Characterization of the radical scavenging activity of lignins??natural antioxidants

2004 ◽  
Vol 95 (3) ◽  
pp. 309-317 ◽  
Author(s):  
T DIZHBITE
2020 ◽  
Vol 10 (3) ◽  
pp. 133-136
Author(s):  
Ahlem Karbab ◽  
Kamel Mokhnache ◽  
Lekhmici Arrar ◽  
Abderahmane Baghiani ◽  
Seddik Khennouf ◽  
...  

The purpose of this study was to prepare three sub-fractions from Pituranthos scoparius roots (PSR), characterize their phytochemicals contents and to investigate their free radical scavenging activity by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and hydroxyl scavenging activities. Tannins, flavonoids, steroids, and other bioactive compounds were found in the different sub-fractions. The Ethyle acetate extract (EAE) and chloroform extract (ChE) exhibited the highest antioxidant activity using ABTS (17.8 ± 0.87 µg/mL and 18.15 ± 0.68 µg/mL), respectively. Whereas, Crude extract (CrE) have been presented strong hydroxyl scavenging activity (14.9 ± 0.8 µg/mL). This study indicates that PSR extracts has potent free radical scavenging, and may prove to be of potential health benefit as well as additional resources for natural antioxidants. Keywords: Medicinal plant; phytochemical screening; sub-fractions, free radical scavenging.


2010 ◽  
Vol 5 (6) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Kuo-Chen Cheng ◽  
Man-Chun Hsueh ◽  
Hou-Chien Chang ◽  
Alan Yueh-Luen Lee ◽  
Hui-Min Wang ◽  
...  

Two novel antioxidants, obtusilactone A (1) and (-)-sesamin (2) have been identified in Cinnamomum kotoense Kanehira. Both showed effective 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity compared with vitamin C, and reducing power compared with BHA. These results suggest that these constituents of C. kotoense act as natural antioxidants and play a potential role in cancer prevention.


2021 ◽  
pp. 72-76
Author(s):  
Regi J. Thomas ◽  
M. Shareefa ◽  
H. Harsha ◽  
Anitha Karun

Coconuts with various traits are available in different coconut growing countries. The pink husk is one such trait that has already been reported in coconut. There is a demand for tender nut water from pink husked types of coconut to treat hepatitis by traditional medicinal practitioners. Present studies were carried out to characterize pink husked types identified in Guam Tall variety of coconut. There were no morphological differences with respect to the nut characters between pink and non-pink husked types. Biochemical characterization of pink husked types revealed significantly higher total phenol content in the tender nut water of pink husked types than normal husked types. A significantly higher protein content of 86 mg 100 mL-1 was noted in pink husked type, compared to normal husked type with 58.7 mg 100 mL-1. Higher free radical scavenging activity based on DPPH assay with pink husked type was recorded with an IC50 value of 266.7 compared to normal type with an IC50 value of 358. Similarly, phosphomolybdate assay also revealed higher scavenging activity of pink husked type based on the IC50 value of 415.2 compared to 637.9 observed in normal husked type. Anthocyanin content of 25.98 mg 100g-1 fresh weight was noted in the exocarp of pink husked types, and it was negligible in normal husked type. These results justify the use of pink husked coconuts in various traditional medicines. There is tremendous potential for exploiting pink husked types of coconut in the pharmaceutical industry.


Author(s):  
Suresh Kumar P. Nair ◽  
Kumar Ganesan ◽  
Henok Azalewor ◽  
Neethu Letha ◽  
Sharmila Gani

Antioxidants are the chemical substances which prevent the free radicals damage in the body. Numerous researches are going globally focussed on investigating natural antioxidants of plants origins. The aims of the present study were to evaluate preliminary phytochemical investigation and in vitro antioxidant activities of Ethiopian indigenous medicinal plants, Ocimum lamiifolium Hochst. ex Benth and Ocimum basilicum L. Aqueous, benzene and hexane crude leaves extracts of O. lamiifolium and O. basilicum were subjected to qualitative phytochemical screening using standard procedures. In addition, we investigated the antioxidant potential of crude aqueous leaves extract of O. lamiifolium and O. basilicum using tests involving inhibition of superoxide anions, DPPH, H2O2, NO and ABTS. Preliminary phytochemical investigation for benzene, hexane and aqueous extracts found alkaloids, sterols, carbohydrate and glycosides, tannins and flavonoids. The fraction inhibition of lipid peroxide at the first stage of oxidation illustrated antioxidant activity of O. lamiifolium and O. basilicum as 90% and 88% compared to those of gallic acid (97%) and BHT (84%) respectively. Also, the aqueous leaves extract of O. lamiifolium and O. basilicum exhibited significant DPPH free radical scavenging activity, nitric acid free radical scavenging activity assay, superoxide anion scavenging activity, ABTS scavenging activity and hydrogen peroxide free radical scavenging assay. Our findings provide confirmation that the aqueous leaves extract of O. lamiifolium and O. basilicum are potential source of natural antioxidants, and this warranted its uses in traditional medicine systems.


Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 996
Author(s):  
Vito Michele Paradiso ◽  
Federica Flamminii ◽  
Paola Pittia ◽  
Francesco Caponio ◽  
Carla Di Mattia

Omics approaches are recently being applied also in food lipid oxidation, to increase knowledge of oxidation and antioxidation mechanisms. The so-called oxidomics throws a wider spot of light on the complex patterns of reactions taking place in food lipids, especially in dispersed systems. This research aimed to investigate the radical scavenging activity of olive oil phenolic antioxidants (OPAs) in O/W emulsions, as affected by the phase in which they were added. This allowed one to assess whether different behaviors could be expected from antioxidants originally present in phenolic-rich olive oils compared to natural antioxidants added in the water phase during emulsion production. Hydroperoxide decomposition kinetics and the analysis of volatile pattern provided an outline of antioxidation mechanisms. Though being effective in slowing down oxidation when added both in the oil and water phase, OPAs interfered in different ways with oxidation pathways, based on the phase in which they were added. OPAs added to the water phase were more effective in slowing down hydroperoxide decomposition due to the hydrophilic radical initiator. On the other hand, OPAs present in the oil were more effective in preventing radical propagation, with relevant consequences on the volatile pattern.


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