arezoo dastpak

  The green synthesis of the silver nanoparticles (AgNPs) is an eco-friendly and straightforward synthesis method. This study aimed to investigate the green synthesis of AgNPs using Nasturtium officinale leaf extract and analysis of their antibacterial activity against some nosocomial pathogens.

The obtained AgNPs were characterized using UV-visible spectroscopy, X-ray diffraction (XRD), and scanning electron microscope (SEM). In addition, the antibacterial activity of synthesized AgNPs and N. officinale leaf extract were performed against five bacterial strains (Staphylococcus epidermidis, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa) by agar disk diffusion assay and minimum inhibitory concentration test.

The green synthesized AgNPs had significant antimicrobial activity against all studied bacteria. In addition, greater inhibition activity was observed against E. coli and P. aeruginosa rather than other bacteria.

The synthesized AgNPs revealed a special antibacterial effect against selected bacteria, compared to leaf extract of N. officinale. Identifying new antibacterial agents with profound efficacy against antibiotic-resistant opportunistic pathogens is essential. These data provide an eco-friendly and rapid green approach for AgNPs synthesis and the potential of AgNPs for use in drug development against nosocomial infections.

Nosocomial infections are one of the most common infections in health centers. The high and inadequate use of broad-spectrum antibiotics has increased the number of nosocomial infections. The aim of this study was to synthesized silver nanoparticles using Dracocephalum kotschyi extract and analysis of its antibacterial activities. In this experimental study, biological synthesis of silver nanoparticles was performed using D. kotschyi extract. Physical and chemical structure of synthesized silver nanoparticle were determined using UV-Vis spectroscopy, XED, FTIR, SEM (scanning electron microscopy) and transmission electron microscopy (TEM). Finally, the antibacterial activity of silver nanoparticles was assessed using two methods including disk diffusion and minimum growth inhibitory concentration (MIC). The results showed that the size of the synthesized nanoparticle was 14.57 nm. The physical and chemical structure of silver nanoparticles was confirmed by XRD, TEM, and SEM. The antibacterial results also showed that Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Listeria monocytogenes were sensitive to 500 μg/ml of silver nanoparticles. The results of this study showed that the silver nanoparticles synthesized by D. kotschyi have an appropriate antibacterial potential against nosocomial pathogens and can act as one of the nano-achievements in helping to management of infectious diseases.

 Subcritical water extraction has been considered due to advantages such as high speed, high efficiency and reduced amount of organic solvents used in the traditional way as well as due to its compatibility with the environment.

 In this study, the essences extraction from fennel seeds was performed by using subcritical water extraction and was compared with hydrodistillation method. Trans-anethole as the main combination has been carried out as a main goal of next experiments. Separating and diagnosis of the extracted trans-anethole were performed by GC-FID and GC / MS. The effect of temperature parameters, Average of particle size and flow intensity was studied on the extraction rate in subcritical water method. Taguchi experimental design was used to facilitate the process of testing and comparing the effective parameters. The ratio of the area of trans-anethole to the obtained internal standard from gas chromatography was calculated as evaluated criteria of parameters and extraction methods of essence from fennel seeds.

 The results of Analysis of variance showed that the temperature and, Average of particle size have a significant effect on the amount of trans-anethole extraction. The highest ratio of trans-anethole to internal standard was obtained at 175 ° C, an average value of 0.398 mm, and a flow rate of 3 ml /min.

 The results of this study showed that the extraction by subcritical water in compare with hydro distillation method is a fast-high-efficiency method for extraction of trans-anethole as a valuable oxygen-containing compound.

In order to compare the efficiency of morphological traits and molecular markers in distinguishing the Consolida species, molecular analysis using nrDNA ITS and cpDNA trnL-trnF with maximum parsimony and Bayesian methods were done in a total of 34 species and forma representing 28 species of Consolida, 6 species of Aconitella, plus two species of Delphinium and two species of Aconitum as out groups.  Beside phenetic analysis for 20 quantitative morphological traits in 17 species of Consolida in Iran are performed. The molecular analysis, based on successive reweighting by rescaled consistency index, revealed that Maximum parsimony method and Bayesian analysis gave very similar results based on individual and combine data sets. In the combined analysis (chloroplast and nuclear DNA) recovered most parsimonious trees (L= 558 steps, CI=0.695, RI=0.827). The ITS results revealed that Consolida is not monophyletic and the genus Aconitella is clearly nested within Consolida. Our results confirms the decrease of C. paradoxa Bunge to a forma of C. rugulosa also confirmed the decrease of C. kabulica as a variety of C. stokciana. One way ANOVA, principal component analysis (PCA) and cluster analysis were used in phenetic analysis to visualize the species among different traits. Most of the quantitative morphological traits which showed significant differences between populations were deleted. PCA and cluster analysis carried out for morphological traits divided the Consolida species in to two cluster and A. barbata has separated from other species. Aconitella species are located in separate cluster and location of other species are almost similar to molecular results.