In Vitro Antioxidant-Activity Evaluation of Gallic-Acid-Grafted Chitosan Conjugate Synthesized by Free-Radical-Induced Grafting Method

2016 ◽  
Vol 64 (29) ◽  
pp. 5893-5900 ◽  
Author(s):  
Qiaobin Hu ◽  
Taoran Wang ◽  
Mingyong Zhou ◽  
Jingyi Xue ◽  
Yangchao Luo
Author(s):  
Dontha Sunitha

<p>ABSTRACT<br />To provide an outlook of the various available methods of antioxidant activity. Various available in vitro and in vivo methods are listed and the<br />procedure to perform the method, its mechanism is also explained in brief. 1,1-diphenyl-2-picrylhydrazyl method was found to be used mostly for the<br />in vitro antioxidant activity evaluation purpose while lipid peroxidation was found as mostly used in vivo antioxidant assay. An ethanol was with the<br />highest frequency as a solvent for extraction purpose. Summarized information on the various methods available provides with reliable information<br />to confirm the benefits of antioxidant effects.<br />Keywords: Antioxidant activity, Reactive oxygen species, Free radical, 1,1-diphenyl-2-picrylhydrazyl, Flavonoid.</p>


Author(s):  
Krishma M. Jadav ◽  
K. N. Ninge Gowda

Objective: Four different extracts of Araucaria columnaris (bark peel) and Cosmos sulphureus (flowers) were screened for their phytochemical composition, and free radical scavenging activities.Methods: DPPH method was used to test the antioxidant activity for extracts.Results: Among the different extracts tested, the methanol extract of both the plant species showed significant radical scavenging activities. Phytochemical analysis of the extracts revealed that the radical scavenging activities might be due to the presence of flavonoids, tannins and phenolic compounds.Conclusion: The results obtained suggest that Araucaria columnaris (bark peel) and Cosmos sulphureus(flowers) could be exploited in the treatment of various diseases like cancer, cardiovascular diseases and infection diseases.  


Author(s):  
Mayavatis Patil

Objective: In the present investigation, phytochemical assay and in vitro antioxidant activity of ethanol (70%), methanol, ethyl acetate and hexane extract of Citrus medica leaves were carried out.Methods: The quantification of total phenolic and alkaloid contents were estimated by taking gallic acid and atropine as standard. In–vitro antioxidant activity of extracts was evaluated by using different free radicals (DPPH, superoxide and free radicals).Results: Ethanol extract of leaves have more phenolic and alkaloid contents than other extracts. The selected plant extract was produced concentration dependent percentage inhibition of different free radicals and produced maximum activity at a concentration of 1000µgm/ml, and there after percentage inhibition was raised gradually to its maximum level with higher concentrations. HPLC analysis revealed the presence of Gallic acid, Catechein, Rutin, Chlorgenic acid, Queracetine and some unknown components which need to be e identified.Conclusion: Among the four extracts, ethanol extract of C. medica showed good antioxidant activity. 


Author(s):  
Animeshchandra G. M. Haldar ◽  
Santosh S. Chhajed ◽  
Debarshi Kar Mahapatra ◽  
Debarshi Kar Mahapatra

In the present investigation, the synthesis of few novel leads bearing 2-(p-hydroxyphenyl)-4–(substitutedphenyl)-1H-1,5–benzodiazepine pharmacophore is described. The substituted chalcone and their derivatives 3(a-j) were synthesized by base catalyzed Claisen-Schmidt condensation between p-hydroxy-acetophenone and appropriate aldehydes. The dibromostyryl ketones 4(a-j) were obtained by the reaction the chalcone with bromine in acetic acid. The dibromostyryl ketone were reacted with methanol in presence of sodium methoxide followed by acidic hydrolysis give 1-(4-hydroxyphenyl)-3-(substitutedphenyl)-1,3-propanediones. The targeted compounds; the substituted 1,5-benzodiazepines were synthesized with o-phenylenediamine and synthesized 1,3-propanediones. The structures of synthesized compounds were confirmed by spectroscopic and analytical techniques (IR, 1H-NMR, and MS). The free radical scavenging activity of the synthesized analogs was monitored by in vitro antioxidant activity protocol. The derivatives 6f, 6g, 6i, and 6j were found to exhibit good antioxidant activity with 59.07%, 41.33%, 68.3% and 60.4% scavenging activity respectively as compared to standard ascorbic acid which demonstrated 79.73% activity. The current research revealed the potential of 2-(p-hydroxyphenyl)-4–(substituted-phenyl)-1H-1,5–benzodiazepine as emerging free radical scavengers. The study helped to establish a structure-activity relationship (SAR) where the substitution on the phenyl moiety of the 1,5-benzodiazepine was found to play profound role and influence over biological activity. The research will open new avenues for the development of antioxidant moieties having perspectives in cancer, inflammation, and several other ailments.


2017 ◽  
Vol 5 (15) ◽  
pp. 2813-2822 ◽  
Author(s):  
Tania Hidalgo ◽  
Lucy Cooper ◽  
Martin Gorman ◽  
Tamara Lozano-Fernández ◽  
Rosana Simón-Vázquez ◽  
...  

Novel biocompatible Ca-gallate MOFs with progressive release of gallic acid associated with a significantin vitroantioxidant effect.


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