首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The P. longifolia mediated silver (PL-AgNPs) nanoparticles are very stable and efficient. UV–Vis spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDX) were used to characterize the produced AgNPs. UV–Vis analysis showed a characteristic peak at 435 nm corresponding to surface plasmon resonance. The synthesis process was spectrophotometrically optimized for various parameters. After optimization, highly stable AgNPs were prepared using 3.0 ml of P. longifolia leaf extract, pH 7.0, 1.0 mM AgNO3, and 60 °C. The zeta potential was measured by DLS, which showed ?20.8 mV and the PDI value was 5.42. TEM and SEM analysis shows a spherical shape of the synthesized nanoparticles, and the size was measured between 10 and 40 nm. EDX analysis showed intense peaks from silver and oxygen and small peaks from various metal atoms such as Na, P, S and Al indicating their presence in trace amounts. The average size of the PL-AgNPs was 14 nm. The phytochemical analysis shows that the presence of alkaloids, essential oils and saponins seems to be responsible for the synthesis of nanoparticles. PL-AgNPs were further investigated for their antifungal activity against Alternaria alternata. The minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC) and effect of nanoparticles on cytomorphology of A. alternata have also been reported. Biosynthesized nanoparticles have proven to be inexpensive, environmentally friendly, stable, easily reproducible, and highly effective against plant-pathogenic fungi.  相似文献   

2.
Chitosan-based silver nanoparticles were synthesized by reducing silver nitrate salts with nontoxic and biodegradable chitosan. The silver nanoparticles thus obtained showed highly potent antibacterial activity toward both Gram-positive and Gram-negative bacteria, comparable with the highly active precursor silver salts. Silver-impregnated chitosan films were formed from the starting materials composed of silver nitrate and chitosan via thermal treatment. Compared with pure chitosan films, chitosan films with silver showed both fast and long-lasting antibacterial effectiveness against Escherichia coli. The silver antibacterial materials prepared in our present system are promising candidates for a wide range of biomedical and general applications.  相似文献   

3.
This study, for the first time, demonstrated an unprecedented approach for the green synthesis of gold (Au) nanoparticles (NPs) using the polysaccharide of Spirulina maxima as a reducing agent. Time-kill kinetic analysis was used to evaluate the antifungal activity of the green synthesized Au NPs against the pathogenic Candida albicans (C. albicans). The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were found to be 32 μg/mL and 64 μg/mL, respectively. Ultra-structural analysis indicated prominent damage on cell wall of the C. albicans after Au NPs treatment, and suggested that the treatment could increase the membrane permeability and disintegration of cells leading to cellular death. The results of propidium iodide (PI) uptake assay showed the higher level of cell death in Au NPs treated C. albicans cells, further confirming the loss of plasma membrane integrity. Cytotoxicity analysis of Au NPs on HEK293T and A549 cells showed no cytotoxic effect up to 64 μg/mL of Au NPs concentration, indicating the potential use in in vivo studies. Also, the recovery of C. albicans infected zebrafish after Au NPs therapy suggest green synthesized Au NPs from S. maxima polysaccharide as a prospective anticandidal agent.  相似文献   

4.
The present study describes the biosynthesis of silver nanoparticles, using the fungus Penicillium verrucosum. The silver nanoparticles were synthesised by reacting silver nitrate (AgNO3) with the cell free filtrates of the fungal culture, and were then characterized by UV–visible spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive, and X-ray diffraction analysis to further evaluate their successful biosynthesis, optical and morphological features (size and shape), and crystallinity. The bioactivity of the synthesized nanoparticles against two phytopathogenic fungi i.e: Fusarium chlamydosporum and Aspergillus flavus was evaluated using nanomaterial seeding media. These biogenic silver nanoparticles were polydisperse in nature, with a size of 10–12 nm. With regard to the antifungal activity, 150 ppm of the nanoparticles suppressed the growth of F. chlamydosporum and A. flavus by about 50%. To the best of our knowledge, this is the first report on the use of P. verrucosum to synthesise silver nanoparticles. The present study demonstrates a novel, simple, and eco-friendly process for the generation of biofunctionally useful biogenic nanoparticles.  相似文献   

5.
Due to drug addiction and the emergence of antibiotic resistance in pathogens, the disease load and medication intake have risen worldwide. The alternative treatment for drug-resistant infections is Nano formulation-based antimicrobial agents. The plant extract of Conocarpus Lancifolius fruits was used to synthesize silver nanoparticles in the current study, and it was further employed as an antimicrobial and anticancer agent. Nanoparticles have been characterized by UV–visible spectrometer revealed the notable peak of λmax = 410–442 nm, which confirms the reduction of silver ion to elemental silver nanoparticles, and the biological moieties in the synthesis were further confirmed by FTIR analysis. The stability and crystalline nature of materials were approved by XRD analysis and expected the size of the nanomaterials of 21 to 173 nm analyzed by a nanophox particle-size analyzer. In vitro, synthesized materials act as an antibacterial agent against Streptococcus pneumonia and Staphylococcus aureus. The inhibition zones of 18 and 24 mm have been estimated to be antibacterial activity against both bacteria. The potency of up to 100% of AgNPs for bacterial strains was incubated overnight at 60 μg/ml. Based on our results, biogenic AgNPs reveal significant activity against fungal pathogen Rhizopusus stolonifera and Aspergillus flavus that cause leading infectious diseases. Additionally, nanomaterials were biocompatible and demonstrated the potential anticancer activities against MDA MB-231 cells after 24-hour exposure.  相似文献   

6.
Two new prenylated para-xylenes, named caulerprenylols A (1) and B (2), were isolated from the green alga Caulerpa racemosa, collected from the Zhanjiang coastline, China. The structures of the two metabolites were elucidated on the basis of detailed spectroscopic analysis. This is the first report of prenylated para-xylenes from marine algae and from marine organisms as well. Moreover, caulerprenylol B (2) is also characterized by an uncommon indane ring system. In in vitro bioassays, the new compounds exhibited a broad spectrum of antifungal activity against Candida glabrata (537), Trichophyton rubrum (Cmccftla), and Cryptococcus neoformans (32609) with MIC80 values between 4 and 64 μg/mL when compared to amphotericin B (MIC80 values of 2.0, 1.0, and 4.0 μg/mL, respectively) as a positive control and showed no growth inhibition activity against the tumor cells HL60 and A549.  相似文献   

7.
Zinc oxide (ZnO) has broad applications in various areas. Nanoparticle synthesis using plants is an alternative to conventional physical and chemical methods. It is known that the biological synthesis of nanoparticles is gaining importance due to its simplicity, eco-friendliness and extensive antimicrobial activity. Also, in this study we report the synthesis of ZnO nanoparticles using Trifolium pratense flower extract. The prepared ZnO nanoparticles have been characterized by UV–Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) with Energy dispersive X-ray analysis (EDX). Besides, this study determines the antimicrobial efficacy of the synthesized ZnO nanoparticles against clinical and standard strains of S. aureus and P. aeruginosa and standard strain of E. coli.  相似文献   

8.
Green nanotechnology has acquired immense demand due to its cost-effective, eco-friendly and benevolent approach for the synthesis of nanoparticles. Among the biological methods, plants aid as a significant green resource for synthesizing nanoparticles that are safe and non-toxic for human use. In the present investigation, Silver nanoparticles (AgNPs) were synthesized using bulbs extract of Allium ampeloprasum under the influence of sunlight irradiation and characterized using different techniques. Distinct in-vitro assays were performed to test the antioxidant and anticandida potential of the synthesized AgNPs. Results suggested the efficient and rapid sunlight-driven synthesis of AgNPs using A. ampeloprasum extract. UV–Vis spectrum showed absorption peak at 446 nm which confirmed the formation of AgNPs. FTIR analysis suggested the presence of functional groups associated with flavonoids and sulfur compounds in A. ampeloprasum extract. The synthesized AgNPs showed Face Centred Cubic (FCC) structure with an average size of 35 nm. Spherical, quasi spherical, triangular and ellipsoidal morphology of the NPs were observed from the TEM micrograph. The synthesized AgNPs showed pronounced free radical scavenging potential for DPPH, ABTS∙+ and H2O2 radicals. The anticandida potency of the synthesized AgNPs was observed as follows: C. albicans ≥ C. tropicalis ≥ C. glabrata ≥ C. parapsilosis ≥ C. krusei. Results showed that sunlight driven nanoparticle synthesis of AgNPs is rapid, facile and exhibit enhanced antioxidant and antifungal activity.  相似文献   

9.
Biofilms confer protection from adverse environmental conditions and can be reservoirs for pathogenic organisms and sources of disease outbreaks, especially in medical devices. The goal of this research was to evaluate the anti-biofilm activities of silver nanoparticles (AgNPs) against several microorganisms of clinical interest. The antimicrobial activity of AgNPs was tested within biofilms generated under static conditions and also under high fluid shears conditions using a bioreactor. A 4-log reduction in the number of colony-forming units of Pseudomonas aeruginosa was recorded under turbulent fluid conditions in the CDC reactor on exposure to 100?mg?ml?1 of AgNPs. The antibacterial activity of AgNPs on various microbial strains grown on polycarbonate membranes is reported. In conclusion, AgNPs effectively prevent the formation of biofilms and kill bacteria in established biofilms, which suggests that AgNPs could be used for prevention and treatment of biofilm-related infections. Further research and development are necessary to translate this technology into therapeutic and preventive strategies.  相似文献   

10.
Mosquitoes play a key role in the transmission of some important diseases. The need for controlling these insects is critical to reduce their risks to human and domesticated animals. Recently the trend to explore effective chemical compounds from local plants has begun as a safe means of control. The present study aimed to evaluate the anti-larval activity of Chrysanthemum extract and the prepared silver nanoparticle (AgNPs) against the Aedes aegypti mosquito, the dengue vector in Saudi Arabia. A series of different concentrations of ethanol extract and extract prepared AgNPs against the fourth-life larvae was tested. The effective concentrations of crude extract and AgNPs ranged from 50 to 250 and 10 to 30 ppm respectively, and the death percentages corresponding to these concentrations ranged from 18 to 92 and 36 to 96% respectively. According to the LC50 values of treated larvae, AgNPs (12.754 ppm) is more effective against A. aegypti mosquito larvae than the crude extract (228.345 ppm) at about 17.9 times. The mixing of the plant extract with the silver nitrate has led to potentiation. This is due to the synergy that occurs between the extract and the silver particles during the reduction process. The compounds in the extract are related to the surface of the particles, increasing the strength of their effects. It is recommend to separate the active elements in the Chrysanthemum plant and its preparation in the form of nanoparticles as a promising compound in mosquito control programs with least damage to human kind and the environment.  相似文献   

11.
Juniperus spp. are used as medicinal plants in many countries like Bosnia, Lebanon, and Turkey. In folk medicines, these plants have been used for treating skin and respiratory tract diseases, urinary problems, rheumatism and gall bladder stones. The objectives of this work were to synthesize silver nanoparticles (AgNPs) using a coniferous tree, Juniperus procera leaf extract and testing the synthesized AgNPs for its antimicrobial potentials, hemolytic activity, toxicity and the proliferative effects against normal and activated rat splenic cells. Leaf extract was prepared using acetone and ethanol as solvents. AgNPs were prepared using the acetone extract. AgNPs were validated using UV–Vis spectroscopy and scanning electron microscopy (SEM). Functional groups in the extract were identified using Fourier Transform Infrared (FT-IR) spectroscopy. SEM images of AgNPs showed spherical and cubic shapes with a uniform size distribution with an average size of 30–90 nm. FT-IR spectroscopy showed the presence of many functional groups in the plant extract. AgNPs showed promising antimicrobial activity against tested bacteria and fungus. AgNPs also expressed a stimulating activity towards the rat splenic cells in a dose dependent manner. Acetone as solvent was safer on cells than ethanol. Green synthesized AgNPs using J. procera might be used as a broad-spectrum therapeutic agent against microorganisms and as an immunostimulant agent.  相似文献   

12.
The current study was performed to develop a simple, safe, and cost-effective technique for the biosynthesis of selenium nanoparticles (SeNPs) from lactic acid bacteria (LAB) isolated from human breast milk with antifungal activity against animal pathogenic fungi. The LAB was selected based on their speed of transforming sodium selenite (Na2SeO3) to SeNPs. Out of the four identified LAB isolates, only one strain produced dark red color within 32 h of incubation, indicating that this isolate was the fastest in transforming Na2SeO3 to SeNPs; and was chosen for the biosynthesis of LAB-SeNPs. The superior isolate was further identified as Lactobacillus paracasei HM1 (MW390875) based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and phylogenetic tree analysis of 16S rRNA sequence alignments. The optimum experimental conditions for the biosynthesis of SeNPs by L. paracasei HM1 were found to be pH (6.0), temperature (35˚C), Na2SeO3 (4.0 mM), reaction time (32 h), and agitation speed (160 rpm). The ultraviolet absorbance of L. paracasei-SeNPs was detected at 300 nm, and the transmission electron microscopy (TEM) captured a diameter range between 3.0 and 50.0 nm. The energy-dispersive X-ray spectroscopy (EDX) and the Fourier-transform infrared spectroscopy (FTIR) provided a clear image of the active groups associated with the stability of L. paracasei-SeNPs. The size of L. paracasei-SeNPs using dynamic light scattering technique was 56.91 ± 1.8 nm, and zeta potential value was −20.1 ± 0.6 mV in one peak. The data also revealed that L. paracasei-SeNPs effectively inhibited the growth of Candida and Fusarium species, and this was further confirmed by scanning electron microscopy (SEM). The current study concluded that the SeNPs obtained from L. paracasei HM1 could be used to prepare biological antifungal formulations effective against major animal pathogenic fungi. The antifungal activity of the biologically synthesized SeNPs using L. paracasei HM1 outperforms the chemically produced SeNPs. In vivo studies showing the antagonistic effect of SeNPs on pathogenic fungi are underway to demonstrate the potential of a therapeutic agent to treat animals against major infectious fungal diseases.  相似文献   

13.
Abstract

Phytosynthesis of silver nanoparticles (AgNPs) using leaf extract of Petiveria alliacea (PA) was the focus of this research work. The PA-AgNPs were characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) study. Studies were made on the AgNPs for antibacterial, antifungal, anticoagulant, free-radical scavenging, and hydrogen peroxide scavenging activities. The crystalline PA-AgNPs were monodispersed, with a size range of 16.70–33.74?nm and maximum absorption at 410?nm. FTIR analysis displayed prominent peaks at 3430.6, 1711.8, and 1165.9/cm, which showed the existence of phenolic compounds and proteins in the synthesis of AgNPs. PA-AgNPs was active against Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus, with 100% inhibition. The PA-AgNPs also displayed good antifungal properties, as the concentrations of 100 and 150?µg/mL had 100% inhibition toward Aspergillus fumigatus and Aspergillus flavus. However, there was 66.67% inhibition of Aspergillus niger. It scavenged both DPPH and H2O2 by 70.69 and 89.02%, respectively. PA-AgNPs also prevented the coagulation of human blood. This study, being the first of its kind to use the leaf extract of PA for the synthesis of AgNPs has shown that PA-AgNPs can find biomedical applications.  相似文献   

14.
Phytophthora diseases cause billions of dollars annually in damage to crops. Nanotechnology provides various metallic nanoparticles exhibiting a strong activity against microbial pathogens. Silver nanoparticles-based products are outstanding samples, which has been produced in large scale and performed well with a high activity against several fungal pathogens. Our previous study indicated oligochitosan-coated silver nanoparticles (OCAgNPs) which were prepared from 3,4 dihydroxyphenyl acetic acid – conjugated oligochitosan and silver nitrate salt performed an enhancement in antibacterial ability at a very low concentration. Objective of this study was to determine the effect of the OCAgNPs on growth and reproduction of Phytophthora capsici, P. nicotianae and P. colocasiae in vitro. The study shown that strong inhibition of mycelial growth, sporangium production, zoospore release and zoospore germination of P. capsici, P. nicotianae and P. colocasiae occurred when exposed to at 9 ppm of OCAgNP. The results demonstrated a great potential of OCAgNPs for controlling growth of Phytophthora.  相似文献   

15.
《Reproductive biology》2020,20(1):97-105
Green synthesized nanoparticles are more advantageous over conventionally prepared ones due to less toxicity, production cost, and environmental hazards. With the widespread of the utilization of nanoparticles, little is known about the maternal-fetal transplacental transfer of green nanoparticles. We have biosynthesized silver nanoparticles using metabolites of Streptomyces malachitus and sunlight then coated them with chitosan. These nanoparticles have been characterized and intraperitoneally administered at doses of 100 mg/kg on the 6th, 8th, and 10th gestational days. On the 18th day of pregnancy, both coated and non-coted NPs were detected in different maternal tissues, placenta, and in fetuses, as determined by estimation of silver content and observation by electron microscopy. Chitosan coating decreased the silver content in different tissues, maybe due to the larger size of coated nanoparticles that retards the transfer. The toxic effects on maternal and fetal tissues were proportional to their silver content, as determined by the liver and kidney functional analysis of pregnant rats and the ultrastructural and histopathological examination of the maternal liver, placenta and fetal liver. The present data suggest that green silver nanoparticles biosynthesized by Streptomyces malachitus cross the placenta and have toxic effects on maternal tissues, placenta, and fetus. Chitosan coating of these nanoparticles decreases the transfer, and consequently, the toxicity. However, it does not prevent this toxicity.  相似文献   

16.
Abstract

We have conducted a thorough study on extracellular biosynthesis of silver nanoparticles (AgNPs) by a halotolerant bacterium Bacillus endophyticus SCU-L, which was identified by 16S rRNA gene sequencing analysis. This strain was selected during an ongoing research programme aimed at finding a novel biological method for green nanosynthetic routes using the extremophiles in unexplored hypersaline habitats. The biosynthesized AgNPs were characterized and analyzed with UV–vis spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy and X-ray diffraction. Further, the AgNPs were found to be spherical in shape with an average particle size of about 5.1?nm, and it was stable in aqueous solution for three months period of storage at room temperature under dark condition. Also, the synthesized AgNPs significantly presented antimicrobial activity against Candida albicans, Escherichia coli, Salmonella typhi and Staphylococcus aureus. The above results suggested that the present work may provide a valuable reference and theoretical basis for further exploration on microbial biosynthesis of AgNPs by halotolerant bacteria.  相似文献   

17.
《Fungal biology》2020,124(7):671-681
Silver nanoparticles (Ag NP) were synthesized using rice leaf extract and optimized synthetic conditions were found to be 0.4 % leaf extract, 0.6 mM AgNO3 and 30 min of autoclaving. Produced NP were characterized using UV–vis, DLS, zeta potential, XRD, TEM and FTIR. Ag NP formation was established from UV–vis spectra and NP showed zeta potential value of −27.4 mV. NP were spherical, polydisperse and average size was 16.5 ± 6.2 nm. Antifungal activity of Ag NP was assessed by poisoned food technique and resazurin broth dilution against mycelium and sclerotia of fungus R. solani, the causative agent of sheath blight disease in rice. Results confirmed effective hyphal growth inhibition and % growth inhibition was dose dependent (2.5–10 μg/mL). Ag NP showed enhanced mycelial inhibition (81.7–96.7 %) at 10 μg/mL. MIC values of Ag NP were in the range of 5–10 and 15–20 μg/mL towards fungal mycelium and sclerotia, respectively. Ag NP treatment (20 μg/mL) completely inhibited the disease incidence at 20 μg/mL. Ag NP treatment (10 μg/mL) caused 1.3 and 1.5 times enhancement in seedling vigor index. Hence, Ag NP can be utilized towards management and control of various fungal diseases of crops.  相似文献   

18.
Tender coconut water is a pure and nutritious drink which play important role as nutraceuticals and pharmaceuticals contributes to the rapid growth of the functional food industry. In the mean-time the safety and shelf-life of the food is crucial for the both product as well as consumers. The intervention or application of nanotechnology gives immense a solution for the prolonged sustainability of the food products. This work reports on the nature of physiological changes of coconut liquid endosperm along with the interaction of its DNA with green route synthesized Ag nanoparticles (AgNPs) using Garuga pinnata leaf, an important ethnomedicinal plant. The physical and nutritional study of the coconut water were carried by UV–visible, XRD, NMR analysis whereas the synthesized Ag nanoparticles (AgNPs) were characterized by UV–Visible spectrophotometer, Raman Spectroscopy, DLS, AFM and FE-SEM analysis. The pH of the endosperm was found to decrease from 6.31 to 4.01, following an exponential decay trend and giving a decay constant of ~8.8 h. The broad absorption peak at ~310 nm gradually turns featureless with elapse of time. The proton nuclear magnetic resonance (H1-NMR) spectrum essentially revealed the presence of esters or organic acids, confirming a sudden fall in the rate of intensity in the immature coconut endosperms as compared to the matured coconut cases. While the pentosyl methyl group (~1.4–1.5 ppm) concentration is observably lowered, free amino acid (~1 ppm) is apparently suppressed in the former specimen. Gel electrophoresis of 10 kb DNA with Ag nanoparticles (AgNPs) showed a gradual decrease of band intensity for a concentration varying between 3:1 and 1:1. The less intense band was due to the lack of migration of DNA into the micropores of the gel as a consequence of interaction of negatively charged DNA with negatively charged AgNPs. The study of DNA interaction with AgNPs could help identifying and addressing the nature of degradation process while considering prevention from microbial attack and make the coconut water as potential functional food entity.  相似文献   

19.
Scutellaria barbata is a perennial herb which was vastly prescribed in Chinese medicine to treat inflammations, infections and it is also used a detoxifying agent. We synthesized silver nanoparticles with Scutellaria barbata extract and characterized the nanoparticles with UV–Vis spectroscopic analysis, TEM, AFM, FTIR and XRD. The biofilm inhibiting property of synthesized silver nanoparticles were examined with XTT reduction assay and the antimicrobial property was examined with well diffusion method. The silver nanoparticles were also coated with cotton fabrics and their efficacy against antimicrobials was analyzed to prove its application. The cytotoxic property of synthesized silver nanoparticles was examined with L929 fibroblast cells using MTT assay. Finally we analyzed the wound healing property of synthesized silver nanoparticles with wound scratch assay. The result of our UV–Vis spectroscopic analysis confirms Scutellaria barbata aqueous extract reduced silver ions and synthesized silver nanoparticles. The characterization studies TEM, AFM, FTIR and XRD confirms the synthesized silver nanoparticles are in ideal shape and size to be utilized as a drug. The XTT reduction assay proves silver nanoparticles effectively inhibits the biofilm formation in both resistant and sensitive strains. Antimicrobial sensitivity tests confirms synthesized silver nanoparticles and cotton coated synthesized silver nanoparticles both are effective against gram positive, gram negative and fungal species. Further the results of MTT assay confirms the synthesized silver nanoparticles are non toxic and finally the wound healing potency of the nanoparticles was confirmed with wound scratch assay. Over all our results authentically confirms the silver nanoparticles synthesized with Scutellaria barbata aqueous extract is potent wound healing drug.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号