scholarly journals Synthesis and Evaluation of Antioxidant Properties of 2-Substituted Quinazolin-4(3H)-ones

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6585
Author(s):  
Janez Mravljak ◽  
Lara Slavec ◽  
Martina Hrast ◽  
Matej Sova
Keyword(s):  
Antioxidant Activity ◽  
Phenyl Ring ◽  
Biological Activities ◽  
Antioxidant Properties ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Ortho Position ◽  
Dpph Assay ◽  
Metal Chelating ◽  
Methoxy Substituent

Quinazolinones represent an important scaffold in medicinal chemistry with diverse biological activities. Here, two series of 2-substituted quinazolin-4(3H)-ones were synthesized and evaluated for their antioxidant properties using three different methods, namely DPPH, ABTS and TEACCUPRAC, to obtain key information about the structure–antioxidant activity relationships of a diverse set of substituents at position 2 of the main quinazolinone scaffold. Regarding the antioxidant activity, ABTS and TEACCUPRAC assays were more sensitive and gave more reliable results than the DPPH assay. To obtain antioxidant activity of 2-phenylquinazolin-4(3H)-one, the presence of at least one hydroxyl group in addition to the methoxy substituent or the second hydroxyl on the phenyl ring in the ortho or para positions is required. An additional ethylene linker between quinazolinone ring and phenolic substituent, present in the second series (compounds 25a and 25b), leads to increased antioxidant activity. Furthermore, in addition to antioxidant activity, the derivatives with two hydroxyl groups in the ortho position on the phenyl ring exhibited metal-chelating properties. Our study represents a successful use of three different antioxidant activity evaluation methods to define 2-(2,3-dihydroxyphenyl)quinazolin-4(3H)-one 21e as a potent antioxidant with promising metal-chelating properties.

scholarly journals Formulation Effects in the Antioxidant Activity of Extract from the Leaves of Cymbopogon citratus (DC) Stapf

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4518
Author(s):  
Raquel Sousa ◽  
Artur Figueirinha ◽  
Maria Teresa Batista ◽  
Maria Eugénia Pina
Keyword(s):  
Antioxidant Activity ◽  
Perennial Grass ◽  
Antioxidant Properties ◽  
Dosage Forms ◽  
Oral Dosage ◽  
Dpph Assay ◽  
Cymbopogon Citratus ◽  
The World ◽  
Food And Beverage ◽  
Oral Dosage Forms

Cymbopogon citratus DC (Stapf.) is a perennial grass and it is distributed around the world. It is used as a condiment for food and beverage flavouring in the form of infusions and decoctions of its dried leaves. Our previous studies have shown antioxidant, anti-inflammatory and gastroprotective activities for the infusion and its phenolic fractions. The aim of the present work was to develop oral dosage forms from a Cymbopogon citratus extract to be used as a functional food with antioxidant properties. Initially, an essential oil-free infusion was prepared, lyophilized and characterized by HPLC-PDA. Total phenols were quantified with the Folin–Ciocalteu method and the antioxidant activity was assessed by DPPH assay. Gelatine capsules containing the extract with different excipients, selected after DSC and IR trials, were prepared. A formulation exhibiting better antioxidant behaviour in a gastric environment was attained. These results suggest that the proposed formulation for this extract could be a valuable antioxidant product and, consequently, make an important contribution to “preventing” and minimizing diseases related to oxidative stress conditions.

scholarly journals Synthesis and Antioxidant Activity of Caffeic Acid Derivatives

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2199 ◽  
Author(s):  
Katarzyna Sidoryk ◽  
Anna Jaromin ◽  
Nina Filipczak ◽  
Piotr Cmoch ◽  
Marcin Cybulski
Keyword(s):  
Organic Chemistry ◽  
Antioxidant Activity ◽  
Caffeic Acid ◽  
Wittig Reaction ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Water Medium ◽  
One Pot ◽  
Safe Alternative ◽  
Caffeic Acid Derivatives

A series of caffeic acid derivatives were synthesized via a modified Wittig reaction which is a very important tool in organic chemistry for the construction of unsaturated carbon–carbon bonds. All reactions were performed in water medium at 90 °C. The aqueous Wittig reaction worked best when one unprotected hydroxyl group was present in the phenyl ring. The olefinations in the aqueous conditions were also conducted with good yields in the presence of two unprotected hydroxyl groups. When the number of the hydroxyl groups was increased to three, the reaction yields were worse, and the derivatives 12, 13, and 18 were obtained with 74%, 37%, and 70% yields, respectively. Nevertheless, the Wittig reaction using water as the essential medium is an elegant one-pot synthesis and a greener method, which can be a safe alternative for implementation in organic chemistry. The obtained compounds were tested for their antioxidant activity, and 12, 13, and 18 showed the highest activities. Moreover, all synthesized compounds displayed no cytotoxicity, and can therefore be used in the pharmaceutical or cosmetic industry.

scholarly journals GC-MS analysis and biological activities of Thymus vulgaris and Mentha arvensis essential oil

2019 ◽  
Vol 44 (3) ◽  
pp. 388-396
Author(s):  
Ashfaq Ahmad Khan ◽  
Muhammad Shoaib Amjad ◽  
Saboon
Keyword(s):  
Antioxidant Activity ◽  
Essential Oil ◽  
Biological Activities ◽  
Colorimetric Method ◽  
Diffusion Method ◽  
Total Phenolic ◽  
Thymus Vulgaris ◽  
Dpph Assay ◽  
Mentha Arvensis ◽  
Ms Analysis

Abstract Background Essential oils are chemical products produced by odoriferous glands from a variety of plants. These essential oil have many health benefits i.e. antiseptic, anti-inflammatory and antimicrobial activities. So due to these medicinal properties present study was designed to analyze essential oil of Thymus vulgaris and Mentha arvensis for their chemical composition and biological activities. Materials and methods Essential oil from these plants were extracted by hydrodistillation method, and analyzed by GC-MS. To test the microbial activity of these oil disk diffusion method and micro wells method were used. For free radical scavenging DPPH assay was used. However total phenolic content was measured by colorimetric method. Results The GC-MS analysis of T. vulgaris oil showed the presence of 47 chemical compounds among which thymol, terpinene, p-cymene and carvacrol were major. However essential oil of M. arvensis showed the presence of 28 constituents, among which the Menthone, Menthol, Isomenthone, Eucalyptol, neo-Menthol, cis-Piperitone oxide, Linalool, Thymol, Limonene, and α-Phellandrene were major. Essential oil from both these plant tested for antimicrobial activity showed that the T. vulgaris oil was effective against seven bacterial strains and the essential oil of M. arvensis was effective against six bacterial strain. The antioxidant activity of both samples by DPPH assay which showed positive result. Conclusion As both species showed the presence of active components, positive microbial activities, and antioxidant activity so, research should be carried on for further biological activities of these oil for betterment of living beings.

Chelating and antioxidant activity of lignans from Chilean woods (Cupressaceae)

Holzforschung ◽  
2009 ◽  
Vol 63 (5) ◽  
Author(s):  
César Donoso-Fierro ◽  
José Becerra ◽  
Evelyn Bustos-Concha ◽  
Mario Silva
Keyword(s):  
Antioxidant Activity ◽  
Fungicidal Activity ◽  
Extracellular Enzymes ◽  
Antioxidant Properties ◽  
Degradation Process ◽  
Saprophytic Fungi ◽  
Metal Chelating ◽  
Methanolic Extracts ◽  
Fitzroya Cupressoides

Abstract Wood species resistant to biodegradation by fungi contain phenolic compounds with proven fungicidal activity. Saprophytic fungi are able to colonize wood and later begin to break down its polymeric components through metal-dependent reactions. These generate free radicals at the onset of the degradation process. Later on, extracellular enzymes are active that use metallic cofactors. Five lignans were isolated from the methanolic extracts of the Chilean heartwoods (Austrocedrus chilensis, Fitzroya cupressoides, and Pilgerodendron uviferum) belonging to the Cupressaceae: isotaxiresinol, secoisolariciresinol, isolariciresinol, didemethylmatairesinol, and matairesinol. Their structures were determined spectroscopically. The antioxidant activity of the methanolic extracts and the isolated compounds was determined in vitro against the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and their iron-chelating capacity was evaluated by the Chrome Azurol S assay. All isolated methanolic extracts and lignans exhibited antioxidant activity against DPPH and Fe-chelating capacity with values greater than 87%. This may be interpreted that the antioxidant properties and metal-chelating capacity of these compounds have a protective effect on the wood of these species when exposed to attacks by saprophytic fungi.

Antioxidant Properties of Carbon Black in Unsaturated Elastomers. Studies with cis-Polybutadiene

1965 ◽  
Vol 38 (3) ◽  
pp. 636-646
Author(s):  
J. T. Gruver ◽  
K. W. Rollmann
Keyword(s):  
Antioxidant Activity ◽  
Carbon Black ◽  
Antioxidant Properties ◽  
Chain Scission ◽  
Oxygen Absorption ◽  
Hydroxyl Groups ◽  
Carbon Blacks ◽  
Crosslinking Reactions ◽  
Absorption Measurements

Abstract The thermal antioxidant behavior of carbon black was studied in vulcanized cis-polybutadiene and related to the surface chemistry of the black. Continuous and intermittent stress relaxation and oxygen absorption measurements were employed to determine the antioxidant ability of the carbon blacks. The blacks were characterized by the surface concentrations of oxygen-containing functional groups, using methods described in the literature. Antioxidant activity was found to be highest in carbons containing relatively large amounts of bound oxygen. These carbons are also acidic and decompose peroxides by the ionic mechanism. This was demonstrated with cumyl peroxide. However, even though the acidity and ability to decompose cumyl peroxide to phenol and acetone could be destroyed by methylation, this treatment did not seriously impair the antioxidant activity, so that the role of acidic groups appears to be minor. Evidence is presented which suggests strongly that the antioxidant behavior of carbon blacks is due to surface quinones, possibly hydrogen-bonded with adjacent hydroxyl groups. Measurements made on samples vulcanized in peroxide and sulfur curing systems indicate that the antioxidant behavior of carbon black is independent of the method of vulcanization in the absence of other antioxidants. A characteristic feature of the antioxidant action of carbon blacks is their tendency to repress the oxidative crosslinking reactions, the relative amount of compensation of chain scission by crosslinking being smaller than in gum vulcanizates.

scholarly journals Phenolic Profile and Antioxidant Activity of Pulp and Peel from Peach and Nectarine Fruits

2016 ◽  
Vol 44 (1) ◽  
pp. 175-182 ◽  
Author(s):  
Branka T. STOJANOVIC ◽  
Snezana S. MITIC ◽  
Gordana S. STOJANOVIC ◽  
Milan N. MITIC ◽  
Danijela A. KOSTIC ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Prunus Persica ◽  
Biological Activities ◽  
Economic Value ◽  
Antioxidant Properties ◽  
Fruit Peel ◽  
Extraction Solvent ◽  
Phenolic Profiles ◽  
Antioxidant Characteristics

Peach (Prunus persica L.) is a fruit of high nutritional and economic value. Carbohydrates, dietary fibers, minerals and organic acids are among the major constituents of peach fruit, which contribute to the nutritional quality of both fresh fruits and juice. Polyphenolic compounds found in peach may play an important role in physiological functions related to human health. Different polyphenolics may have varied biological activities including antioxidant activity. In this study antioxidant characteristics between peel and pulp of different peach cultivars (‘Radmilovčanka’, ‘June Gold’, ‘Blake’, ‘Hale’, ‘Vesna’, ‘Adria’) and one of nectarine (‘Fantasia’) were investigated. The peel and pulp extracts showed a huge amount of total phenolics (TP), total flavonoids (TF), total hydroxycinnamates (TH) and total flavonols (TFL), ranging from 42.7-211.4, 11.1-128.5 mg GAE/100 g fresh weight (f.w.) (TP), 21.9 -94.9, 5.0-58.9 mg CE/100 g f.w. (TF), 28.4-389.2, 8.5-165.8 mg kg-1 f.w. (TH) and 17.3-54 mg kg-1 f.w. (TFL). High contents of phenolic compounds were significantly correlated with high antioxidant capacities. Peach pulp and peel differ significantly in their phenolic profiles: the pulp contains mainly chlorogenic, neochlorogenic and p-coumaric acids, whereas the peel possesses chlorogenic, neochlorogenic and p-coumaric acids together with several flavonol glycosides in huge amounts. Our results indicate that cultivar and extraction solvent play important roles in phenolic compositions and antioxidant properties of peach and nectarine extracts, which was shown using statistical analysis (ANOVA). There are high correlations between extracted phenolic compounds and peach and nectarine cultivars, and used solvent and part of the fruit (peel and pulp).

scholarly journals Synthesis and biological activities of some indoline derivatives

2009 ◽  
Vol 74 (12) ◽  
pp. 1377-1387 ◽  
Author(s):  
Milind Rode ◽  
Sahebrao Rindhe ◽  
Bhausaheb Karale
Keyword(s):  
Antioxidant Activity ◽  
Aromatic Amines ◽  
Benzoyl Chloride ◽  
Stannous Chloride ◽  
Biological Activities ◽  
Gram Negative Bacteria ◽  
Good Activity ◽  
Dpph Assay ◽  
Gram Negative

The reaction of indoline with a substituted benzoyl chloride in the presence of K2CO3 in THF gave compound 4. Compound 4 was subjected to chlorosulphonation to obtain compound 5. Condensation of aromatic amines with compound 5 led to the synthesis of indoline derivatives 6(a-f). Similarly, 5-nitroindoline was treated with a substituted benzoyl chloride to obtain the nitro compound 9, which was reduced using stannous chloride and reacted further with aromatic sulphonyl chloride to obtain the indoline derivatives 11(a-e). These compounds were tested for antibacterial, anti-tuberculosis and antifungal activity. Some of them showed very good activity against some gram-positive and gram negative bacteria, fungal strains and also Mycobacterium tuberculosis. All of the synthesized compounds were subjected to antioxidant activity testing using the in vitro DPPH assay and most of them showed very good activity.

scholarly journals Antioxidant Activity of Plant Extracts from Colombian Coffee-Growing Eco-Region

2017 ◽  
Vol 13 (1) ◽  
pp. 56-59
Author(s):  
Aura M. Blandón ◽  
Oscar M. Mosquera ◽  
Antônio E. G. Sant’ana ◽  
Aldenir F. Dos Santos ◽  
Luana L. S. Pires
Keyword(s):  
Antioxidant Activity ◽  
Plant Species ◽  
Plant Extracts ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Antioxidant Potential ◽  
Dpph Assay ◽  
Methanolic Extracts ◽  
In Vitro Antioxidant Activity

The present study describes the in vitro antioxidant activity of methanol extracts of 34 plant species collected in the Colombian coffee-growing eco-region belonging to Euphorbiaceae, Piperaceae and Solanaceae families. The antioxidant properties of extracts were evaluated by determining radical scavenging power measured with a DPPH assay. The methanolic extracts of  Hyeronimia antioquiensis, Mabea montana, and Alchornea grandis species (Euphorbiaceae), presents EC50 values equal to 0.686, 12.35, and 13.01 µg/mL, respectively, showing high antioxidant potential.

scholarly journals Habitat Affects the Chemical Profile, Allelopathy, and Antioxidant Properties of Essential Oils and Phenolic Enriched Extracts of the Invasive Plant Heliotropium Curassavicum

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 482 ◽  
Author(s):  
Ahmed M. Abd-ElGawad ◽  
Abdelsamed I. Elshamy ◽  
Saud L. Al-Rowaily ◽  
Yasser A. El-Amier
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Essential Oils ◽  
Invasive Plant ◽  
Biological Activities ◽  
Antioxidant Properties ◽  
Bioactive Constituents ◽  
Chenopodium Murale ◽  
Two Samples ◽  
Ic50 Values

The variation in habitat has a direct effect on the plants and as a consequence, changes their content of the bioactive constituents and biological activities. The present study aimed to explore the variation in the essential oils (EOs) and phenolics of Heliotropium curassavicum collected from the coastal and inland habitats. Additionally, we determined their antioxidant and allelopathic activity against the weed, Chenopodium murale. Fifty-six compounds were identified as overall from EOs, from which 25 components were identified from the coastal sample, and 52 from the inland one. Sesquiterpenes were the main class in both samples (81.67% and 79.28%), while mono (3.99% and 7.21%) and diterpenes (2.9% and 1.77%) represented minors, respectively. Hexahydrofarnesyl acetone, (-)-caryophyllene oxide, farnesyl acetone, humulene oxide, farnesyl acetone C, and nerolidol epoxy acetate were identified as major compounds. The HPLC analysis of MeOH extracts of the two samples showed that chlorogenic acid, rutin, and propyl gallate are major compounds in the coastal sample, while vanilin, quercetin, and 4′,7-dihydroxyisoflavone are majors in the inland one. The EOs showed considerable phytotoxicity against C. murale with IC50 value of 2.66, 0.59, and 0.70 mg mL−1 for germination, root, and shoot growth, respectively from the inland sample. While the coastal sample attained the IC50 values of 1.58, 0.45, and 0.66 mg mL−1. MeOH extracts revealed stronger antioxidant activity compared to the EOs. Based on IC50 values, the ascorbic acid revealed 3-fold of the antioxidant compared to the EO of the coastal sample and 4-fold regarding the inland sample. However, the ascorbic acid showed 3-fold of the antioxidant activity of the MeOH extracts of coastal and inland samples. Although H. curassavicum is considered as a noxious, invasive plant, the present study revealed that EO and MeOH extracts of the H. curassavicum could be considered as promising, eco-friendly, natural resources for antioxidants as well as weed control, particularly against the weed, C. murale.

Antioxidant properties of ethenyl indole: DPPH assay and TDDFT studies

2020 ◽  
Vol 44 (21) ◽  
pp. 8960-8970 ◽  
Author(s):  
Jagdeep Kumar ◽  
Naresh Kumar ◽  
Nitin Sati ◽  
Prasanta Kumar Hota
Keyword(s):  
Antioxidant Activity ◽  
Vitamin E ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Dependent Manner ◽  
Dpph Assay ◽  
Strong Electron ◽  
Electron Withdrawing Substituents

Ethenyl indole exhibits antioxidant activity in a substituent dependent manner. Ethenyls bearing strong electron withdrawing substituents show weak or no antioxidant activities, whereas ethenyls with electron donating substituents exhibit antioxidant properties comparable to vitamin E.

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