Bio-Fe3O4-MNPs catalyzed green synthesis of pyrrolo[2,1-a]isoquinoline derivatives using isoquinolium bromide salts: study of antioxidant activity

2019 ◽  
Vol 97 (12) ◽  
pp. 848-855
Author(s):  
Maryam Abbasi ◽  
Fariba Zamani Hargalani ◽  
Siavash Afrashteh ◽  
Rezvaneh Rostamian

In this research, a novel, one-pot, efficient procedure with high yield for the synthesis of pyrrolo[2,1-a]isoquinoline derivatives using multi-component reaction of isoquinoline, alkyl bromides, and triphenylphosphine in the presence of Fe3O4-MNPs as catalyst under solvent-free conditions at room temperature is investigated. This study highlights an easy, simple, rapid, and clean method for the preparation of pyrrolo[2,1-a]isoquinoline derivatives. The Fe3O4-MNPs in these reactions were produced employing a green procedure by reduction of ferric chloride solution with pomegranate peel water extract. Additionally, antioxidant activity was studied for the some newly synthesized compounds such as 5a–5d using the DPPH radical trapping and reducing potential of ferric ion experiments and comparing the results with the results of synthetic antioxidants (2-tert-butylhydroquinone, TBHQ; butylated hydroxytoluene, BHT). As a result, compounds 5a–5d show trace DPPH radical trapping and excellent reducing power of ferric ion.

2020 ◽  
Vol 22 (10) ◽  
pp. 728-739
Author(s):  
Naghmeh F. Hamedani ◽  
Maryam Ghazvini ◽  
Fatemeh Sheikholeslami-Farahani ◽  
Mohammad T.B. Jamnani

Objective: KF/Clinoptilolite nanoparticles are employed as as a heterogeneous catalyst for the preparation of pyrido[2,1-a]isoquinoline derivatives through a four-component reaction of isoquinoline, two different alkyl bromides and an electron deficient internal alkynes at ambient temperature in water as green solvent. Methods: In this research, (2,2-Diphenyl-1-picrylhydrazyl) radical trapping and reducing potential of ferric ion experiments was used for determining antioxidant activity of some newly synthesized compounds such as 5a, 5c, 5f and 5g and comparing results with synthetic antioxidants (TBHQ and BHT). Results: Compounds 5a, 5c, 5f and 5g display trace DPPH radical trapping and excellent reducing power of ferric ion. Furthermore, the power of some prepared compounds against Gram-positive and Gram-negative bacteria was proved by employing the disk dispersion experiment. Conclusion: The obtained results of disk diffusion test showed that compounds 5a, 5d and 5e prevented the bacterial growth. The reported procedure shows the advantages of clean reaction, high yield and simple purification.


2019 ◽  
Vol 97 (4) ◽  
pp. 270-276 ◽  
Author(s):  
Elham Ezzatzadeh ◽  
Zinatossadat Hossaini ◽  
Ali Varasteh Moradi ◽  
Masoomeh Salimifard ◽  
Saeid Afshari-Sharif Abad

Zinc oxide (ZnO) nanoparticles, as a simple and recyclable catalyst, were easily synthesized and used for the synthesis of 1,3-cyclopentadiene derivatives by a four-component reaction of terminal alkynes, sulfonyl azides, activated acetylenic compounds, and isocyanides in the presence of copper iodide in acetonitrile at room temperature. In these reactions, 1,3-cyclopentadiene derivatives were obtained in good yield and in a short reaction time. In this research, antioxidant activity was investigated for the some newly synthesized compounds such as 5a–5d using the DPPH radical trapping and reducing potential tests of ferric ion and comparing results with synthetic antioxidants (TBHQ and BHT). In this study, compounds 5a–5d show good DPPH radical trapping and excellent reducing power of ferric ion.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Nur Sumirah Mohd Dom ◽  
Nurshieren Yahaya ◽  
Zainah Adam ◽  
Nik Mohd Afizan Nik Abd. Rahman ◽  
Muhajir Hamid

The present study aimed to evaluate the potential of standardized methanolic extracts from seven Ficus deltoidea varieties in inhibiting the formation of AGEs, protein oxidation, and their antioxidant effects. The antiglycation activity was analyzed based on the inhibition of AGEs, fructosamine, and thiol groups level followed by the inhibition of protein carbonyl formation. The antioxidant activity (DPPH radical scavenging activity and reducing power assay) and total phenolic contents were evaluated. After 28 days of induction, all varieties of Ficus deltoidea extracts significantly restrained the formation of fluorescence AGEs by 4.55–5.14 fold. The extracts also reduced the fructosamine levels by 47.0–86.5%, increased the thiol group levels by 64.3–83.7%, and inhibited the formation of protein carbonyl by 1.36–1.76 fold. DPPH radical scavenging activity showed an IC50 value of 66.81–288.04 μg/ml and reducing power activity depicted at 0.02–0.24 μg/ml. The extent of phenolic compounds present in the extracts ranged from 70.90 to 299.78 mg·GAE/g. Apart from that, correlation studies between the activities were observed. This study revealed that seven varieties of Ficus deltoidea have the potential to inhibit AGEs formation and possess antioxidant activity that might be attributed to the presence of phenolic compounds.


2011 ◽  
pp. 279-288 ◽  
Author(s):  
Anita Klaus ◽  
Maja Kozarski ◽  
Miomir Niksic

Ganoderma lucidum (Leyss.:Fr.) Karst is one of the medicinal mushrooms, which possesses enviable antioxidant properties. Objective of this investigation was to evaluate antioxidant activity, reducing power, scavenging abilities on 1.1-diphenyl-2-picrylhydrazyl (DPPH) radicals and chelating effects on ferrous ions of hot water extracts obtained from carpophore and spores of this mushroom. Hot water extract from carpophore (Gl-I) showed high antioxidant activity of 85.7 ? 0.7%, at 10 mg/ml, while antioxidant activity of hot water extract from spores (Gl-Is) was 9.2 ? 0.3% at 10 mg/ml. Reducing power of Gl-I reached a plateau of 3.4 ? 0.1 at 20 mg/ml, and 0.3 ? 0.0 at 20 mg/ml for Gl-Is. At 10 mg/ml, scavenging ability on DPPH radicals of Gl-I increased to 96.8 ? 2.5%, whereas Gl-Is scavenged DPPH radicals by 69.6 ? 2.5% at 10 mg/ml. Gl-I chelated 81.6 ? 3.6 % of ferrous ions at 20 mg/ml, while the chelating effect of Gl-Is was 73.8 ? 1.7%. The antioxidative activities of hot water extracts from carpophore and spores of the mushroom G. lucidum were concentration dependent and increased with an increase in the concentration.


2019 ◽  
Vol 70 (7) ◽  
pp. 2684-2689
Author(s):  
Emin Cadar ◽  
Rodica Sirbu ◽  
Alef Ibram ◽  
Ana Maria Ionescu

Seaweeds are widely used in the life science as source of compounds with diverse structural forms and biological activities, therefore, potential source of new antioxidant activity. The algae of the Black Sea have not been adequately explored for their potential as a source of bioactive substances. In this context, Brown algae Cystoseira barbata isolated from Black Sea coastal waters of Romania, were evaluated for their bioactivity potential. The results from Cystoseira barbata were obtained: for total phenolic content obtained in ethanolic extracts (TPC): 385.6 � 1.85 mg GAE/100 g f.w. Phenolic Acids quantified by HPLC-DAD from hydroethanolic extract of Cystoseira barbata from Black Sea was 80.14% from total phenolic content identified. We showed that Cystoseira barbata from the Romanian shore of the Black Sea contains vanillic acid in highest quantity (99.5�0.08 mg/100 g f.w.), followed by benzoic acid (65.7�0.06 mg/100 g f.w.) and feluric acid (54.5�0.01 mg/100 g f.w.). The smallest quantities were for gallic acid (3.5�0.03 mg/100 g f.w.), pyrogallol acid (4.2�0.05 mg/100 g f.w.) and 4-amino-benzoic acid (5.2�0.09 mg/100 g f.w.). Cystoseira barbata has a total content of large phenols and also has strong antioxidant and antimicrobial activity. Antioxidant activity (ACL) was studied using DPPH radical scavenging activity and reducing power. The extracts containing high levels of total phenolic content were also potent DPPH radical scavengers. The IC50 (�g/mL) for Cystoseira barbata in methanolic extract was 942.92� 2.56 �g/mL. High absorbance obtained from reducing power assay indicates high reducing power, measured values of absorbance varied from 0.0901 at 0.9223.


Author(s):  
ABDELFATTAH EL MOUSSAOUI ◽  
FATIMA ZAHRA JAWHARI ◽  
DALILA BOUSTA ◽  
AMINA BARI

Objective: In this study, we were interested in qualitative, quantitative phytochemical characterization and evaluation of the antioxidant capacity of the total extracts of a plant from northern Morocco, the species selected for this study is Withania frutescens. Materials and Methods: Analysis of mineral elements by inductive coupling plasma-atomic absorption spectroscopy (ICP-AES), phytochemical screening, polyphenol and tannin assays, evaluation of antioxidant activity by the 1,2-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging method and reducing power. Results: The plant contains alkaloids, saponins, tannins, mucilages, and coumarins. It has a relatively high content of total polyphenols and tannins of 19.53±0.018 μg genetic generalized epilepsy/mg MS and 6.258±0.062 μg Eqcat/mg MS, respectively. The analysis of mineral elements by ICP-AES shows that our species is rich in mineral elements which are calcium, magnesium, and sodium, and it is devoid of metallic elements such as nickel, lead, cadmium, and cobalt. The evaluation of antioxidant activity by the DPPH free radical scavenging method shows that the half maximal inhibitory concentration of the tested extracts has an antiradical activity of about 0.056±0.008 μg/ml for the ethanol extract and 0.213±0.004 μg/ml for the methanol extract compared to the butylated hydroxytoluene value of 0.009±0.0004 μg/ml which was used as a reference. The reducing capacity test shows that methanolic extract has a high antioxidant capacity (0.213±0.006) compared to ethanolic extract (0.043±0.004) but remains low compared to ascorbic acid (0.003±0.0004) which was used as reference. Conclusion: Phytochemical analysis of W. frutescens shows that this plant is rich in high quantities of alkaloids, saponins, mucilage, tannins, and coumarins. It contains an average amount of total polyphenols and tannins that confer significant antioxidant activity to the plant studied.


2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Liling Triyasmono ◽  
Beny Rahmanto ◽  
Wawan Halwany ◽  
Fajar Lestari ◽  
Muhammad Ikhwan Rizki ◽  
...  

ABSTRAK Daya reduksi merupakan salah satu indikator potensi aktivitas suatu senyawa sebagai antioksidan. Penelitian ini bertujuan untuk menentukan daya reduksi ekstrak etanol biji Aquilaria microcarpa, Aquilaria malaccensis, dan Aquilaria beccariana terhadap Ion Ferri (Fe3+). Serbuk kering biji A. microcarpa, A. malaccensis, dan A. beccariana dimaserasi menggunakan etanol 70%. Daya reduksi ditentukan dengan metode FRAP (ferric reducing antioxidant power) yang didasarkan atas kemampuan senyawa dalam mereduksi senyawa besi(III)-tripiridil-triazin menjadi besi(II)-tripiridil triazin pada pH 3,6. Absorbansi diukur menggunakan spektrofotometer UV-Vis pada panjang gelombang 598 nm. Hasil penelitian menunjukkan ekstrak etanol biji A. microcarpa, A. malaccensis, dan A. beccariana mempunyai daya reduksi berturut-turut sebesar 6,39±1,58; 119,95±28,04; dan 62,12±6,57 µM ekivalen troloks/g ekstrak. Kata kunci: biji, Aquilaria microcarpa, Aquilaria malaccensis, Aquilaria beccariana, FRAP ABSTRACT Reducing power is one indicator of potential antioxidant activity of a compound. This study aims to determine the reduction power of the ethanol extract of the seeds of Aquilaria microcarpa, Aquilaria malaccensis, and Aquilaria beccariana against Ferric ion (Fe3+). Dry powder of A. microcarpa, A. malaccensis, and A. beccariana seeds was macerated using 70% ethanol. Reducing power determined using FRAP (ferric reducing antioxidant power) that is based on the ability of the compounds in reducing iron compounds (III) -tripiridil-triazine to iron (II) -tripiridil triazine at pH 3.6. The absorbance was measured using a UV-Vis spectrophotometer at a wavelength of 598 nm. The results showed ethanol extract of seeds of A. microcarpa, A. malaccensis, and A. beccariana have reducing power of 6.39 ± 1.58; 119.95 ± 28.04; and 62.12 ± 6.57 µM troloks equivalents / g extract respectively. Key words: seeds, Aquilaria microcarpa, Aquilaria malaccensis, Aquilaria beccariana, FRAP


2018 ◽  
Vol 15 (3) ◽  
pp. 699-709
Author(s):  
Vinothkanna Annadurai ◽  
Sekar Soundarapandian

Ayurveda contains a variety of medicines including the polyherbal fermented traditional medicines namely Arishta and Asava. It remains as a rich source of bioactive phytochemicals including antioxidants. There are scanty publications on the antioxidant activity of these medicines. There is a need to explore the natural antioxidants to replace synthetic counterparts which requires an assessment in terms of antioxidant activity by in vitro analysis. This study employs a range of antioxidant assay systems containing various free radicals (DPPH, hydroxyl, hydrogen peroxide, super oxide, nitric oxide and ABTS), Inhibition of free radical generation (metal chelating) and H+ – donating ability (reducing power) were performed. Ashokarishta, Aswagandharishta and Dasamoolarishta exhibited higher degree of antioxidant activities but less than the corresponding standards. Based on IC50 values, the hydrogen peroxide scavenging ability of Ashokarishta is comparable to the standard L-ascorbic acid. In ABTS assay, Aswagandharishta and Dasamoolarishta are comparable to the standard Butylated hydroxytoluene (BHT). These may be due to the phytochemical heterogeneity of the samples assayed. Thus study can lead to the sourcing of Ayuvedic polyherbal fermented medicines as a novel source of natural antioxidant molecules that might be acting as free radical quencher or scavenger and to treat human ailments.


Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 971 ◽  
Author(s):  
Ingrida Tumosienė ◽  
Kristina Kantminienė ◽  
Ilona Jonuškienė ◽  
Artūras Peleckis ◽  
Sergey Belyakov ◽  
...  

A series of novel 1-(5-chloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic acid derivatives containing chloro, hydroxyl, isopropyl, nitro, nitroso, and amino substituents at benzene ring and 1-(5-chloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carbohydrazide derivatives bearing heterocyclic moieties were synthesized. Antioxidant activity of the synthesized compounds was screened by DPPH radical scavenging method and reducing power assay. A number of compounds were identified as potent antioxidants. Antioxidant activity of 1-(5-chloro-2-hydroxyphenyl)-4-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)pyrrolidin-2-one has been tested to be 1.5 times higher than that of a well-known antioxidant ascorbic acid. 1-(5-Chloro-2-hydroxyphenyl)-4-(4-methyl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)pyrrolidin-2-one has shown 1.35 times higher antioxidant activity than that of vitamin C by DPPH radical scavenging method and optical density value of 1.149 in reducing power assay. The structure of 1-(5-chloro-2-hydroxyphenyl)-N-(1,3-dioxoisoindolin-2-yl)-5-oxopyrrolidine-3-carboxamide was unambiguously assigned by means of X-ray diffraction analysis data.


2020 ◽  
Vol 23 (5) ◽  
pp. 446-454
Author(s):  
Faezeh Shafaei ◽  
Asef H. Najar

Aims & Objective: In this work, pyran derivatives were synthesized via a multicomponent reaction of ninhydrin, α-haloketones, dialkyl acetylenedicarboxylate, and triphenylphosphine in the presence of iron oxide magnetic nanoparticles (Fe3O4-MNPs) as efficient nanocatalyst in ethanol at room temperature. Materials & Methods: The biosynthesis of Fe3O4-MNPs was performed by Clover Leaf water extract. In addition, antioxidant activity was examined for the prepared compounds employing DPPH radical scavenging and ferric reduction activity potential (FRAP) experiment and comparing results with synthetic antioxidants (TBHQ and BHT). Results: Compound 5b showed excellent radical trapping activity and good reducing activity relative to standards (BHT and TBHQ). Conclusion: Some advantages of this procedure are: the workup of reaction is easy and the products can be separated easily by filtration. Fe3O4-MNPs display a good improvement in the yield of the product and showed significant reusable activity.


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