Forty-two medicinal plants were collected depending on their availability on Egypt. These plant were extracted and screened for their activity towards green synthesis of AgNPs. A new modified method was used in order to screen large number of extracts in short time (high throughput screening). In this method, the synthesized nanoparticles were evaluated in using 96-well plate which is transparent to facilitate the color monitoring and easy to be read spectrophotometrically using microplate reader. The green synthesis activity by the different plant extracts was monitored and evaluated by color change and UV-Vis absorption at time intervals.
Out of these 42 plants, only 3 plants viz.,Pyllanthusemblicafruits, Psidium guajava leaves and Lawsoniainermisleaves, showed high AgNPs synthetic activity. The most active plant extracts were further partitioned with ethyl acetate. The results showed that the EtOAc fraction of the three active plants showed superior AgNPs green synthesis over their remaining aqueous. Thus, chromatographic columns were used to isolate the active compounds from the EtOAc fraction of each plant.
Metal nanoparticles synthesis is a leading topic of research in modern material science owing to their distinctive potential applications in the field of electronic, optoelectronic, information storage and Health care. Among the all noble metal nanoparticles, silver nanoparticles are one the main products in the field of nanotechnology which has acquired limitless attention due to their unique properties such as chemical stability, good conductivity, catalytic and most important antibacterial, antiviral and antifungal activities. Nevertheless, there is still need for economic commercially viable as well as environmentally clean synthesis route to synthesize the silver nanoparticles.
Table of Contents
Summary
Introduction
Methods
Chapter 1: Chromatographic investigation of the ethyl acetate fraction of emblica:
Chapter 2: Chromatographic investigation of ethyl acetate fraction of Psidium guajava leaves:
Chapter 3: Chromatographic investigation of ethyl acetate fraction of Lawsonia inermis leaves:
Research Objectives & Key Themes
The primary objective of this study is to investigate the potential of forty-two Egyptian medicinal plants to facilitate the green synthesis of silver nanoparticles (AgNPs) from aqueous silver nitrate solutions. The research aims to isolate, characterize, and evaluate the bioactive phytocomponents responsible for this synthesis process, specifically assessing the antioxidant and anticancer activities of both the plant extracts and the resulting silver nanoparticles.
- Screening and identification of plant extracts for green nanoparticle synthesis.
- Optimization of the synthesis process using different plant-derived fractions.
- Characterization of produced AgNPs through UV-Vis, FTIR, and Transmission Electron Microscopy (TEM).
- Chromatographic isolation and structural elucidation of bioactive molecules (using NMR, MS, etc.).
- In vitro biological evaluation of the synthesized AgNPs regarding cytotoxicity and antioxidant potential.
Excerpt from the Book
Identification of compound E4:
Compound E4 was isolated as white amorphous powder (15 mg). It is soluble in methanol; ethanol; slightly soluble in methylene chloride and insoluble in petroleum ether. The Rƒ value is 0.22 [Pet. ether-EtOAc-HOAc 5:5:0.2, silica gel]. It gave gray color with vanillin /sulfuric acid spray followed by heating on hot plate. The methanolic solution of compound E4 gave a violet color with 5% FeCl3 indicating its phenolic nature.
The FT-IRνmaxspectrum (Figure)showed strong absorption bands at 2923& 2852 cm-1 (alkane C-H stretching), 3441 cm-1 (hydroxyl group) and band at 1644 cm-1 (carbonyl groups).1H-NMR spectrum of compound E4(Figure & Table)showed the presence of five aromatic signals at δ7.38 (d, 1.5 Hz), 7.23 (d, 1.5 Hz), 7.21 (s), 7.20 (s) and 7.10 (s) with integration ratio of 1: 1: 1: 2: 1, respectively. APT spectrum of E4 (Figure & Table) showed the presence of 22 carbon signal discriminated into 17 quaternary carbons and 5 methine carbons. The most characteristic quaternary signals are resonating at δ170.4, 170.3, 167.4 and 167.1 which suggest the presence of several aromatic carboxylic groups. By reviewing the reported data of Phyllanthus emblica, several galloyl derivatives have been isolated and identified from this plant (LUO et al., 2009b).
Summary of Chapters
Summary: Provides an overview of silver nanoparticle synthesis, highlighting the transition from hazardous chemical methods to eco-friendly green synthesis using plant extracts.
Introduction: Reviews the use of natural products in medicine and the fundamental principles of green nanotechnology, including the benefits of plant-mediated nanoparticle production.
Methods: Details the experimental protocols for plant collection, extraction, green synthesis of AgNPs, and the analytical and biological characterization techniques employed.
Chapter 1: Chromatographic investigation of the ethyl acetate fraction of emblica: Details the isolation and structural identification of five compounds (E1-E5) from the ethyl acetate fraction of Phyllanthus emblica fruits.
Chapter 2: Chromatographic investigation of ethyl acetate fraction of Psidium guajava leaves: Describes the isolation and identification of five compounds (G1-G5) from the leaves of Psidium guajava.
Chapter 3: Chromatographic investigation of ethyl acetate fraction of Lawsonia inermis leaves: Focuses on the chromatographic separation and characterization of three compounds (H1-H3) derived from henna leaves.
Keywords
Green Chemistry, Nanotechnology, Silver Nanoparticles (AgNPs), Plant Extracts, Phyllanthus emblica, Psidium guajava, Lawsonia inermis, Cytotoxicity, Antioxidant activity, Chromatography, FTIR, TEM, Phytochemicals, Galloyl derivatives, Flavonoids.
Frequently Asked Questions
What is the core focus of this research?
The research focuses on the biological, or "green," synthesis of silver nanoparticles using various Egyptian medicinal plant extracts as an environmentally friendly alternative to traditional chemical methods.
What are the primary plant subjects investigated?
The study specifically isolates and analyzes compounds from three highly active plants: Phyllanthus emblica fruits, Psidium guajava leaves, and Lawsonia inermis leaves.
What is the ultimate goal of the synthesis?
The goal is to develop an efficient, low-cost, and non-toxic synthesis route for silver nanoparticles that possess potent biological properties for potential applications in health care, such as anticancer and antioxidant agents.
Which scientific methods are used to characterize the nanoparticles?
The study utilizes UV-Vis spectroscopy to monitor plasmon resonance, FTIR to identify capping functional groups, and Transmission Electron Microscopy (TEM) to assess particle size and morphology.
What does the main body of the text cover regarding chemical analysis?
The main chapters detail the systematic chromatographic isolation and structural identification of pure compounds from the selected plant extracts, using advanced techniques like NMR (1H and 13C) and HRMS to confirm their identities.
Which criteria are used to characterize the success of the green synthesis?
Success is measured by the color change of the solution (from yellow to brown), the increase in UV-Vis absorption peaks related to Surface Plasmon Resonance, and the physical stability of the produced nanoparticles.
What is the significance of the "Emblifatmin" compound identified in this study?
Emblifatmin (E4) is a new compound isolated from Phyllanthus emblica for the first time, characterized in this study as a symmetric hexagalloyl structure that contributes to the plant's green synthesis activity.
How does the study compare the activity of different phytochemical moieties?
The study concludes through Structure-Activity Relationship (SAR) analysis that compounds containing galloyl moieties exhibit higher activity towards silver ion reduction compared to compounds containing a flavonoid nucleus.
- Quote paper
- Farid Badria (Author), Mohamed AbouHabieb (Author), Fatma Abdel Bar (Author), 2017, Synthesis of Nanoparticles Using Green Chemistry, Munich, GRIN Verlag, https://www.grin.com/document/509334
