Assessment of antioxidant activities and phenolic contents of some edible plants

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
I Orhan ◽  
M Kartal ◽  
FS Şenol ◽  
M Abou-Asaker ◽  
B Şener
2008 ◽  
Vol 7 (1) ◽  
Author(s):  
Bimo Budi Santoso

<strong><em>Flavanoid, steroid, and terpenoid contents of 20 Manokwari medicinal plants were analyzed.  The antioxidant activity, total phenolic contents and antitumor activity of 20 Manokwari medicinal plants were also evaluated. The result shows that 83% positif to flavanoid test, 59% positif to terpenoid test and only 25% positif steroid. Antioxidant activity and total phenolic contents evaluated using Ferric Thiocianate (FTC) and Folin-Ciocalteu methods respectively. Antioxidant activity and total phenolic contents of medicinal plants were extracted by the traditional method, boiling in water and also in 80% methanol. Twenty plants evaluated in both exstracts have significantly varies of antioxidant activities and phenolic contents,  A significant and linier correlation coefficient between the antioxidant activity and the total phenolic content was found in both aqueous (R<sup>2</sup>= 0,77) and methanol (R<sup>2</sup> = 0,85). Antitumor activity was tested using cell maurine P-388 and only 2 of medicinal plants are active to inhibit cell maurine P-388. Comparing extraction efficiency of the two methods, the methanol extracted phenolic compounds more efficiently, and antioxidant activity of the extract was higher.</em></strong>


Antioxidants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 215 ◽  
Author(s):  
Cai-Ning Zhao ◽  
Guo-Yi Tang ◽  
Shi-Yu Cao ◽  
Xiao-Yu Xu ◽  
Ren-You Gan ◽  
...  

Tea is among the most consumed drink worldwide, and its strong antioxidant activity is considered as the main contributor to several health benefits, such as cardiovascular protection and anticancer effect. In this study, the antioxidant activities of 30 tea infusions, which were obtained by the mimic of drinking tea of the public, from green, black, oolong, white, yellow and dark teas, were evaluated using ferric-reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, ranging from 504.80 ± 17.44 to 4647.47 ± 57.87 µmol Fe2+/g dry weight (DW) and 166.29 ± 24.48 to 2532.41 ± 50.18 µmol Trolox/g DW, respectively. Moreover, their total phenolic contents (TPC) were detected by Folin-Ciocalteu assay and were in the range of 24.77 ± 2.02 to 252.65 ± 4.74 mg gallic acid equivalent (GAE)/g DW. Generally, Dianqing Tea, Lushan Yunwu Tea, and Xihu Longjing Tea showed the strongest antioxidant activities among 30 teas. Furthermore, the phenolic compounds in tea infusions were identified and quantified, with catechins most commonly detected, especially in green tea infusions, which were main contributors to their antioxidant activities. Besides tea polyphenols, considerable content of caffeine also presented in 30 tea infusions.


Food Research ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 547-556
Author(s):  
U. Tobgay ◽  
P. Boonyanuphong ◽  
P. Meunprasertdee

Pigmented rice is considered as the good source of phytochemicals which contains more phenolic contents and higher antioxidant activities compared with non-pigmented rice. However, those phytochemicals are normally extracted using inorganic solvent, using water was rarely found. This study was aimed to compare extraction methods on antioxidant contents and activities of two types of Thai pigmented rice (black glutinous rice and red non-glutinous rice). Pigmented rice was extracted either conventional method alone or a combination of ultrasonic plus conventional method with different solvents (methanol and hot water). Phenolic contents were analyzed by spectrophotometric assay and high-performance liquid chromatography (HPLC). Antioxidant activities were investigated by radical scavenging capacity (ABTS and DPPH). The results showed that ultrasonic pretreatment significantly enhanced the total phenolic, flavonoid, anthocyanin contents and higher antioxidant activities compared with conventional extraction irrespective of solvents and rice varieties. Ultrasonic methanol (UM) extraction proved to extract significant higher content of all the compounds analyzed in both the rice varieties. In contrast, hot water (HW) extracts exhibited the lowest amount of bioactive compounds. However, there was no significant difference between methanol extraction alone and ultrasonic pretreatment with hot water extract on antioxidant contents for black glutinous rice. The contents of individual anthocyanins and flavonoids (cyanidin 3-O-glucoside, peonidin 3-O-glucoside, and quercetin) were significantly increased with ultrasonic pretreatment compare to the conventional method in black glutinous rice while failed to detect the red rice variety. The black glutinous rice contained significantly higher contents of all analyzed compounds and antioxidant activities than red rice. In conclusions, our results demonstrated that ultrasonic pretreatment significantly enhanced antioxidant extraction with higher activities compared with conventional extraction irrespective of solvents and rice varieties. Furthermore, the efficiency of ultrasonic together with hot water extraction was almost equal to methanol extraction which was the one effective solvent for extracting antioxidant.


2008 ◽  
Vol 107 (1) ◽  
pp. 296-304 ◽  
Author(s):  
Haifeng Zhao ◽  
Wei Fan ◽  
Jianjun Dong ◽  
Jian Lu ◽  
Jian Chen ◽  
...  

2019 ◽  
Vol 20 (21) ◽  
pp. 5427 ◽  
Author(s):  
Lingguang Yang ◽  
Peipei Yin ◽  
Xinxin Cao ◽  
Yujun Liu

Daxueteng, the liana stem of Sargentodoxa cuneata, is a widely used Traditional Chinese Medicine facing the overflow of its commercial adulterants. A method for discriminating adulterants and screening potential candidate alternatives of S. cuneata was thus established. Total phenols and flavonoids of S. cuneata and its six adulterants and their abilities to scavenge DPPH• and ABTS•+, to absorb peroxyl radicals (ORAC), and to inhibit AAPH-induced supercoiled plasmid DNA strand scission were comprehensively assessed. Polygonum cuspidatum and Bauhinia championii, two of the six adulterants of S. cuneate, shared considerably higher antioxidant activities as well as phenolic contents and, therefore, were considered as potential candidate alternatives. Phenolic compositions of the two potential candidate alternatives and S. cuneata itself were further determined by UPLC-QTOF-MS/MS. Totally 38 phenolics, including four hydroxybenzoic acids, two tyrosols, two caffeoylquinic acids, seven flavanol or its oligomers, two lignans, three hydroxycinnamic acids, six stilbenes, seven anthraquinones, and five flavanones were determined from three species. Furthermore, contents of different phenolic categories were semi-quantified and the major antioxidant contributors of S. cuneata and the two potential candidate alternatives were subsequently determined. It is concluded that tyrosols and caffeoylquinic acids were unique categories making great antioxidant contributions in S. cuneata and thus were considered as effective biomarkers in distinguishing its potential candidate alternatives.


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