Aims The aim of this research is to conduct green synthesis of silver nanoparticles in an eco-friendly, economical and more effective approach using Acacia cyanophylla plant extract as well as to study the effect s of the preparation conditions on the size of synthesized nanoparticles and its antibacterial activity. Methodology In this study, silver nanoparticles have been synthesized by reduction method using aqueous silver nitrate solution and aqueous extract of Acacia cyanophylla . Then, their characterization has been studied by several methods, such as visual inspection, UV–Vis spectroscopy, dynamic light scattering and scanning electron microscope. In addition, the effects of (silver nitrate: extract) ratio, type extract, temperature and reaction time have been studied on the size of prepared silver nanoparticles. Furthermore, the antibacterial effect of these nanoparticles was studied on Escherichia coli using micro-dilution method and determination the Minimum Inhibitory Concentration (MIC). Results The results showed that the silver nanoparticles prepared using Acacia cyanophylla extract have reported visible yellowish brown color formation and the absorption peak at 460 nm indicated the biosynthesis of silver nanoparticles. Moreover, they have average diameter (88.11) nm and the polydispersity index (PdI) was suitable. The optimal conditions for synthesis silver nanoparticles were using aqueous extract in 9:1 ratio (silver nitrate: extract) at 35 °C for 48 h. These silver nanoparticles were stable in the in the fridge at 5 °C for a maximum period of 15 days. On the other hand, the antibacterial tests showed that these nanoparticles have high antibacterial activity where the MIC value ranged between (3.125–12.5) μg/ml on E. coli isolates. Conclusion We conclude that Acacia cyanophylla extract is considered effective as a reducing agent for the preparation of stable silver nanoparticles in certain conditions and this silver nanoparticle has a high antibacterial activity.

Aims: The green synthesis of silver nanoparticles in an eco-friendly, economical and more effective approach using (Acacia cyanophylla, Phlomis syriaca and Scolymus hispanicus) plants extracts and describing their main chemical properties and study the effect of its chemical composition on producing silver nanoparticles. Methodology: In this study, aqueous and ethanolic extracts of the three plants were evaluated for antioxidant activity using 2,2-diphenyl-l-picrylhydrazyl (DPPH) assay, Total polyphenol and flavonoid contents were determined using spectrophotometric method, but  total saponins were determined by weight method, The synthesis of silver nanoparticles was performed by a reduction method using aqueous silver nitrate solution and aqueous extracts of the three plants. Then study its characterization in a number of ways, such as visual inspection, UV-Vis spectroscopy and dynamic light scattering. Results: The results showed that the total phenolic content ranged in extracts between (13.08 ±2.279 to 98.39 ±4.755 mg GAE/g DW). While the total flavonoid contents varied from (19.83 ±2.384 to 121.64 ±6.469 mg RE/g DW. Antioxidant activity was expressed as IC50 and the obtained results ranged from (IC50= 0.027 ±0.00038 to 0.878 ±0.045 mg/ml), the results indicated that the ethanolic Acacia cyanophylla extract from the six examined extracts showed the highest phenolic and flavonoid concentration and strong antioxidant activity. Also, the saponins content in the three plants ranged from (0.46 to 2.53)% and the highest amount of saponins reported in Acacia cyanophylla plant. The silver nanoparticles prepared using Acacia cyanophylla extract have reported visible yellowish brown color formation and the absorption peak at 460 nm indicates the biosynthesis of silver nanoparticles and they have average diameter (134.1) nm and the polydispersity index (PdI) was suitable (0.260). Conclusion: Acacia cyanophylla extract has been considered as the best reducing agent among the selected plant extracts for the preparation of stable colloidal silver nanoparticles, this is due to their high content of flavonoids, phenols and saponins.

Background Acacia cyanophylla is a medicinal plant of the Fabaceae family that is widely distributed in Australia and Asia, also it has many medicinal properties such as antibacterial and antioxidant activity. Thin layer chromatography (TLC) is wildly used in natural product extract analysis as a finger print. Aim and objective: This study is aimed to conducting a qualitative detection of the active compounds in Acacia cyanophylla, Phlomis syriaca and Scolymus hispanicus plants by thin layer chromatography (TLC) method and studying their antibacterial activity. Methods: the qualitative detection of three plants was conducting using thin layer chromatography (TLC) method. Then, aqueous and ethanolic extracts of the aerial parts of the three plants were extracted using an Ultrasonic bath.  The antibacterial activity on E. coli isolates for six extracts was evaluated using minimum inhibitory concentration (MIC) test. The active compounds that may be responsible for the antibacterial effect was isolated by direct bioautograph method. Results: Performing Thin-layer chromatography TLC tests show  that the three plant contain flavonoids, saponin, bitter principles and essential oils, and all extracts showed antibacterial activity on E. coli isolates, but the ethanolic extract of Acacia cyanophylla was the most effective as the MIC values ranged from 0.097to 3.125mg/mL. Bioautography showed that Escherichia coli was inhibited by most of the separated flavonoids on the TLC plates where four inhibiting spots appeared in yellow color with Acacia cyanophylla and five spots with Scolymus hispanicus, while only one spot appeared with Phlomis syriaca. Conclusion: Acacia cyanophylla extract has been considered as the best antibacterial properties among the selected plants due to the presence of flavonoids                    Peer Review History: Received: 19 July 2021; Revised: 7 August; Accepted: 2 September, Available online: 15 September 2021 Academic Editor:  Ahmad Najib, Universitas Muslim Indonesia, Makassar, Indonesia, ahmad.najib@umi.ac.id UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.  Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. Sangeetha Arullappan, Universiti Tunku Abdul Rahman, Malaysia, sangeetha@utar.edu.my Taha A.I. El Bassossy, Medicinal and Aromatic Plants Department, Desert Research Center, Cairo, Egypt, tahachemist2008@gmail.com Similar Articles: EVALUATION OF ANTIBACTERIAL RESISTANCE OF BIOFILM FORMS OF AVIAN SALMONELLA GALLINARUM TO FLUOROQUINOLONES

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