Continuous Hot Pressurized Solvent Extraction of 1,1-Diphenyl-2-picrylhydrazyl Free Radical Scavenging Compounds from Taiwan Yams (Dioscorea alata)

2004 ◽  
Vol 52 (7) ◽  
pp. 1945-1949 ◽  
Author(s):  
Po-Yen Chen ◽  
Yu-Xun Tu ◽  
Cheng-Tar Wu ◽  
Ting-Ting Jong ◽  
Chieh-Ming J. Chang
2020 ◽  
Author(s):  
Sakina Yagi ◽  
Zeinab T.E Hussain

Abstract Objective Hibiscus sabdariffa L., also known as roselle and karkadeh, is commonly used in traditional medicine and has many applications on food, pharmaceutical and cosmetic industries. More than 100 cultivars of H. sabdariffa are found. Despite the fact that Sudan is considered as one of the principal producer of H. sabdariffa there has been limited systematic study on the efficiency of different solvent extraction on its bioactive molecules. Therefore, this study was designed to investigate the chemical constituents of H. sabdariffa calyx using acetone, ethanol (EtOH), 50% EtOH and water as extraction solvents and their impact on the DPPH free radical scavenging activity. Results Results showed that the total polyphenol, flavonoids and vitamin C contents of the dried calyces were significantly (P < 0.05) affected by the solvent extraction used. HPLC analysis using 16 standards revealed the presence of 11–13 compounds in the four extracts with the 50% EtOH extract recovered the highest concentrations of identified compounds. Moreover, the 50% EtOH extract revealed highest DPPH free radical scavenging activity (IC50 1.544 ± 0.3 µg/mL). Based on these results, maceration the calyx on 50% EtOH was therefore suggested for optimal extraction of bioactive compounds with high antiradical activity from H. sabdariffa calyx.


2018 ◽  
Vol 20 (2) ◽  
pp. 200-204
Author(s):  
Md Akbar Hossain ◽  
Md Enamul Haque ◽  
Md Hassan Kawsar ◽  
Md Sohel Rana

The methanol extract of aerial parts of Dioscorea alata and its organic and aqueous soluble materials were subjected to screenings for antioxidant, cytotoxic, thrombolytic, membrane stabilizing and antimicrobial activities. The polyphenol content and DPPH free radical scavenging assay were conducted to evaluate the antioxidant activity. The total phenolic content was found to vary for different test samples ranging from 23.69 ± 0.25 to 26.60 ± 0.22 mg of GAE/gm of dried extract. In DPPH method the chloroform soluble fraction (CSF) of D. alata revealed the highest free radical scavenging activity with IC5025.33 ± 0.05 μg/ml. The petroleum ether soluble fraction (PESF) exhibited highest cytotoxic potential having LC50 value of 6.1 μg/ml. During the membrane stabilizing assay, the aqueous soluble fraction (AQSF) inhibited 31.91% and 47.55% haemolysis of RBC in hypotonic solution- and heat-induced method, respectively. In thrombolytic assay, the chloroform soluble fraction (CSF) displayed 40.45% clot lysis. On the other hand the carbon tetrachloride (CTCSF) and chloroform soluble fraction (CSF) revealed mild to moderate antimicrobial activity with zone of inhibition ranging from 8 to 12 mm.Bangladesh Pharmaceutical Journal 20(2): 200-204, 2017


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