scholarly journals Effect of Bucillamine on Free-Radical-Mediated Degradation of High-Molar-Mass Hyaluronan Induced in vitro by Ascorbic Acid and Cu(II) Ions

Polymers ◽  
2014 ◽  
Vol 6 (10) ◽  
pp. 2625-2644 ◽  
Author(s):  
Mária Baňasová ◽  
Katarína Valachová ◽  
Jozef Rychlý ◽  
Ivica Janigová ◽  
Katarína Csomorová ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Free Radical ◽  
Molar Mass ◽  
High Molar Mass

Dithiols as more effective than monothiols in protecting biomacromolecules from free-radical-mediated damage: in vitro oxidative degradation of high-molar-mass hyaluronan

2014 ◽  
Vol 68 (10) ◽  
Author(s):  
Mária Baňasová ◽  
Katarína Valachová ◽  
Ivo Juránek ◽  
Ladislav Šoltés
Keyword(s):  
Free Radical ◽  
Molar Mass ◽  
Radical Scavenging ◽  
Oxidative Degradation ◽  
Free Radical Scavenging ◽  
Dpph Assay ◽  
High Molar Mass ◽  
High Concentrations ◽  
Free Radical Scavenging Activities

AbstractOxidative stress and the resulting damage to cellular and extracellular components has been observed in a variety of degenerative processes, including degenerative joint disorders, where high-molar-mass hyaluronan (HA) is often found to be massively degraded. The present study sought to test the hypothesis that dithiols are more effective in protecting biomacromolecules from free-radicalmediated damage than monothiols. The materials/thiols tested included bucillamine (BUC), dithioerythritol (DTE), dithiothreitol (DTT) and glutathione (GSH), as a reference, for their effectiveness in protecting HA from oxidative degradation induced in vitro. Since HA degradation results in a decrease in its dynamic viscosity, rotational viscometry was applied to follow HA oxidative degradation. The free-radical-scavenging activities of the thiols tested were determined by 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) assays. It was found that all the dithiols in the concentration range tested protected HA from the oxidative degradation. On the other hand, monothiol GSH exerted protection only at high concentrations (10 μmol L−1 and 100 μmol L−1) and 1 μmol L−1 of GSH even exhibited a prodegradative effect. The ABTS assay revealed free-radical scavenging activities in the following order: BUC, DTT, DTE, GSH, and that of the DPPH assay: BUC, DTE, DTT, GSH. In conclusion, it was demonstrated that dithiols may be more effective than monothiols in affording biomacromolecule protection from oxidative degradation.

scholarly journals Free-radical degradation of high-molar-mass hyaluronan induced by ascorbate plus cupric ions: Testing of stobadine and its two derivatives in function as antioxidants

2012 ◽  
Vol 31 (01) ◽  
pp. 57-64 ◽  
Author(s):  
Lubica Surovcikova-Machova ◽  
Katarina Valachova ◽  
Maria Banasova ◽  
Vladimir Snirc ◽  
Elena Priesolova ◽  
...  
Keyword(s):  
Free Radical ◽  
Molar Mass ◽  
High Molar Mass ◽  
Radical Degradation

Free Radical Scavenging and Antioxidant Activity of Ascorbigen Versus Ascorbic Acid: Studies in Vitro and in Cultured Human Keratinocytes

2008 ◽  
Vol 56 (24) ◽  
pp. 11694-11699 ◽  
Author(s):  
Anika E. Wagner ◽  
Patricia Huebbe ◽  
Tetsuya Konishi ◽  
M. Mamunur Rahman ◽  
Meiko Nakahara ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Radical Scavenging ◽  
Human Keratinocytes ◽  
Free Radical Scavenging

scholarly journals Potential Antioxidant Activity of New Tetracyclic and Pentacyclic Nonlinear Phenothiazine Derivatives

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Godwill Azeh Engwa ◽  
Eugene Lekem Ayuk ◽  
Benardeth Ujunwa Igbojekwe ◽  
Marcellus Unaegbu
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Membrane Damage ◽  
The Body ◽  
Phenothiazine Derivatives ◽  
Antioxidant Agents ◽  
Group 3

The global increase in oxidative stress related diseases such as cancer, cardiovascular, and inflammatory diseases caused by overwhelming level of free radicals in the body has encouraged the search for new antioxidant agents. Based on the ability of newly synthesized phenothiazine derivatives (6-chloro-11-azabenzo[a]phenothiazine-5-one and 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one) to oxidize H2O2, a known free radical to sulfoxide, this study assessed the in vitro and in vivo antioxidant activity. The synthesized phenothiazine derivatives exhibited reducing power potential to convert Fe3+to Fe2+and high ability to scavenge H2O2free radical in vitro. These activities were comparable to ascorbic acid, a standard antioxidant. The catalase activity significantly increased (p<0.05) in groups 1 and 2 animals that received the phenothiazine derivatives compared to the controls (groups 3 and 4) suggesting the ability of the phenothiazine derivatives to scavenge H2O2in vivo. The malondialdehyde level in groups 1 and 2 animals was lower than that in group 3 that received the reference compound (ascorbic acid) and group 4 that received the solvent suggesting the ability of the phenothiazine derivatives to prevent lipid membrane damage. AST and bilirubin levels were higher in group 2 animals which received 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one compared to group 3, the positive control. The results suggest that phenothiazine derivatives, especially 6-chloro-11-azabenzo[a]phenothiazine-5-one, possess antioxidant activity though 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one was slightly toxic. This activity may be due to the presence of electron donors such as sulfur as well as the richness of hydrogen in the additional benzene rings for substitution. Further study is needed to identify tolerable doses for possible therapeutic purposes.

Evaluation of Bioactive Component, Free Radical Scavenging Potentials and Protein Qualities of Gomphrena celosoides and Zea mays Leaves

2020 ◽  
Vol 16 (7) ◽  
pp. 1108-1115
Author(s):  
Bob-Chile A. Adaeze ◽  
Peter U. Amadi
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Amino Acid ◽  
Unsaturated Fatty Acids ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Bioactive Components

Background: The assessment of underexploited leaves has become crucial to supplement the rapidly depleting sources of bioactive components as well as provide available nutrient sources for local inhabitants. Methods: This study thus investigated the bioactive components of the oil, and fatty acid composition, free radical scavenging potentials, and protein qualities of leaves of Z. mays and G. celosioides using standard methods. The bioactive components of the oils and fatty acids were determined by Gas Chromatograpy, while the amino acid and in-vitro antioxidant potentials were determined using a Technicon Sequential Multi-Sample (TSM) Amino Acid Analyzer, and spectrophotometer, respectively. Results: The Z. Mays leaves showed the abundance of farnesene, hexadecanoic acids, and caryophellene while G. celosioides produced high level of octadecadienoic acid, hexadecanoic acid, and phytol. Z. mays and G. celosioides contained 72.48% and 60.55% unsaturated fatty acids respectively, with the abundance of linolenic acid for Z. mays and oleic acid for G. celosioides. The result for the in vitro antioxidant % inhibition showed a concentration dependent free radical scavenging potentials of the leaves. Both G. celosioides and Z. mays produced greater 1,1-diphenyl-2- picrylhydrazyl (DPPH), and hydrogen peroxide radical scavenging potentials than ascorbic acid, while at 40ppm the nitric oxide and 2,2- azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical % inhibition of Z. mays leaves were lower than those for ascorbic acid. Discussion: The number of essential amino acids in both plants were 48.20 and 39.25 g/100g, total branched chain amino acids (TBCAA) were 21.15 and 16.92 g/100g, predicted protein efficiency ratios (P-PERs) were in the range of 3.02-3.23 and 2.68-2.77, and the essential amino acid index (EAAI) were 1.52 and 1.48, for Z. mays and G. celosioides leaves respectively. Conclusion: From these results, the utilization of Z. mays and G. celosioides for high quality protein, unsaturated fatty acids and potent antioxidant sources, should be massively encouraged.

USE OF THE PURIFIED APPLE PECTIN FOR STABILIZATION OF ASCORBIC ACID IN FRESH JUICES

2019 ◽  
Author(s):  
Н.Ш. КАЙШЕВА ◽  
А.Ш. КАЙШЕВ ◽  
Л.Б. ГУБАНОВА ◽  
А.Б. САМОРЯДОВА
Keyword(s):  
Ascorbic Acid ◽  
Fruits And Vegetables ◽  
Molar Mass ◽  
Mass Ratio ◽  
High Molar Mass ◽  
Before And After ◽  
The Stability ◽  
Characteristic Maximum ◽  
Differential Spectroscopy

Исследована возможность применения очищенных пектинов для стабилизации аскорбиновой кислоты (АК) в фреш-соках с концентрацией 10–6–10–4г/мл. В работе использованы: АК, щавелевая кислота (ЩК), свекловичный (СП), цитрусовый (ЦП) и яблочный (ЯП) пектины с высокой молярной массой 61000–87500 г/моль и степенью этерификации 46,5–76,3%, предназначенные для фармацевтического применения. Фреш-соки получены посредством отжима ягод, плодов и овощей (18 видов). Установлено отсутствие мешающего влияния пектинов на определение АК методом дифференциальной спектроскопии в УФ-области – характеристический максимум поглощения АК 264 нм. По серии растворов АК (0,25–1,25) · 10–3% определен удельный показатель поглощения АК 727, в соответствии с которым оценено содержание АК в модельных растворах со вспомогательными веществами при хранении. Устойчивость АК составляет, сут: в присутствии ЩК 5, СП 4, ЦП 6, ЯП 10. Установлено оптимальное массовое соотношение АК : ЯП как 1 : 16, что использовано для купажирования фреш-соков, в которых предварительно определена концентрация АК 0,40–19,99 мг % методом титрования 2,6-дихлорфенолиндофенолятом натрия. Сравнительная оценка соков до и после купажирования ЯП при хранении (20°С, 10 сут) показала, что ЯП способствует смещению рН в оптимальную для АК область рН 4,5–8,0; увеличению вязкости соков на 5–148% и сроков хранения в 3,3–59 раз. Относительная погрешность различных определений (n = 5, P = 95%, t = 2,57) составила ± (0,7–5,6)%. Доказана возможность применения очищенного ЯП в качестве стабилизатора АК в фреш-соках с концентрацией АК 10–6–10–4 г/мл, что создает перспективы безопасного «продления жизни» соков. The possibility of using purified pectins to stabilize ascorbic acid (AA) in fresh juices with a concentration of 10–6–10–4g/ml was investigated. In the work were used: АA, oxalic acid (OA), beetroot, citrus and apple pectins (BP, CP and AP) with high molar mass (61000–87500 g/mol) and the degree of etherification (46,5–76,3%), intended for pharmaceutical use. Fresh juices were obtained by pressing berries, fruits and vegetables (18 kinds). Absence of interfering effect of pectins on the determination of AA by differential spectroscopy in the UV region (characteristic maximum absorption of AA – 264 nm) was established. According to the series of AA solutions (0,25–1,25) · 10–3%, the specific absorption rate of AA 727 was determined, according to which the content of AA in model solutions with auxiliary substances during storage was estimated. The stability of AA in the presence of OA is 5 days, BP – 4 days, CP – 6 days, AP – 10 days. The optimal mass ratio of AA : AP 1 : 16 was established, which was used for blending fresh juice, in which the concentration of AA (0,40–19,99 mg %) was previously determined by the method of titration with 2,6-dichlorphenolindophenol sodium. A comparative assessment of juices before and after blending during storage (20°C, 10 days) showed that AP contributes to the displacement of pH in the optimal for AA area of pH 4,5–8,0; increase in the viscosity of juices by 5–148% and shelf life of 3,3–59 times. The relative error of different definitions (n = 5, P = 95%, t = 2,57) was ± (0,7–5,6)%. Thus, the possibility of using purified AP as an AA stabilizer in fresh juices with the concentration of AA 10–6–10–4g/ml is proved, which creates prospects for safe prolonging the life of juices.

scholarly journals EVALUATION OF ANTIOXIDANT EFFECT OF ALCOHOLIC ROOTS EXTRACT OF EUPHORBIA HIRTA LINN. – IN VITRO

2021 ◽  
pp. 111-114
Author(s):  
RASHMI WADHWA ◽  
PANKAJ GUPTA
Keyword(s):  
Ascorbic Acid ◽  
Free Radical ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Total Phenolic ◽  
Root Extract ◽  
Alcoholic Extract ◽  
Flavonoid Content ◽  
Euphorbia Hirta

Objective: The main objective of the present study was to undergo an investigation on free radical scavenging activity of the roots of Euphorbia hirta Linn. and was compared with a standard antioxidant compound like ascorbic acid. Methods: Euphorbia hirta roots extract was tested for total flavonoid content, total phenolic content, and in vitro antioxidant activity by 1, 1-diphenyl- 2-picrylhydrazyl (DPPH) free radical scavenging assay (DPPH) assay, superoxide anion radical scavenging assay, and nitric oxide scavenging assay. Results: The alcoholic roots extract of E. hirta was screened for free radical scavenging and antioxidant activities using three different methods. It was found that percentage inhibition of the extract was concentration-dependent. Total phenolic content and total flavonoid content were found to be 265.72±1.3 and 45.67±1.14, respectively. The alcoholic extract of E. hirta produced a dose-dependent inhibition of superoxide radicals ranging from 40.14±0.14 to 70.93±0.10. The mean IC50 values for DPPH radical by root extract of E. hirta and ascorbic acid were found to be 18.12 μg/ml and 13.17 μg/ ml, respectively. The alcoholic extract of E. hirta produced dose-dependent inhibition of nitric oxide radicals scavenging effect ranging from 17.05±0.18 to 51.08±0.30. The alcoholic extract of E. hirta and ascorbic acid shows mean IC50 values for superoxide radical as 23.64 μg/ml and 14.36 μg/ml, respectively. Conclusions: The present study showed that E. hirta possesses a considerable amount of both phenolic and flavonoid content. The alcoholic root extract also shows good antioxidant potential. The results of the present study also encourage for further in vivo studies and isolation and characterization of active compounds.

scholarly journals Synthesis of some novel 3- (4-ethoxyphenyl) -5- (4-substituted) -4,5-dihydro-1H-pyrazole derivatives as potent antioxidant agents

2020 ◽  
Vol 11 (2) ◽  
pp. 1571-1577
Author(s):  
Lakshminarayanan B ◽  
Kannappan N ◽  
Subburaju T ◽  
Kalaichelvan V K
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Assay Method ◽  
Antioxidant Agents ◽  
Ic50 Value

Pyrazolines are the most useful heterocyclic moiety in Pharmaceutical and Chemical fields and as the most potential molecules for the design of new chemical entities. Nitrogen-containing heterocyclic compounds, pyrazolines and their derivatives showed a variety of pharmacological activities, including antioxidant properties. In the present study, eleven novel ethoxylated pyrazoline derivatives were synthesized by condensing chalcones with electron releasingethoxy group at one end and different electron-donating, electron-withdrawing groups in another end with hydrazine hydrate andalcohol. The compounds synthesized were structural elucidated by their spectroscopic studies. All the compounds synthesized were evaluated for their in vitro antioxidant potential by 2,2’-diphenyl-1-picrylhydrazyl (DPPH)and hydrogen peroxide free radical scavenging assay methods.Some of these molecules possess moderate to good antioxidant activitywhen compared to standard ascorbic acid. The compound with methoxy group (EH2) exhibits potent antioxidant activity with IC50 value of 9.02 and 9.44µg/ml in DPPH and hydrogen peroxide assay method respectively and the compound with hydroxy group (EH9) also showed potent antioxidant activity with IC50 value of 12.41 and 14.56µg/ml in DPPH and hydrogen peroxide free radical scavengingassay method respectively when compared to standard. The compounds containing electron-donating substituents were found to be good antioxidantswhen compared to standard ascorbic acid.

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