scholarly journals Microwave-Assisted Synthesis, Characterization, Antimicrobial and Antioxidant Activity of Some New Isatin Derivatives

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.

2018 ◽  
Vol 8 (6) ◽  
pp. 22-27
Author(s):  
TR Prashith Kekuda ◽  
Nitish A. Bharadwaj ◽  
MB Sachin ◽  
BK Sahana ◽  
GS Priyanka

Objectives: Argyreia cuneata (Willd.) Ker Gawl. belongs to the family Convolvulaceae. The present study was performed to screen the potential of crude extract of various parts of A. cuneata to exhibit antimicrobial activity. Methods: Extraction of shade dried and powdered leaf, stem and flower of A. cuneata was carried out by maceration technique. Antibacterial and antifungal activity of extracts was evaluated by Agar well diffusion and Poisoned food technique respectively. Antioxidant activity was determined by DPPH radical scavenging, ABTS radical scavenging and ferric reducing assays. Results:  All extracts were effective in inhibiting test bacteria and the susceptibility of bacteria to extracts was in the order: Bacillus cereus > Shigella flexneri > Escherichia coli > Salmonella typhimurium. Leaf extract and stem extract exhibited highest and least antibacterial activity, respectively. Extracts were effective in causing inhibition of seed-borne fungi viz. Aspergillus niger and Bipolaris sp to >50%. Leaf extract exhibited marked antifungal activity followed by flower extract and stem extract. All extracts were shown to exhibit concentration dependent scavenging and reducing activity. Antioxidant activity of extracts observed was in the order: leaf extract > flower extract > stem extract.  Conclusion: Among various parts of A. cuneata, leaf extract exhibited marked antimicrobial and antioxidant activity. The plant can be employed as an effective antimicrobial and antioxidant agent in suitable form. Further studies may be undertaken to recover phytochemicals from the plant and to investigate the antimicrobial and antioxidant activity of isolated components. Keywords: Argyreia cuneata, Maceration, Antimicrobial, Agar well diffusion, Poisoned food technique, Antioxidant


2017 ◽  
Vol 9 (4) ◽  
pp. 615
Author(s):  
Mukesh Kumar Yadav ◽  
Santosh Kumar Singh ◽  
JS Tripathi ◽  
YB Tripathi

<p><em>Centella asiatica</em> also known as <em>mandukparni </em>or Indian pennywort or <em>jalbrahmi</em>, which has been used as a medicine in the Ayurveda from ancient times and mentioned in many classical texts of Ayurveda. <em>Centella asiatica</em> has long been used to improve memory and cognitive function.</p><p>The study aimed to identify the phytochemicals present in different solvent extracts of <em>Centella asiatica </em>(i.e. PECA- Petroleum ether extract of <em>C. asiatica, </em>CCA- Chloroform extract of <em>C. asiatica, </em>EACA- Ethyl acetate extract of <em>C. asiatica,</em> ECA- Ethanolic extract of <em>C. asiatica, </em>HACA- Hydro-alcoholic extract of <em>C. asiatica</em>)<em> </em>and evaluate the respective in-vitro antioxidant potentials. <em></em></p><p>The phytochemical screening of extracts was done with standardized procedures and the antioxidant potential of different solvent extracts of <em>Centella asiatica</em> was assessed by its free radical scavenging activity 2, 2-diphenyl -1- picrylhydrazyl (DPPH) as well as hydrogen peroxide scavenging assay respectively for reducing capability.</p><p>In all different solvent extracts of <em>C. asiatica</em> revealed excellent free radical scavenging activity as revealed by 2-2- diphenyl-1-picryl-hydrazyl (DPPH) assay with  EC<sub>50</sub> values for ECA=128.752±1.85 μg/ml, HACA=274.884±1.21 μg/ml and hydrogen peroxide assay against the standard (Butylated hydroxytoluene) BHT, with the EC<sub>50</sub> values ECA=429.69±0.92 μg/ml HACA=458.08±0.58 μg/ml while rest solvent extracts shown very less antioxidant activity.</p><p> The present study indicates that the <em>Centella asiatica</em> extracts have good antioxidant activity which can be used in stress and anxiety and also a good source to be used as natural drugs.</p>


2019 ◽  
Vol 123 (3) ◽  
pp. 241-254 ◽  
Author(s):  
T. Ruskovska ◽  
V. Maksimova ◽  
D. Milenkovic

AbstractOxidative damage of cells and tissues is broadly implicated in human pathophysiology, including cardiometabolic diseases. Polyphenols, as important constituents of the human diet and potent in vitro free radical scavengers, have been extensively studied for their beneficial effects on cardiometabolic health. However, it has been demonstrated that the in vivo antioxidant activity of polyphenols is distinct from their in vitro free radical-scavenging capacity. Indeed, bioavailability of nutritional polyphenols is low and conditioned by complex mechanisms of absorption, distribution, metabolism and excretion. Nowadays, it is commonly accepted that the cellular antioxidant activity of polyphenols is mainly carried out via modification of transcription of genes involved in antioxidant defence. Importantly, polyphenols also contribute to cardiometabolic health by modulation of a plethora of cellular processes that are not directly associated with antioxidant enzymes, through nutri(epi)genomic mechanisms. Numerous human intervention studies have demonstrated beneficial effects of polyphenols on the key cardiometabolic risk factors. However, inconsistency of the results of some studies led to identification of the inter-individual variability in response to consumption of polyphenols. In perspective, a detailed investigation of the determinants of this inter-individual variability will potentially lead us towards personalised dietary recommendations. The phenomenon of inter-individual variability is also of relevance for supplementation with antioxidant (pro)vitamins.


2010 ◽  
Vol 5 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Boobalan Raja ◽  
Kodukkur Pugalendi

AbstractIn this study, an aqueous extract of leaves from Melothria maderaspatana was tested for in vitro antioxidant activity. Free radical scavenging assays, such as hydroxyl radical, hydrogen peroxide, superoxide anion radical and 2,2-diphenyl-1-picryl hydrazyl (DPPH), 2,2’-azinobis-(3-ethyl-enzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and reducing power assay, were studied. The extract effectively scavenged hydroxyl radical, hydrogen peroxide and superoxide anion radicals. It also scavenged DPPH and ABTS radicals. Furthermore, it was found to have reducing power. All concentrations of leaf extract exhibited free radical scavenging and antioxidant power, and the preventive effects were in a dose-dependent manner. The antioxidant activities of the above were compared to standard antioxidants such as butylated hydroxytoluene (BHT), ascorbic acid, and α-tocopherol. The results obtained in the present study indicate that the M. maderaspatana extract could be considered a potential source of natural antioxidant.


2007 ◽  
Vol 34 (8) ◽  
pp. 714 ◽  
Author(s):  
Abby K. van den Berg ◽  
Timothy D. Perkins

Foliar anthocyanins are hypothesised to provide an additional source of photoprotection from photooxidative stress to the leaves in which they occur through their ability to scavenge excess free radical species. Although demonstrated to significantly enhance the antioxidant status of red morphs of fully expanded leaves of some species, the contribution of anthocyanins to the antioxidant capacity of the juvenile and senescing leaves in which they frequently occur has not been examined. Antioxidant activity of extracts from anthocyanic and non-anthocyanic juvenile and senescing sugar maple (Acer saccharum Marsh.) leaves from similar light environments was assessed using the stable free radical 1,1-diphenyl-2-picryl hydrazyl (DPPH). Anthocyanin content was significantly correlated with antioxidant activity in extracts of anthocyanic juvenile leaves but only weakly correlated in extracts of anthocyanic senescing leaves. In addition, the antioxidant activity of anthocyanic and non-anthocyanic leaves was equal in both juvenile and senescing leaves. Thus, although anthocyanins may contribute to the antioxidant capacity of anthocyanic juvenile and senescing sugar maple leaves, these results are not consistent with the hypothesis that anthocyanins provide an enhancement to the photoprotection available in either leaf type through free radical scavenging. The results suggest anthocyanins may be part of alternative strategies employed by anthocyanic juvenile and senescing maple leaves to achieve similar levels of antioxidant capacity as their non-anthocyanic counterparts to cope with the same set of environmental challenges.


Author(s):  
Sandeep Sandeep ◽  
Abhilasha Mittal ◽  
Abhilasha Mittal

 Objective: The objective of the study was to investigate the pharmacological evaluation of previously isolated compounds (CR-1 to CR-5) from the areal part of Cuscuta reflexa Roxb. is reported.Methods: The antimicrobial and antioxidant activity of the isolated compounds (CR-1 to CR-5) from C. reflexa was determined by the disc-diffusion method and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) model, respectively. The antimicrobial activity was performed against four strains Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa.Results: The results revealed that highest zone of inhibition is measured by compound CR-5 against E. coli. The antioxidant activity is evaluated for in vitro antioxidant activity using DPPH radical scavenging activity, inhibitory concentration 50% (IC50) (120.92–76.38 %), respectively. The results indicate that isolated compound CR-1 and CR-2 having IC50 76.38 and 76.94 μg/ml, respectively, showed potent antioxidant activity comparable to standard ascorbic acid (IC50 43.42 μg/ml).Conclusion: This study suggests that areal part of C. reflexa have bioactive compounds for a new antimicrobial and antioxidant drug development.


2008 ◽  
Vol 56 (24) ◽  
pp. 11694-11699 ◽  
Author(s):  
Anika E. Wagner ◽  
Patricia Huebbe ◽  
Tetsuya Konishi ◽  
M. Mamunur Rahman ◽  
Meiko Nakahara ◽  
...  

2014 ◽  
Vol 6 (3) ◽  
pp. 543-552 ◽  
Author(s):  
N. Jahan ◽  
M. S. Parvin ◽  
A. Khan ◽  
N. Das ◽  
M. S. Islam ◽  
...  

Pterygota alata is a large deciduous tree of Malvaceae family. The present study was designed to evaluate in vitro antioxidant activity of stem bark of the plant. Ferric reducing power (FRP) test, 1, 1- diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging test and total antioxidant capacity (TAC) assay were used to detect the antioxidant activity. Total phenolic and flavonoid contents were also determined as they are well known phytochemicals with antioxidant property. The bark of the plant showed efficient reducing power as well as free radical scavenging property (IC50 values 52.25 - 172.05). The bark also found rich in total phenolic and flavonoid content. The highest amount of total phenolic content was found in chloroform soluble fraction (29.898 µg/mL) followed by ethyl acetate soluble fraction (15.88 µg/mL). The highest content of total flavonoid also detected in chloroform soluble fraction (107.56 µg/mL) but followed by crude ethanol extract (98.66 µg/mL). Overall, the bark of the plant possesses significant antioxidant activity, therefore can be used as a good natural source of antioxidant. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i3.17586 J. Sci. Res. 6 (3), 543-552 (2014)


Author(s):  
Shubharani Ramnath ◽  
Sivaram Venkataramegowda

Antioxidants from the natural products are essential to prevent the progression of free radical mediated diseases. In the present study, ethanol extract of propolis collected from different geographical origin were evaluated for their free radical scavenging potential by employing different in-vitro assays such as DPPH, ABTS, Nitric oxide and Hydrogen peroxide. All the tested samples contained considerable amount of total phenols and vitamin C content. In the entire assay, the percentage of inhibition increased with the increase in concentration. Among the propolis samples collected, the highest activity was found in Tamil Nadu, Kerala, Karnataka and Haryana. The difference in the antioxidant activity level was obtained from the assay may reflect a relative difference in the ability of antioxidant compounds to scavenge different free radicals in the extract. Phenols and vitamin C are the major contributors to antioxidant activity in propolis. The propolis from these locations may be of considerable interest in preventing the ill effects of excessive free radical generation in the human body.


Author(s):  
Bindhu R. Kamath ◽  
Sabeena Kizhedath

Background: The use of medicinal plants for maintaining good health is getting attention worldwide. Antioxidants play an important role to protect damage caused by oxidative stress. In the present study methanolic extracts of Cassia fistula  was determined using DPPH for its antioxidant activity. Phytochemical investigation confirmed the presence of bioactive ingredients in the extract.Methods: The antioxidant activity of methanolic extract of Cassia fistula was evaluated using DPPH free radical assay. DPPH (1,1-diphenyl-2-picrylhydrazyine) free radical analysis is one of the accurate and frequently employed method for evaluating antioxidant activity.Results: The methanolic extracts showed increase in radical scavenging activity as concentration increases. The IC50 values were calculated for the methanolic extract. Ascorbic acid was used as control. Cassia fistula exhibited IC 50 of 79.42µg/ml.Conclusions: Scientific evidence suggests that antioxidants reduce the risk for chronic diseases including cancer and heart disease and infectious diseases. Further evaluation of pharmacological activities of Cassia fistula may prove useful in treatment of cancer and heart diseases.


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