scholarly journals Antioxidant Activities of Alkyl Substituted Pyrazine Derivatives of Chalcones—In Vitro and In Silico Study

Antioxidants ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 90 ◽  
Author(s):  
Višnja Stepanić ◽  
Mario Matijašić ◽  
Tea Horvat ◽  
Donatella Verbanac ◽  
Marta Kučerová-Chlupáčová ◽  
...  
Keyword(s):  
In Silico ◽  
Density Functional ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Redox Status ◽  
Trypan Blue Exclusion ◽  
Cellular Effects ◽  
Dft Modeling

Chalcones are polyphenolic secondary metabolites of plants, many of which have antioxidant activity. Herein, a set of 26 synthetic chalcone derivatives with alkyl substituted pyrazine heterocycle A and four types of the monophenolic ring B, were evaluated for the potential radical scavenging and antioxidant cellular capacity influencing the growth of cells exposed to H2O2. Before that, compounds were screened for cytotoxicity on THP-1 and HepG2 cell lines. Most of them were not cytotoxic in an overnight MTS assay. However, three of them, 4a, 4c and 4e showed 1,1-diphenyl-2-picrylhydrazyl (DPPH●) radical scavenging activity, through single electron transfer followed by a proton transfer (SET-PT) mechanism as revealed by density functional theory (DFT) modeling. DFT modeling of radical scavenging mechanisms was done at the SMD//(U)M052X/6-311++G** level. The in vitro effects of 4a, 4c and 4e on the growth of THP-1 cells during four days pre- or post-treatment with H2O2 were examined daily with the trypan blue exclusion assay. Their various cellular effects reflect differences in their radical scavenging capacity and molecular lipophilicity (clogP) and depend upon the cellular redox status. The applied simple in vitro-in silico screening cascade enables fast identification and initial characterization of potent radical scavengers.

α-Glucosidase Inhibition, Antioxidant and Docking Studies of Hydroxycoumarins and their Mono and Bis O-alkylated/acetylated Analogs

2018 ◽  
Vol 15 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Parvesh Singh ◽  
Nomandla Ngcoya ◽  
Ramgopal Mopuri ◽  
Nagaraju Kerru ◽  
Neha Manhas ◽  
...  
Keyword(s):  
In Silico ◽  
Biological Activities ◽  
Wide Spectrum ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Catalytic Site ◽  
Docking Simulations ◽  
In Silico Docking ◽  
Anti Oxidant

Background: Diabetes Mellitus (DM) is a complex metabolic disease illustrated by abnormally high levels of plasma glucose or hyperglycaemia. Accordingly, several α-glucosidase inhibitors have been developed for the treatment of diabetes and other degenerative disorders. While, a coumarin ring has the privilege to represent numerous natural and synthetic compounds with a wide spectrum of biological activities e.g. anti-cancer, anti-HIV, anti-viral, anti-malarial, anti-microbial, anti-convulsant, anti-hypertensive properties. Besides this, coumarins have also shown potential to inhibit α-glucosidase leading to a generation of new promising antidiabetic agents. However, the testing of O-substituted coumarins for α-glucosidase inhibition has evaded the attention of medicinal chemists. Methods: For O-alkylation/acetylation reactions, the hydroxyl coumarins (A-B) initially activated by K2CO3 in dry DMF were reacted with variedly substituted haloalkanes at room temperature under nitrogen. The synthesized compounds were tested for their α-glucosidase (from Saccharomyces cerevisiae) inhibitory activity and anti-oxidant activity using DPPH radical scavenging activity. In silico docking simulations were conducted using CDocker module in DS (Accelrys) to explore the binding modes of the representative compounds in the catalytic site of α-glucosidase. Results: All the coumarin analogues (A1, B1, A2-A10, B2-B8) including their precursors (A-B) were evaluated for their in vitro α-glucosidase inhibition using acarbose as a standard inhibitor. All the mono O-alkylated coumarins (except A1) showed significant (p <0.05) α-glucosidase inhibition relative to the hydroxyl coumarin (A) with IC50 values ranging between 11.084±0.117 to 145.24± 29.22 µg/mL. Compound 7-(benzyloxy)-4, 5-dimethyl-2H-chromen-2-one (A9) bearing a benzyl group (Ph-CH2-) at position 7 showed a remarkable (p <0.05) increase in the activity (IC50 = 11.084±0.117 µg/mL), almost four-fold more than acarbose (IC50 = 40.578±5.999 µg/mL). The introduction of –NO2 group dramatically improved the anti-oxidant activity of coumarin, while the O-alkylation/acetylation decreased the activity. Conclusion: The present study describes the synthesis of functionalized coumarins and their evaluation for α-glucosidase inhibition and antioxidant activity under in vitro conditions. Based on IC50 data, the mono O-alkylated coumarins were observed to be stronger inhibitors of α-glucosidase with respect to their bis O-alkylated analogues. Coumarin (A9) bearing O-benzyloxy group displayed the strongest α-glucosidase inhibition, even higher than the standard inhibitor acarbose. The coumarin (A10) bearing –NO2 group showed the highest anti-oxidant activity amongst the synthesized compounds, almost comparable to the ascorbic acid. Finally, in silico docking simulations revealed the role of hydrogen bonding and hydrophobic forces in locking the compounds in catalytic site of α-glucosidase.

scholarly journals Radical-Scavenging and UV-Radiation Absorption Activities of Aaptamine Derivatives: DFT and TD-DFT Studies

2021 ◽  
Author(s):  
Thi Hoai Nam Doan ◽  
Thi Le Anh Nguyen ◽  
Nguyen Thi Ai Nhung ◽  
Duong Tuan Quang ◽  
Duy Quang Dao
Keyword(s):  
Density Functional ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Radiation Absorption ◽  
Functional Theory ◽  
Radical Adduct ◽  
Td Dft ◽  
Potential Applications

Antioxidant and UV absorption activities of three aaptamine derivatives including piperidine[3,2-b]demethyl(oxy)aaptamine (C1), 9-amino-2-ethoxy-8-methoxy-3H-benzo[de][1,6]naphthyridine-3-one (C2), and 2-(sec-butyl)-7,8-dimethoxybenzo[de]imidazo[4,5,1-ij][1,6]-naphthyridin-10(9H)-one (C3) were theoretically studied by density functional theory (DFT). Optimized geometries of C1C3 and theirs intrinsic thermochemical properties such as bond dissociation energy, proton affinity, and ionization potential were calculated at DFT/M05-2X/6-311++G(d,p) level of theory in vacuo and in water. The results show that C1C3 exhibited similar potent antioxidant activities, which are comparable to well-known antioxidants such as Trolox or cembrene. The radical scavenging activity of the antioxidants were then investigated by evaluation the Gibbs free energy (ΔrG0) of the reaction between C1C3 and the HOO●/HO● radicals via four mechanisms, including: hydrogen atom transfer (HAT), single electron transfer (SET), proton loss (PL) and radical adduct formation (RAF). Kinetic calculation reveals that HOO● scavenging in water is occurred via HAT mechanism with C1@C19 while RAF is more dominant with C2 and C3. Antioxidant activity of aaptamine derivatives can be classified as C1 > C3 > C2. In addition, all compounds are active in UV-Vis absorption; the excitations of which are determined as π-π* transition. Overall, the results suggest the potential applications of the aaptamines in pharmaceutics and cosmetics, i.e. as sunscreen and antioxidant ingredient<br>

In vitro antioxidant activity and phytochemical analyses of Acalypha godseffiana (Euphobiaceae) leaf extracts

2021 ◽  
Vol 25 (1) ◽  
pp. 75-79
Author(s):  
S.O. Olubodun ◽  
G.E. Eriyamremu ◽  
M.E. Ayevbuomwan ◽  
C.I. Nzoputa
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Antioxidant Vitamin ◽  
Phytochemical Analysis ◽  
Leaf Extracts ◽  
Anti Oxidant ◽  
In Vitro Antioxidant Activity

The presence of various bioactive components makes it necessary to analyse plants for their potential to act as a source of useful treatments and cures for many inflammatory, infectious and pathogenic diseases. This study was carried out to determine phytochemicals and in-vitro antioxidant activities of the leaf extracts of Acalypha godseffiana. The leaves of A. godseffiana were collected, dried, pulverized and extracted separately with methanol and water using maceration method. The extract was concentrated in vacuo with rotary evaporator at 40oC. The extracts were subjected to quantitative phytochemical analysis and different anti-oxidant analytical procedures like FRAP, DPPH etc to determine the radical scavenging capabilities. The results of phytochemical analysis estimated the quantities and revealed the presence of alkaloids, flavonoids, tannins, saponins and terpenoids which varied in both extracts. The methanol and aqueous extracts exhibited antioxidant activities with relatively high IC50 (IC50 = 3.67 ìg/ml and 4.42ìg/ml respectively) which accounted for a low free radical-scavenging activity when compared with the reference antioxidant, vitamin C (IC50 = 1.51ìg/ml). The results of the study indicates that A. godseffiana leaf extracts contain secondary metabolites and possesses antioxidant properties.

Investigation of the Anti-cataract and Antioxidant Activities of Cnidoscolus aconitifolius Leaves Extract In vitro

2021 ◽  
pp. 28-38
Author(s):  
Henry Bulama ◽  
Daniel Dahiru ◽  
Joshua Madu
Keyword(s):  
Total Protein ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Control Group ◽  
Scavenging Activity ◽  
Aqueous Fraction ◽  
Cnidoscolus Aconitifolius

Background: Cataract is a major cause of visual impairment and blindness around the world. This study evaluated the in vitro antioxidant and anti-cataract activities of Cnidoscolus aconitifolius leaves extract and fractions. Antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiozoline-6-sulfonic acid) (ABTS), total reducing power, and hydrogen peroxide scavenging assays. Anti-cataract potential was evaluated in vitro using goat lenses divided into eight groups of different treatments and incubated in artificial aqueous humor at 37 °C for 72 hours. Glucose-induced opacity in the lenses was observed and biochemical indices quantified (catalase, Malondialdehyde (MDA) and total protein in the lens homogenate). Results: The crude extract and its fractions possess substantial antioxidant activities. The aqueous fraction exhibited the best DPPH radical scavenging activity (IC50 value 78.599 µg/ml); while the dichloromethane fraction exhibited the highest ABTS radical scavenging activity with IC50 66.68 µg/ml. The anti-cataract evaluation of crude and fractions at 250 μg/ml showed a significant increase (p<0.05) in the total protein and catalase activity compared to the cataract control group. The malonaldehyde level decreased significantly (p<0.05) in all the treated groups.

scholarly journals Antioxidant and Anti-Inflammatory Activities of Six Flavonoids from Smilax glabra Roxb

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5295
Author(s):  
Xinyu Zhao ◽  
Ruyi Chen ◽  
Yueyue Shi ◽  
Xiaoxi Zhang ◽  
Chongmei Tian ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Raw264.7 Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Preparative Hplc ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power ◽  
Anti Inflammatory

This study aimed to isolate, prepare and identify the main flavonoids from a standardized Smilax glabra flavonoids extract (SGF) using preparative HPLC, MS, 1H NMR and 13C NMR, determine the contents of these flavonoids using UPLC, then compare their pharmacological activities in vitro. We obtained six flavonoids from SGF: astilbin (18.10%), neoastilbin (11.04%), isoastilbin (5.03%), neoisoastilbin (4.09%), engeletin (2.58%) and (−)-epicatechin (1.77%). The antioxidant activity of six flavonoids were evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2′-Azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS+) radical scavenging activity and ferric reducing antioxidant power (FRAP). In addition, the anti-inflammatory activity of six flavonoids were evaluated by determining the production of cytokines (IL-1β, IL-6), nitric oxide (NO) using enzyme linked immunosorbent assay and the NF-κB p65 expression using Western blotting in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The results showed that (−)-epicatechin, astilbin, neoastilbin, isoastilbin and neoisoastilbin had strong antioxidant activities, not only in DPPH and ABTS+ radicals scavenging capacities, but in FRAP system. Furthermore, all the six flavonoids could significantly inhibit the secretion of IL-1β, IL-6, NO (p < 0.01) and the protein expression of NF-κB p-p65 (p < 0.01) in LPS-stimulated RAW264.7 cells. This study preliminarily verified the antioxidant and anti-inflammatory activities of six flavonoids in S. glabra.

scholarly journals Behaviour of 9-Ethyl-9H-carbazole Hydrazone Derivatives Against Oxidant Systems

2019 ◽  
Vol 92 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Cigdem Karaaslan ◽  
Hande Gurer-Orhan ◽  
Sibel Suzen ◽  
Luciano Saso ◽  
Omidreza Firuzi ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Amyloid Β ◽  
In Vitro Assays ◽  
Cytotoxic Activities ◽  
Scavenging Activity ◽  
Neuroprotective Effects ◽  
Neuronal Pc12 Cells

Antioxidants are helpful in prevention of several diseases related with oxidative stress including neurodegenerative disorders. In recent studies, carbazoles were given proof of promising antioxidant activities. In this article, 9-ethyl-9H-carbazole hydrazone derivatives were synthesized, characterized and their in vitro antioxidant activity and possible cytotoxic effects were investigated. Furthermore, protective effect of the synthesized derivatives against amyloid β-induced damage in PC12 neuronal cells was examined by using MTT assay. The newly synthesized carbazoles were found to have radical scavenging activity with a varying potency both in cell-free and cell-based in vitro assays. Several compounds, especially such as 3d and 3e, 3m and 3n bearing two halogen groups on the phenyl ring, were found to have cytotoxic activity. However, their cytotoxic activities were not higher than that of melatonin. Several compounds also significantly protected neuronal PC12 cells against amyloid β-induced damage, which can be defined as neuroprotective agents. (4-(2-((9-Ethyl-9H-carbazol-3-yl)methylene)hydrazinyl)benzonitrile) 3r was found as the most active compound with both radical scavenging activity and neuroprotective effects against amyloid β-induced damage. These findings might provide an alternative strategy for developing novel carbazole derivatives for management of neurodegenerative diseases, such as Alzheimer's disease.

scholarly journals A Review of Recent Studies on the Antioxidant Activities of a Third-Millennium Food: Amaranthus spp.

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1236
Author(s):  
Seon-Joo Park ◽  
Anshul Sharma ◽  
Hae-Jeung Lee
Keyword(s):  
Antioxidant Activity ◽  
Bioactive Peptides ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Sustainable Food ◽  
Amaranth Species ◽  
Amaranthus Spp

Amaranth (Amaranthus spp.) plant commonly refers to the sustainable food crop for the 21st century. The crop has witnessed significant attention in recent years due to its high nutritional value and agronomic advantages. It is a relatively well-balanced cosmopolitan food that is a protector against chronic diseases. Usually, the antioxidant activities of amaranth are held responsible for its defensive behavior. Antioxidant activity of plants, generally, is attributed to their phytochemical compounds. The current interest, however, lies in hydrolysates and bioactive peptides because of their numerous biological functions, including antioxidant effect. While the importance of bioactive peptides has been progressively recognized, an integrated review of recent studies on the antioxidant ability of amaranth species, especially their hydrolysates and peptides has not been generated. Hence, in this review, we summarize studies focused on the antioxidant capacity of amaranth renewal over the period 2015–2020. It starts with a background and overall image of the amaranth-related published reviews. The current research focusing on in vitro, in vivo, and chemical assays-based antioxidant activity of different amaranth species are addressed. Finally, the last segment includes the latest studies concerning free radical scavenging activity and metal chelation capacity of amaranth protein hydrolysates and bioactive peptides.

In Vitro Antioxidant Activities of Polysaccharides from Auricularia auriada

2011 ◽  
Vol 183-185 ◽  
pp. 104-109
Author(s):  
Ning Zhang ◽  
Zhen Yu Wang ◽  
Hua Zhang ◽  
Jian Ren ◽  
Xiu Mei Hao
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Water Soluble ◽  
Peroxide Radical ◽  
Scavenging Effect ◽  
Radical Scavenging Effect ◽  
Chelating Ability

This study aims to evaluate the antioxidative activities of water and alkaline solution pH=8, 50% ethanolic (APP1 or SAPP1), 75% ethanolic (APP2 or SAPP2) and 100% ethanolic (APP3 or SAPP3) extracts of A. auricular. The antioxidant activities, including the ABTS, superoxide anion radical-scavenging effect, hydrogen peroxide radical-scavenging effect and chelating ability on ferrous ions were studied in vitro. A comparison of the 50% effective concentration (EC50) values of different antioxidative reactions revealed that SAPP3 was more effective in scavenging ABTS, hydrogen peroxide and chelating ability on ferrous ions.SAPP2 showed a higher superoxide radical-scavenging activity. The alkali-soluble polysaccharides extracts showed higher radical-scavenging effect than water-soluble polysaccharides.

scholarly journals In vitro antioxidant activity of the methanolic extract of leaves of a hill tract plant Begonia roxburghii

2021 ◽  
Vol 9 (1-2) ◽  
pp. 79-89
Author(s):  
Taslima Akter ◽  
Afra Nawar ◽  
Md Nur Alam ◽  
Md Rafiquzzaman
Keyword(s):  
Ascorbic Acid ◽  
Methanolic Extract ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Assay Method ◽  
Scavenging Activity ◽  
Negative Results

The study was designed to investigate the antioxidant activities of the methanolic extract of leaves of Begonia roxburghii by five different in vitro methods namely Folin-Ciocalteu, total flavonoid content, phosphomolybdenum, total reducing power determination, and DPPH scavenging activity. Phenol content (Gallic acid equivalent) was found as 180.40±0.03 mg/g of the dry sample by the Folin-Ciocalteu method. Flavonoid assay method revealed the content of flavonoids (Quercetin equivalent) as 60.43±0.27 mg/g of the dry sample. Total antioxidant capacity of the extract was observed 243.43±0.11 mg/g ( ascorbic acid equivalent) by phosphomolybdenum method. Free radical scavenging activity (measured by the DPPH test) of the methanolic extract was found 158.36±0.22 μg/mL whereas ascorbic acid, the standard, showed 19.53±0.04 μg/mL. The methanolic extract of Begonia roxburghii leaves exhibited positive and linear dose dependent reducing power activity and its activity was comparable to the standard ascorbic acid for a given dose. Phytochemical screening of the extract showed positive results for alkaloids, carbohydrates, flavonoids, glycosides, saponins, steroids, and tannins, which demonstrate definite pharmacological actions on human body. The extract showed negative results for the steroids. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 79-89, 2020 (June & December)

scholarly journals Antioxidant Activities of the Leaf Extract and Fractions of Dryopteris filix-mas (L.) Schott could be Attributed to The Abundance of Polyphenol Compounds

2020 ◽  
Vol 9 (1) ◽  
pp. 1-6
Author(s):  
Earnest Oghenesuvwe Erhirhie ◽  
Emmanuel Emeka Ilodigwe ◽  
Daniel Lotanna Ajaghaku ◽  
Blessing Ogechukwu Umeokoli ◽  
Peter Maduabuchi Eze ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Leaf Extract ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Bioactive Compound ◽  
Ethyl Acetate Fraction ◽  
In Vitro Assays ◽  
Anti Oxidant

Dryopteris filix mas (D filix-mas) is wildly used in ethnomedicine for the management of rheumatoid arthritis, wounds and other diseases. We investigated the anti-oxidant activities of its leaf extract, and chromatographic fractions. The ethanol leaf extract was partitioned into four fractions; n-hexane, ethyl acetate, n-butanol and water. Ferric reducing anti-oxidant power (FRAP), 1, 1-diphenyl-2-picrylhydrazil (DPPH) and nitric oxide (NO) scavenging in vitro assays were carried out on the extract and fractions at 6.25, 12.5, 25, 50, 100, 200, 400 and 800 µg/mL. The most active fraction (ethyl acetate fraction) was further purified using chromatographic techniques to isolate its major compound whose structure was elucidated using ID nuclear magnetic resonance (NMR) and mass spectrometry. The ethyl acetate fraction produced the highest free radical scavenging activity among the other fractions. The fraction (VLC-E7) from which the bioactive compound, quercetin-3-O-αL-rhamnopyranoside, was isolated had the best FRAP and DPPH scavenging activities with EC50 and IC50 values of 88.81 ± 3.41 and 26.87 ± 0.24 respectively more than the ethyl acetate fraction. This study revealed that the polyphenol flavonoid, quercetin-3-O-αL-rhamnopyranoside could be responsible for antioxidant activity of ethno-medicinal property of D filix-mas leaf.

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