the hitherto unreported potential for coassembly of cell-penetrating peptides with other entities. The coassembly of R8 with small molecules highlights an attractive strategy for tuning the functional properties of each component.

Preparation of modified silica gel supported silver nanoparticles and its evaluation using zone of inhibition for water disinfection

In this work, preparation of modified silica gel supported silver nanoparticles and its evaluation using zone of inhibition for water disinfection were investigated. The silica contents of the teff straw [TS] and teff straw ash [TSA] are 5.92 and 92.21 %, respectively. The calcinated TS ash at 700 °C was mixed with NaOH solution. The solution is then neutralized with HCl solution and then gel formation using the sol gel method. The silica gel yield was recorded and characterized. The SG with major silica functional group, amorphous structure, high porosity from the morphology, high surface area of 807.163 m2/g, pore volume of 0.34 cm3/g, pore diameter of 1.70 nm and silica gel purity of 99.39 % were achieved at a calcination temperature of 700 °C. It is then; further modified using trimethylchlorosilane (TMCS)/ethanol/hexane at different volumetric ratio and the resulting product is modified silica gel (MSG). MSG has excellent hydrophobic properties that have been required during water treatment. In this method, MSG with a major silica functional group, well ordered structure due to the TMCS modifier, maximum surface area of 510.40 m2/g was achieved at volumetric ratio of 0.25:0.25:1 of TMCS/ethanol/hexane, respectively. Then, MSG supported AgNPs (MSG-AgNPs) was prepared by mixing different concentrations of AgNPs-MSG and characterized. The MSG-AgNPs have shown AgNPs on the surface of MSG from the EDX result, different absorbance, pore from the morphology, with a maximum surface area of 475.0 m2/g was obtained at 1.5 mM of AgNPs concentrations. The performance of MSG-AgNPs was evaluated using zone of inhibition measurement and batch disinfection studies against E. coli and S. aureus. At 1.5 x 108 CFU/mL initial bacterial concentrations, the maximum inhibition zone diameter was 12.80 and 14.30 mm for E. coli and S. aureus, respectively.

From plant to nanomaterial: Green extraction of nanomucilage from Cordia dichotoma fruit and its multi-faceted biological and photocatalytic attributes

This study aimed to evaluate the extraction efficiency of mucilage from Cordia dichotoma fruits using various aqueous extraction methods, including microwave-assisted water extraction (MWE), hot-water extraction (HWE), and cold-water extraction (CWE). Different analytical techniques were employed to characterize the Cordia dichotoma mucilage (CDM). Additionally, the functional properties, anti-microbial, anti-inflammatory, and dye reduction potential of CDM were assessed. The results indicated a significantly (p < 0.05) higher yield of CDM (13.44 ± 0.94 %) using MWE compared to HWE (12.08 ± 0.82 %) and CWE (7.59 ± 0.73 %). The optimal extraction condition was utilized for the spray-drying process, yielding a spray-dried mucilage powder (SDMP) with a yield of 9.52 ± 1.27 %. The presence of galactose and arabinose as major sugar and functional groups such as OH, COOH, CH, and NH from proteins, uronic acids, and sugars were identified. CDM predominantly comprises galactose and arabinose as major sugars. CDM particles exhibited an irregular morphology and demonstrated thermal stability, with maximum weight loss occurring between 221.83 and 478.66 °C. The particle size of CDM was 681.16 ± 2.18 nm with a zeta potential of −21.46 ± 1.72 mV. Rheological analysis revealed that CDM exhibits shear-thinning behavior. Furthermore, CDM displayed inherent biological activities, including antimicrobial and anti-inflammatory properties. The dye reduction potential of CDM was evidenced by an 88.67 % degradation of indigo carmine dye. In summary, this study provides insights into the cost-effective extraction methods for CDM and its potential utilization as an eco-friendly material for dye reduction.

Effects of soil composition and curing conditions on the strength and durability of Cr3+-crosslinked biopolymer-soil composites

Stabilized soil composites incorporating Cr3+-crosslinked xanthan gum (CrXG), a self-stiffening cation-crosslinked biopolymer, have recently emerged as sustainable construction materials for earthen structures. However, the influence of curing conditions and soil composition in altering the mechanical properties of CrXG–soil composites has so far received limited attention. This study investigates the effects of fine contents and curing conditions on the time-dependent strength development and durability of CrXG-soil composites. CrXG-soil composites, ranging from poorly graded sand to clayey silty sand, are subjected to unconfined compressive strength (UCS) and durability tests under various curing conditions, including wet, submerged, and dry conditions. Microscopic structural changes are characterized using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The results showed that the UCS of CrXG-soil composite increases nonlinearly, reaching up to 4.8 times the initial wet UCS after 28 days of curing, closely aligning with predictions from a hyperbolic model. Notably, CrXG-soil compositions with a clay-sand mixture (CSM) containing 15 % fine content (CSM15) demonstrated consistent strength parameters across all curing conditions in UCS tests. CSM15 also maintains a 90 % of durability index after eight dry-wet cycles and a dry UCS of 300 kPa after 130 days of atmospheric weathering. Microscopic-scale analysis confirms the stable agglomeration of CrXG-clay matrices between sand grains, with the peak wavelength of the major functional group remaining constant, even under multiple cycles. These findings contribute to a deeper understanding of CrXG–soil composites, offering valuable insights into optimizing soil compositions and enhancing the technical feasibility of applying these composites as a sustainable surface protection strategy for earthen structures, such as levees and road slopes.

Distributions of nutrients, trace metals, phytoplankton composition, and elemental consumption in the Ross and Amundsen Seas

The Southern Ocean (SO) not only functions as an important carbon sink but also serves as a crucial source of intermediate and deep waters to lower latitudes. The Ross Sea and Amundsen Sea in the West Antarctic are highly productive regions of the Southern Ocean, critically vulnerable to climate change. Hence, comprehending the source-sink patterns of nutrients, particularly trace metals, in these regions is of paramount significance for understanding their ecological effect and the effect on elemental distribution in global ocean. Here, we reported the surface and vertical distributions of phytoplankton composition, Chlorophyll-a (Chl-a), particulate organic carbon (POC), macronutrients, and trace metals (TMs) in the Ross and Amundsen Seas. Deplete dissolved iron concentrations were observed in surface waters averaging 0.17 ± 0.09 nM. High POC and Chl-a were observed that corresponded to elevated Fe in shallow subsurface water (100–300 m), while low POC and Chl-a were found to associate with depleted iron (∼0.1 nM) throughout the upper water column down to 300 m. Sea-ice melting and islands were found to be possible external TMs sources in the Amundsen Sea offshore. Phytoplankton act as a sink for trace metals and regulate the elemental concentration and composition of water bodies, while also being influenced by environmental conditions such as temperature, salinity, and the mixing layer depth. Elemental consumptions in surface water were associated with diatom abundance in both Ross and Amundsen Seas. Based on elemental drawndown ratios in the surface mixed layer, the stoichiometries of the two major phytoplankton functional groups, diatoms and haptophytes, were estimated. Our observations offered insights into the relationships among iron supply, nutrients distribution patterns, and phytoplankton composition in the Southern Ocean.

Marine microbial exopolysaccharide route synthesis of Ag and Pd metal nanoparticles: A possible anticancer, and antioxidant applications

The present research aimed develop an innovative and efficient method for fabricating silver and palladium nanoparticles (NPs)by using exopolysaccharide (EPS) from the seaweed-associated endo-symbiotic bacteria Exiguobacterium profundum (OP919469). Through, the application is a combined precipitation approach, EPS acts as a reducing and stabilising agent for the production of NPs. The major functional groups of NPs such as C–H, N–H, C–C, and C–O stretching’s were detected. The structural morphology of NPs showed a mixture of needle, spherical, and triangle-shaped with size between 10 and 50 nm. The purity of EPS was confirmed by high-performance liquid chromatography which revealed 99.81% purity. The NPs revealed strong anti-cancer and antioxidant properties. In addition, the NPs have been shown to dose-dependent toxicity with reduced hatching, survival rate, and abnormalities in zebrafish. The biochemical assay revealed that the EPS loaded NPsdid not induce oxidative stress up to 120 hpf in contrast to hydrogen peroxide which had a significant effect (P < 0.0001) on glutathione-S-transferase, catalase (P < 0.0017), and superoxide dismutase (P < 0.0001). Overall, our finding indicates that the molecular and functional characteristics of EPS and EPS loaded NPs represent future potential applications in the drug delivery and healthcare sectors.

Kinetics analysis of PAHs degradation using SiO2–ZnO nanoparticles and evaluating their antibacterial and antibiofilm efficacy

The adsorption of Polycyclic aromatic hydrocarbons (PAHs) using nanoparticles is gaining significant attention due to the rapid removal or treatment rates. In this study, Silicon Dioxide-Zinc Oxide nanoparticles (SiO2–ZnO NPs) were synthesized to adsorb pyrene. Physicochemical characterization of SiO2–ZnO NPs showed plasmon resonance at 323 nm, agglomeration, irregular dispersion, and diameters of 90–100 nm. FT-IR analysis identified major functional groups on SiO2–ZnO NPs, including alkyne, amine, and isothiocyanate. SiO2–ZnO NPs demonstrated significant pyrene adsorption at pH 5, with 10 μg/mL of SiO2–ZnO NPs and 2 μg/mL of PAHs, performing better under UV irradiation. Two isotherm models, adsorption isotherm and kinetics adsorption, were used to analyze the PAHs adsorption by SiO2–ZnO NPs. Additionally, SiO2–ZnO NPs were tested for antibacterial and antibiofilm activities against both Gram-negative and Gram-positive bacteria. At a concentration of 150 μg/mL, SiO2–ZnO NPs produced inhibition zones of 21.57 mm, 20.30 mm, 19.30 mm, and 11.30 mm against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Klebsiella pneumoniae, respectively. They also inhibited and disrupted biofilms of Micrococcus luteus and Acinetobacter baumannii. Furthermore, SiO2–ZnO NPs exhibited photocatalytic degradation of lead, achieving 68.24% degradation within 5 h of treatment. Therefore, SiO2–ZnO NPs are efficient candidates for multiple applications, including pyrene adsorption, bacterial biofilm disruption, and lead degradation under sunlight.

Biosynthesis, antimicrobial and in vitro antiproliferative activities of silver/silver chloride nanoparticles from mixed fruit extracts of Capsicum frutescens and Tamarindus indica

Silver/silver chloride nanoparticles were formed by treating mixed extracts of Capsicum frutescens and Tamarindus indica (CT) with 5 mM AgNO3 in sunlight for 120 min, which was confirmed by a UV–visible spectrophotometer as a comparatively sharp peak was observed at 465 nm. Crystalline properties of Ag/AgCl-NPs were examined through X-ray diffraction method. The nearly spherical shape of Ag/AgCl-NPs was confirmed by scanning electron microscopy and the average size of particle was approximately 72.2 nm. The existence of elemental Ag was assessed with an energy-dispersive spectrometer whereas two major functional groups as capping agents were obtained using Fourier transform infrared spectroscopy. The CT extract-mediated Ag/AgCl-NPs showed moderate toxicity determined against brine shrimp nauplii with an LD50 value of 177.9 μg/mL. The nanoparticles showed 92.6 % growth-suppressive activity against S. aureus, 81.1 % against S. boydii, 60.3 % against S. dysenteriae, and 50 % against E. coli at the concentration of 50 µg/mL in disc diffusion assay. The recorded free radical scavenging activities of Ag/AgCl-NPs were 55.79 % at 60 µg/mL for DPPH and 64.93 % at 100 µg/mL for ABTS. MTT colorimetric assay confirmed the antiproliferative activity of Ag/AgCl nanoparticles against EAC and MCF-7 cells (42.7 % and 47.4 %) at concentrations of 50 µg/mL and 128 µg/mL, respectively.

Phytoplankton biomass responses to a marine heat wave align with altered nitracline depth

AbstractThe 2014–2015 warm anomaly (aka “the Blob”), the largest of periodic and intensifying marine heat wave (MHW) perturbations in the northeast Pacific, may provide some insight about the future warmer ocean. Here, we use mixed‐layer carbon estimates for total phytoplankton, major size classes and functional groups from 45 CalCOFI cruises to: (1) compare 2014–2015 MHW impacts in the southern California Current System to baseline estimates from 2004 to 2013 and (2) to test a space‐for‐time exchange hypothesis that links biomass structure to variability of nitracline depth (NCD). Seasonal and inshore‐offshore analyses from nine stations revealed almost uniform 2°C MHW warming extending 700 km seaward, fourfold to sixfold declines in nitrate concentration and 18‐m deeper NCDs. Phytoplankton C decreased 16–21% compared to 45–65% for Chl a, with the threefold difference due to altered C : Chl a. Among size classes, percent composition of nanoplankton decreased and picophytoplankton increased, driven by higher Prochlorococcus biomass, while Synechococcus and picoeukaryotes generally declined. Diatom and dinoflagellate C decreased in both onshore and offshore waters. Seasonally, the MHW delayed the normal winter refresh of surface nitrate, resulting in depressed stocks of total phytoplankton and nanoplankton, Synechococcus and picoeukaryotes during winter. Consistent with the space‐for‐time hypothesis, biomass variations for baseline and MHW cruises followed similar (not significantly different) slope relationships to NCD. All biomass components, except Prochlorococcus, were negatively related to NCD, and community biomass structure realigned according to regression slopes differences with NCD variability. Empirically derived biomass‐NCD relationships could be useful for calibrating models that explore future food‐web impacts in this coastal upwelling system.

HPTLC FINGERPRINTS AND FTIR ANALYSIS FOR AUTHENTICATION AND QUALITY CONTROL OF Holostemma ada-kodien Schult.

Plant-derived pharmaceuticals are gaining increased acceptance in treating various ailments, but ensuring their quality is crucial. Both conventional and modern techniques are employed to validate the quality. High performance thin layer chromatography (HPTLC) and Fourier transform infra-red (FTIR) analysis were conducted to analyse and identify the various phytoconstituents in serial root extract of Holostemma ada-kodien. The peaks observed in HPTLC fingerprint profile corresponding to different phytoconstituents served as markers for standardizing drug; while FTIR analysis aids in identifying the major functional groups present. Thirteen bands were noted for hexane extract of H. ada-kodien in short UV in track I, while chloroform and methanol extracts showed eight bands each. In track II, the hexane extract exhibited eight bands, while chloroform and methanol extracts showed eleven and eight bands, respectively, under similar conditions. The hexane extract in long UV showed a maximum area of 78.4 and 71.59%, in track 1 and 2, respectively, with respective spanning from Rf 0.61 to 0.75 and 0.51 to 0.73. The methanol extract in visible light in track I showed a maximum area of 46.87%, spanning from Rf 0.73 to 0.98, and in track II, it displayed a maximum area of 36.59%, spanning from Rf 0.75 to 0.96 with 10 µL applied. Methanolic root extract of H. ada-kodien showed clear banding patterns in HPTLC fingerprints which seemed to be a dependable technique to detect adulteration while FTIR technique revealed functional groups of methanol root extracts.

Shifts in the nitrogen cycle under different fertilizer management practices

Human population is dependent on agricultural production, but these activities pose multiple threats to soil health and indirectly to ecological sustainability. Synthesis of fertilizers proved to be a miraculous solution to enhance soil productivity, but this advancement came with many unseen risks. Long-term research stations that have decades long experiments with fertilizers additions are paramount in better understanding long-term impact of fertilizer use. Our study focused on ammonium and nitrate levels found in soils in an experiment of inorganic nitrogen addition than began in 1975. We further directed our attention to soil mineralization potential, nitrate reductase activities and densities of two major microbial functional groups: ammonifiers and denitrifiers. Our data suggests that ammonium has a stronger tendency of soil buildup than nitrate and that increased levels of inorganic nitrogen species also impacted molecular compartments and processes such as mineralization potential, soil microbiota and enzymatic activities. Another result indicates that analysed soils reached a storage limit for phosphorus which threatens to overburden other ecosystems.

Characterization and antioxidant effect of mucilage in leaves from Cocculus hirsutus.

Natural polysaccharides are attractive biodegradable polymers. Among the natural plant-based polysaccharides, mucilage is an interest for numerous biomedical applications. Hence, mucilage was isolated from the leaves of Cocculus hirsutus (Family; Menispermaceae) and tested for its phytochemicals, physio-chemical characteristics using standard procedure such as solubility, pH, swelling index etc., and structural characterization studies using FTIR, GC-MS and SEM followed by antioxidant and in vitro cytotoxic assays. The phytochemical results showed the presence of carbohydrates, amino acids, flavonoids, alkaloids, tannins, terpenes, saponin, glycosides and steroids. The yield percentage of mucilage was 26% and showed swelling index of 6.8-7.4. The FTIR spectra of mucilage showed characteristics strong peaks of major functional groups. The SEM image showed the porous and rough surface morphological characters of mucilage. The obtained mucilage showed antioxidant potential by DPPH, FRAP and Total reducing power assay and also exhibited non-cytotoxic character against fibroblast cell lines. Thus, the isolated mucilage showed promising characteristics which can be exploited for various biological applications from food to drug release studies.

Fast Bacterial Succession Associated with the Decomposition of Larix gmelinii Litter in Wudalianchi Volcano.

In order to understand the role of microorganisms in litter decomposition and the nutrient cycle in volcanic forest ecosystems, the dominant forest species Larix gmelinii in the volcanic lava plateau of the Wudalianchi volcano was considered as the research object. We analyzed the response of bacterial community structure and diversity to litter decomposition for 1 year, with an in situ decomposition experimental design using litter bags and Illumina MiSeq high-throughput sequencing. The results showed that after 365 days, the litter quality residual rate of Larix gmelinii was 77.57%, and the litter N, P, C:N, C:P, and N:P showed significant differences during the decomposition period (p < 0.05). The phyla Cyanobacteria and the genus unclassified_o_Chloroplast were the most dominant groups in early decomposition (January and April). The phyla Proteobacteria, Actinobacteriota, and Acidobacteriota and the genera Massilia, Pseudomonas, and Sphingomona were higher in July and October. The microbial communities showed extremely significant differences during the decomposition period (p < 0.05), with PCoa, RDA, and litter QRR, C:P, and N as the main factors driving litter bacteria succession. Microbial functional prediction analysis showed that Chloroplasts were the major functional group in January and April. Achemoheterotrophy and aerobic chemoheterotrophy showed a significant decrease as litter decomposition progressed.

Impact of Penetration Enhancer and Natural Oil on Transdermal Delivery of Modified Karaya Gum Gel

The etodolac based modified karaya gum (MKG) gel was developed using 32 factorial design to enhance the therapeutic effect of gel to treat inflammation. Gels were prepared with different concentrations of MKG and arachis oil using 32 factorial design. The percentage of drug content was found in the range of 96 to 99%, viscosity results shown in the range of 842 CPS to 2560 CPS and in vitro drug release was found to be in range of 38% to 98% respectively. Whereas ex-vivo permeation studies of etodolac gel and pure etodolac solution across the burned pig skin were shown 72% and 42% respectively. The drug and excipient compatibility studies by FTIR confirms that, there is no major functional group change was observed. The results concluded that, the combination of MKG and arachis oil were improved the penetration of etodolac through burned pig skin thereby the combination of PE and oil successfully enhanced the therapeutic effect of etodolac.

Increase in precipitation will facilitate the ecological stability of desert steppe in the future

Community stability plays a vital role in ensuring the consistent provision of ecosystem services despite climatic changes. It is presumed that future changes to annual precipitation will impact the ecological stability of many systems, particularly the ‘fragile’ desert steppe. However, most studies of ecological stability are inferred from short-term field precipitation manipulation experiments. There is still extensively to learn regarding how the desert steppe reacts to long-term changes in precipitation. We conducted a 7-year experimental study monitoring the aboveground biomass of major plant functional groups (perennial grasses, perennial forbs, annual herbs, and semi-shrubs) under four experimentally manipulated precipitation gradients [reducing natural precipitation by 50% (-50%), natural precipitation (CK), increasing natural precipitation by 50% (+50%), and increasing natural precipitation by 100% (+100%)] to evaluate how changes in precipitation affect the biomass stability of plant communities. We did observe higher levels of species asynchrony, resistance, resilience, and temporal stability of community and functional groups in experimental plots receiving more precipitation. Interestingly, the contribution of species richness to community stability was not observed in our experiment. The increase in soil water content in the 20–30 cm soil layer caused by increased precipitation promoted the resilience of perennial grasses but inhibited the resistance of perennial forbs. At the same time, the decrease in soil inorganic nitrogen caused by increased rainfall inhibited the resilience of perennial grasses. Notably, community resilience predominantly hinged on the resilience of perennial grasses, while community resistance was primarily dictated by the resistance of perennial forbs. Moreover, species asynchrony emerged as the primary regulator of community temporal stability. Our long-term experimental evidence underscores the transformative potential of precipitation in reshaping grassland stability across both functional and structural dimensions. Importantly, sustaining the high stability of perennial herbs emerges as a strategic avenue for enhancing the ecological stability of the desert steppe in the face of evolving precipitation patterns.

Steam Explosion-Assisted Extraction of Polysaccharides from Pleurotus eryngii and Its Influence on Structural Characteristics and Antioxidant Activity.

Pleurotus eryngii (PE) has been sought after for its various health benefits and high content of phenolic compounds. This study explored the feasibility of steam explosion (SE)-assisted extraction of polysaccharides with high antioxidant capacities from PE. An orthogonal experimental design (OED) was used to optimize the SE-assisted extraction of PE. The influence of the optimized SE-assisted extraction on the physicochemical properties of PE polysaccharides was determined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), monosaccharide compositional analysis and antioxidant capacity assays. Under optimal SE conditions, SE-assisted extraction increased the polysaccharide yield by 138% compared to extraction without SE-assistance. In addition, SEM demonstrated that SE-assisted extraction markedly altered the spatial structure of Pleurotus eryngii polysaccharides (PEP), and monosaccharide compositional analysis revealed that this pretreatment significantly increased the proportions of some monosaccharides, such as glucose, rhamnose and arabinose, in the isolated PEP. FTIR spectra indicated no change in the major chemical functional groups of PEP. PEP extracted by SE-assisted extraction had significantly increased free radical scavenging and antioxidant capacities. In conclusion, SE-assisted extraction appears to be a novel polysaccharide extraction technology, which markedly increases extraction yields and efficiency and can increase the biological activity of polysaccharide extracts.

Structural Characterization and Immunological Activity of Polysaccharide Degradation Products from Phlebopus portentosus

Phlebopus portentosus is an edible and medicinal mushroom with a delicious taste and high nutritional value. The oligosaccharides derived from P. portentosus may be the material basis for its biological activity. The degradation of polysaccharide and the maintenance of its activity after degradation are key steps in related research. This study applied an acid degradation method to prepare P. portentosus refined polysaccharide (PPRP) with a smaller molecular weight, and the optimal hydrolysis conditions determined were a temperature of 80 °C, an acid concentration of 2 mol/L, and a hydrolysis time of 2 h. The polysaccharide structure and immune activity were then further investigated. The results showed that the PPRP comprised two fractions with approximate weights of 61,600 Da and 5500 Da. The monosaccharide composition of PPRP was mannose, rhamnose, glucose, and galactose, with a molar ratio of 1.00: 22.24: 2.93: 1.03. The major functional groups included O-H, C-H, C-O, and C-O-C. The glycosidic bond types were mainly α- and β-glycosidic bonds. Cell experiments demonstrated that PPRP could significantly increase the proliferation of macrophages and enhance the cytotoxicity of NK cells. Moreover, PPRP also significantly promoted the proliferation of B lymphocytes and T lymphocytes, especially at a concentration of 200 μg/mL. This study furnishes scientific evidence underlining the significant potential of PPRP in immune activity, thereby serving as a material basis and scientific bedrock for further investigations into the mechanism of P. portentosus oligosaccharide activity.

Green synthesis of rice straw-derived silica nanoparticles by hydrothermal process for antimicrobial properties and effective degradation of dyes

Rice straw is considered a major agricultural waste that has become a major threat to the environment. However, waste valorization of rice straws is a major challenge for the whole world. Therefore, this research aimed to utilize the different varieties of rice straw including Parmal rice straw (PRS), and Basmati rice straw (BRS) for the synthesis of silica nanoparticles (SiNPs) using hydrothermal autoclave method to precisely modify the particle size, and distribution, morphology and purity. This method uses water as a reaction medium under high temperature and pressure, which results in energy savings and reduced chemical waste compared to traditional methods. Furthermore, SiNPs were characterized using different analytical techniques. SEM showed the rough, compact, and highly ordered surface for both samples, while the SNP exhibited irregular shapes and rough surfaces. Rice straw powder revealed major functional groups at 787 cm−1, 1461 cm−1, and 2919.10 cm−1. BRS and PRS showed thermal stability up to 380 ℃ and 250 ℃, respectively. The particle size of BRS and PRS were found to be 112.47±1.23 nm and 114.98±1.23 nm, respectively. PRS-SiNPs showed the effective dye reduction ability for anthraquinone (96.79%± 0.39) and alizarin yellow (92.63%± 0.17) in 30 min. Additionally, the SiNPs exhibited potential bactericidal activity against Staphylococcus aureus and Escherichia coli in terms of zone of inhibition. Overall, the SiNPs synthesized from PRS demonstrated superior photocatalytic efficiency in the reduction of dyes compared to those synthesized from BRS.

Antimicrobial Activity of Green Synthesized Copper Nanoparticles (CuNPs) Using Aqueous Extract of &lt;i&gt;Psidium guajava&lt;/i&gt; on Clinical Bacteria Isolates

The eco-friendly synthesis of nanoparticles using an aqueous plant extract as a capping and stabilizing agent has garnered substantial attention, particularly in pharmaceuticals and drug delivery applications. This study focused on utilizing copper sulfate pentahydrate (CuSO4·5H2O) as a precursor to synthesize copper nanoparticles at both pH 4-5 and pH 8, with Psidium guajava (leaves and fruits) extract playing a crucial role. Fourier transform infrared (FTIR) spectroscopy identified four major functional groups at distinct peaks, confirming their responsibility for capping and stabilizing the synthesized P.g-CuNPs. Scanning electron microscopy (SEM) revealed spherical shapes with an average particle size range of 20-30 nm. Energy-dispersive X-ray (EDX) analysis confirmed the presence of pure copper (Cu) at 54.15%. The antimicrobial study demonstrated that P.g-CuNPs synthesized at pH 4-5 exhibited complete growth inhibition of all tested bacterial strains at varying concentrations. Furthermore, serially diluted P.g-CuNPs (pH 5) inhibited Salmonella spp, E. coli, and Streptococcus spp at 100 μg/mL, while P.g-CuNPs (pH 8) only inhibited E. coli at the same concentration. Notably, acid-based synthesized P.g-CuNPs exhibited higher efficacy in the antimicrobial study compared to their alkaline-based counterparts. This study suggests the potential biomedical applications of P.g-CuNPs, including therapeutic drugs for microbial infectious diseases, integration into textile coatings, and nanocapsulation for food storage to extend shelf life.