scholarly journals Gelatin-Based Hydrogels for the Controlled Release of 5,6-Dihydroxyindole-2-Carboxylic Acid, a Melanin-Related Metabolite with Potent Antioxidant Activity

Antioxidants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 245 ◽  
Author(s):  
Maria Laura Alfieri ◽  
Giovanni Pilotta ◽  
Lucia Panzella ◽  
Laura Cipolla ◽  
Alessandra Napolitano
Keyword(s):  
Carboxylic Acid ◽  
Antioxidant Properties ◽  
Prolonged Storage ◽  
Porcine Skin ◽  
Antioxidant Power ◽  
High Mechanical Strength ◽  
Amide Coupling ◽  
Physiological Relevance ◽  
Kinetics Of ◽  
Related Metabolite

The ability of gelatin-based hydrogels of incorporating and releasing under controlled conditions 5,6-dihydroxyindole-2-carboxylic acid (DHICA), a melanin-related metabolite endowed with marked antioxidant properties was investigated. The methyl ester of DHICA, MeDHICA, was also tested in view of its higher stability, and different solubility profile. Three types of gelatin-based hydrogels were prepared: pristine porcine skin type A gelatin (HGel-A), a pristine gelatin cross-linked by amide coupling of lysines and glutamic/aspartic acids (HGel-B), and a gelatin/chitosan blend (HGel-C). HGel-B and HGel-C differed in the swelling behavior, showed satisfactorily high mechanical strength at physiological temperatures and well-defined morphology. The extent of incorporation into all the gelatins tested using a 10% w/w indole to gelatin ratio was very satisfactory ranging from 60 to 90% for either indoles. The kinetics of indole release under conditions of physiological relevance was evaluated up to 72 h. The highest values were obtained with HGel-B and HGel-C for MeDHICA (90% after 6 h), and an appreciable release was observed for DHICA reaching 30% and 40% at 6 h for HGel-B and HGel-C, respectively. At 72 h, DHICA and MeDHICA were released at around 30% from HGel-A at pH 7.4, with an increase up to 40% at pH 5.5 in the case of DHICA. DHICA incorporated into HGel-B proved fairly stable over 6 h whereas the free compound at the same concentration was almost completely oxidized. The antioxidant power of the indole loaded gelatins was monitored by chemical assays and proved unaltered even after prolonged storage in air, suggesting that the materials could be prepared in advance with respect to their use without alteration of their efficacy.

Evaluation of diuretic and antioxidant properties in aqueous bark and fruit extracts of pine

2020 ◽  
Vol 17 ◽  
Author(s):  
Hadi Shariati ◽  
Mohammad Hassanpour ◽  
Gholamreza Sharifzadeh ◽  
Asghar Zarban ◽  
Saeed Samarghandian ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Content ◽  
Antioxidant Properties ◽  
Pine Bark ◽  
Male Rats ◽  
Total Phenolic ◽  
Dependent Manner ◽  
Aqueous Extracts ◽  
Antioxidant Power ◽  
Dose Dependent

Objective: The present study has been carried out to evaluate the diuretic and antioxidant properties of pine herb in an animal model. Materials and Methods: 45 adult male rats were randomly divided into nine groups including: groups I (the negative control), groups II (positive control, furosemide 10 mg/kg), groups III to VIII (treatment groups received 100, 200, 400 mg/kg of the aqueous extracts of bark and fruit) and group IX received the combination of aqueous extract of bark (100 mg/kg) and the fruit (100 mg/kg). The urine output, glomerular filtration rate (GFR), electrolytes, urea, and creatinine levels were evaluated . Furthermore, the phenolic content and antioxidant activity of both extracts were also assessed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and Folin–Ciocalteu methods. Results: The aqueous extracts of the pine bark and fruit increased the urinary output in a dose-dependent manner. The combination of the two extracts compared to the other extracts alone significantly increased the serum potassium level. This study also showed each extract increase creatinine clearance in a dose-dependent manner (p<0.01 and p<0.05). The increase of GFR in the combination group was not significant. The current data showed a significant increase in the total phenolic content in pine bark extract in compared with the fruit extract. Conclusion: The pine bark and fruit can be useful in the prevention and treatment of kidney stones due to the high antioxidant activity.

Kinetics of Substitution of 4-Methoxyphenylazo Groups of 2,6-Dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic Acid by Reaction with 4-Nitrobenzenediazonium Cation

1994 ◽  
Vol 59 (7) ◽  
pp. 1665-1672 ◽  
Author(s):  
Jaroslava Horáčková ◽  
Vojeslav Štěrba
Keyword(s):  
Carboxylic Acid ◽  
Rate Constant ◽  
Kinetics Of

Kinetics have been studied of gradual replacement of 4-methoxyphenylazo groups in 2,6-dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic acid (IIIa) by 4-nitrophenylazo groups using the reaction with 4-nitrobenzenediazonium cation (IIc) in acetate and phosphate buffers. The rate constant of replacement of the second methoxyphenylazo group is lower by a factor of ca 60. From the experimentally found pKa values of the corresponding azohydrazone compounds with methoxy, chloro, or nitro substituent at 4-position (IIIa - IIIf) it has been concluded that the 5(3)-(4-methoxyphenylazo)-3(5)-(4-nitrophenylhydrazono) derivative is formed in the first step.

scholarly journals Interactions between polyphenolic antioxidants quercetin and naringenin dictate the distinctive redox-related chemical and biological behaviour of their mixtures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Monika Baranowska ◽  
Zuzanna Koziara ◽  
Klaudia Suliborska ◽  
Wojciech Chrzanowski ◽  
Michael Wormstone ◽  
...  
Keyword(s):  
Differential Pulse ◽  
Current Approach ◽  
Biological Behaviour ◽  
Antioxidant Power ◽  
Kinetics Of Oxidation ◽  
Ht29 Cells ◽  
Reducing Activity ◽  
Pulse Voltammetry ◽  
Cellular Tests ◽  
Kinetics Of

AbstractFood synergy concept is suggested to explain observations that isolated antioxidants are less bioactive than real foods containing them. However, mechanisms behind this discrepancy were hardly studied. Here, we demonstrate the profound impact of interactions between two common food flavonoids (individual: aglycones quercetin—Q and naringenin—N− or their glycosides rutin—R and naringin—N+ vs. mixed: QN− and RN+) on their electrochemical properties and redox-related bioactivities. N− and N+ seemed weak antioxidants individually, yet in both chemical and cellular tests (DPPH and CAA, respectively), they increased reducing activity of mixtures synergistically. In-depth measurements (differential pulse voltammetry) pointed to kinetics of oxidation reaction as decisive factor for antioxidant power. In cellular (HT29 cells) tests, the mixtures exhibited properties of a new substance rather than those of components. Pure flavonoids did not influence proliferation; mixtures stimulated cell growth. Individual flavonoids tended to decrease global DNA methylation with growing concentration; this effect was more pronounced for mixtures, but not concentration-dependent. In nutrigenomic studies, expression of gene set affected by QN− differed entirely from common genes modulated by individual components. These results question the current approach of predicting bioactivity of mixtures based on research with isolated antioxidants.

scholarly journals Antioxidant Capacity and Phenolic and Sugar Profiles of Date Fruits Extracts from Six Different Algerian Cultivars as Influenced by Ripening Stages and Extraction Systems

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 503
Author(s):  
Malika Tassoult ◽  
Djamel Edine Kati ◽  
María África Fernández-Prior ◽  
Alejandra Bermúdez-Oria ◽  
Juan Fernandez-Bolanos ◽  
...  
Keyword(s):  
Sugar Content ◽  
Antioxidant Properties ◽  
Dry Weight ◽  
Natural Antioxidants ◽  
Antioxidant Power ◽  
Fruit Extracts ◽  
Ripening Stages ◽  
Date Fruit ◽  
Ferric Reducing Antioxidant Power ◽  
First Time

The study investigated the phenols, sugar and the antioxidant capacities of date fruit extracts obtained by organic solvents and by hydrothermal treatment from six different Algerian cultivars at two ripening stages for the first time. The analyzed cultivars exhibited potent antioxidant properties (ferric reducing antioxidant power (FRAP), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacities) and different phenols regardless of the solvents and the maturity stages. About 18 phenols were identified and quantified, mainly in the hydrothermal extracts. The earlier stages were characterized by high amounts of o-coumaric acid, cinnamic acid and luteolin, with a noticeable absence of quercetin. The tamr stage presented the highest sugar content (78.15–86.85 mg/100 mg dry weight (DW)) with an abundance of glucose. Galactose was present only in some cultivars from the kimri stage (tamjouhert). Uronic acids were mostly detected at the tamr stage (4.02–8.82 mg gallic acid equivalent/100 mg dried weight). The obtained results highlight the potential of using date fruit extracts as natural antioxidants, especially at industrial scales that tend use hydrothermal extraction.

scholarly journals Synthesis and antioxidant properties of 2-(3-(hydroxyimino)methyl)-1H-indol-1-yl)acetamide derivatives

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Chandravadivelu Gopi ◽  
Magharla Dasaratha Dhanaraju
Keyword(s):  
Antioxidant Activity ◽  
Condensation Reaction ◽  
Antioxidant Properties ◽  
Side Chain ◽  
Antioxidant Power ◽  
H Nmr ◽  
Antioxidant Agents ◽  
Phenyl Rings ◽  
Ferric Reducing Antioxidant Power ◽  
Ft Ir

Abstract Background The main aim of this work was to synthesise a novel N-(substituted phenyl)-2-(3-(hydroxyimino) methyl)-1H-indol-1-yl) acetamide derivatives and evaluate their antioxidant activity. These compounds were prepared by a condensation reaction between 1H-indole carbaldehyde oxime and 2-chloro acetamide derivatives. The newly synthesised compound structures were characterised by FT-IR, 1H-NMR, mass spectroscopy and elemental analysis. Furthermore, the above-mentioned compounds were screened for antioxidant activity by using ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods. Result The antioxidant activity result reveals that most of the compounds were exhibiting considerable activity in both methods and the values are very closer to the standards. Among the synthesised compounds, compound 3j, 3a and 3k were shown remarkable activity at low concentration. Conclusion Compounds 3j, 3a and 3k were shown highest activity among the prepared analogues due to the attachment of halogens connected at the appropriate place in the phenyl ring. Hence, these substituted phenyl rings considered as a perfect side chain for the indole nucleus for the development of the new antioxidant agents.

scholarly journals Effect of Parinari curatellifolia Peel Flour on the Nutritional, Physical and Antioxidant Properties of Biscuits

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1262
Author(s):  
Shonisani Eugenia Ramashia ◽  
Felicia Matshepho Mamadisa ◽  
Mpho Edward Mashau
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Properties ◽  
Polyphenolic Compounds ◽  
Total Phenolic ◽  
Crude Fibre ◽  
Yellowness Index ◽  
Antioxidant Power ◽  
Parinari Curatellifolia ◽  
Ferric Reducing Antioxidant Power ◽  
The Impact

This study investigated the impact of Parinari curatellifolia peel flour on the nutritional, physical and antioxidant properties of formulated biscuits. Biscuits enriched with 5%, 10%, 15% and 20% of Parinari (P). curatellifolia peel flour were formulated and characterised. Thermal, physicochemical, polyphenolic compounds and antioxidant properties of flour and biscuits were determined. The incorporation of P. curatellifolia peel flour significantly increased (p < 0.05) thermal properties (onset, peak and conclusion temperatures) of flour. However, enthalpy of gelatinisation, viscosity and pH of flour samples decreased. Nutritional analysis revealed an increase in ash (0.74% to 2.23%) and crude fibre contents (0.39% to 2.95%) along with an increase of P. curatellifolia peel flour levels. Protein content and carbohydrates decreased while moisture content was insignificantly affected by the addition of P. curatellifolia peel flour. The L*, b* values and whiteness index of formulated biscuits decreased while parameter a* value (10.76 to 21.89) and yellowness index (69.84 to 102.71) decreased. Physical properties such as diameter (3.57 mm to 3.97 mm), spread ratio (2.67 to 3.45) and hardness (1188.13 g to 2432.60 g) increased with the inclusion levels of peel flour while weight and thickness decreased. The inclusion of P. curatellifolia improved the polyphenolic compounds and antioxidant activity of biscuits with values of total flavonoids content ranging from 0.028 to 0.104 mg CE/g, total phenolic content increasing from 20.01 mg to 48.51 mg GAE/g, ferric reducing antioxidant power (FRAP) increasing from 108.33 mg to 162.67 mg GAE/g and DPPH (2,2-diphenyl-1-picrylhydrazyl) from 48.70% to 94.72%. These results lead to the recommendation of the utilisation of P. curatellifolia peel flour to enhance the nutritional value, polyphenolic compounds and antioxidant activity of bakery products such as biscuits.

scholarly journals Genetic and Pre- and Postharvest Factors Influencing the Content of Antioxidants in Cucurbit Crops

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 894
Author(s):  
Cecilia Martínez ◽  
Juan Luis Valenzuela ◽  
Manuel Jamilena
Keyword(s):  
Abiotic Stresses ◽  
Nutritional Value ◽  
Antioxidant Properties ◽  
Plant Diseases ◽  
Human Diet ◽  
Antioxidant Power ◽  
Factors Influencing ◽  
Cultivated Species ◽  
Plant Families ◽  
Valuable Compounds

Cucurbitaceae is one of the most economically important plant families, and includes some worldwide cultivated species like cucumber, melons, and squashes, and some regionally cultivated and feral species that contribute to the human diet. For centuries, cucurbits have been appreciated because of their nutritional value and, in traditional medicine, because of their ability to alleviate certain ailments. Several studies have demonstrated the remarkable contents of valuable compounds in cucurbits, including antioxidants such as polyphenols, flavonoids, and carotenoids, but also tannins and terpenoids, which are abundant. This antioxidant power is beneficial for human health, but also in facing plant diseases and abiotic stresses. This review brings together data on the antioxidant properties of cucurbit species, addressing the genetic and pre- and postharvest factors that regulate the antioxidant content in different plant organs. Environmental conditions, management, storage, and pre- and postharvest treatments influencing the biosynthesis and activity of antioxidants, together with the biodiversity of this family, are determinant in improving the antioxidant potential of this group of species. Plant breeding, as well as the development of innovative biotechnological approaches, is also leading to new possibilities for exploiting cucurbits as functional products.

scholarly journals In Vitro Antioxidant Activity of Litsea martabanica Root Extract and Its Hepatoprotective Effect on Chlorpyrifos-Induced Toxicity in Rats

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1906
Author(s):  
Phraepakaporn Kunnaja ◽  
Sunee Chansakaow ◽  
Absorn Wittayapraparat ◽  
Pedcharada Yusuk ◽  
Seewaboon Sireeratawong
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Properties ◽  
Water Extract ◽  
Acetylcholinesterase Activity ◽  
Liver Cells ◽  
Scientific Data ◽  
Total Phenolic ◽  
Root Extract ◽  
Antioxidant Power ◽  
Detoxifying Agent

In Thailand, people in the highland communities whose occupational exposure to pesticides used the root of Litsea martabanica as a detoxifying agent. However, the scientific data to support the traditional use of this plant are insufficient. This study aimed to evaluate the antioxidant activity and anti-pesticide potential of L. martabanica root extract. Antioxidant properties were investigated by 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assay, superoxide radicals scavenging assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, ferric reducing antioxidant power (FRAP), and total phenolic content determination. In all assays, L. martabanica extracts and their fractions exhibited high antioxidant activities differently. The water extract is traditionally used as a detoxifying agent. Therefore, it was chosen for in vivo experiments. The rats received the extract in a way that mimics the traditional methods of tribal communities followed by chlorpyrifos for 16 days. The results showed that acetylcholinesterase activity decreases in pesticide-exposed rats. Treatment with the extract caused increasing acetylcholinesterase activity in the rats. Therefore, L. martabanica extract may potentially be used as a detoxifying agent, especially for the chlorpyrifos pesticide. The antioxidant properties of L. martabanica may provide a beneficial effect by protecting liver cells from damage caused by free radicals. Histopathology results revealed no liver cell necrosis and showed the regeneration of liver cells in the treatment group. L. martabanica extract did not cause changes in behavior, liver weight, hematological and biochemical profiles of the rats.

THE TRANSMISSION OF POLAR EFFECTS: IV. THE KINETICS OF ESTERIFICATION WITH DIAZODIPHENYLMETHANE OF SUBSTITUTED HETEROCYCLIC CARBOXYLIC ACIDS

1966 ◽  
Vol 44 (13) ◽  
pp. 1493-1499 ◽  
Author(s):  
Keith Bowden ◽  
D. C. Parkin
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Rate Coefficients ◽  
Relative Ability ◽  
Indole Carboxylic Acid ◽  
Kinetics Of ◽  
Electron Effects

The rate coefficients for the reaction with diazodiphenylmethane, in ethanol at 30.0°, of a number of substituted indole-2-carboxylic acids, indole-3-carboxylic acids, coumarin-3-carboxylic acids, coumarilic acids, and N-phenylglycines have been determined. The effect of substitution is assessed by use of adapted Hammett and Dewar–Grisdale relations. The relations give good correlations for oxygen-ring heterocyclic systems, and the relative ability of the systems to transmit π-electron effects has been determined. An anomalous perturbing effect appears to operate in the indole-carboxylic acid systems.

scholarly journals IN VITRO TOTAL PHENOLICS, FLAVONOIDS CONTENTS, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITES OF VARIOUS SOLVENT EXTRACTS FROM THE MEDICINAL PLANT PHYSALIS MINIMA LINN

2017 ◽  
Vol 9 (3) ◽  
pp. 192 ◽  
Author(s):  
Venkanna Banothu ◽  
Uma Adepally ◽  
Jayalakshmi Lingam
Keyword(s):  
Medicinal Plant ◽  
Ethyl Acetate ◽  
Methanol Extract ◽  
Total Phenolics ◽  
Antioxidant Properties ◽  
Dry Weight ◽  
Aluminium Chloride ◽  
Total Phenolic ◽  
Antioxidant Power

Objective: To estimate the in vitro total phenolics, flavonoids contents, antioxidant and antimicrobial activities of various solvent extracts from the medicinal plant Physalis minima Linn.Methods: The crude bioactive were extracted from the dried powder of Physalis minima using methanol, ethyl acetate, chloroform and hexane solvents. Total phenolic content (TPC) and total flavonoid content (TFC) were estimated using Folin-Ciocalteu and aluminium chloride colorimetric methods respectively. 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays were used to determine the in vitro antioxidant capacity. The antimicrobial assay was done through agar well diffusion; minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using broth microdilution methods against the Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris) and Gram-positive bacteria (Staphylococcus aureus).Results: TPC expressed as gallic acid equivalents (GAE) ranged from 60.27±1.73-151.25±2.50 mg GAE/g dry weight, and TFC expressed as quercetin equivalents (QE) ranged from 56.66±0.80-158.84±2.30 mg QE/g dry weight. Methanol extract showed the highest antioxidant activity followed by ethyl acetate, chloroform, hexane extract and the IC50 values of methanol extract for scavenging DPPH and ABTS free radicals were 280.23±5.75-173.40±0.38µg/ml, respectively. All the extracts have shown potent antimicrobial activity for the zone of inhibition ranged from 9-35 mm; MICs and MBCs values ranged from 0.125-4.0 and 0.25-8.0 mg/ml, respectively towards tested pathogenic species.Conclusion: The comprehensive analysis of the present results demonstrated that Physalis minima possess high potential antioxidant properties which could be used as a viable source of natural antioxidants in treating infections caused by above-mentioned pathogens.

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