scholarly journals EFFECT OF UNDER CONVENTIONAL SOLVENT EXTRACTION ON POLYPHENOL CONCENTRATIONS AND ANTIOXIDANT ACTIVITIES IN Thespesia lampas.

2017 ◽  
Vol 5 (10) ◽  
pp. 1749-1757
Author(s):  
Sunayana Nath ◽  
◽  
Bhawana Pathak. ◽  
Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1290
Author(s):  
Noha Khalil ◽  
Mokhtar Bishr ◽  
Mohamed El-Degwy ◽  
Mohamed Abdelhady ◽  
Mohamed Amin ◽  
...  

Background: Khella (Ammi visnaga Lam.) fruits (Apiaceae) are rich in furanochromones, mainly khellin and visnagin, and are thus incorporated in several pharmaceutical products used mainly for treatment of renal stones. Methods: The objective of this study was to compare the yield of khellin and visnagin obtained using different conventional solvents and supercritical fluid extraction (SCFE) with carbon dioxide (containing 5% methanol as co-solvent). Water, acetone and ethanol (30% and 95%) were selected as conventional solvents. Results: Highest extract yield was obtained from 30% ethanol (15.44%), while SCFE gave the lowest yield (4.50%). However, the percentage of furanochromones were highest in SCFE (30.1%), and lowest in boiling water extract (5.95%). HPLC analysis of conventional solvent extracts showed other coumarins that did not appear in supercritical fluid extraction chromatogram due to non-selectivity of solvent extraction. Ammi visnaga extracts as well as standard khellin and visnagin were tested for their cytotoxic activity using sulforhodamine B assay on breast cancer (MCF-7) and hepatocellular carcinoma (Hep G2) cell lines. Results revealed a strong cytotoxic activity (IC50 < 20 µg/mL) for the SCFE and standard compounds (khellin and visnagin) (IC50 ranging between 12.54 ± 0.57 and 17.53 ± 1.03 µg/mL). However, ethanol and acetone extracts had moderate cytotoxic activity (IC50 20–90 µg/mL) and aqueous extract had a weak activity (IC50 > 90 µg/mL). Conclusions: Thus, supercritical fluid extraction is an efficient, relatively safe, and cheap technique that yielded a more selective purified extract with better cytotoxic activity.


2013 ◽  
Vol 834-836 ◽  
pp. 577-581
Author(s):  
Jian Chao Deng ◽  
Gai Gai Niu ◽  
Lai Hao Li ◽  
Xian Qing Yang ◽  
Yong Chuan Deng ◽  
...  

Flavonoids was isolated from canavalia maritime by accelerated solvent extraction (ASE) coupled with high-speed counter-current chromatography (HSCCC). The antioxidant activities of flavonoids were investigated in vitro and evaluated by IC50. The results indicated that flavonoids possessed obvious reducing power and significant inhibitory effects on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical. These results suggest that canavalia maritime flavonoids could be a suitable natural antioxidant for humans.


1979 ◽  
Vol 52 (5) ◽  
pp. 949-961 ◽  
Author(s):  
G. Scott ◽  
K. V. Smith

Abstract The antioxidant activities of a number of N-phenyl nitrones containing phenolic functions were compared with N-methyl nitrones and conventional antioxidants in peroxide and TMTD sulphurless vulcanizates. The N-phenyl nitrones were found to be effectively bound during vulcanization; whereas, the N-methyl nitrones were not. Unhindered phenols reacted to a higher degree and were relatively more effective than the typical hindered phenol antioxidant structures. A conventional bisphenol was effective in the sulphurless vulcanizate after solvent extraction, but this is considered to be due to the formation of an insoluble zinc salt. Synergism was observed in the TMTD sulphurless vulcanizate both before and after extraction.


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