Green synthesis of metal nanoparticles using plants

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

Synthesis of metallic nanoparticles using plant extracts.

In materials science, “green” synthesis has gained extensive attention as a reliable, sustainable, and eco-friendly protocol for synthesizing a wide range of materials/nanomaterials including
 metal/metal oxides nanomaterials, hybrid materials, and bioinspired materials. As such, green synthesis is regarded as an important tool to reduce the destructive effects associated with the traditional methods of synthesis for nanoparticles commonly utilized in laboratory and industry. In this review, we summarized the fundamental processes and mechanisms of “green” synthesis approaches, especially for metal and metal oxide [e.g., gold (Au), silver (Ag), copper oxide (CuO), and zinc oxide (ZnO)] nanoparticles using natural extracts. Importantly, we explored the role of biological components, essential phytochemicals (e.g., flavonoids, alkaloids, terpenoids, amides, and aldehydes) as reducing agents and solvent systems. The stability/toxicity of nanoparticles and the associated surface engineering techniques for achieving biocompatibility are also discussed. Finally, we covered applications of such synthesized products to environmental remediation in terms of antimicrobial activity, catalytic activity, removal of pollutants dyes, and heavy metal ion sensing.

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‘Green’ synthesis of metals and their oxide nanoparticles: applications for environmental remediation

Silver nanoparticles (NPs) have been the subjects of researchers because of their unique properties (e.g., size and shape depending optical, antimicrobial, and electrical properties). A variety of preparation techniques have been reported for the synthesis of silver NPs; notable examples include, laser ablation, gamma irradiation, electron irradiation, chemical reduction, photochemical methods, microwave processing, and biological synthetic methods. This review presents an overview of silver nanoparticle preparation by physical, chemical, and biological synthesis. The aim of this review article is, therefore, to reflect on the current state and future prospects, especially the potentials and limitations of the above mentioned techniques for industries.

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Synthesis of silver nanoparticles: chemical, physical and biological methods.

Synthesis of silver nanoparticles using Acalypha indica leaf extracts and its antibacterial activity against water borne pathogens.

Melanins are enigmatic pigments that are produced by a wide variety of microorganisms including several species of bacteria and fungi. For more than 40 years, fungi have been known to produce pigments called melanins. Melanin pigment production by mushrooms was not intensively studied. The present study was carried out on isolation and characterization of melanin from an edible mushroom Pleurotus
 cystidiosus var. formosensis. The mushroom produced dark mucous mass of hyaline arthrospores on mycelium. The coremia exclusively produced dikaryotic arthrospores with the remnant of a clamp connection. Continuous cell extension and division in the coremium stipe supplied cells for arthroconidiation at the coremium apex, which is surrounded by a liquid droplet (coremioliquid). The black coloured coremea (conidia) were produced by Antromycopsis macrocarpa (anamorph of P. cystidiosus) when cultured on potato dextrose agar medium. The agar plate was incubated at continuous light illumination for high amount of pigment (coremea) production. The slimy layer of the coremea was extracted and partially purified by alkaline and acid treatment. The black pigment was confirmed as melanin based on UV, IR and EPR spectra apart from chemical analysis. This is the first report on characterization of melanin obtained from Pleurotus
 cystidiosus var. formosensis.

Isolation and characterization of melanin pigment from Pleurotus cystidiosus (telomorph of Antromycopsis macrocarpa)

In vitro and in vivo anticancer effects of Lithospermum erythrorhizon extract on B16F10 murine melanoma.

Schizandrin C exerts anti-neuroinflammatory effects by upregulating phase II detoxifying/antioxidant enzymes in microglia.

Two hybrid strains were obtained through protoplasmic fusion between Pleurotus ostreatus var. florida and Pleurotus djamor var. roseus. The hybrid strains showed intermediate morphology (colony morphology, cultural characteristics, and fruiting body) to parents. The size and RFLP pattern of two recombinant hybrids were similar, and differed from the parental Pleurotus species. The internal transcribed spacer sequence data revealed that hybrids showed close clad with variety of Pleurotus spp. The hybrid strains showed maximum biological efficiency (138.97%) than the parental strains (110.48-119.19%). In addition, maximum proximate composition, energy values (268.28 kcal), vitamins (thiamine, riboflavin, pyridoxine, folic acid, and calcium pentothenate) and mineral contents (potassium, phosphorus, iron, calcium, and zinc) were recorded in hybrid strain. The hybrid Pleurotus sp. HS would be an important resource of food for mankind, utilize variety of agricultural waste, high amount of nutritional properties and essential food for human health.

Seetharaman Rajasekar

Papers

Synthesis of silver nanoparticles using Acalypha indica leaf extracts and its antibacterial activity against water borne pathogens.

Isolation and characterization of melanin pigment from Pleurotus cystidiosus (telomorph of Antromycopsis macrocarpa)

In vitro and in vivo anticancer effects of Lithospermum erythrorhizon extract on B16F10 murine melanoma.

Schizandrin C exerts anti-neuroinflammatory effects by upregulating phase II detoxifying/antioxidant enzymes in microglia.

Improving biological efficiency of Pleurotus strain through protoplast fusion between P. ostreatus var. florida and P. djamor var. roseus