Abstract
Zinc oxide nanoparticles (ZnO NPs) were synthesized using barberry (Berberis vulgaris) extract via heating method. The effects of the amount of barberry extract (15–35 ml) and the reaction time (30–90 min) on the antibacterial (clear zone diameter, mm) and antioxidant (%) activities of the synthesized ZnO NPs were investigated by response surface methodology. Main reducing and stabilizing compounds of barberry extract were identified by gas chromatography and Fourier transform infrared spectroscopy. Spherical ZnO NPs with an average size of 20 nm were successfully fabricated at optimal synthesis conditions using 35 ml of barberry extract and 30 min reaction time. ZnO NPs were determined to have a zeta potential of –15.3 mV and an antioxidant activity of 28.8%. The antibacterial activity of fabricated ZnO NPs was tested against Staphylococcus aureus and found to possess significant (p<0.05) inhibitory effect against this microorganism.
1 Introduction
In recent years, scientists and researchers show significant interest in nanoparticles (NPs) due to their unique properties such as smaller size and larger surface area than the micro-structured materials. Their novel structures display enhanced physical, chemical, and biological activities which in turn, increases drastically their applications in biological science, biomedical and clinical medicine [1], [2].
Nanotechnology is also being utilized in medicine for therapeutic drug discovery and delivery for many diseases and disorders. Metal oxide NPs such as MgO, TiO2, ZnO, CuO2, and SiO2 are antimicrobial agents used as nanomedicines. Among many nanostructured metal oxides, ZnO has attracted attention due to its unique characteristic features and wide range of uses in the fields of technology and science such as optics, electronics, cosmetics, food additives, biosensors, and drug deliveries [1], [3], [4]. ZnO is chemically stable under processing condition, nontoxic, biocompatible, low cost, and ecofriendly. It is one of the essential minerals for human health used as antibiotics by inhibiting the wide range of resisted pathogens activity in food processing environment [1], [4].
Various synthetic techniques have been used to fabricate ZnO nanocrystals [5], [6]. Khalil et al. using thermal decomposition synthesized nano-sized ZnO powders from zinc acetate. Using urea and zinc nitrate as raw materials, Moussawi and Patra prepared ZnO nanocrystals by a homogeneous precipitation method followed by thermal treatment and plant extract [5]. Indeed, plant extracts and essential oils can be good alternatives. Extracts of plant possess substances such as carbohydrates, polyphenols, proteins, flavonoids, pigments, and several secondary metabolites which can be used for synthesis of nanoparticles [7], [8], [9]. However, few studies have been done on ZnO NPs synthesis using plant extracts [3], [10].
A plant in different areas can show different components and properties. Also the type and technique of extracted essence can play an important role in experimental antibacterial results [11], [12]. In several studies are reported that barberry (Berberis vulgaris) has antibacterial effects in body and in vitro. It has been reported that all parts of this plant have medicinal properties, such as antioxidant, anti-emetic, tonic, anti-pruritic, antipyretic, and cholagogue actions. They have been also used in jaundice, cholecystitis, leishmaniasis, cholelithiasis, malaria, dysentery, and gall stones [13], [14], [15], [16], [17], [18]. Several researches have indicated that the fruit of this plant is widely used as a food additive and berries are edible, purple in color with sharp flavor [13], [17].
It is mentioned that some polyphenol, alkaloid compounds are present in the structure of barberry and they prevent the activity of bacteria [15], [19]. Antioxidant containing compounds are abundantly available in natural herbs such as barberry which protect the cells, against free radicals damage [20]. Free radicals show presence of excess number of electrons and thus they are highly active compounds and have charge [21]. The interaction of free radicals with lipophilic biomolecules yields new radicals such as hydroperoxides and different peroxides. There are various antioxidant compounds in different parts of plants. Flavonoids and phenols are two main antioxidants which act toward these radicals and reduce their activities [20], [22], [23], [24].
Therefore, the main objectives of the present study were to: (i) analyze and use aqueous barberry extract for ZnO NPs synthesis using gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FT-IR); (ii) study the effects of barberry extract and reaction time on the antibacterial and antioxidant activities of the fabricated ZnO NPs; and (iii) evaluate the physico-chemical properties of the synthesized ZnO NPs.
2 Materials and methods
2.1 Materials
Barberry was obtained from a local market in Tabriz, Iran. Zn (NO3)3·6H2O, was used as ZnO salt that was purchased from Sigma-Aldrich; ethanol 80% (Merck co., Berlin, Germany) was used for plant extraction. Staphylococcus aureus (PTCC 1112) was purchased from microbial Persian type culture collection (PTCC, Tehran, Iran). Nutrient agar (NA) was purchased from Biolife (Biolife Co. Milan, Italy). In order to prepare all aqueous solutions, deionized double distilled water was used.
2.2 Preparation of plant extraction
For this purpose 1 g of barberry with 100 ml ethanol 80% was extracted by maceration. Extracts were filtered with Whatman No. 1 filter paper (Chm, F2042-Spain). The filtrates obtained from extracts were evaporated by dry rotary evaporator (Stuart, RE300-England) at 40°C and were stored at 4°C.
2.3 Synthesis of ZnO NPs
In order to prepare ZnO NPs, 6 ml of barberry extract was diluted in 300 ml of double distilled water. After that, 2 g of Zn (NO3)3·6H2O was added into 20 ml of diluted barberry extract and then placed in a stirrer at 60°C for 1 h. Different concentrations of the extract were used in the reaction mixture. Prepared solutions were heated in a furnace (Stuart, BIBIY-023155-England) maintained at 400°C for 2 h to obtain a light yellow colored powder. The fabricated ZnO NPs were then evaluated.
2.4 Physico-chemical analyses
The main biomolecules and chemical functional groups of the barberry extract were identified using GC-MS (Agilent 6890, Santa Clara, CA, USA) and FT-IR, respectively. For this analysis, GC-MS system with a 30 m×0.25 mm HP-5 capillary column was coupled with a HP 5989A mass spectrometer which operated in electron ionization mode at 70 eV. Helium was used as the carrier gas. The FT-IR spectra of extract were recorded on a Bruker Tensor 27 spectrometer (Bruker, Germany) using KBr pellets in the 4000–400 cm−1 region.
The structural properties and morphology of the synthesized ZnO NPs were monitored by X-Ray diffractometry (XRD: D5000, Siemens) using Cu Kα radiation and scanning electron microscopy (SEM: mv 2300, Com scan), respectively. Dynamic light scattering particle size analyzer (Nanotrac Wave, Microtrac, USA) was used to measure the particle size of the fabricated ZnO NPs.
2.5 Antibacterial assay
For evaluation of antibacterial activity of the synthesized ZnO NPs, the effect of NPs was tested on the prepared bacterial suspensions. The well diffusion method was carried out to examine the antibacterial activity. In fact, the bacterial species (Gram positive) (S. aureus) were inoculated on a Nutrient Agar (NA Merck, Germany) media at the plates with diameter of 90 mm and then some holes (with diameter of 5 mm) were created in the culture. Barberry extract, Zn (NO3)3·6H2O, and ZnO NPs were separately poured into the holes. Provided plates were then placed in an incubator at 37°C for 24 h. The results of my preliminary studies indicated that the synthesized ZnO NPs had less antibacterial activities toward Eschericia coli (Gram negative). Therefore, antibacterial activities of fabricated ZnO NPs were evaluated only against Gram positive bacteria.
2.6 Determination of antioxidant activity
To assess the scavenging ability on 2,2-diphenyl-2-picrylhydrazyl (DPPH), various concentrations of ZnO NPs were added into 1 ml of methanol (50%) solution containing DPPH (1 mM). After that, the mixture was shaken strongly and left to stand for 30 min in the dark before measuring the absorbance at 520 nm against a blank [3]. Then the scavenging ability was calculated using the following equation (Eq. 1):
where I% is the inhibition percent, Acontrol is the absorbance of the control reaction (containing all reagents except the test compound), and Asample is the absorbance of the test compound. UV-visible spectroscopy measurements (250–800 nm, Perkin Elmer, Germany) were accomplished to measure absorbance and antioxidant activity.
2.7 Design of experiments and statistical data analysis
Response surface methodology (RSM) using a central composite design (CCD) with two independent variables (synthesis parameters), namely amount of plant extract (15–35 ml) (X1) and reaction time (30–90 min) (X2), was applied to determine the antibacterial activity (Y1) and antibacterial assay (Y2) of the ZnO NPs solution. The response variables were chosen according to the literatures [9], [12].
As compared to other experimentation methodologies, which are established on a classical one-variable-a time optimization, RSM has several advantages including creating numerous valuable data using a small run of experiments and the ability of estimating the independent variables interactions on the response variables. Therefore, it is a proper method which can be used to optimize the main independent parameters of the process to obtain a product with desired attributes [25], [26]. Therefore, 13 experiment runs, including four factorial points (levels ±1), four star points (levels ±α), and five central points were generated using the software Minitab v.16 statistical package (Minitab Inc., PA, USA) (Table 1). All experiments were carried out throughout a day which indicates that the design of the experiment included one block. In order to estimate the pure error, a central point was repeated five times [27]. All experiments were carried out throughout the day by using one block. A second-order polynomial equation (Eq. 2) was used to correlate Y1 and Y2 of the ZnO NPs solution with the studied synthesis variables.
Experimental runs according to the central composite design and response variables for ZnO NPs synthesis.
| Sample no. | Amount of extract (ml) X1 | Reaction time (min) X2 | Antibacterial (clear zone diameter, mm) Y1 | Antioxidant (%) Y2 | ||
|---|---|---|---|---|---|---|
| Expa | Preb | Expa | Preb | |||
| 1 | 25.0 | 60 | 19 | 19.0000 | 2.0 | 2.7000 |
| 2 | 25.0 | 90 | 20 | 20.0518 | 5.3 | 4.7896 |
| 3 | 25.0 | 30 | 19 | 19.1982 | 7.1 | 5.7604 |
| 4 | 25.0 | 60 | 19 | 19.0000 | 4.0 | 2.7000 |
| 5 | 17.92 | 81.21 | 18 | 17.9179 | 8.5 | 8.4682 |
| 6 | 32.07 | 38.78 | 21 | 20.8321 | 4.6 | 5.8818 |
| 7 | 17.92 | 38.78 | 18 | 17.8143 | 8.0 | 9.1546 |
| 8 | 25.0 | 60 | 19 | 19.0000 | 3.0 | 2.7000 |
| 9 | 25.0 | 60 | 19 | 19.7582 | 2.0 | 2.7000 |
| 10 | 15.0 | 60 | 17 | 17.1376 | 11.8 | 11.3892 |
| 11 | 25.0 | 60 | 19 | 19.9481 | 2.5 | 2.7000 |
| 12 | 32.07 | 81.21 | 22 | 21.9357 | 3.9 | 5.1954 |
| 13 | 35.0 | 60 | 22 | 22.1124 | 8.2 | 6.7608 |
aExperimental values of studied responses. bPredicted values of studied responses.
where β0 is a constant, βi, βii, and βij correspond to the linear, quadratic and interaction effects, respectively. The appropriateness of the model was studied accounting for the coefficient of determination (R2) and adjusted coefficient of determination (R2-adj). Analysis of variance was also used to provide the significance of determinations of the resulted models in terms of p value and F ratio. High values of F ratio and small p values (smaller than 0.05) were considered as statistically significant. Based on the fitted polynomial equations, three-dimensional surface plots and two-dimensional contour plots were plotted to predict the independent variable interactions [27].
In order to obtain the optimum values for reaction time and amount of plant extract with the desired response variables, numerical multiple response and graphical optimizations were used [28]. In fact, optimal conditions for the independent parameters were obtained by estimating the resulted surface plots. Finally, for verification of the validity of the statistical experimental approaches, three additional approval tests were performed at obtained optimum synthesis conditions. Therefore, it is a proper technique which can be used to optimize the main independent parameters of the process [28], [29].
3 Results and discussion
3.1 Extract specifications
The FT-IR spectrum of the extract of barberry (Figure 1) showed some peaks centered at 3402, 1496, 1235, 1126, 1049, 864, and 462 cm−1 which represent free OH in molecule and OH group forming hydrogen bonds, carbonyl group (C=O), stretching C=C aromatic ring and C–OH, C–H, C=C aromatic, and alkylhalides stretching vibrations, respectively [30], [31]. The results indicated that polyhydroxyl phenolics and flavonoids in the plant extract are the main biomolecules which can reduce zinc ions and convert them to ZnO NPs.
FT-IR spectrum of barberry extract.
GC-MS analysis (Figure 2) was also used to identify the whole active ingredients in the leaf extracts which were responsible for the synthesis of ZnO NPs. It was found that there were approximately 17 active compounds recorded within 33 min of retention time. However, in addition to the phenolic compounds and flavonoids, there were six prominent compounds found at different peaks of chromatogram. They were included: methyl cyclohexane, 7-methyl-3,4,5,6-tetrahydro-2H-azepine, 1, 4-dimethyl benzene, n-nonane, n-decane, and undecane which may influence the reduction process and stability of the synthesized ZnO NPs.
GC-MS chromatogram of barberry extract.
3.2 Fitting the response surface models
According to the achieved values for the designed experiments (Table 1) and by applying multiple regression analysis, second-order polynomial models for studying two ZnO synthesis parameters were fitted. The estimated regression coefficients and corresponding significance of regressions for the models are given in Table 2. The F ratio values and p values of all the main, quadratic, and interaction terms of the obtained final models are also shown in Table 3. Generally, higher F ratio value and lower p value indicate higher importance of the chosen term on the responses. High values of the R2 and R2-adj for the obtained models were a good measure for overall models performance and their accuracy. Moreover, obtained insignificant lack of fits for achieved models confirmed their sufficient fitness to the synthesis parameter effects (Table 2). As clearly observed in Table 3, the main terms of the synthesis variables had significant (p<0.05) effects on all responses of the synthesized ZnO NPs. The obtained results indicated that the main term of time (X2) the quadratic term of time
Regression coefficients, R2, R2-adj, and probability values for the fitted models.
| Regression coefficient | Antibacterial (clear zone diameter, mm) | Antioxidant (%) |
|---|---|---|
| β0 (constant) | 20.8341 | 59.6000 |
| β1 (main effect) | –0.1638 | –3.4189 |
| β2 (main effect) | –0.1108 | –0.3595 |
| β11 (quadratic effect) | 0.0062 | 0.0637 |
| β22 (quadratic effect) | 0.0007 | 0.0029 |
| β12 (interaction effect) | 0.0017 | – |
| R2 | 99.45% | 89.33% |
| R2-adj | 98.90% | 84.00% |
β0 is a constant, and β1, β2, β11, β22, and β12 are the linear, quadratic, and interaction coefficients of the quadratic polynomial equation, respectively.
p-Value and F ratio of the regression coefficients in the obtained models.
| Antibacterial (Y2) | Antioxidant (Y1) | |||
|---|---|---|---|---|
| p-Value | F ratio | p-Value | F ratio | |
| Main effects | ||||
| X1 | 0.097 | 4.15 | 0.000 | 54.42 |
| X2 | 0.006 | 21.05 | 0.020 | 8.38 |
| Quadratic effects | ||||
| | 0.008 | 18.75 | 0.000 | 48.12 |
| | 0.008 | 18.75 | 0.023 | 7.85 |
| Interacted effects | ||||
| X1X2 | 0.033 | 8.5 | – | – |
1, Amount of extract (ml); 2, reaction time (min).
3.2.1 The antibacterial activity of ZnO NPs
The antibacterial activity of the obtained ZnO NPs against S. aureus (clear zone) ranged from 18 to 22 mm for different samples (Table 1). The changes in the antibacterial activity of ZnO NPs could also be explained as a function of reaction time and the amount of extract in Figure 3A. As clearly observed in this figure, at a constant and high reaction time for synthesis of ZnO NPs, by increasing the amount of the extract, the diameter of formed clear zone enhanced. However, at a constant and low reaction time, there was an insignificant increase in the clear zone. This indicates that the interaction of amount extract and reaction time had significant (p<0.05) effect on antibacterial activity of the synthesized ZnO NPs. The results indicated that by enhancing the amount of extract, the antibacterial activity of the formed ZnO NPs increased. The results can be explained by the fact that by increasing the amount of barberry extract, the concentration of the reducing agents in the extract increased which in turn, increased the concentration of synthesized ZnO NPs. The obtained results were in agreement with the findings of Madan et al. [3]. They found that by increasing the amount of Azadirachta indica extract, the concentration of green synthesized ZnO NPs increased and their antibacterial activities were also increased. As clearly observed in Figure 3B, the maximum antibacterial activities of fabricated ZnO NPs against S. aureus were obtained at high amount of barberry extract and reaction time.
Response surface (A) and contour plots (B) for antibacterial ••• of ZnO NPs as a function of significant (p<0.05) interaction effects of reaction time and amount of extract.
3.2.2 Antioxidant activity of synthesized ZnO NPs
The antioxidant assay of the synthesized ZnO NPs ranged from 2% to 11.8% (Table 1). The obtained results indicated that ZnO NPs could be synthesized using natural reductants existing in barberry extract without applying other chemical reducing agents. Figure 4A, shows the antioxidant activity of the formed ZnO NPs as a function of reaction time and amount of extract. As clearly observed in this figure, at a constant reaction time, by increasing the amount of the barberry extract, the antioxidant activities of the fabricated ZnO NPs decreased and increased, respectively. The antioxidant activity of ZnO may be due to the transfer of electron density located at oxygen to the odd electron located at nitrogen atom in DPPH. This reduction gives the evidence toward the free radical scavenging capacity of ZnO NPs and indicated the formation of ZnO NPs [3]. After formation of ZnO NPs, by increasing their concentration, their antioxidant activity was increased. The result was similar to the findings of Madan et al. [3]. As clearly observed in Figure 4B, the maximum antioxidant activity was obtained at low and high amount of barberry extract and reaction time, respectively.
Response surface (A) and contour plots (B) for the antioxidant assay of produced ZnO NPs solution as a function of significant (p<0.05) interaction effects of reaction time and amount of extract.
3.3 Optimization of synthesis parameters for the ZnO NPs production
The ZnO NPs synthesis would be optimized when the process resulted in synthesized ZnO NPs with the highest antioxidant and antibacterial activities. For this reason, graphical optimization based on an overlaid contour plot was used to find the optimum region for the synthesis parameters (Figure 5). The indicated white color area in Figure 5, demonstrated the desired reaction time and the amount of extract areas to get the optimum ZnO NPs. Numerical multiple optimizations were also used to find the exact optimum values of studied synthesis variables. The results also demonstrated that the synthesis conditions with 35 ml of extract and 30 min synthesis reaction time for fabrication of the ZnO NPs would give the most desirable NPs. At the optimum conditions, ZnO NPs were fabricated with antibacterial activity of 21.81 mm (clear zone) and antioxidant of 10.42%. Moreover, three ZnO NPs solutions were synthesized based on the suggested optimal values by numerical multiple optimization and characterized in terms of studied response variables. The insignificant differences found between the predicted and experimental values of the optimum suggested sample which was reconfirmed by the adequacy of the fitted models for studied responses.
Overlaid contour plot of ZnO NPs’ antibacterial activity and antioxidant assay with acceptable levels as function of time and amount of extract.
3.4 Physico-chemical characteristics of synthesized ZnO NPs at obtained optimum conditions
Figure 6 shows the XRD pattern of the synthesized ZnO NPs using barberry extract. A definite line broadening of the XRD peaks showed that the synthesized powder included particles with diameter of nanometer. The diffraction peaks detected at 2θ values are 32.1°, 37.2°, 47.5°, 56.5°, 63.5°, and 67.8° (JPCDS card number: 36-1451). The absence of any additional peaks declares that these are free from impurities [23]. Their diameter was calculated using Debye-Scherrer formula, the maximum crystal size of the sample was found to be 59 nm.
XRD pattern of the synthesized ZnO NPs at optimum conditions.
The measured experimental value for the zeta potential of the synthesized ZnO NPs was –15.3 mV, which indicates its high stability (Figure 7).
Zeta potential distribution of synthesized ZnO NPs at optimum conditions.
The SEM analysis was done to evaluate the shape and microstructure of the synthesized ZnO NPs. A typical SEM image of the synthesized ZnO NPs is shown in Figure 8. As clearly observed, the synthesized NPs were well dispersed with spherical structures. This spherical shape indicated that the synthesized NPs had minimum surface energy and high thermodynamic stability, which confirmed the high value of the zeta potential of the synthesized ZnO NPs. The SEM images showed successful synthesis of spherical NPs with an average particle size of 20 nm.
SEM images of ZnO NPs synthesized at optimum conditions.
The antibacterial activity of ZnO NPs was evaluated at obtained optimum conditions. Effects of synthesized ZnO NPs on growth of Gram positive bacteria (S. aureus) during incubation are shown in Figure 9. As shown in this figure, the growth of Gram positive bacteria was significantly inhibited by the presence of ZnO NPs (bottom disc) as compared to the control sample (Zn (NO3)3.6H2O) (top disc). Madan et al. also indicated that synthesized ZnO NPs using neem extract had high antibacterial activity toward S. aureus as compared to that of against E. coli [3].
Zone of inhibition produced by ZnO NPs (bottom disc) as compared to the zinc nitrate (top disc) against Staphylococcus aureus.
The antioxidant property of the formed ZnO NPs was assessed at optimum synthesis conditions. The obtained results for the DPPH scavenging activity of ZnO NPs was 28.8%, which in turn, shows high antioxidant value of the synthesized ZnO NPs. The obtained result was in agreement with the findings of Madan et al. [3].
4 Conclusions
A rapid one-step green approach was developed for ZnO NPs synthesis without using any toxic chemicals. Barberry extract acted mainly as a reducing agent during ZnO NPs synthesis. The results indicated the usefulness of RSM for studying the effects of the synthesis conditions on the dependent variables and to optimize them to get the most desirable ZnO NPs. The fabricated ZnO NPs showed significant antibacterial activity against S. aureus. This rapid synthesis method developed from the present study can be used as a favorable technique for the synthesis of other noble metal and metal oxide NPs.
About the author
Younes Anzabi received his BSc and MSc degrees in veterinary medicine (Iran). He obtained his PhD in microbiology from Islamic Azad University, Science and Research Branch, Tehran in 2005. He joined Tabriz Branch, Islamic Azad University, Iran in 2005 and is currently working as an associate professor in the faculty of Veterinary Medicine. He is the head of the microbiology section in the Department of Pathobiology. His fields of interest include biotechnology, food microbiology, antimicrobial, and antioxidant properties of herbs.
References
[1] Dhivya R, Ranjani J, Rajendhran J, Rajasekaran M, Annaraj J. Adv. Mater. Lett. 2015, 6, 505–512.10.5185/amlett.2015.5766Search in Google Scholar
[2] Upadhyaya L, Singh J, Agarwal V, Pandey A, Verma SP, Das P, Tewari R. J. Polym. Res. 2014, 21, 1–9.Search in Google Scholar
[3] Madan H, Sharma S, Suresh D, Vidya Y, Nagabhushana H, Rajanaik H, Anautharaju KS, Prashantha SC, Sadananda Maiya P. Spectrochim.Acta Mol. Biomol. Spectrosc. 2016, 152, 404–416.10.1016/j.saa.2015.07.067Search in Google Scholar PubMed
[4] Hanley C, Layne J, Punnoose A, Reddy K, Coombs I, Coombs A, Coombs A, Feris K, Wingett D. Nanotechnology 2008, 19, 295103.10.1088/0957-4484/19/29/295103Search in Google Scholar PubMed PubMed Central
[5] Khalil MI, Al-Qunaibit MM, Al-Zahem AM, Labis JP. Arabian J. Chem. 2014, 7, 1178–1184.10.1016/j.arabjc.2013.10.025Search in Google Scholar
[6] Moussawi RN, Patra D. RSC Adv. 2016, 6, 17256–17268.10.1039/C5RA20221CSearch in Google Scholar
[7] Thuille N, Fille M, Nagl M. Int. J. Hyg. Environ. Health 2003, 206, 217–221.10.1078/1438-4639-00217Search in Google Scholar PubMed
[8] Burt S. Int. J. Food Microbiol. 2004, 94, 223–253.10.1016/j.ijfoodmicro.2004.03.022Search in Google Scholar PubMed
[9] Eskandari-Nojehdehi M, Jafarizadeh-Malmiri H, Rahbar-Shahrouzi J. Nanotechnol. Rev. 2016, 5, 537–548.10.1515/ntrev-2016-0064Search in Google Scholar
[10] Moussawi RN, Patra D. Sci. Rep. 2016, 6, 24565.10.1038/srep24565Search in Google Scholar PubMed PubMed Central
[11] Chitsaz M. Dan. Med. J. 2006, 14, 1–8.Search in Google Scholar
[12] Mohammadlou M, Jafarizadeh-Malmiri H, Maghsoudi H. Green Process. Synth. 2017, 6, 31–42.Search in Google Scholar
[13] Akbulut M, Calisir S, Marakoglu T, Coklar H. J. Food Process Eng. 2009, 32, 497–511.10.1111/j.1745-4530.2007.00229.xSearch in Google Scholar
[14] Fathollahzadeh H, Rajabipour A. Int. Agrophys. 2008, 22, 299–302.Search in Google Scholar
[15] Ardestani SB, Sahari MA, Barzegar M, Abbasi S. J. Food Pharm. Sci. 2013, 1, 2–9.Search in Google Scholar
[16] Khosrokhavar R, Ahmadiani A, Shamsa F. J. Med. Plants 2010, 3, 99–105.Search in Google Scholar
[17] Özgen M, Saraçoğlu O, Geçer EN. Hortic. Environ. Biotechnol. 2012, 53, 447–451.10.1007/s13580-012-0711-1Search in Google Scholar
[18] Pruthi N, Chawla G, Yadav S. Nat. Prod. Rad. 2008, 7, 40–44.Search in Google Scholar
[19] Mohammadlou M, Maghsoudi H, Jafarizadeh-Malmiri H. Int. Food Res. J. 2015, 23, 446–463.Search in Google Scholar
[20] Ijinu T, Latha P, George V, Pushpangadan P. Ann. Phytomed. 2016, 5, 85–90.Search in Google Scholar
[21] Sarker MAK, Rinta SK, Sayeed A. J. Pharm. Phytochem. 2016, 5, 260–263.Search in Google Scholar
[22] Barros L, Ferreira M-J, Queiros B, Ferreira IC, Baptista P. Food Chem. 2007, 103, 413–419.10.1016/j.foodchem.2006.07.038Search in Google Scholar
[23] Leong L, Shui G. Food Chem. 2002, 76, 69–75.10.1016/S0308-8146(01)00251-5Search in Google Scholar
[24] Re R, Pellegrini N, Proteggente A, Pannala A, Yang M, Rice-Evans C. Free Radic. Biol. Med. 1999, 26, 1231–1237.10.1016/S0891-5849(98)00315-3Search in Google Scholar
[25] Anarjan N, Jafarizadeh-Malmiri H, Nehdi IA, Sbihi HM, Al-Resayes SI, Tan CP. Int. J. Nanomed. 2015, 10, 1109–1118.10.2147/IJN.S72835Search in Google Scholar PubMed PubMed Central
[26] Anarjan N, Nehdi I A, Sbihi HM, Al-Resayes SI, Jafarizadeh-Malmiri H, Tan CP. Molecules 2014, 19, 14257–14265.10.3390/molecules190914257Search in Google Scholar PubMed PubMed Central
[27] Gharibzahedi SMT, Mousavi SM, Hamedi M, Khodaiyan F, Razavi SH. Carbohydr. Polym. 2012, 87, 1611–1619.10.1016/j.carbpol.2011.09.067Search in Google Scholar
[28] Anarjan N, Jaberi N, Yeganeh-Zare S, Banafshehchin E, Rahimirad A, Jafarizadeh-Malmiri H. J. Am. Oil Chem. Soc. 2014, 91, 1397–1405.10.1007/s11746-014-2482-6Search in Google Scholar
[29] Bezerra MA, Santelli RE, Oliveira EP, Villar LS, Escaleira LA. Talanta 2008, 76, 965–977.10.1016/j.talanta.2008.05.019Search in Google Scholar PubMed
[30] Nasrollahzadeh M, Maham M, Rostami-Vartooni A, Bagherzadeh M, Sajadi SM. RSC Adv. 2015, 5, 64769–64780.10.1039/C5RA10037BSearch in Google Scholar
[31] Saraji M, Ghani M. J. Chromatogr. A 2014, 1366, 24–30.10.1016/j.chroma.2014.09.024Search in Google Scholar PubMed
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