scholarly journals Synthesis of Benzoxazole Associated Benzothiazine-4-ones and their in vitro and in silico Antimicrobial, Antioxidant Activities

2020 ◽  
Vol 33 (1) ◽  
pp. 137-150
Author(s):  
T.R. Padmini ◽  
H.M. Vagdevi ◽  
Usha Jinendra

In present study, a series of 3-[(5-methyl-1,3-benzoxazol-2-yl)amino]-2-phenyl-2,3-dihydro-4H-1,3- benzothiazin-4-ones (6a-n) were synthesized and elucidated by elemental, FT-IR, 1H & 13C NMR and LC-MS studies. The in vitro antibacterial screening against Gram-positive bacterial strains such as B. subtilis, S. aureus, S. epidermidis and Gram-negative bacteria such as E. coli, P. aeruginosa was carried in comparison with tetracycline as reference standard. Antifungal activities against different fungal strains namely R. oryzae, A. niger, A. favus, C. albicans and S. cerevisiae have been evaluated by comparing with fluconazole as reference standard. Compounds 6b, 6c, 6e, 6j, 6m and 6n emerged as highly potent antimicrobial agents. The DPPH radical scavenging assay of the synthesized moieties showed good antioxidant potency comparable to standard ascorbic acid. The molecular docking simulation studies of all the title compounds in their active conformation analogues with target proteins (PDB ID 2XCT-antibacterial, PDB ID 1IYL-antifungal, PDB ID 2HCK- antioxidant) exhibited good binding interactions in top scoring poses. The pharmacokinetic properties prediction by ADMET descriptors and Lipinski′s rule of five endorse the properties of newly synthesized compounds to a drug molecule. The results of the docking protocols were compatible with the in vitro studies which validates the potency of the molecules.

Author(s):  
SAMRIDHI THAKRAL ◽  
VIKRAMJEET SINGH

Objective: The aim of this study was to evaluate 2,4-dichlorobenzoic acid derivatives as antimicrobial agents through in vitro, QSAR and molecular docking studies. Methods: The compounds were subjected to in vitro antimicrobial screening by test tube dilution method and the structural characteristics governing the antimicrobial potential were studied using QSAR methodology. These compounds were also screened for docking simulation to find out binding confirmation of reported compounds with PDB 1aj0 and 5fsa using AutoDock tools and discovery studio. Results: The antimicrobial evaluation data indicated that compounds 13 and 18 were found to be the most effective against all the bacterial strains and Aspergillus niger while compounds 1 and 14 exhibited more antifungal potential against Candida albicans. QSAR studies confirmed the role of molar refractivity and Balaban index (J) as controlling parameters for antimicrobial potential. Molecular modeling study revealed that compounds interact with the active site of PDB by hydrophobic, hydrogen bonding, and Van der Wall interactions. Conclusion: These test compounds were identified as potent candidates for the control of microbial strains tested, and structural relationship with activity may provide valuable information for further design and synthesis of compounds with antimicrobial potential.


2021 ◽  
Author(s):  
Poulomi Ghosh ◽  
Souren Goswami ◽  
Sujit Roy ◽  
Ria Das ◽  
Tista Chakraborty ◽  
...  

AbstractObjectivesThe present study aimed to analyze a comparative in vitro free radical scavenging and antibacterial potentials of leaf aqueous and the successive extract fractions of Callistemon citrinus.MethodsFor in vitro antioxidant activity assessments, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, Fe3+ ion reducing antioxidant power (FRAP) assay, and total antioxidant capacity of the extracts were tested. Antibacterial potentials were tested through Agar well diffusion method using both gram-positive and gram-negative bacterial strains.ResultsData indicate the polar successive aqueous fraction (AQF) possesses the highest free radicals scavenging capacity, with lowest EC50 (the required extract concentration to scavenge half of the free radicals) for DPPH and FRAP assays, and contains the highest total phenolics (308.2±5.9 µg tannic acid equivalent/mg dry extract, DE), flavonoids (516.7±3.5 µg quercetin equivalent/mg DE), total antioxidant capacity (441.48±12.8 µg ascorbic acid equivalent/mg DE). Phenolics and flavonoids contents were positively correlated with the in vitro antioxidant activities. The antibacterial study indicates the petroleum ether and chloroform are suitable solvents for extracting antibacterial phytochemicals from C. citrinus leaves that are effective against both gram-positive and negative bacterial strains.ConclusionThe most polar fraction i.e. the successive aqueous extract fraction of C. citrinus leaves exhibited the highest antioxidant activities while the most non-polar petroleum ether extract fraction showed the highest antibacterial potentials thus these extract fractions might have therapeutic importance.


2020 ◽  
Vol 14 (1) ◽  
pp. 58-68
Author(s):  
Dattatraya G. Raut ◽  
Sandeep B. Patil ◽  
Prafulla B. Choudhari ◽  
Vikas D. Kadu ◽  
Anjana S. Lawand ◽  
...  

Background: The present research work is focused on the development of alternative antioxidant and anti-inflammatory agents. The review of the literature reveals that many benzofused thiazole analogues have been used as lead molecules for the design and development of therapeutic agent, including anticancer, anti-inflammatory, antioxidant and antiviral. The synthesized benzofused thiazole derivatives are evaluated for in vitro antioxidant, anti-inflammatory activities and molecular docking study. Thus, the present research work aims to synthesize benzofused thiazole derivatives and to test their antioxidant and antiinflammatory activities. Objective: To design and synthesize an alternative antioxidant and anti-inflammatory agents. Methods: The substituted benzofused thiazoles 3a-g were prepared by cyclocondensation reaction of appropriate carboxylic acid with 2-aminothiophenol in POCl3 and heated for about 2-3 h to offer benzofused thiazole derivatives 3a-g. All the newly synthesized compounds were in vitro screened for their anti-inflammatory and antioxidant activities by using a known literature method. Results: At the outset, the study of in vitro indicated that the compounds code 3c, 3d and 3e possessed distinct anti-inflammatory activity as compared to a standard reference. All the tested compounds show potential antioxidant activity against one or more reactive (H2O2, DPPH, SO and NO) radical scavenging species. Additionally, docking simulation is further performed to the position of compounds 3d & 3e into the anti-inflammatory active site to determine the probable binding model. Conclusion: New anti-inflammatory and antioxidant agents were needed; it has been proved that benzofused thiazole derivatives were 3c, 3d and 3e constituted as an interesting template for the evaluation of new anti-inflammatory agents and an antioxidant’s work also may provide an interesting template for further development.


2020 ◽  
Vol 11 ◽  
pp. 37-43
Author(s):  
Prof. Teodora P. Popova ◽  
Toshka Petrova ◽  
Ignat Ignatov ◽  
Stoil Karadzhov

The antimicrobial action of the dietary supplement Oxidal® was tested using the classic Bauer and Kirby agar-gel diffusion method. Clinical and reference strains of Staphylococcus aureus and Escherichia coli were used in the studies. The tested dietary supplement showed a well-pronounced inhibitory effect against the microbial strains commensurable with that of the broad-spectrum chemotherapeutic agent Enrofloxacin and showed even higher activity than the broad spectrum antibiotic Thiamphenicol. The proven inhibitory effect of the tested dietary supplement against the examined pathogenic bacteria is in accordance with the established clinical effectiveness standards for antimicrobial agents.


2020 ◽  
Vol 18 (4) ◽  
pp. 354-359
Author(s):  
Shirin Tarbiat ◽  
Azize Simay Türütoğlu ◽  
Merve Ekingen

Alzheimer's disease is a neurodegenerative disorder characterized by memory loss and impairment of language. Alzheimer's disease is strongly associated with oxidative stress and impairment in the cholinergic pathway, which results in decreased levels of acetylcholine in certain areas of the brain. Hence, inhibition of acetylcholinesterase activity has been recognized as an acceptable treatment against Alzheimer's disease. Nature provides an array of bioactive compounds, which may protect against free radical damage and inhibit acetylcholinesterase activity. This study compares the in vitro antioxidant and anticholinesterase activities of hydroalcoholic extracts of five cultivars of Rosa Damascena Mill. petals (R. damascena 'Bulgarica', R. damascena 'Faik', R. damascena 'Iranica', R. damascena 'Complex-635' and R. damascena 'Complex-637') from Isparta, Turkey. The antioxidant activities of the hydroalcoholic extracts were tested for ferric ion reduction and DPPH radical scavenging activities. The anti-acetylcholinesterase activity was also evaluated. All rose cultivars showed a high potency for scavenging free radical and inhibiting acetylcholinesterase activity. There was a significant correlation between antioxidant and acetylcholinesterase inhibitory activity. Among cultivars, Complex-635 showed the highest inhibitory effect with an IC50 value of 3.92 µg/mL. Our results suggest that all these extracts may have the potential to treat Alzheimer's disease with Complex-635 showing more promise.


2019 ◽  
Vol 16 (3) ◽  
pp. 245-248
Author(s):  
Hummera Rafique ◽  
Aamer Saeed ◽  
Ehsan Ullah Mughal ◽  
Muhammad Naveed Zafar ◽  
Amara Mumtaz ◽  
...  

Background: (±)-6,8-Dihydroxy-3-undecyl-3,4-dihydroisochromen-1-one is one of the structural analog of several substituted undecylisocoumarins isolated from Ononis natrix (Fabaceae), has been successfully synthesized by direct condensation of homopthalic acid (1) with undecanoyl chloride yields isochromen-1-one (2). Methods: Alkaline hydrolysis of (2) gave the corresponding keto-acid (3), which is then reduced to hydroxy acid (4) then its cyclodehydration was carried out with acetic anhydride to afford 3,4- dihydroisochromen-1-one (5). Followed by demethylation step, the synthesis of target 6,8- dihydroxy-7-methyl-3-undecyl-3,4-dihydroisocoumarin (6) was achieved. Results: In vitro antibacterial screening of all the synthesized compounds were carried out against ten bacterial strains by agar well diffusion method. Conclusion: Newly synthesized molecules exhibited moderate antibacterial activity and maximum inhibition was observed against Bacillus subtilus and Salmonella paratyphi.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
G. Kiran ◽  
T. Maneshwar ◽  
Y. Rajeshwar ◽  
M. Sarangapani

A series of β-Isatin aldehyde-N,N′-thiocarbohydrazone derivatives were synthesized and assayed for theirin vitroantimicrobial and antioxidant activity. The new compounds were characterized based on spectral (FT-IR, NMR, MS) analyses. All the test compounds possessed a broad spectrum of activity having MIC values rangeing from 12.5 to 400 μg/ml against the tested microorganisms. Among the compounds3e,3jand3nshow highest significant antimicrobial activity. The free radical scavenging effects of the test compounds against stable free radical DPPH (α,α-diphenyl-β-picryl hydrazyl) and H2O2were measured spectrophotometrically. Compounds3j,3n,3l, and3e, respectively, had the most effective antioxidant activity against DPPH and H2O2scavenging activity.


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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xuemei Ma ◽  
Jiayi Yu ◽  
Jing Jing ◽  
Qian Zhao ◽  
Liyong Ren ◽  
...  

AbstractPectin is a kind of natural and complex carbohydrates which is extensively used in food, chemical, cosmetic, and pharmaceutical industries. Fresh sunflower (Helianthus annuus L.) heads were utilized as a novel source of pectin extracted by ammonium oxalate. The conditions of the extraction process were optimized implementing the response surface methodology. Under optimal extraction parameters (extraction time 1.34 h, liquid–solid ratio 15:1 mL/g, ammonium oxalate concentration 0.76% (w/v)), the maximum experimental yield was 7.36%. The effect of spray-drying and freeze-drying on the physiochemical properties, structural characteristics, and antioxidant activities was investigated by FT-IR spectroscopy, high performance size exclusion chromatography, and X-ray diffraction. The results showed freeze-drying lead to decrease in galacturonic acid (GalA) content (76.2%), molecular weight (Mw 316 kDa), and crystallinity. The antioxidant activities of pectin were investigated utilizing the in-vitro DPPH and ABTS radical-scavenging systems. This study provided a novel and efficient extraction method of sunflower pectin, and confirmed that different drying processes had an effect on the structure and properties of pectin.


Author(s):  
Abhishek Chatterjee ◽  
Dileep Singh Baghel ◽  
Bimlesh Kumar ◽  
Saurabh Singh ◽  
Narendra Kumar Pandey ◽  
...  

Objective: The aims of the present investigation were to develop the herbal and/or herbomineral formulations of Hinguleswara rasa and to compare their anti-inflammatory and antioxidant activities, in vitro, with that of standard drug samples.Methods: This study was an interventional investigation in three samples: In the first sample, Hinguleswara rasa (HR1) was prepared as per methodology described in Rasatarangini using Shuddha Hingula (10 g), Shuddha Vatsanabha (10 g), and Pippali (10 g). In the second and third sample, respectively, Hinguleswara rasa was prepared by replacing Shuddha Hingula with Kajjali where Kajjali made from Hingulotha parada and Sodhita parada constitutes two varieties of Hinguleswara rasa, i.e. HR2 and HR3. In vitro antioxidant activity was studied using 2,2-diphenyl-1-picrylhydrazyl, and the absorbance was recorded at 517 nm. For evaluating the in vitro anti-inflammatory studies, the inhibition of albumin denaturation technique was performed.Results: The results showed that the formulation of Hinguleswara rasa has shown dose-dependent activity which was observed in 100 μg concentration. HR1, HR2, and HR3 showed 36.11, 17.22, and 16.11% radical scavenging activity.Conclusion: It could be concluded that the changes made in the formulations did not affect the in vitro anti-inflammatory and antioxidant effects of the herbomineral formulations.


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