Synthesis and analysis of silica nanocarriers for pectinase immobilization: Enhancing enzymatic stability for continuous industrial applications.

Pectinolytic enzymes are among the important group of industrial enzymes that have wide applications in different food industries. In this study, pectinase-based silica nanocarriers were synthesized using co-precipitation and cross-linking techniques. The resulting silica nanoparticles were investigated using scanning electron microscopy (SEM), energy-dispersive electron microscopy (EDEX), and X-ray diffraction (XRD) for determination of its morphology, elemental composition, and crystalline pattern. Under the optimal immobilization conditions like 1.5 % glutaraldehyde, 3000 IU/mg pectinase concentration, 90 min immobilization time and 40 °C immobilization temperature, pectinase showed maximum immobilization yield. The immobilization of pectinase onto the silica nanocarriers led to enhanced catalytic characteristics, displaying higher enzymatic activity across various temperature and pH levels compared to soluble pectinase. Moreover, the immobilization substantially improved the temperature stability of pectinase, exhibiting 100 % of its initial activity even after 120 h of pre-incubation at 50 °C. Additionally, the silica nanocarrier pectinase retained 100 % of its original activity even after being reused 10 times in a single batch of reactions. These findings indicate that the immobilization of silica nanocarriers effectively enhances pectinase's industrial capabilities, making it economically feasible for industrial use and an efficient system for various biotechnological applications.

PEGylated Graphene Oxide as a Nanodrug Delivery Vehicle for Podophyllotoxin (GO/PEG/PTOX) and In Vitro α-Amylase/α-Glucosidase Inhibition Activities.

This study aims to develop a nanodrug delivery system containing podophyllotoxin (PTOX), a known anticancer drug, loaded on graphene oxide (GO). The system's ability to inhibit α-amylase and α-glucosidase enzymes was also investigated. PTOX was isolated from Podophyllum hexandrum roots with a yield of 2.3%. GO, prepared by Hummer's method, was converted into GO-COOH and surface-mobilized using polyethylene glycol (PEG) (1:1) in an aqueous medium to obtain GO-PEG. PTOX was loaded on GO-PEG in a facile manner with a 25% loading ratio. All the samples were characterized using FT-IR spectroscopy, UV/visible spectroscopy, and scanning electron microscopy (SEM). In FT-IR spectral data, GO-PEG-PTOX exhibited a reduction in acidic functionalities and there was an appearance of the ester linkage of PTOX with GO. The UV/visible measurements suggested an increase of absorbance in 290-350 nm regions for GO-PEG, suggesting the successful drug loading on its surface (25%). GO-PEG-PTOX exhibited a rough, aggregated, and scattered type of pattern in SEM with distinct edges and binding of PTOX on its surface. GO-PEG-PTOX remained potent in inhibiting both α-amylase and α-glucosidase with IC50 values of 7 and 5 mg/mL, closer to the IC50 of pure PTOX (5 and 4.5 mg/mL), respectively. Owing to the 25% loading ratio and 50% release within 48 h, our results are much more promising. Additionally, the molecular docking studies confirmed four types of interactions between the active centers of enzymes and PTOX, thus supporting the experimental results. In conclusion, the PTOX-loaded GO nanocomposites are promising α-amylase- and α-glucosidase-inhibitory agents when applied in vitro and have been reported for the first time.

Monitoring of Anthracene Using Nanoscale Au-Cu Bimetallic Alloy Nanoparticles Synthesized with Various Compositions.

Bimetallic alloy Au-Cu nanoparticles (Au-Cu alloy NPs) were synthesized using a chemical reduction method for sensing applications. Electronic absorption spectroscopy (UV-visible spectroscopy), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used for the confirmation and morphological studies of the synthesized nanoparticles. The composition of Au-Cu alloy NPs was studied by energy-dispersive spectroscopy (EDS). The high crystallinity of Au-Cu alloy NPs was demonstrated by XRD analysis. Both XRD and SEM analyses revealed that the nanoparticles' size ranges from 15 to 25 nm. Pyrrole was polymerized into polypyrrole (PPy) over a neat and clean glassy carbon electrode (GCE) by potentiodynamic polymerization. The sensitivity of GCE was improved by modifying it into a composite electrode. The composite electrode was developed by coating GCE with an overoxidized PPy polymer followed by Au-Cu alloy NPs. The ratio of Au and Cu was carefully controlled. The composite electrode (PPyox/Au-Cu/GCE) successfully detected an environmental toxin anthracene with a detection limit of 0.15 µM, as evidenced by cyclic voltammetry (CV), square-wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS).

Effect of protein and oil volume concentrations on emulsifying properties of acorn protein isolate.

This study aims to extract acorn protein isolate (API) from locally abundant waste acorn fruit and investigate its emulsification behavior by mixing different protein (0.1-2% w/v) and oil volume concentrations (5-45% v/v). Significant decrease in emulsifying activity index (EAI) and an increase in emulsifying stability index (ESI) were observed with an increase in API concentrations (P < 0.05). Droplet sizes of emulsions and viscosity were observed to decrease significantly (P < 0.05) with increase in API concentration while the increase was observed in interfacial protein concentration (Г). In contrast, increase in oil volume concentration results in increase of droplet sizes, packing fractions and viscosity, while decrease in Г values was observed. The results reveal that main fractions of API (66.2-14.4 kDa) were migrated to oil-water interface for emulsion stabilization. These results demonstrate the potential application of API in food formulation and development.

Effects of Maillard reaction on physicochemical and functional properties of walnut protein isolate.

In this study, the Maillard reaction (MR) of glucose was applied to improve the physicochemical and functional properties of walnut protein isolate (WNPI). The MR products (MRPs) were prepared with glucose at 0 h (MRP0), 1 h (MRP1), 2 h (MRP2) and 3 h (MRP3) heating at 95 °C. The Infra-Red spectrum showed reduction of amide and S-H functionalities in MRPs with complete intermixing of glucose in MRP3. Scanning electron microscopy indicated changes in the morphology of MRP3 which also exhibited promising antioxidant effect. Significant decrease (P < 0.05) in hydrophobicity values (Ho) and increase (P < 0.05) in emulsifying activity/emulsifying stability indexes values were observed for MRPs. Uniform droplet distribution was observed in microscopy of emulsions while an increase in the interfacial protein concentration ( Г) was obtained for MRPs. These results suggest that MR is useful in improving the utilization of this protein in food product development.

Electrospun nanostructured Co3O4/BiVO4 composite films for photoelectrochemical applications.

Co3O4/BiVO4 (Co/BiV) based nanostructured photoanode films were fabricated by simple facile electrospinning method and were characterized by a variety of techniques. It was found that the films have web-linked structure, composed of BiVO4 and Co3O4 nanostructures. The photoanode was used for the photoelectrochemical (PEC) degradation of bisphenol-A (BPA) by illumination at 0.25 V vs. SCE assisted by 1 mM peroxymonosulfate (PMS). The removal percentage of BPA was enhanced to 96% for the Co/BiV film that was much better than that of BiVO4 film, which was 48%. The pseudo-first kinetic constants were raised from 0.1126 min-1 to 0.4714 min-1, respectively. The enhanced PEC performance of Co/BiV films can be attributed its p-n heterojunction setup and synergetic contribution of PMS, which efficiently inhibits the recombination of photogenerated electron-hole pairs. The free radicals quenching experiment and electron spin resonance suggested that the major reactive oxygen species were photogenerated holes, superoxide radicals and sulfate radicals. These findings demonstrate that PMS assisted Co/BiV films, are good candidates for PEC application in environmental purification.

Effect of extraction methods on structural, physiochemical and functional properties of dietary fiber from defatted walnut flour.

The effect of different extraction methods i.e. extraction with alkali (AEDF), enzyme (EEDF) and enzyme plus shear emulsifying hydrolysis (SEDF) on structure, physiochemical as well as the functional characteristics of dietary fiber (DF) from defatted walnut flour were studied. AEDF process showed significantly higher (P < 0.05) amount of water retention capacity (WRC; 5.39 g/g), water swelling capacity (WSC; 3.16 g/mL), and particle size; while, shown lower value of oil adsorption capacity (OAC; 29 g/g) amongst all. Compared to AEDF, no major differences were observed in network except the matrix in EEDF and SEDF was more porous and honey comb like. DF extracted through AEDF, EEDF and SEDF showed good viscosity and emulsifying activity however, less stability indices. The results from this study suggest that AEDF and EEDF and SEDF had specific effects on the structure-functional properties of DF from defatted walnut flour, which has great potential in food applications.

Facile Electrospinning Synthesis of Carbonized Polyvinylpyrrolidone (PVP)/g-C3 N4 Hybrid Films for Photoelectrochemical Applications.

The film-forming ability and conductivity of graphitic carbon nitride (g-C3 N4 ) are still unsatisfying, despite much progress having been made in g-C3 N4 -related photocatalysts. New methods for synthesizing g-C3 N4 films coupled with excellent conductive materials are of significance. Herein, a facile method for synthesizing novel carbonized polyvinylpyrrolidone (PVP)/g-C3 N4 (CPVP /g-C3 N4 ) films have been developed through an electrospinning technique. Nanocarbons are generated by in situ carbonization of PVP in the films, which could enhance the photoelectrochemical (PEC) performance of the films due to its good conductivity. The coverage of the CPVP /g-C3 N4 film is good and the films exhibit excellent PEC performance. Furthermore, the thickness of the films can be adjusted by varying the electrospinning time and substantially controlling the PEC performance, of which the photocurrent densities under visible-light irradiation are 3.55, 4.92, and 6.64 µA cm-2 with spinning times of 40, 70, and 120 min, respectively. The photocurrent does not decrease until testing at 4000 s and the coverage is still good after the tests, which indicates the good stability of the films. The excellent PEC performance of the films and facile preparation method enables promising applications in energy and environmental remediation areas.

Corrigendum: Bioassay-Guided Isolation of Sesquiterpene Coumarins from Ferula narthex Bioss: A New Anticancer Agent.

[This corrects the article on p. 26 in vol. 7, PMID: 26909039.].

Bioassay-Guided Isolation of Sesquiterpene Coumarins from Ferula narthex Bioss: A New Anticancer Agent.

The main objective of cancer management with chemotherapy (anticancer drugs) is to kill the neoplastic (cancerous) cell instead of a normal healthy cell. The bioassay-guided isolation of two new sesquiterpene coumarins (compounds 1 and 2) have been carried out from Ferula narthex collected from Chitral, locally known as "Raw." Anticancer activity of crude and all fractions have been carried out to prevent carcinogenesis by using MTT assay. The n-hexane fraction showed good activity with an IC50 value of 5.434 ± 0.249 µg/mL, followed by crude MeFn extract 7.317 ± 0.535 µg/mL, and CHCl3 fraction 9.613 ± 0.548 µg/mL. Compounds 1 and 2 were isolated from chloroform fraction. Among tested pure compounds, compound 1 showed good anticancer activity with IC50 value of 14.074 ± 0.414 µg/mL. PASS (Prediction of Activity Spectra) analysis of the compound 1 was carried out, in order to predicts their binding probability with anti-cancer target. As a results the compound 1 showed binding probability with human histone acetyltransferase with Pa (probability to be active) value of 0.303. The compound 1 was docked against human histone acetyltransferase (anti-cancer drug target) by using molecular docking simulations. Molecular docking results showed that compound 1 accommodate well in the anti-cancer drug target. Moreover the activity support cancer chemo preventive activity of different compounds isolated from the genus Ferula, in accordance with the previously reported anticancer activities of the genus.