Biosynthesis of silver and gold nanoparticles using Musa acuminata colla flower and its pharmaceutical activity against bacteria and anticancer efficacy.

Synthesis of nanoparticles using plant sources as reducing agent has become important, as physical and chemical methods are costlier and affects environment. Hence it is important to develop environment friendly nanoparticle synthesis by avoiding the use of toxic chemicals. The present study aimed to synthesize silver nanoparticles (Ag Nps) and gold nanoparticles (AuNps) using Musa acuminata colla flower and its pharmaceutical activity against extended spectrum beta-lactamase (ESBL) gene producing bacteria and anticancer efficacy. The synthesized Ag and Au NPs were analysed by means of UV-Vis, FTIR, XRD,SEM and EDAX evidenced the bioreduction of Ag+ ions to Ag0 and Au3+ ions to Au0 respectively. Both nanoparticles and flower extracts were studied for antibacterial activity of ESBL gene producing bacteria by disc diffusion and microdilution (Resazurin) method. In vitro anticancer efficacy (MCF-7) and toxicity (VERO) of AgNPs, AuNPs, aqueous extract and ethanol extract of flowers were performed by MTT assay. IC50 value for DPPH analysis was at 390 μg and 460 μg for ethanol and aqueous extract respectively. Total antioxidant content was found be 740 μg/mg and 460 μg/mg for ethanol and aqueous extract. GCMS analysis authenticated the existence of the compounds namely, 9,12-octadecadienoic acid(z,z)- and n-hexadecanoic acid in the crude extract of the samples. Among the samples, AgNPs had best antibacterial activity. AgNPs and AuNPs were confirmed by colour change to reddish brown and ruby red. Further ƛmax were obtained at 474 and 540 nm by UV - visible spectrum. SEM analysis revealed the particle size ranges from 12.6 to 15.7 nm for silver and 10.1 to 15.6 nm for gold nanoparticles. The EDAX spectrum shows a strong signal for elemental Ag and Au at ~ 3 keV and 1.5 keV. The XRD patterns for silver and gold nanoparticles at 36.701, 42.900, 63.281 and 76.398 corresponding to the lattice planes 2.4467, 2.1064, 1.46839, 1.24564 nm and 27.32, 36.7228, 39.56, 42.888, 63.253, 63.253, 65.02 and 76.383 corresponding to the lattice planes 3.262, 2.44530, 2.276, 2.1070, 1.46897, 1.4332 and 1.24585 nm. The IC50 values for MCF-7 and VERO cells were 30.0 μg/ml and 55.0 μg/ml respectively.

Valsalam S ，Agastian P ，Esmail GA ，Ghilan AM ，Al-Dhabi NA ，Arasu MV ... -  《-》

Rapid biosynthesis and characterization of silver nanoparticles from the leaf extract of Tropaeolum majus L. and its enhanced in-vitro antibacterial, antifungal, antioxidant and anticancer properties.

Eco-friendly biosynthesis of nanoparticles from medicinal plants as reducing agent has gained importance due to its potential therapeutic uses. In the present study Silver nanoparticles (AgNPs) were eco-friendly synthesized using the leaf extracts of the medicinal plant Tropaeolum majus. The obtained AgNPs were characterized by UV - visible spectrum, FTIR, SEM and XRD which clearly showed the reduction of Ag+ ions to Ag0. In addition, the aqueous and ethanolic extracts were analyzed for phytochemicals and its antioxidant activities. GC-MS spectrum showed the presence of 25 compounds with benzeneacetic acid as the dominant contents. The synthesized AgNPs revealed maximum absorption spectrum at 463 nm and FTIR vibrational peaks at 3357.46, 21,966.52, 2118.42, 1637.27, 658.571 and 411.728 cm-1 respectively. SEM and XRD studies evidenced the nature of nanocrystalline with face centered cubic (fcc) crystal structure. Both AgNPs and plant extracts showed more inhibition activity against Pseudomonas aeroginosa compared to other bacteria with MIC value of 6.25 μg/ml. Antifungal activities was higher for Penicilium notatum with MIC value 31.2 μg/ml. The IC50 values for MCF7 for aqueous extract were found to be 4.68 μg/ml, ethanol extract 7.5 μg/ml, AgNPs 2.49 μg/ml, and doxorubicin 1.4 μg/ml. The IC50 values for VERO cell line for aqueous extract was 8.1 μg/ml, ethanol extract with 6.8 μg/ml, silver nanoparticles 5.3 μg/ml and doxorubicin 2.6 μg/ml respectively. Conclusively, the antibacterial, antifungal, antioxidant and anticancer properties of the synthesized AgNPs from Tropaeolum majus act as major therapeutic drug for microbial infectious disease and other health associated disorders.

Valsalam S ，Agastian P ，Arasu MV ，Al-Dhabi NA ，Ghilan AM ，Kaviyarasu K ，Ravindran B ，Chang SW ，Arokiyaraj S ... -  《-》

Ionic liquid functionalized biogenic synthesis of AgAu bimetal doped CeO(2) nanoparticles from Justicia adhatoda for pharmaceutical applications: Antibacterial and anti-cancer activities.

The noble metal such as Ag and Au doped CeO2 nanoparticles was successfully prepared by ionic liquid assisted hydrothermal method in the presence of Justicia adhatoda leaves extract and were used as an antibacterial and anticancer agent. The FT-IR and Raman spectrum exhibit the peaks at 460 and 464 cm-1 assigned to CeO stretching vibrations of NPs. The electron microscopic micrographs confirmed the spherical shaped morphology of prepared NPs. The insertion of Ag and Au ions into the CeO2 surface creates lattice defects the leads to reduce the band gap energy of Ag-Au/CeO2 at 3.15 eV. The XRD results suggested the average crystalline size of the silver‑gold loaded CeO2 was 28 nm. From the elemental mapping images, we have visualized that existence and uniform distribution of Ag, Au, Ce, and O in the prepared nanomaterials. The antibacterial activity of unloaded and bimetal loaded CeO2 NPs was evaluated with Gram-positive and Gram-negative bacteria using disc diffusion assay. The AgAu loaded CeO2 NPs exhibited the highest zone of inhibition against E. coli and S. aureus strains when compared with pristine CeO2, Ag loaded CeO2, and Au loaded CeO2 NPs. In addition, the 100 μg mL-1 of CeO2, Ag/CeO2, Au/CeO2 and Ag-Au/CeO2 NPs exposed the 50, 51, 52 and 56% of anticancer activity against the HeLa cells respectively. Overall, this study concludes that the ionic liquid functionalized green synthesized bimetal loaded cerium oxide NPs showed potent antibacterial and anticancer activities.

Nithya P ，Sundrarajan M 《-》

A facile and green strategy for the synthesis of Au, Ag and Au-Ag alloy nanoparticles using aerial parts of R. hypocrateriformis extract and their biological evaluation.

A facile and green strategy is reported here to synthesize gold (Au), silver (Ag) and gold-silver (Au-Ag) alloy nanoparticles (NPs) through bio-reduction reactions of aqueous corresponding metal precursors mediated by extracts of aerial parts of R. hypocrateriformis, which act as both reducing and stabilizing agents, under microwave irradiation. UV-vis spectrophotometer, XRD, FT-IR, FESEM/TEM, TGA and EDAX analysis were used to characterize the obtained NPs. The formation of NPs is evident from their surface plasmon resonance peak observed at λmax=∼550, 450 and 500nm for Au, Ag and Au-Ag alloy NPs respectively. XRD pattern revealed that fcc structure, while FT-IR spectra signify the presence of phytochemicals adsorbed on NPs. Such a biofunctionalized NPs were characterized by their weight loss, 30% due to thermal degradation of plant phytochemicals observed in TG analysis. The spherical shape of Au, Ag and Au-Ag alloy NPs (∼10-50nm) is observed by FE-SEM/TEM images. EDAX analysis confirms the expected elemental composition. Moreover, these NPs showed enhanced antimicrobial, antioxidant, and anticancer activities, though it is more pronounced for Au-Ag alloy NPs, which is due to the combining effect of phytochemicals, Au and Ag metals. Thus, the biosynthesized NPs could be applied as effective growth inhibitors for various biomedical applications.

Godipurge SS ，Yallappa S ，Biradar NJ ，Biradar JS ，Dhananjaya BL ，Hegde G ，Jagadish K ，Hegde G ... -  《-》

Ecofriendly synthesis of silver and gold nanoparticles by Euphrasia officinalis leaf extract and its biomedical applications.

Singh H ，Du J ，Singh P ，Yi TH ... -  《-》