A review on plants extract mediated synthesis of silver nanoparticles for antimicrobial applications: A green expertise.

Synthesis of metallic nanoparticles using plant extracts.

Nanotechnology is the creation, manipulation and use of materials at the nanometre size scale (1 to 100 nm). At this size scale there are significant differences in many material properties that are normally not seen in the same materials at larger scales. Although nanoscale materials can be produced using a variety of traditional physical and chemical processes, it is now possible to biologically synthesize materials via environment-friendly green chemistry based techniques. In recent years, the convergence between nanotechnology and biology has created the new field of nanobiotechnology that incorporates the use of biological entities such as actinomycetes algae, bacteria, fungi, viruses, yeasts, and plants in a number of biochemical and biophysical processes. The biological synthesis via nanobiotechnology processes have a significant potential to boost nanoparticles production without the use of harsh, toxic, and expensive chemicals commonly used in conventional physical and chemical processes. The aim of this review is to provide an overview of recent trends in synthesizing nanoparticles via biological entities and their potential applications.

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Green Synthesis of Metallic Nanoparticles via Biological Entities

The field of nanotechnology mainly encompasses with biology, physics, chemistry and material sciences and it develops novel therapeutic nanosized materials for biomedical and pharmaceutical applications. The biological syntheses of nanoparticles are being carried out by different macro-microscopic organisms such as plant, bacteria, fungi, seaweeds and microalgae. The biosynthesized nanomaterials have been effectively controlling the various endemic diseases with less adverse effect. Plant contains abundant natural compounds such as alkaloids, flavonoids, saponins, steroids, tannins and other nutritional compounds. These natural products are derived from various parts of plant such as leaves, stems, roots shoots, flowers, barks, and seeds. Recently, many studies have proved that the plant extracts act as a potential precursor for the synthesis of nanomaterial in non-hazardous ways. Since the plant extract contains various secondary metabolites, it acts as reducing and stabilizing agents for the bioreduction reaction to synthesized novel metallic nanoparticles. The non-biological methods (chemical and physical) are used in the synthesis of nanoparticles, which has a serious hazardous and high toxicity for living organisms. In addition, the biological synthesis of metallic nanoparticles is inexpensive, single step and eco-friendly methods. The plants are used successfully in the synthesis of various greener nanoparticles such as cobalt, copper, silver, gold, palladium, platinum, zinc oxide and magnetite. Also, the plant mediated nanoparticles are potential remedy for various diseases such as malaria, cancer, HIV, hepatitis and other acute diseases.

Biosynthesis of metallic nanoparticles using plant derivatives and their new avenues in pharmacological applications – An updated report

In this paper, an aqueous extract of fresh leaves of Pedalium murex was used for the synthesis of silver (Ag) nanoparticles. Different biological methods are gaining recognition for the production of silver nanoparticles (AgNPs) due to their multiple applications. The use of plants in the green synthesis of nanoparticles emerges as a cost-effective and eco-friendly approach. Characterization of nanoparticles was done using different methods, which include; ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared (FTIR), powder X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray analysis (EDAX), fluorescence emission spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DLS), zeta potential and antibacterial activity. UV–visible spectrum of the aqueous medium containing silver nanoparticles showed absorption peak at around 430 nm. Fourier transform infrared spectra had shown that the biomolecule compounds were responsible for the reduction and capping material of silver nanoparticles. XRD study showed the particles to be crystalline in nature, with a face-centered cubic (fcc) structure. The size and stability were detected using DLS and zeta potential analysis. The antibacterial activity of AgNPs against generally found bacteria was assessed to find their potential use in silver-containing antibacterial product.

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Characterization of silver nanoparticles by green synthesis method using Pedalium murex leaf extract and their antibacterial activity

Biosynthesis of silver nanoparticles using citrus sinensis peel extract and its antibacterial activity

SUMMARY Antioxidant property of Phyllosticta sp. culture filtrate extracted with ethanol was evaluated in vitro. ABTS and DPPH radicals were used to evaluate their antioxidant activity. Antioxidant components like total phenol and flavonoid were also determined. The ethanolic extract of Phyllosticta sp. showed potent antioxidant activity against both ABTS and DPPH radicals with the EC 50 value of 580.02 ± 0.57µg/ml and 2030.25±0.81 µg/ml respectively. Total amount of phenol and flavonoid quantified were of 18.33 ± 0.68 gallic acid equivalents per gram and 6.44 ± 1.24 µg/mg of quercetin equivalent respectively. In conclusion, the culture filtrate of Phyllosticta sp. may have potential source of natural antioxidant. Key words: Antioxidant, ABTS, DPPH, phenol, Phyllosticta sp . K. Srinivasan et al. Antioxidant Activity of Endophytic Fungus Phyllosticta sp. isolated from Guazuma tomentosa . J Phytol 2/6 (2010) 37-41.

Antioxidant activity of endophytic fungus phyllosticta sp. isolated from guazuma tomentosa

The fresh juice of Musa stem (Puttubale) was tested for its antilithiatic activity. Zinc discs were implanted in the urinary bladder of albino rats to induce urolithiasis. The stones formed were mainly of magnesium ammonium phosphate with traces of calcium oxalate. Musa stem juice (3 mL/rat/day orally) was found to be effective in reducing the formation and also in dissolving the pre-formed stones.

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Evaluation of Musa (Paradisiaca Linn. cultivar)--"Puttubale" stem juice for antilithiatic activity in albino rats.

Context: Lead is the conventional shielding material against gamma/X-rays. It has some limitations such as toxic, high density, nonflexibility, and also bremsstrahlung production during electron interaction. It may affect the accuracy of radiotherapy outcome. Aims: To theoretically analyze the radiation shielding properties of flexible polyvinyl alcohol/iron oxide polymer composite with five different concentrations of magnetite over the energy range of 15 KeV–20 MeV. Subjects and Methods: Radiological properties were calculated based on the published literature. Attenuation coefficients of pure elements are generated with the help of WinXCOM database. Results: Effective atomic numbers and electron density are increased with the concentration of magnetite. On the other hand, the number of electrons per gram decreased. Mass attenuation coefficient (μ/ϼ) and linear attenuation coefficients (μ) are higher in the lower energy <100 KeV, and their values decreased when the energy increased. Computed tomography numbers (CT) show the significant variation between the concentrations in <60 KeV. Half-value layer and tenth-value layers are directly proportional to the energy and indirectly proportional to the concentration of magnetite. Transmission curve, relaxation length (ƛ), kinetic energy released in the matter, and elemental weight fraction are also calculated and the results are discussed. Conclusions: 0.5% of the magnetite gives superior shielding properties compared with other concentrations. It may be due to the presence of 0.3617% of Fe. Elemental weight fraction, atomic number, photon energy, and mass densities are the important parameters to understand the shielding behavior of any material.

K. Srinivasan

Papers

Biosynthesis of silver nanoparticles using citrus sinensis peel extract and its antibacterial activity

Antioxidant activity of endophytic fungus phyllosticta sp. isolated from guazuma tomentosa

Evaluation of Musa (Paradisiaca Linn. cultivar)--"Puttubale" stem juice for antilithiatic activity in albino rats.

Evaluation of radiation shielding properties of the polyvinyl alcohol/iron oxide polymer composite

Synthesis, anticancer, structural, and computational docking studies of 3-benzylchroman-4-one derivatives.