STRUCTURAL AND THERMAL STABILITY OF AG NANOPARTICLES SYNTHESIZED FROM ARTEMISIA LERCHIANA: SEM, EDX, XRD AND TG-DTA ANALYSES

The recent research in nanoparticles synthesis field utilizes biological synthesis rather than chemical and physical methods in order to get uniform size and non-toxic of nanoparticles, further in biological synthesis the microbial synthesis is time consuming and requires sterilized conditions wherein green synthesis can overcome these drawbacks. The green synthesis of silver nanoparticles from many plant extracts finding quit attraction to many research scholars though very minute work has been done by using Hibiscus leaf extract. In this research work comparative experimental investigation is done on green synthesis of silver nanoparticles from three extracts Hibiscus leaf extract, followed by characterization was done by UV-Spectrophotometer, XRD, FTIR, AFM and SEM analysis. The silver nanoparticles of size 25-50 nm were synthesized by Hibiscus leaf extract. The silver nanoparticles were later treated with 4 different antibiotics wherein erythromycin showed three-fold increments in its efficiency.

White biotechnology can be regarded as applied biocatalysis, with enzymes and microorganisms, aiming at industrial production of bulk and fine chemicals to food and animal feed additives. In its turn biocatalysis has many attractive features in the context of greenchemistry: mild reaction conditions (physiological pH and temperature); environmentally compatible catalysts and solvent (often water) combined with high activities; and chemo-, regio-, and stereoselectivities in multifunctional molecules. This affords processes which are shorter, generate less waste, and are, therefore, both environmentally and economically more attractive than conventional routes. This special issue includes aspects involving the use of white biotechnology (enzymes, microorganisms, and plant tissues) within the green chemistry concept, concerning the use of alternative solvents (supercritical fluids, pressurized gases, ionic liquids, and micellar systems) and energies (microwaves and ultrasound); sustainable approaches for production of fine and bulk chemicals (aromas, polymers, pharmaceuticals, and enzymes); use of renewable resources or agroindustrial residues; biocatalysts recycling; and waste minimization. This special issue contains six papers, where three are related to green synthesis of nanoparticles and one paper covers biological pretreatment for enzymatic hydrolysis and bioethanol production. Two papers regard the use of alternative reaction systems. In the first paper entitled “Green synthesis of silver nanoparticles using Pinus eldarica bark extract,” S. Iravani and B. Zolfaghari present the optimization of the biosynthesis production of silver nanoparticles through the evaluation of Pinus eldarica bark extract quantity, substrate concentration, temperature, and pH on the formation of such material. The preparation of nanostructured silver particles using P. eldarica bark extract provides an environmentally friendly option, as compared to currently available chemical and/or physical methods. The second paper, “Green and rapid synthesis of anticancerous silver nanoparticles by Saccharomyces boulardii and insight into mechanism of nanoparticle synthesis,” by A. Kaler et al. describes an ecofriendly method for the synthesis of silver nanoparticles (AgNPs) by cell free extract (CFE) of Saccharomyces boulardii. In addition to the optimization of relevant synthesis parameters as culture age, cell mass concentration, temperature, and reaction time, the paper presents particles characterization by UV-Visible spectroscopy, EDX (energy dispersive X-Rays) analysis, transmission electron microscopy, and zeta potential, as well as the elucidation of proteins/peptides role in nanoparticles formation and stability and their anticancer activity. The method therein described a method that does not require tedious downstream processing and it may be scaled up to develop a viable technology for the Ag-nanoparticle synthesis. In the third paper, “Biosynthesis, antimicrobial and cytotoxic effect of silver nanoparticles using a novel Nocardiopsis sp. MBRC-1,” P. Manivasagan et al. present another green approach for biosynthesis of nanoparticles using the culture supernatant of Nocardiopsis sp. MBRC-1 to achieve the reduction of silver ions from a silver nitrate solution. The obtained nanoparticles were characterized by UV-visible, TEM, FE-SEM, EDX, FTIR, and XRD spectroscopy. The prepared silver nanoparticles exhibited strong antimicrobial activity against bacteria and fungi. Cytotoxicity of biosynthesized AgNPs against in vitro human cervical cancer cell line (HeLa) showed a dose-response activity. In the fourth paper, “Biological pretreatment of rubberwood with Ceriporiopsis subvermispora for Enzymatic hydrolysis and bioethanol production,” F. Nazarpour et al. investigate a novel feedstock for enzymatic hydrolysis and bioethanol production using biological pretreatment: rubberwood (Hevea brasiliensis). To improve ethanol production, rubberwood was pretreated with white rot fungus Ceriporiopsis subvermispora to increase fermentation efficiency. The fungal pretreatment provides a cost-effective method for reducing the recalcitrance of rubberwood with high selectivity of lignin degradation rate and minimal cellulose loss for enzymatic hydrolysis and bioethanol production. In the fifth paper, the research of G. D. Yadav and S. Devendran entitled “Microwave assisted enzymatic kinetic resolution of (±)-1-phenyl-2-propyn-1-ol in non-aqueous media,” proposes a kinetic resolution of 1-phenyl-2-propyn-1-ol, an important chiral synthon, through esterification with acyl acetate. The authors investigate synergism between microwave irradiation and enzyme catalysis. The lipase (Novozym 435) catalyzed kinetic resolution under microwave irradiation. The maximum conversion of 48.78% was obtained in 2 h using 10 mg enzyme loading with equimolar concentration of alcohol and ester at 60°C under microwave irradiation. From the progress curve analysis, it was found that reaction followed the ping-pong bi-bi mechanism with dead end inhibition of alcohol. Beside the previous papers herein described, the preparation of chiral secondary alcohols using lipase catalyzed kinetic resolution is mild and clean as compared to chemical process. In the seventh paper entitled “Demonstration of redox potential of Metschnikowia koreensis for stereoinversion of secondary alcohols/1,2-diols,” by V. S. Meena et al. reports the Metschnikowia koreensis-catalyzed one-pot deracemization of secondary alcohols/1,2-diols and their derivatives with in vivo cofactor regeneration. This ecofriendly method afforded the product in high yield (88%) and excellent optical purity (>98% ee), minimizing the requirement of multistep reaction and expensive cofactor. Bernardo Dias Ribeiro Isabel Marrucho Luciana Goncalves Maria Alice Z. Coelho

Silver nanoparticles (AgNP) have been already proposed for many advanced research approaches in the fields of therapeutics and nanomedicine due to their non-antigenicity and more potent optical characteristics along with their respective antioxidant and antimicrobial properties in effective site specific targeted drug-delivery practices systems. In last few years, chemically synthesized metal based nanoparticles has been studies for their biological and delivery behaviours because of use of various chemical and bio-hazardous chemicals in their preparations. Various previous studies on green synthesis of silver metal based nanoparticles have been designed which involved biological sources like microorganisms, plants and herbal extracts as cost effective, eco-friendly and non-toxic approaches. So that, green synthesis of silver nanoparticles has been much exploited in wider range of applications in the field of biomedical, therapeutics, nanomedicine and pharmaceuticals as more potent and safe drug delivery vehicles as compared to chemically preparations of silver nanoparticles. Therefore, in this review, we recollected the comparative studies based on advantages of green approaches of silver nanoparticles over their respective chemical preparations. Keywords: Silver nanoparticles, Green synthesis, Therapeutics, Nanomedicine, Drug delivery vehicles.

Green synthesis and characterization of silver nanoparticles using belladonna mother tincture and its efficacy as a potential antibacterial and anti-inflammatory agent

Abstract: Nanoparticles (NPs) are tiny particles with their dimensions ranging between1and100 nm. These are gaining cumulative attention owing to their vast use in different fields of applications. There are three main methods for synthesizing NPs; namely, physical, chemical and biological methods. Physical methods consume a lot of energy and time, require expensive vacuum systems and high temperatures and on top of all, they are not environmentally friendly. Chemical methods, in general, are expensive, increase the particle toxicity and perhaps harm human health and the environment. In addition, hazardous chemicals gather on the top of NPs and confine their applications. Therefore, green method is an alternative replacement to the traditional chemical and physical methods for synthesizing NPs. The existing phytochemicals, for instance in plant extracts, own a remarkably high ability for reducing metal ions within a short time comparing with other microorganisms, which require a longer incubation period. This study is concentrating on green synthesis of silver (Ag) NPs, owing to the significance of Ag NPs whose optical properties depend on their size and shape. In addition, Ag NPs possess numerous applications, especially in solar cells, water treatment and medicine. This review aims to highlight the remarkable growth of green synthesis of Ag NPs, in terms of publications, citations, active and productive researchers, targeting journals and the eminent countries in this regard. This review, also, is highlights the most utilized plants for producing Ag NPs in fourteen years; i.e., 2007-2021.This review, also, evaluating the most acceptable proposed mechanism for biosynthesizing Ag NPs using plant extracts. We believe that this review article will facilitate and brighten the road in front of researchers who want to initiate their study with the biosynthesis of Ag NPs from plant extracts. Keywords: Silver nanoparticles, Green synthesis, Plant extracts, Stabilizing agents, Reducing agents.

Nanoparticles are molecules in the range of 1 nm to 100 nm and they can be synthesized by physical, chemical and biological methods. Green synthesis involves the production of nanoparticles from bacteria, fungi, algae, plants and plant extracts. Plant extracts with their chemical constituents can capture the target metals from their salt solution and transform the metal particles into nanoparticles with the cellular catalysts. The present study focuses on the green synthesis of silver nanoparticles using the liquid endosperm of coconut, the coconut water (Cocos nucifera), Liquid endosperm of palm fruit (Borassus flabellifer) and coconut Toddy as the reducing agent. The bio-reduction of aqueous silver ions by coconut water is identified by its colour change. During the synthesis of silver nanoparticles, the colour of the solution changed from milky white to brown. The characterization of synthesized AgNPs (Silver Nanoparticles) was done by Fourier Transform Infrared Spectroscopy and UV-Vis Spectroscopy. The peaks obtained at 250 and 350 nm confirmed the presence of synthesized Silver Nanoparticles. The antibacterial activity of the synthesized nanoparticles was studied on Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes using disc diffusion method. The recent approach of green synthesis is quite impressive due to its eco- friendly, economical, feasible and non- toxic nature.

One-pot green synthesis, optimization, and characterization of silver nanoparticles from Mitragyna parvifolia: A novel therapeutic strategy for rheumatoid arthritis targeting COX-2 and TNF- α.

Background: Appearance of antibiotic resistance has raised the demand to find alternative therapies and modified drug delivery system of medicinal plants to treat bacterial infections.
 Objective: The aim of this study is the green synthesis and characterization of silver nanoparticles by using crude extract of Crotalaria burhia and to evaluate their antibacterial potential.
 Methods: The roots and stems of plant were used to prepare the crude extract. The phytochemical analysis of different compounds in extract was performed. 1mM AgNO3 and different concentrations of plant extract were used for the green synthesis of silver nanoparticles. The particles size and zeta potential were measured by zeta sizer while surface morphology of silver nanoparticles was observed with Scanning Electron Microscope (SEM). The antibacterial activity of silver nanoparticles was performed by 96 well microdilution plate method.
 Results: The particle size and zeta potential of optimized formulation was 92 nm and -24.8 mV. The SEM analysis showed that silver nanoparticles are irregular and spherical shape. The antibacterial activity showed that MIC value of silver nanoparticles was lower for E. coli than S. aureus.
 Conclusion: Silver nanoparticles possess potent bactericidal activity against E. coli and moderate activity against S. aureus. It had been concluded that these nanoparticles can be used against multi-drug resistant bacterial infections.

AimThis study aims to synthesize silver nanoparticles (AgNPs) using herbal formulations derived from Zingiber officinale (ginger) and Ocimum gratissimum and to evaluate their anti-inflammatory and antidiabetic activities in vitro.MethodsThe synthesis of AgNPs was performed using Z. officinale and O. gratissimum, and the AgNPs were confirmed by analyzing their ultraviolet-vis spectra. The anti-inflammatory activity was assessed using two assays, specifically the bovine serum albumin (BSA) denaturation assay and the egg albumin (EA) denaturation assay. The antidiabetic activity was assessed using the α-amylase inhibitory assay and the β-glucosidase inhibitory assay.ResultsThis study evaluated the anti-inflammatory and antidiabetic activities of green-synthesized AgNPs using Z. officinale and O. gratissimum. The maximum absorption peak was observed for AgNPs at ~433 nm (wavelength). In the BSA denaturation assay, 78% inhibition was observed at a concentration of 50 μl. Similarly, in the EA denaturation assay, an inhibition of 74% was observed at the same concentration compared to the standard. In terms of antidiabetic activity, when compared to the standard at a concentration of 50 μl, the α-amylase inhibitory assay and the β-glucosidase inhibitory assay showed approximately 78% and 80% inhibition, respectively.ConclusionThe use of Z. officinale and O. gratissimum extracts for the synthesis of AgNPs using a green synthesis method presents a sustainable and environmentally friendly approach. The synthesized AgNPs demonstrated significant anti-inflammatory and antidiabetic efficacy, suggesting their potential application in pharmaceuticals for treating diabetes and inflammation. Further research is necessary to investigate the effectiveness and safety of these substances in humans and to understand their underlying mechanisms of action.

Green synthesis, characterization and biocompatibility evaluation of silver nanoparticles using radish seeds

Review: 63 refs.

Nanotechnology is an escalating field that has made its contribution to all spheres of human life. The green synthesis of nanoparticles has paved for better methodologies and approaches in the medicinal field. Nowadays silver, gold and other metallic nanoparticles are used as an efficient carrier for drug molecules for developing novel drug delivery systems. In course of synthesizing these nanoparticles various chemicals, solvents and reagents are used which harms our eco system directly or indirectly. Silver nanoparticles (Ag NPs) have been widely used as a novel therapeutic agent extending its use as antibacterial, antifungal, anti-viral and anti-inflammatory agent. Silver nanoparticles (Ag NPs) prepared by green synthesis have many advantages over conventional methods involving chemical agents associated with environmental toxicity. Green synthetic methods include polysaccharide method, irradiation method, biological method, polyoxometallates method and tollens method. Green synthesis of nanoparticles is found to be an emerging branch of nanotechnology. The use of environmentally benign materials like plant leaf extract for the synthesis of nanoparticles offers numerous benefits of eco-friendliness and compatibility for pharmaceutical and biomedical applications as they do not use toxic chemicals in the synthesis protocols. Rapid and green synthetic methods using various plant extracts have shown a great potential in silver nanoparticles (Ag NPs) synthesis. This review article describes the bio-inspired synthesis of nanoparticles that provides advancement over chemical and physical methods as it is cost effective, eco-friendly and more effective in a variety of applications.

The extract of Carpesium cernuum whole plant was successfully used as a green factory for the synthesis of silver nanoparticles in a one-step, one-pot process. The extract efficiently reduced silver ions to spherical silver nanoparticles. The size was measured as 13.0 ± 0.2nm from high resolution transmission electron microscopic images. The reaction yield was determined to be 99.6% using inductively coupled plasma optical emission spectroscopy. The silver nanoparticles were highly stable for 28days at ambient temperature without forming agglomeration or aggregation of nanoparticles. Dose-dependent antioxidant activity of the silver nanoparticles was observed in terms of the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl radicals. The silver nanoparticles also exerted cytotoxicity on Mus musculus skin melanoma cells (B16F10) and human lung cancer cells (A549) in a dose-dependent manner. Specifically, the cytotoxicity of the silver nanoparticles on A549 cells was closely associated with apoptotic cell death. Cellular uptake of the silver was evaluated via inductively coupled plasma mass spectrometry, and a higher percentage of silver was taken up by A549 cells (22.6%) than by B16F10 cells (17.3%). This result indicated that higher cellular uptake of silver nanoparticles resulted in higher cytotoxicity on A549 cells. Therefore, plant extracts are capable of being valuable natural sources for the green synthesis of silver nanoparticles that exhibit potent biological activities for pharmaceutical and biomedical applications in future nanomedicine.

The green synthesis of nanoparticles is an important branch and a relatively new emerging field in nanotechnology which is easy, environmentally friendly, cost effective, and economically efficient in comparison with the chemical and physical methods. In the present work, for the first time, green synthesis of silver nanoparticles (AgNPs) was carried out by using fructose solution as a reducing agent at room temperature. The silver nanoparticles were characterized by UV-Vis, FTIR, XRD, and TEM analysis. The UV-Vis spectral studies confirmed the surface plasmon resonance of the green synthesized silver nanoparticles. The role of different functional groups in formation of the AgNps was shown by FTIR. X-ray diffraction results confirmed the formation of the the AgNPs and TEM results indicated that the average particle size of the silver nanoparticles was 13.24±8.591 nm.

Background: Silver nanoparticles possess distinctive characteristics, including chemical stability, high thermal and electrical conductivity, and linear optical properties, making them unique and fascinating. The rise of green synthesis methods for silver nanoparticles is garnering significant interest among researchers, surpassing traditional chemical and physical approaches due to the environmentally friendly, cost-effective, and convenient nature of synthesis. This approach stands as a viable alternative across various sectors, encompassing research, industry, and environmental safety initiatives. Method: Parmotrema permutatum was utilized in the synthesis of silver nanoparticles, followed by their characterization using ultraviolet-visible spectroscopy, Fourier-transformed infrared spectroscopy, X-ray diffraction, energy dispersive X-ray analysis, and scanning electron microscopy. These nanoparticles are subsequiently employed for detecting methylene blue, formaldehyde, and hazardous mercury metal ions as well as photocatalytically degrading methylene blue. objective: Green Synthesis of Silver Nanoparticle Using Parmotrema parmutatum Extract and Its Application in Colorimetric Sensing Results: The silver nanoparticle synthesized was confirmed by a color change and the maximum peak of the SPR band was at 420 nm in the UV spectrum. The crystal has face-centered cubic (FCC) structure with an average size of 12.78 nm. The lichen extract contains polyphenolic groups which act as capping agents. synthesized silver nanoparticles were used to detect formaldehyde and hazardous Hg2+ ions separately. A color change was observed. The detection limit of Hg2+ was 600 μL. Likewise, silver nanoparticles were used to degrade methylene blue. The blue color of methylene blue disappeared. The efficiency of silver nanoparticles was found to be 72% in 4 hours and 87.82% in 24 hours. Conclusion: Parmotrema permutatum has the potential to reduce Ag2+ to Ago and acts as a capping and stabilizing agent, it can be used to biosynthesize silver nanoparticles and can detect formaldehyde, and Hg2+ ions, in addition, it also degrades methylene blue photolytically.