Green Synthesis

Improvement of the medical textile industry has received more attention recently, especially with widespread of microbial and viral infections. Medical textiles with new properties, such as bacterial pathogens self-cleaning, have been explored with nanotechnology. In this study, an endophytic actinomycetes strain of Streptomyces laurentii R-1 was isolated from the roots of the medicinal plant Achillea fragrantissima. This is used as a catalyst for the mediated biosynthesis of silver nanoparticles (Ag-NPs) for applications in the textile industry. The biosynthesized Ag-NPs were characterized using UV-vis spectroscopy, Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and X-ray Diffraction (XRD), which confirmed the successful formation of crystalline, spherical metal nanoparticles. The biosynthesized Ag-NPs exhibited broad-spectrum antibacterial activity. Our data elucidated that the biosynthesized Ag-NPs had a highly cytotoxic effect against the cancerous caco-2 cell line. The selected safe dose of Ag-NPs for loading on cotton fabrics was 100 ppm, regarding their antibacterial activity and safe cytotoxic efficacy. Interestingly, scanning electron microscope connected with energy dispersive X-ray spectroscopy (SEM-EDX) of loaded cotton fabrics demonstrated the smooth distribution of Ag-NPs on treated fabrics. The obtained results highlighted the broad-spectrum activity of nano-finished fabrics against pathogenic bacteria, even after 5 and 10 washing cycles. This study contributes a suitable guide for the performance of green synthesized NPs for utilization in different biotechnological sectors.

FREE TO DOWNLOAD FOR 50 DAYS AT https://authors.elsevier.com/c/1bHZh3IWkc0GxH.  Various quantities of ginger (Zingiber officinale) root extract were used to prepare X-type Barium–Zinc hexaferrite with the chemical composition Ba2Zn2Fe28O46. The powders were prepared using a combustion treatment method, being pre-heated at 550 °C for 4 h with the ginger as a fuel, followed by final heating to 900 °C for 5 h and natural cooling to room temperature to obtain Ba2Zn2Fe28O46 hexagonal ferrite powder. The phase composition of heated powder samples was investigated by X-ray diffraction (XRD), indicating the formation of a mixture of X-type and hematite (α-Fe2O3). Up to 82.6%, X-ferrite was formed at 900 °C with 52.5 g of ginger root extract. Dielectric analysis of the prepared samples shows the frequency-dependent phenomena. All samples were hard magnets, with coercivity values (HC) between 262.2 and 318.3 kA m−1, and squareness ratios > 0.5. The sample prepared with 52.5 g ginger root extract possesses the highest value of saturation magnetisation (MS = 33.87 Am2 kg−1) in comparison with the other prepared samples. Therefore, ginger was shown to be a useful natural plant extract as a reducing fuel for the low-temperature synthesis of X-ferrites. The sample prepared with 35 g ginger root extract shows a broad loss tangent resonance peak between 10 kHz and 100 kHz, while other samples show loss tangent resonance peaks between 300 kHz and 2 MHz frequency range.

A green, phytogenic and cost effective synthesis of tin oxide nanoparticles (SnO 2 NPs) using aqueous leaf extract of Tradescantia spathacea is reported. The structural, surface morphological and optical studies have been performed using X-ray diffraction (XRD), Fourier-Transform Infrared spectroscopy (FT-IR), Scanning Electron mi-croscopy (SEM), UV-visible diffuse reflectance spectroscopy (UV-vis-DRS), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET). XRD pattern shows SnO 2 with tetragonal structure of crystallite size ranging 9-22 nm. The FTIR spectra exhibits the presence of hydroxyl groups, amines, alkenes and phenols from the aqueous leaf extract which are responsible for the synthesis of narrow band gap SnO 2 NPs. The SEM analysis suggests slight agglomeration morphology with particle size in the range of 46-89 nm. The band gap energy obtained was in range of 2.51-3.3 eV. Photoantioxidant activities of SnO 2 NPs in the dark and under visible light illumination were carried out. The SnO 2 NPs showed enhanced photoantioxidant activities under visible light irradiation.

50 days' free access: https://authors.elsevier.com/c/1eh8Mvn2L-k8U    Ba2Zn2Fe28O46 hexaferrite was prepared using green synthesis with different quantities of ginger root extract (obtained from 0.0, 17.5, 35, 52.5 and 70 g of ginger root) as a natural antioxidant reducing agent. The dried precipitates were preheated at 550 °C/4 h and finally heated at 1200 °C/5 h. The effect of ginger root extract on structural, phase purity, magnetic, Mӧssbauer and low frequency (10 Hz–2 MHz) dielectric properties were investigated. XRD analysis of samples prepared with extracts from 35, 52.5, and 70 g of ginger depicted pure X-phase, while the other samples (0.0, 17.5 g) showed the secondary phase of M-type (BaM, BaFe12O19) along with hematite (12% α-Fe2O3). Hence, samples with greater amounts of ginger extract formed single-phase X-type hexaferrite. Saturation magnetization (MS) varied from 40.8 A m2/kg without ginger extract to 69.8 A m2/kg with extract from 52.5 g ginger, and was <65 A m2/kg for all samples made with the ginger extract. All synthesized samples were relatively soft ferrites, and coercivity increased with amount of ginger extract used. The Mӧssbauer spectra explored six sextets of five magnetic sub-lattices, and the presence of Fe3+ (99.4–97.3 %) and Fe2+ (0.6–2.7 %) ions, with more Fe2+ present in the extract-derived samples. The variations in MS based on hysteresis loops were in agreement by Mössbauer spectroscopy. The use of the extract also significantly reduced the grain size, from 3.3 μm without ginger extract to 0.7–1.7 μm with the extract, with a corresponding increase in coercivity from 16 to 40–80 kA/m. The samples prepared with extracts from 35 g to 52.5 g ginger root possessed considerable real dielectric constant compared to the others, but the extract also increased conductivity in the high-frequency region. Complex impedance displayed low values in the high-frequency region, and Cole-Cole plots revealed that the main contribution to conductivity in extract-based samples was from the grains. The reducing action of the green extract not only produced single phase X ferrite, but it also reduced grain size to ∿1–2 μm and greatly increased MS.

Recent studies on the exploration of eco-friendly approach by utilizing large-scale waste materials as potential catalyst in biodiesel production have attracted much attention. The development of heterogeneous catalysts especially from calcium has gained much awareness due to the large availability of calcium-rich waste materials and their corresponding high catalytic activity in the transesterification of oil. Most of the waste materials employed as heterogeneous catalysts have an abundance of natural Ca content and they have high catalyst activity and selectivity despite being environment-friendly and cost-effective. Heterogeneous catalysts with high activity can be produced from Ca based waste materials when calcined at high temperatures. This review gives a brief overview of the developments of various Ca based catalysts derived from waste materials as an efficient catalyst for biodiesel production with significant yield. Industrial wastes (red mud, slag, ash) and biological catalysts (chicken eggshells, mollusk shells, animal bones) possess enormous potential towards developing an economical catalyst and subsequently, low-cost biodiesel generation. However, future challenges await a better utilization of useless wastes into a useful resource to satisfy human needs.

This study reports the formation of 5-FU co-crystals with four different pharmacologically safe co-formers; Urea, Thiourea, Acetanilide and Aspirin using methanol as a solvent. Two fabrication schemes were followed i.e., solid-state grinding protocol, in which API and co-formers were mixed through vigorous grinding while in the other method separate solutions of both the components were made and mixed together. The adopted approaches offer easy fabrication protocols, no temperature maintenance requirements , no need of expensive solvents, hardly available apparatus, isolation and purification of the desired products. In addition, there is no byproducts formation, In fact, a phenomenon embracing the requirements of green synthesis. Through FTIR analysis; for API the NAH absorption frequency was recorded at 3409.02 cm À1 and that of AC@O was observed at 1647.77 cm À1. These characteristics peaks of 5-FU were significantly shifted and recorded at 3499.40 cm À1 and 1649.62 cm À1 for 5-FU-Ac (3B) and 3496.39 cm À1 and 1659.30 cm À1 for 5-FU-As (4B) co-crystals for NAH and AC@O groups respectively. The structural differences between API and co-crystals were further confirmed through PXRD analysis. The characteristic peak of 5-FU at 2h = 28.79918 o was significantly shifted in the graphs of co-crystals not only in position but also with respect to intensity and FWHM values. In addition, new peaks were also recorded in all the spectra of co-formers confirming the structural differences between API and co-formers. In addition, percent growth inhibition was also observed by all the co-crystals through MTT assay against HCT 116 colorectal cell lines in vitro. At four different concentrations; 25, 50, 100 and 200 mg/mL, slightly different trends of the effectiveness of API and co-crystals were observed. However; among all the co-crystal forms, 5-FU-thiourea co-crystals obtained through solution method (2B) proved to be the most effective growth inhibitor at all the four above mentioned concentrations.

Introduction: The use of plants is one of the most effective methods for the synthesis of nanoparticles based on green chemistry. The magnetic properties of nanoparticles let the attached drugs conduct by a magnetic field in the body. This study aimed to use the magnetic iron oxide nanoparticles synthesized via green chemistry as a carrier for the chloramphenicol drug delivery system.

Materials & Methods: Extraction of Echinops Persicus was performed at 60°C by water solvent. Iron oxide nanoparticles were synthesized using plant extract as a reducing agent. The synthesized iron oxide nanoparticles were characterized by ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), particle size analyzer (PSA), and fourier-transform infrared spectroscopy (FT-IR). The antibacterial activity of coated nanoparticles was also investigated in this study.

Findings: The results of the XRD showed the cubic shape of iron oxide nanoparticles. The mean size of the nanoparticles was determined to be in the range of 16-56 nm. The coating of chloramphenicol on iron oxide nanoparticles was confirmed by transmission electron microscopy (TEM). Moreover, FT-IR confirmed the functionalization of Fe3O4 nanoparticles with chloramphenicol. The magnetic iron oxide nanoparticles coated with chloramphenicol showed good antibacterial activity against infectious Gram-positive and Gram-negative bacteria. The highest antimicrobial activity and the diameter of the growth inhibition zone of Staphylococcus aureus (11.25±0.35) and Escherichia coli (9.5±0.17) were determined at a concentration of 100 μg/ml.

Discussions & Conclusions: According to the results of this study, the coating of Iron oxide nanoparticles with chloramphenicol antibiotics increased the antimicrobial properties of nanoparticles and confirmed the appropriateness of the loading method of chloramphenicol antibiotics.