A Relationship between the Critical Oxidation Potentials and Antioxidant Activities of Rubber Antioxidants

1939 ◽  
Vol 12 (2) ◽  
pp. 287-291 ◽  
Author(s):  
C. M. Doede
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Optimum Range ◽  
Oxidation Potentials ◽  
A Value ◽  
Physico Chemical ◽  
Sole Criterion

Abstract 1. According to the data presented, all of the compounds tested which exhibit marked antioxidant activity have an Ec value between 0.65 volt and 0.90 volt. Many substances exist which have an Ec value within the optimum range, but do not have much antioxidant activity. The condition that the Ec value for a good antioxidant falls between 0.65 volt and 0.90 volt seems to be necessary but not sufficient. 2. A value of Ec within an optimum range seems to be only one of several possible physico-chemical phenomena which govern the rubber antioxidant activity of a compound. 3. The determination of the Ec value of a compound should not be used as the sole criterion of that compound's antioxidant activity.

scholarly journals Antioxidant Evaluation and Heavy Metals Accumulation Of Capsicum Annuum L. Cultivars

2021 ◽  
Vol 50 (3) ◽  
pp. 507-513
Author(s):  
- Azizuddin ◽  
- Kiran ◽  
Kousar Yasmeen
Keyword(s):  
Antioxidant Activity ◽  
Capsicum Annuum ◽  
Chemical Properties ◽  
Capsicum Annuum L ◽  
Nutritional Components ◽  
Physico Chemical ◽  
Antioxidant Evaluation ◽  
Safe Limits ◽  
Metals Accumulation

Capsicum annuum L. commonly known as chilli provides dietary fibers, minerals and vitamins. In this study, three different chilli cultivars commonly named as Dandi, Ghotki and German were studied for the determination of physico-chemical properties, antioxidant activity and metal content. German showed maximum nutritional components as compared to Ghotki and Dandi such as TA (0.43 %), TDS (1.95 g/l), TSS (1.29 °Brix) and TSC (1108.72 mg/100 g). Dandi showed higher TPC (6286.60 mg/100 g) and TFC (258.88 mg/100 g) with significant antioxidant activity through DPPH (37.27 % inhibition) and RPA (1134.80 mg/100 g). Fe was found in sufficient amount among chilli cultivars and metals accumulation was within the standard safe limits. Bangladesh J. Bot. 50(3): 507-513, 2021 (September)

scholarly journals Determination of antiradical and antioxidant activity: basic principles and new insights.

2010 ◽  
Vol 57 (2) ◽  
Author(s):  
Gunars Tirzitis ◽  
Grzegorz Bartosz
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Basic Principles ◽  
Definition Of

Although the term 'antioxidant' is used very frequently, there are problems with the definition of antioxidants and estimation of antioxidant activity. The distinction between antioxidant and antiradical activities is not always obvious. This minireview discusses critically the principles, advantages and limitations of the most frequently used methods of estimation of antiradical and antioxidant activities.

scholarly journals CHEMICAL CONSTITUENTS, IN VITRO ANTIOXIDANT ACTIVITY, ORAL ACUTE TOXICITY AND LD50 DETERMINATION OF MORINGA OLEIFERA LEAVES

2017 ◽  
Vol 9 (5) ◽  
pp. 240
Author(s):  
Manal Mortady Hamed ◽  
Aboelfetoh Mohamed Abdalla ◽  
Mosad Ahmed Ghareeb ◽  
Said Abdelhalim Saleh
Keyword(s):  
Antioxidant Activity ◽  
Acute Toxicity ◽  
Antioxidant Activities ◽  
Total Phenolic ◽  
Dry Extract ◽  
Phenolic Contents ◽  
Moringa Oleifera Leaves ◽  
Oral Acute Toxicity

Objective: The objective of this study was undertaken to estimate the total phenolic contents (TPCs), in vitro antioxidant of different solvent extracts of M. oleifera leaves, oral acute toxicity and LD50 determination of the 85% methanolic extract as well as the chromatographic isolation and identification of the extract constituents.Methods: The antioxidant activity of different solvent extracts of Moringa oleifera leaves were estimated using three antioxidant assays and the total phenolic contents (TPCs) were also evaluated using Folin-Ciocalteu’s assay. The n-BuOH extract undergoes further chromatographic isolation owing to the high antioxidant activity using 2, 2'-diphenyl-1-picrylhydrazyl radical (DPPH) method, which resulted in the isolation of seven compounds.Results: The results showed that the TPCs values of the tested extracts were varied from 309.52 to 43.28 mg gallic acid equivalent/g dry extract. The reducing power antioxidant activities (RPAA) were 0.434, 0.402, 0.395, 0.149, 0.143 and 0.124, while the total antioxidant capacity (TAC) values were 316.43, 203.35, 181.56, 86.70, 76.62 and 50.83 mg ascorbic acid equivalent/g dry extract; for n-BuOH, EtOAc, 85% MeOH, H2O, CH2Cl2, and pet. ether extracts, respectively. The oral acute toxicity study of the 85% methanol extracts of M. oleifera and M. peregrina revealed that; their LD50 values were 3458.3 and 4125 mg/kg respectively, thus the two plants could be classified as slightly toxic in the scale of Hodge and Sterner which reflected their nutrient values as edible plants. The isolated compounds were identified on the basis of their 1H and 13C-NMR spectra as; cis-p-coumaric acid 4-O-(2'-O-β-D-apiofuranosyl)-β-D-glucopyranoside (1), chlorogenic acid (2), niazirin (3), 3,4-dihydroxy-β-phenylethoxy-O-α-L-rhamnopyranosyl-(l→2)-α-L-rhamnopyranosyl-(1→3)-4-O-caffeoyl-β-D-glucopyranoside (4), gallic acid (5), taxifolin (6), and benzyl-carbamo-thioethionate (7).Conclusion: The M. oleifera leaves showed promising antioxidant activities and slightly toxic behavior.

scholarly journals Determination of Phenolic Compounds and Antioxidant Activity in Vegetables Consumed in Mekelle Tigray Ethiopia

2016 ◽  
Vol 4 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Teklit G. Amabye ◽  
Frehiwot Mekonen
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Phenolic Content ◽  
Antioxidant Activities ◽  
Research Studies

Vegetables are widely consumed in Mekelle and imported from different regions and zones of the countries. This study was performed to evaluate the phenolic content and antioxidant activity of vegetables commonly consumed in Mekelle. Kale, carrot, cabbage and barcoli were used in the study. This research studies in detail the contents of phenolic compounds determined by the Folin−Ciocalteu reagent and the antioxidant activities determined by DPPH (using diphenyl-p-picrylhydrazyl radical). Among all vegetables kale showed highest phenolic content followed by barcoli, cabbage and carrot   and the highest antioxidant activity were barcoli followed by kale, cabbage and carrot   which was expressed in % of DPPH consumption after 30 minutes of reaction.  The data shows the importance of antioxidant activity of vegetables in the diet. 

scholarly journals Chemical Compounds, Physicochemical Properties, and Antioxidant Activity of A. cardamomum Leaves and Rhizomes Oils on Different Distillation Time

2020 ◽  
Vol 11 (1) ◽  
pp. 35-40
Author(s):  
Rini Pujiarti ◽  
Aisyah Kusumadewi
Keyword(s):  
Antioxidant Activity ◽  
Physicochemical Properties ◽  
Antioxidant Activities ◽  
Optical Rotation ◽  
Chemical Properties ◽  
Acid Number ◽  
Water Steam ◽  
Main Compound ◽  
Physico Chemical ◽  
Dpph Method

Amomum cardamomum is a local cardamom that grows widely and recently developed as and agroforestry crops in Indonesia. Its seeds, leaves and rhizomes are sources of essential oil. Essential oils from cardamom have many benefits for health and flavouring agent. The objectives of this study were to elucidate the yield, chemical composisition, physico-chemical properties, and antioxidant activities of leaves and rhizomes oils of cardamom were distillated using water-steam distillation for 4, 6, and 8 hours. The chemical composition were analyzed by GC-MS, physicochemical properties were analyzed used ISO standard and antioxidant activity were analyzed by DPPH method. The results showed that A. cardamomun oils yield between 0.06-0.33%. The main compound in the oils is 1,8-cineole with the highest percentage was obtained from cardamom rhizomes oil was distillated for 6 hours (60.63%). The results of each sample almost have the same quality with specific gravity between 0.899 – 0.909; refractive index between 1.476-1.478; optical rotation between (+)2.05⁰-(+)2.38⁰; miscibility in 70% alcohol between 1:7-1:9; and acid number between 0.49-0.69. The leaves and rhizomes oils of A. cardamomum showed potent antioxidant activity with the highest antioxidant were obtained from cardamom rhizomes oil were distillated for 8 hours with IC50: 0.039 g/ml.

Contribution of organic bee pollen to the determination of the botanical origin of honey and its impact on its biological properties

2021 ◽  
Vol 18 ◽  
Author(s):  
Amar Otmani ◽  
Nadia Amessis-Ouchemoukh ◽  
Zina Mouhoubi-Tafinine ◽  
Kenza Tighlit ◽  
Ibtissam Redouan ◽  
...  
Keyword(s):  
Physicochemical Parameters ◽  
Antioxidant Activities ◽  
Reducing Power ◽  
Antibacterial Activities ◽  
Biological Properties ◽  
Total Phenolic ◽  
Botanical Origin ◽  
Sensitivity Testing ◽  
Physico Chemical

Background: Honey is a sweet and flavorful natural product which comes from a lot of nectar of medicinal plants. Objective: The aims of this study were to determine the botanical origin, physicochemical parameters and the antioxidant contents and antibacterial activities of some Algerian honeys. Method: The physico-chemical parameters of the honeys analyzed were measured using the methods established by the European Honey Commission. The antioxidant contents were determined using colorimetric assays, and the antioxidant activities were estimated using reducing power, DPPH, ABTS, and FRAP assays. Antibacterial activities were measured using sensitivity testing and minimal inhibitory concentration. Results: The majority of the samples analyzed were monofloral honeys (Fabaceae) and other medicinal plant pollens were shown (Asteraceae, Tiliaceae, Myrtaceae and Apiaceae). The physicochemical parameters of the honeys were in accordance with the legislation, and the analyses of proline and HMF confirmed their authenticity. The content of total phenolic compounds and total flavonoids ranged from 26 to 159 mg GAE/100 g and 10 to 43 mg EC/100 g, respectively. The analyzed honeys showed variable antioxidant activities that differed from one honey to another, and antibacterial activity tests showed that S. aureus and K. pneumoniae were the most sensitive strains with inhibition zones of 24 to 28 mm and 8 to 35 mm in diameter, respectively. Very high correlations were observed between color, antioxidants and antioxidant activities. Conclusion: This study confirmed the powerful properties of honey to trap free radicals and to inhibit bacterial growth that could be used as a therapeutic agent.

scholarly journals Analytical characterization of some pasteurized apple juices during storage

2015 ◽  
Vol 26 (1) ◽  
pp. 7-11
Author(s):  
Cristina Damian ◽  
Ana Leahu ◽  
Mircea Oroian ◽  
Sorina Ropciuc
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Activity Levels ◽  
Total Antioxidant Activity ◽  
Ascorbic Acid Concentration ◽  
Rotational Viscometer ◽  
Total Antioxidant ◽  
Radical Method

AbstractThe aim of the study was to assess the effect of three weeks of storage on the chemical and rheological properties of apple juices obtained from Idared and Jonatan apples variety. Total antioxidant activity, levels of bio-active compound groups and the viscosity were measured to characterize the investigated juices. The method applied for the determination of ascorbic acid concentration was with 2, 6-diclorophenolindophenol. Total phenols (TP) in apple juices were determined using the Folin-Ciocalteau method and antioxidant activity by the use of DPPH free radical method. The viscosity of apple juices was investigated by a rotational viscometer, Brookfield viscometer (Brookfield Engineering Inc., Model RV-DV I Prime) with RV spindles. During three weeks of storage, different rates of all measured properties have been observed decreasing for both studied apples varieties juices. The juices from Jonatan apples have higher antioxidant activities that are correlated with the higher content in polyphenols and lower values of viscosity.

scholarly journals Uji Aktivitas Antibakteri dan Antioksidan Ekstrak Pigmen Klorofil Rumput Laut Caulerpa racemosa (Forsskal) J.Agardh

2018 ◽  
Vol 3 (2) ◽  
pp. 53-58
Author(s):  
Lisiard Dimara ◽  
Tien Y.B Yenusi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antioxidant Activity ◽  
Key Words ◽  
Antioxidant Activities ◽  
Caulerpa Racemosa ◽  
Chlorophyll Pigment ◽  
Paper Disc

The determination of antimicrobial and antioxidant activities of Chlorophyll pigment of Caulerpa racemosa (Forsskal) J.Agardh is described in this study. The aim of the study was to find out the effectiveness of chlorophyll extract in inhibiting growth of Staphylococcus aureus and Escherichia coli. Paper disc method was used to study the hampering the ability of chlorophyll toward both bacteria, and the DPPH (1,1-difenil-2-dipikrilhidrazil) method was used to find out the antioxidant activity. The result showed that extract chlorophyll can inhibit the growth of both bacteria at the concentration of 100% with the inhibition diameter zone 2.170 cm and 2.100 cm respectively. Whereas the IC50 of the chlorophyll is 2350.3 ppm can be served as an antioxidants.   Key words: antibacterial, antioxidants, chlorophyll, Caulerparacemosa (Forsskål) J.Agardh.

scholarly journals Physico-chemical characteristics, antibacterial, and antioxidant activities of genuine forest honey from East Kalimantan

Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 1969-1978
Author(s):  
Y.A. Prayitno ◽  
A. Emmawati ◽  
A. Rahmadi
Keyword(s):  
Antioxidant Activity ◽  
Antibacterial Activity ◽  
Tropical Forests ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Physicochemical Characteristics ◽  
Glucose Levels ◽  
East Kalimantan ◽  
Good Antibacterial Activity ◽  
Physico Chemical

In the dense tropical forests of Kalimantan, Apis dorsata produces forest honey with pollen diversity that has the potential to have unique antibacterial and antioxidant properties. This study is aimed to report the physicochemical characteristics, antioxidant activity and antibacterial analysis of forest honey from East Kalimantan. A total of nine samples of forest honey were purchased from local buyers of several regions. The power of hydrogen (pH), water content, diastase enzymes, fructose levels, and glucose levels were measured. Antioxidant activity was measured with ABTS assay. Antibacterial activity was conducted against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and S. enterica serovar Typhi. Fourier Transform Infra-Red (FTIR) identified antibacterial functional groups. Honey samples from tropical forests in East Kalimantan had pH between 2.93±0.06 and 3.83±0.06, a moisture content between 18.44±0.64 and 25.67±0.29%, fructose levels between 7.85±0.05 and 17.73±0.13%, and glucose levels between 1.24±0.16 and 17.34±0.14%. Goa Tembenus honey showed the highest IC50 antioxidant activity and the highest Diastase Enzyme activity. Goa Tembenus and Bongan honey showed good antibacterial activity against Gram-positive and Gram-negative. Minimum inhibitory levels of honey were found at concentrations of 25% and 30%. Honey from tropical forests in East Kalimantan has H2O2 as an antibacterial component.

scholarly journals Determination of Multiple Antioxidant Activities of Endemic Tricholoma anatolicum H.H Doğan & Intini Collected from Turkey

2018 ◽  
Vol 6 (11) ◽  
pp. 1582 ◽  
Author(s):  
Hatıra Taşkın ◽  
Tülin Eker ◽  
Fuat Bozok ◽  
Hasan Hüseyin Doğan ◽  
Saadet Büyükalaca
Keyword(s):  
Antioxidant Activity ◽  
Methanol Extract ◽  
Antioxidant Activities ◽  
Far East ◽  
Reducing Power ◽  
Total Phenolic ◽  
Mushroom Species ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power

Tricholoma anatolicum H.H. Doğan & Intini is known as the most prized mushroom species in Feke region of Turkey. This mushroom species is collected from Cedar (Cedrus libani) forests and therefore is named as Cedar mushroom in this region. It is collected and consumed by local collectors and also exported to Far East countries such as Japan by exporting companies. Therefore, it is important to investigate the nutritional and medical importance of this species. The aim of this study is to reveal the antioxidant activity of methanol extract in different concentrations (1, 2 and 4 mg/mL) of T. anatolicum H.H. Doğan & Intini collected from Feke district of Adana province of Turkey in 2015. In this study, it was determined that total phenolic content of this mushroom was 56 mg/kg. 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and reducing power (RP) activities given in trolox (µM) and ferric-reducing antioxidant power (FRAP) given in FeSO4 (µM) were found as 449, 180, 337 and 2 at the highest concentration (4 mg/mL), respectively. As a result, it could be suggested that methanol extract of T. anatolicum H.H. Doğan & Intini has significantly antioxidant activity.

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