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    A density functional theory study of the reactivity descriptors and antioxidant behavior of Crocin

    , Article Computational and Theoretical Chemistry ; Volume 1013 , June , 2013 , Pages 123-129 ; 2210271X (ISSN) Akhtari, K ; Hassanzadeh, K ; Fakhraei, B ; Fakhraei, N ; Hassanzadeh, H ; Zarei, S. A ; Sharif University of Technology
    The molecular characteristics of Crocin (digentiobiosyl-8,8'-diapocarotene-8,8'-oate; C44H64O24), naturally occurring carotenoid pigment compound, such as: the ionization potential (I), electron affinity (A), electronegativity (χ), electrophicility (ω), and hardness have been calculated using Density Functional Theory (DFT) approach with B3LYP/6-31G(d,p) level of theory. The plots of Frontier Molecular Orbital and molecular electrostatic potential (MEP) for Crocin molecule along with the spin density distribution for its cation radical have been demonstrated. For the first time, we indicated the chemically active sites of the Crocin molecule by Fukui functions. Calculated components of... 

    Electrochemical oxidation mechanisms of the antioxidants daidzein and 7-Hydroxy-4-chromone

    , Article Electroanalysis ; Volume 24, Issue 3 , 2012 , Pages 618-626 ; 10400397 (ISSN) Fernandes, I. P. G ; Oliveira, S. C. B ; Ghalkhani, M ; Shahrokhian, S ; Oliveira Brett, A. M ; Sharif University of Technology
    The electrochemical behavior of antioxidants daidzein (DZ) and 7-hydroxy-4-chromone (7-OH-4-CHM) was investigated. The oxidation of DZ is irreversible, pH-dependent, and occurs in two steps, the first of 4′-OH on the B-ring and the second on the 7-OH on the A-ring. The oxidation of 7-OH-4-CHM occurs on the 7-OH on the A-ring, is irreversible, pH-dependent and proceeds in a single step. The DZ diffusion coefficient was calculated in pH7.0 phosphate buffer to be D DZ=8.1×10 -5cm 2s -1. The detection limits of DZ and 7-OH-4-CHM was calculated as LOD DZ=0.08μM and LOD 7-OH-4-CHM=0.13μM  

    Gelatin-based functional films integrated with grapefruit seed extract and TiO2 for active food packaging applications

    , Article Food Hydrocolloids ; Volume 112 , 2021 ; 0268005X (ISSN) Riahi, Z ; Priyadarshi, R ; Rhim, J. W ; Bagheri, R ; Sharif University of Technology
    Elsevier B.V  2021
    Gelatin-based functional films were prepared by the addition of grapefruit seed extract (GSE, 5 wt% based on gelatin) and various amounts of TiO2 (0.5, 1.0, 3.0, and 5.0 wt% based on gelatin). TiO2 was evenly dispersed in the gelatin film, but the film surface roughness was increased as the concentration of TiO2 increased. The mechanical strength and water contact angle (WCA) of the composite film were the highest, while the water vapor permeability (WVP) was the lowest when 0.5 wt% TiO2 was used. The addition of GSE slightly reduced the UV light transmittance, but the addition of TiO2 almost completely prevented the UV light transmission. The addition of GSE and TiO2 did not significantly... 

    Preparation and characterization of poly-lactic acid based films containing propolis ethanolic extract to be used in dry meat sausage packaging

    , Article Journal of Food Science and Technology ; Volume 57, Issue 4 , 2020 , Pages 1242-1250 Safaei, M ; Roosta Azad, R ; Sharif University of Technology
    Springer  2020
    In this study, active poly lactic acid (PLA) films containing 0, 10, 20 and 40% w/w propolis extract (PE), as active agent, were developed. A high amount of phenolic content (PC) was measured in PE. The antioxidant effect of active PLA films was determined by measuring the PC of sausage slices after 0, 2 and 4 days storage at refrigerator. Results showed that phenolic compounds of PE were released from PLA films in quantities proportional to PE concentration. Disc diffusion test indicated that PE showed an inhibitory effect against Staphylococcus aureus and Pseudomonas aeruginosa bacterial species but was more effective against gram-positive species. PE containing PLA films had antimicrobial... 

    Investigation of Antioxidant & Antimicrobial Characteristics of Plums

    , M.Sc. Thesis Sharif University of Technology Biglary Makvandy, Fatemeh (Author) ; Maghsoody, Vida (Supervisor) ; Razavi, Jalil (Supervisor)
    Food rich in antioxidants plays an essential role in the prevention of diseases and plum is an example of these food .Our objective in this research was to determine the amount of variation in total phenolic compound present in plum fruits, so that it can be utilized in breeding programs to enhance the health benefits.Total phenolic content of the fruits, which were determined in 7 genotypes by using 4 solvents (water , methanol , ethanol , acetone) to extract phenolic compound, ranged from 178 to 497 mg/100 gr for methanol, from 306 to 407.33 mg/100 gr for ethanol , from 300 to 392 mg/100 gr for acetone and from 193 to 281.25 mg/100 gr for water. The results show that the methanol... 

    Comparative Study of Anti-oxidant Property of Fullerene C60 and its Amine Derivatives: the Effect of Transition Metal Complexes

    , M.Sc. Thesis Sharif University of Technology Tangeysh, Behzad (Author) ; Ghanbari, Bahram (Supervisor)
    Since the discovery of fullerene C60, its chemical and physical properties have been a hot topic in the field of research. For the past two decades remarkable developments achieved in the field of fullerenes chemistry. The aim of this study is comparative study of antioxidant property of fullerene C60 and its amine derivatives and the effect of transition metal complexes. At the outset the anti-oxidative property of fullerene C60 and its amine derivatives explored and it was found that by increasing the chain length of amines, the anti-oxidative property of aminofullerenes increased respectively. In next step the effect of CoSALEN complex on anti-oxidative property of fullerene was... 

    Highly Sensitive Detection of Captopril by Fluorescein-5-Isothiocyanate-Modified Gold Nanoparticles Based on FRET& Antioxidant Activity Assay in Iranian Tea Using the Generation and Growth of Metalic Nanoparticles

    , M.Sc. Thesis Sharif University of Technology Bohloul, Arash (Author) ; Bagheri, Habib (Supervisor) ; Hormozi Nezhad, Mohammad Reza (Supervisor)
    The research of this work was divided into two parts. First, A novel fuorescence sensor based on fluorescence resonance energy transfer for the determination of captopril was developed. FITC molecules that are highly fluorescent in alkaline solution fluoresce weakly when they are adsorbed onto AuNP surfaces (based on affinity of AuNPs and isothiocyanate group on FITC) as a result of fluorescence resonance energy transfer. In the presence of captopril, FITC molecules are released from the AuNP surface in order to stronger affinity to AuNPs surface than FITC molecule (in order to thiol group in captopril) so the florescence intensity of FITC restore. This phenomenon was used for quantitative... 

    Determination of antioxidant component and activity of rice bran extract

    , Article Scientia Iranica ; Volume 18, Issue 6 , December , 2011 , Pages 1402-1406 ; 10263098 (ISSN) Arab, F ; Alemzadeh, I ; Maghsoudi, V ; Sharif University of Technology
    Rice bran is one of the most important co-products in the rice milling. In this research, antioxidant activity of two Iranian rice bran varieties, Fajr and Tarem, extracted by three different solvents (methanol, ethanol and ethyl acetate) was evaluated. The order of antioxidant activity was evaluated by measurement of total phenolic content, antioxidant activity in linoleic acid system, reducing power and scavenging capacity by DPPH radical. The methanolic extract of Fajr rice bran showed a total phenolic content of 3.31 mg Gallic acid/gr rice bran and a DPPH free radical-scavenging activity of 93.91%, achieved at 50 mg/ml concentration, and a percent inhibition of linoleic acid peroxidation... 

    A quantum chemical study on the OH radical quenching by natural antioxidant fisetin

    , Article Journal of Physical Organic Chemistry ; Volume 30, Issue 11 , 2017 ; 08943230 (ISSN) Bayat, A ; Fattahi, A ; Sharif University of Technology
    In this work, the antioxidant ability of fisetin was explored toward hydroxyl (•OH) radical in aqueous and lipid solution using density functional level of theory. Different reaction mechanisms have been studied: hydrogen atom transfer, single electron transfer followed by proton transfer, and radical adduct formation, and sequential proton loss electron transfer. Rate constants for all possible reaction sites have been calculated using conventional transition state theory in conjunction with the Collins-Kimball theory. Branching ratios for the different channels of reaction are reported for the first time. Results show that the reactivity of fisetin toward hydroxyl (•OH) radical takes place... 

    Improved salinity tolerance in early growth stage of maize through salicylic acid foliar application

    , Article Italian Journal of Agronomy ; Volume 16, Issue 3 , 2021 ; 11254718 (ISSN) Sultan, I ; Khan, I ; Chattha, M. U ; Hassan, M. U ; Barbanti, L ; Calone, R ; Ali, M ; Majeed, S ; Ghani, M. A ; Batool, M ; Izzat, W ; Usman, S ; Sharif University of Technology
    Page Press Publications  2021
    Soil salinity threatens agricultural production worldwide by constraining plant growth and final crop yield. The early stages are most sensitive to salinity, in response to which salicylic acid (SA) has demonstrated beneficial effects in various plant species. Based on this, a maize (Zea mays L.) pot experiment was set up combining three levels of soil salinity (0, 6 and 12 dS m–1), obtained through NaCl addition, with three levels of SA (0, 300 and 600 mM), applied by leaf spraying 20 days after seedling emergence. Fifteen days later, the following traits were assessed: morphology (plant height, leaf number), growth (root and shoot dry weight), leaf water status [relative water content... 

    The Study of Antioxidant Mechanism of some Flavonoids without and in Presence of Cyclodextrins: Theoretical Point of View

    , Ph.D. Dissertation Sharif University of Technology Gerayeli, Narges (Author) ; Tafazzoli, Mohsen (Supervisor) ; Ghiasi, Mina (Co-Supervisor)
    Antioxidants are compounds with anti-cancer, anti-bacterial, anti-viral, anti-aging and anti-allergic properties. In the present study, a quantum mechanical approach has been used to shed light on the presence effect of glycoside group on the antioxidant ability of chrysin as one of the most important consumable flavonoids and two glycoside derivatives, chrysin-6-C-fucopyranoside and chrysin-3-malonyl-6-C-fucopyranoside which has electron-withdrawing group (EWG) in its C3 of glycoside group. Density functional theory (DFT) using B3LYP and UB3LYP functional and split-valance 6-311++G ** basis set were used to optimize chrysin, its different derivatives, and their radicals. Analysis of... 

    Large scale inkjet-printing of carbon nanotubes electrodes for antioxidant assays in blood bags

    , Article Journal of Electroanalytical Chemistry ; Vol. 717-718 , 2014 , Pages 61-68 ; ISSN: 15726657 Lesch, A ; Cortes Salazar, F ; Prudent, M ; Delobel, J ; Rastgar, S ; Lion, N ; Tissot J. D ; Tacchini, P ; Girault, H. H ; Sharif University of Technology
    Herein, we present the large scale fabrication of carbon nanotubes (CNT) electrodes supported on flexible polymeric sheets by subsequent multilayer inkjet printing of a silver layer for electrical connection, CNT layers as active electrode material and an insulation layer to define a stand-alone CNT active electrode area with high accuracy. Optical and electrochemical characterization using several redox mediators demonstrates the reproducibility of the electrode surfaces and their functionality even with a single inkjet printed CNT layer. These electrodes are targeted to the clinical sector for the determination of the antioxidant power (AOP) of biologically relevant fluids by... 

    Theoritecal Investigation of Kinetics and Thermodynamic of Vitamin Antioxidants Reaction Mechanism, in Particular Vitamin C, with Free Radicals

    , M.Sc. Thesis Sharif University of Technology Safari Yazd, Hoda (Author) ; Gholami, Mohammad Reza (Supervisor)
    Antioxidants are compounds which prevent free radicals from aggregation and formation in body cells. vitamin C, E and carotene are among the most important antioxidant that have reduction properties. free radicals have great chemical reactivity which can react with different types of compound in human body such as lipids, cell membrane and proteins and cause different illnesses. Antioxidants with various mechanisms such as hydrogen atom transfer, single electron transfer SPLET, sequential proton loss electron transfer and radical adduct formation can stable free radicals and also become non-active compounds, antioxidant properties of these compounds related to structure and their functional... 

    The Development of Anti-Microbial PLA Nanocomposites

    , M.Sc. Thesis Sharif University of Technology Haj Seyyd Ahmadi, Reyhaneh (Author) ; Frounchi, Masoud (Supervisor)
    One of the great challenges of food industry is the lack of packing materials which can disperse active compositions properly for variety of applications; therefore an antioxidant/antibacterial release system of poly lactic acid in a specific time is a necessity for being used in food packing industry. Most of the researches have been done in the field of drug release system, yet numbers of researches done in the field of food industry are rare. Rate of antibacterial/antioxidant release from polymeric film is relatively fast also calculated based on Fick’s second law of diffusion; therefore primary poly lactic acid is modified by adding ameliorative agents such as poly ethylene glycol and... 

    Effect of Al antioxidant on the rate of oxidation of carbon in MgO-C refractory

    , Article Journal of the American Ceramic Society ; Volume 90, Issue 2 , 2007 , Pages 509-515 ; 00027820 (ISSN) Sadrnezhaad, S.K ; Nemati, Z. A ; Mahshid, S ; Hosseini, S ; Hashemi, B ; Sharif University of Technology
    Kinetics of air oxidation of MgO-C-Al refractory at 600°-1300°C were investigated using the software based on the modifled shrinking core model (KDA). Commercial bricks containing 88.5% MgO, 10% residual carbon, and 1.5% aluminum anti-oxidant were oxidized isothermally with air. Combination of experimental data with model calculations indicated gas diffusion through solid material and pores as a major controlling step. Previously observed chemisorption process was eliminated from the rate-controlling mechanism with addition of aluminum antioxidant. Comprehensive rate equations were devised for MgO-C-Al and MgO-C oxidation reactions. Overall activation energies of Q id (internal diffusion) =... 

    Extraction of Anthocyanins and Total Phenolics from Dried Red Grape Skin by Super Heated Solvent and Production of NanoPparticle by Super Critical Fluid

    , M.Sc. Thesis Sharif University of Technology Shahmahmoodi, Mohammad (Author) ; Goodarznia, Iraj (Supervisor)
    Red grape skin has a lot of antioxidant that called Anthocyanins. In this research this material has been studied and amount of extraction of them have been studied by changing the operational parameter and particle size in taguchi procedure. Pressurized liquid extraction (PLE) was used to extract Anthocyanins from Dried Red Grape Skin (DRGS) with acidified Ethanol solvent (1 %( v/v) of HCl) in 90-120°C, 10-40 bar, and 30 min extraction time. In this study, effect of particle size distribution of DRGS was considered and the results showed that with increasing the temperature (from 90 to 120 °C in 10 °C increments) and decreasing the pressure and particle size the extraction of Anthocyanins... 

    An Investigation on Aging of Rubber Compounds Against Acidic Gases

    , M.Sc. Thesis Sharif University of Technology Aminizadeh, Pooria (Author) ; Mousavi, Abbas (Supervisor) ; Shojaei, Akbar (Supervisor)
    Aging of rubber compounds at high temperature and pressure acidic gas is a challenge for using them for a long time. Therefore, in this thesis aging of NBR/PVC compounds against H¬2S and CO2 has been investigated. The main method have been used is Full Factorial Design of Experiment. The parameters have been examined are content of zinc oxide, plasticizer RPO ASTM 290 and antioxidant 4010 NA. The content have been set in tow levels and effect of each have investigated in ambient and 120 degree of centigrad temperature. The results show that the effect of antioxidant 4010 NA on aging of compounds is negative and zinc oxide and plasticizer RPO ASTM 290 are positive  

    Inhibitory activity on type 2 diabetes and hypertension key-enzymes, and antioxidant capacity of veronica persica phenolic-rich extracts

    , Article Cellular and Molecular Biology ; Volume 62, Issue 6 , 2016 , Pages 80-85 ; 01455680 (ISSN) Sharifi Rad, M ; Tayeboon, G. S ; Sharifi Rad, J ; Iriti, M ; Varoni, E. M ; Razazi, S ; Sharif University of Technology
    Cellular and Molecular Biology Association  2016
    Veronica genus (Plantaginaceae) is broadly distributed in different habitats. In this study, the inhibitory activity of free soluble and conjugated phenolic extracts of Veronica persica on key enzymes associated to type 2 diabetes (α-glucosidase and α-amylase) and hypertension (angiotensin I converting enzyme, ACE) was assessed, as well as their antioxidant power. Our results showed that both the extracts inhibited α-amylase, α-glucosidase and ACE in a dose-dependent manner. In particular, free phenolic extract significantly (P < 0.05) inhibited α-glucosidase (IC50 532.97 μg/mL), whereas conjugated phenolic extract significantly (P < 0.05) inhibited a-amylase (IC50 489.73 μg/mL) and ACE... 

    The free radical scavenging activity of lespedezacoumestan toward ˙OH radical: a quantum chemical and computational kinetics study

    , Article Journal of Physical Organic Chemistry ; Volume 31, Issue 2 , February , 2018 ; 08943230 (ISSN) Bayat, A ; Fattahi, A ; Sharif University of Technology
    John Wiley and Sons Ltd  2018
    The free radical activity of lespedezacoumestan was investigated toward hydroxyl (˙OH) radical in polar and nonpolar media using density functional theory. Four reaction mechanisms including radical adduct formation, hydrogen atom transfer, sequential single electron-proton transfer (SET-PT), and sequential proton loss electron transfer were considered. The rate constants and branching ratio for all possible sites of reaction were calculated and reported for the first time. According to the obtained results, lespedezacoumestan reacts faster with ˙OH radical in aqueous solution than in nonpolar media. Also, lespedezacoumestan is an excellent ˙OH radical scavenger regardless of the environment... 

    Gas chromatographic fingerprint analysis of secondary metabolites of Stachys lanata (Stachys byzantine C. Koch) combined with antioxidant activity modelling using multivariate chemometric methods

    , Article Journal of Chromatography A ; Volume 1602 , 2019 , Pages 432-440 ; 00219673 (ISSN) Aminfar, P ; Abtahi, M ; Parastar, H ; Sharif University of Technology
    Elsevier B.V  2019
    S. lanata has been traditionally used as a medicinal plant due to its various biological activities such as antioxidant activity. Therefore, identification and quality control studies of this plant are of great importance. To this end, gas chromatography (GC) combined with chemometrics was proposed for fingerprint analysis of S. lanata samples. This study sought to classify GC fingerprints of twenty-eight S. lanata samples from eight different regions of Iran and more importantly, to correlate fingerprints to the antioxidant activity to select S. lanata volatile antioxidant markers. S. lanata samples were classified into five and three classes using partial least squares-discriminant...