Design, Synthesis and Characterization of Novel Quinoline Derivatives from Substituted Acetophenone as an Antioxidant Agent

2020 ◽  
Vol 10 (4) ◽  
pp. 495-501
Author(s):  
Archana Singh ◽  
Karuna S. Shukla ◽  
Monika Chaudhary

Background:: In a search for new antioxidant agents, a series of eleven diversely substituted quinoline containing chalcone derived from a quinoline scaffold were synthesized and evaluated as antioxidant agents. Methods:: Compounds were prepared via Claisen-Schmidt condensations of 2, 6-dichloroquinoline- 3-carbaldehyde with appropriately substituted acetophenones. All the synthesized compounds were characterized by spectral (FTIR, mass by ESI and 1H NMR) and elemental analysis. The synthesized compounds were investigated for their in vitro antioxidant activity by FRAP assay method. Results:: Among the screened compounds QHM-1, QH-1, QDB-1 and QE-1 exhibited significant antioxidant activities. Conclusion:: It can be predicted that electron releasing groups with higher resonating structures makes the compound more potent than the compounds with electron releasing group and less resonating structures. The electron releasing behavior of compounds proved them good terminators of radical chain reactions.

2020 ◽  
Vol 5 (1) ◽  
pp. 45-50
Author(s):  
V.D. Sonawane ◽  
B.D. Sonawane ◽  
M.J. Dhanavade ◽  
K.D. Sonawane ◽  
R.B. Bhosale

In present study, a novel series of substituted imidazo[2,1-b]thiazole pyrazoline derivatives (2a-e) and (3a-e) from the reference compound imidazo[2,1-b]thiazole chalcones (1a-e) in PEG-400 by using hydrazine hydrate and phenyl hydrazine was synthesized. Characterization of newly synthesized compounds was done using IR and 1H NMR. Further, imidazo[2,1-b]thiazole pyrazoline derivatives were subjected to check their in vitro antioxidant activities at a concentration of 0.5 mmol/L in methanol. Compounds 2c, 2d, 3c, 3d and 3e showed comparatively good activity than standard drug diclofenac. The anti-inflammatory activity of compounds 2c, 2d, 2e, 3c, 3d and 3e were comparable with standard drug. Similarly, all these compounds possess good antioxidant activity as compared to ascorbic acid (vitamin C); compared to the value of DPPH and SOD antioxidant activity 44.18 % and 74.07 %, respectively. These synthesized compounds exhibited a good anti-inflammatory and antioxidant activities hence might be useful in future drug designing studies.


Planta Medica ◽  
2006 ◽  
Vol 72 (11) ◽  
Author(s):  
M Hajimahmoodi ◽  
MR Oveisi ◽  
N Sadeghi ◽  
B Jannat ◽  
E Davoodabadi

2020 ◽  
Vol 3 (1) ◽  
pp. 47
Author(s):  
Nadezhda Petkova ◽  
Manol Ognyanov ◽  
Blaga Inyutin ◽  
Petar Zhelev ◽  
Panteley Denev

Crab apple (Malus baccata (L.) Borkh.) was mainly distributed in Europe as an ornamental plant, but the nutritional properties of its edible fruits were not fully revealed. The aim of the current study was to characterize the phytochemical composition of ripen carb apple fruits and to evaluate their nutritional and antioxidant potentials. The fruits were assayed for moisture and ash content, proteins, lipids, carbohydrates, titratable acidity (TA), pH, total phenolic compounds and natural pigments. Among the analyzed carbohydrates cellulose was found in the highest content (6% dw), followed by sugars (sucrose, glucose and fructose) and 1.8 % dw uronic acids. The total chlorophylls and carotenoids contents in their fruits were 6.51 and 4.80 μg/g fw, respectively. Total monomeric anthocyanins were not detected. The highest content of total phenolic compounds (2.67 mg GAE/g fw) was found in 95 % ethanol extract from fruits, while the total flavonoids were relatively low – 0.1 mg QE/g fw. DPPH assay (17.27 mM TE/g fw) and FRAP assay (14.34 mM TE/g fw) demonstrated in vitro antioxidant activities of crabapple. Malus baccata fruits were evaluated as a rich source of dietary fibers and phenolic compounds with significant antioxidant potential that could be used in human nutrition.


2020 ◽  
Vol 32 (3) ◽  
pp. 580-586
Author(s):  
Ranjit V. Gadhave ◽  
Bhanudas S. Kuchekar

A new series of N-(benzo[d]thiazol-2-yl)-[1,2,4]triazolo[4,3-c]quinazoline-5-carboxamide derivatives were synthesized by condensation of [1,2,4]triazolo[4,3-c]quinazoline-5-carboxylate derivatives with substituted benzothiazoles. The chemical structures of the synthesized compounds were confirmed by FT-IR, MS and 1H NMR spectra. Designed triazoloquinazoline derivatives were docked with oxido-reductase enzyme (PDB Code 4h1j) and DNA gyrase enzyme (PDB Code 3g75). Based on high binding affinity score, the best compound were selected for synthesis and subjected to in vitro antioxidant and antibacterial activity. Compounds 7a and 7d were found to be most active compounds as antioxidant agent among this series when compared with ascorbic acid. Compounds 7a, 7d and 7f were found to be most active compounds as an antibacterial agents among this series when compared with ciprofloxacin against bacterial strains such as S. aureus (ATCC 25923), E. coli (ATCC 25922) and P. aeruginosa (ATCC 27853). Study revealed that the most active compounds after structural modifications can be exploited as lead molecules for other pharmacological activities such as anti-inflammatory, anticancer and antidepressant activities.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1127 ◽  
Author(s):  
Beatriz Chamorro ◽  
David García-Vieira ◽  
Daniel Diez-Iriepa ◽  
Estíbaliz Garagarza ◽  
Mourad Chioua ◽  
...  

Herein, we report the neuroprotective and antioxidant activity of 1,1′-biphenyl nitrones (BPNs) 1–5 as α-phenyl-N-tert-butylnitrone analogues prepared from commercially available [1,1′-biphenyl]-4-carbaldehyde and [1,1′-biphenyl]-4,4′-dicarbaldehyde. The neuroprotection of BPNs1-5 has been measured against oligomycin A/rotenone and in an oxygen–glucose deprivation in vitro ischemia model in human neuroblastoma SH-SY5Y cells. Our results indicate that BPNs 1–5 have better neuroprotective and antioxidant properties than α-phenyl-N-tert-butylnitrone (PBN), and they are quite similar to N-acetyl-L-cysteine (NAC), which is a well-known antioxidant agent. Among the nitrones studied, homo-bis-nitrone BPHBN5, bearing two N-tert-Bu radicals at the nitrone motif, has the best neuroprotective capacity (EC50 = 13.16 ± 1.65 and 25.5 ± 3.93 μM, against the reduction in metabolic activity induced by respiratory chain blockers and oxygen–glucose deprivation in an in vitro ischemia model, respectively) as well as anti-necrotic, anti-apoptotic, and antioxidant activities (EC50 = 11.2 ± 3.94 μM), which were measured by its capacity to reduce superoxide production in human neuroblastoma SH-SY5Y cell cultures, followed by mononitrone BPMN3, with one N-Bn radical, and BPMN2, with only one N-tert-Bu substituent. The antioxidant activity of BPNs1-5 has also been analyzed for their capacity to scavenge hydroxyl free radicals (82% at 100 μM), lipoxygenase inhibition, and the inhibition of lipid peroxidation (68% at 100 μM). Results showed that although the number of nitrone groups improves the neuroprotection profile of these BPNs, the final effect is also dependent on the substitutent that is being incorporated. Thus, BPNs bearing N-tert-Bu and N-Bn groups show better neuroprotective and antioxidant properties than those substituted with Me. All these results led us to propose homo-bis-nitrone BPHBN5 as the most balanced and interesting nitrone based on its neuroprotective capacity in different neuronal models of oxidative stress and in vitro ischemia as well as its antioxidant activity.


2021 ◽  
Vol 16 (8) ◽  
pp. 38-49
Author(s):  
Siva Kumar Kandula ◽  
Satyanarayana Swamy Cheekatla ◽  
Venkata Satya Mahesh Kumar Metta ◽  
Venkata Rajagopal Saladi

Natural antioxidants, in particular phenolic derivatives, are used efficiently to combat against oxidative induced tissue damages. The objective of the study is to determine the antioxidant potential of methanolic extracts obtained from eight marine algal species (Enteromorpha compressa, Chaetomorpha antennina, Caulerpa racemosa, Caulerpa taxifolia, Sargassum vulgare, Padina tetrastromatica, Amphiroa fragilissima and Gracilaria corticata) by assessing their total phenolic content, DPPH scavenging assay, FRAP assay, H2O2 radical and superoxide radical scavenging activities. Among them, P.tetrastromatica, S.vulgare, E.compressa, C.taxifolia display significant antioxidant activities. Further, the aqueous extracts of these four algae are used for bioreduction of silver nitrate to silver nanoparticles (AgNPs) by green synthesis method at room temperature. UV-Visible spectrum revealed the surface plasmon resonance at 430 and 440nm. The characterizations of AgNPs by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) studies revealed the bioreduction and capping of AgNPs. XRD analysis elucidated the synthesized nanoparticles having face centered cubic crystalline geometry, with a mean size of 17 nm. The nanoparticles have better antimicrobial activity against cocci shaped than the rod shaped bacteria. The minimum inhibitory concentration and minimum bactericidal concentration exhibit more activity against S.aureus and B.cereus rather than E.coli.


Author(s):  
Larissa Irene Da Silva ◽  
Arunachalam Karuppusamy ◽  
Fabio Miyajima ◽  
Ivana Maria Povoa Violante ◽  
Isanete Geraldini Costa Bieski ◽  
...  

Objective: The purpose of this study was to evaluate selected Brazilian plants from Juruena valley region of Mato Grosso, for their in vitro antimicrobial and antioxidant activities.Methods: The powder obtained from different parts of the twenty-six (26) plants were macerated in hydroethanolic solution to obtain the extracts. The hydroethanolic extracts were tested for their in vitro antimicrobial activity by determining the MIC using broth microdilution. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical, ferric reducing antioxidant power (FRAP) and nitric oxide (NO) methods were used for the determination of antioxidant activities. Correlation between classes of secondary metabolites and antioxidant activity was assessed.Results: Phanera glabra extract (HEPg) showed broad antibacterial spectrum, presenting the best activity against Klebsiella pneumoniae. Hevea microphylla extract (HEHm) presented a narrow spectrum of antibacterial activity with strong effect against Shigella flexneri. The only plant with broad spectrum antifungal activity was Bertholletia excelsa (HEBe), with moderate activity against strains of Aspergillus and Candida. The following extracts were prominent regarding their activities in the DPPH and FRAP assays-HEBe, Cariniana rubra (HECr) and in the FRAP assay alone, Cedrela odorata (HECo) and HEPg. None of the extracts was active in the NO assay. A significant association was observed between DPPH activity and the total phenolic contents.Conclusion: Our results justified the use of some of the investigated plants in the Brazilian ethnomedicine. The antibacterial activities of these plants are bacteriostatic in nature. These findings support that a number of investigated plants could be a valuable source of new antioxidant and antimicrobial compounds that can potentially deliver novel mechanisms of actions.However, further studies are required.


2021 ◽  
Vol 18 ◽  
Author(s):  
Jagseer Singh ◽  
Pooja A Chawla ◽  
Rohit Bhatia ◽  
Shamsher Singh

: The present work reports synthesis and screening of fifteen 2,5-disubstituted-4-thiazolidinones with different substitutions of varied arylidene groups at imino. The structures of the compounds were confirmed by spectral characterization. The compounds were subjected to in vivo anti-inflammatory and in vitro antioxidant activities. The derivatives possessed remarkable activities quite close to standard drugs used. Unlike conventional non-selective NSAIDs, the synthesized compounds did not contain any acidic group, thereby ensuring a complete cure from ulcers. To further substantiate the claim for safer derivatives, the active compounds were docked against the cyclooxygenase (COX)-2 enzyme. It was found that 4-fluorophenylimino substituent at 2- position and 3-nitro moiety on a 5-benzylidene nucleus of the 4-thiazolidinone derivative fitted in the COX-2 binding pocket. The compounds exhibited remarkable activity in scavenging free radicals, as depicted by the DPPH assay method. The structure-activity relationship was also established in the present work with respect to the nature and position of the substituents. The active compounds were evaluated for drug-like nature under Lipinski’s rule of five, and the toxicity behaviour of active compounds was predicted using ADMETlab software. The compounds have the potential to target degenerative disorders associated with inflammation and the generation of free radicals.


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