@article {1083, title = {Biosynthesis of Silver Nanoparticles from Polyphenolic Extract of Baliospermun solanifolium using Central Composite Design}, journal = {Pharmacognosy Research}, volume = {14}, year = {2022}, month = {October 2022}, pages = {405-411}, type = {Original Article}, chapter = {405}, abstract = {

Background: Plant extracts contain a considerable amount of polyphenols. These polyphenols act as reducing, capping, and stabilizing agents in the formation of silver nanoparticles. Objectives: The objective of the current study is biosynthesis, optimization, and evaluation of silver nanoparticles from the polyphenolic extract of Baliospermum solanifolium. Materials and Methods: Central composite design (CCD) was used to synthesize silver nanoparticles (AgNPs) from the polyphenolic extract of Baliospermum. Preliminary screening was done to find out the upper and lower limits for the optimization study. Four independent variables like Silver nitrate concentrations (mM), Baliospermum extract (\%), stirring time (min), and stirring rate (RPM) were employed. As per the design expert, 30 experiments were performed and their effects on dependent variables were listed. Analysis of synthesized AgNPs was done by visual observation, UV-vis Spectroscopy, Zeta potential, X-ray Diffraction (XRD), FTIR, FESEM, etc. Results: The development of Baliospermum silver nanoparticles was confirmed by a color change from pale yellow to dark brown. Characteristic peak of silver nanoparticles observed at 432 nm. -15 mV Zeta potentials confirmed the stability of silver nanoparticles. The sizes of the produced nanoparticles were measured using a FESEM and ranged from 70 to 140 nm. The crystalline nature of nanoparticles was confirmed with the help of X-ray crystallography. FTIR data strongly revealed the presence of phenolic compounds in the reduction, stabilization, and biosynthesis of AgNPs. Conclusion: Major Optimized factors offered by the Central composite design were 10mM AgNO3, 10 \% Baliospermum extract, 150 min, and 700 rpm. As per the data collected from FTIR and HPLC, silver nanoparticles could be capped with major phenolic groups like ellagic acid, catechins, and quercetin.

}, keywords = {Baliospermum, Central composite design, Design expert, Green synthesis, Silver nanoparticles}, doi = {10.5530/pres.14.4.59}, author = {Sarika Ankushrao Nikam and Shilpa Pravin Chaudhari} } @article {243, title = {Pretreatment and Optimization of Processing Conditions for Extraction of Oleuropein from Olive Leaves using Central Composite Design}, journal = {Pharmacognosy Research}, volume = {11}, year = {2019}, month = {April 2019}, pages = {178-187}, type = {Original Article}, chapter = {178}, abstract = {

Background: The extraction methods used for isolation of biomolecule from Olive leaves show risk of residual solvent and less extraction efficiency. Hence, there is a need to develop novel techniques to encapsulate the risks headed with extraction process. Objective: The goal was to unravel the effect of novel extraction techniques on the extraction efficiency of Oleuropein from Olea europaea, a major secoiridoid resided in Olive leaf. Materials and Methods: Olive leaves were collected, authenticated, and subjected to proximate, phytochemical analysis to contemplate the source of active moiety. The pr{\'e}cised solvent, i.e., water: glycerol (3:1\%v/v) was functionalized to depict the influence of independent variable on response using central composite design. For hot blanching, the independent factors selected were treatment temperature (50{\textdegree}C{\textendash}70{\textdegree}C) and duration of blanching (10{\textendash}30 min) whereas the observed response is percentage extraction efficiency of Oleuropein. The hot blanched leaves were subjected to extraction by cold maceration, microwave-assisted extraction (MAE), and ultrasound-assisted extraction (UAE). The content of Oleuropein was analyzed by high-performance thin-layer liquid chromatography. Results: From the design space, the model is stable at a range of 0.002{\textendash}0.80 which indicates lack of fit is very less and more curvature effects are clearly visualized with P = 5\% level of significance. Maximum response was attained at a temperature of 60{\textdegree}C{\textendash}65{\textdegree}C and duration of 15{\textendash}20 min. Microstructural changes in leaf were observed through scanning electron microscopy studies. From the study, pretreated leaves followed by UAE result in higher yield of Oleuropein compared to MAE and maceration. Conclusion: Hot blanching technique shows a significant linear upswing in the concentration of Oleuropein when compared to direct extraction techniques. Blanching of Olive leaves causes deactivation of enzymes, and further exposure to ultrasonic waves enhances mass transfer of solvent and promotes the release of Oleuropein.

}, keywords = {Central composite design, Extraction efficiency, Hot blanching, Olea europaea, Oleuropein, Olive leaf}, doi = {10.4103/pr.pr_179_18}, author = {P. Sucharitha and S.V. Satyanarayana and K. Bhaskar Reddy} }