scholarly journals Antioxidant activity of phenolic fractions of Mallotus philippinensis bark extract

2009 ◽  
Vol 27 (No. 2) ◽  
pp. 109-117 ◽  
Author(s):  
M. Arfan ◽  
H. Amin ◽  
M. Karamać ◽  
A. Kosińska ◽  
W. Wiczkowski ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antiradical Activity ◽  
Total Phenolics ◽  
Reducing Power ◽  
Solvent System ◽  
Bark Extract ◽  
Total Antioxidant Activity ◽  
Phenolic Constituents ◽  
Total Antioxidant ◽  
Fraction I

Phenolic compounds were extracted from <I>Mallotus philippinensi</I> bark using methanol. Six fractions (I–VI) were separated from the extract on a Sephadex LH-20 column using ethanol and acetone-water as the mobile phases and were evaluated for their total antioxidant activity, antiradical activity against DPPH<sup>•</sup> (2,2-diphenyl-1-picrylhydrazyl radical), and reducing power. The total phenolics and tannin contents in the fractions were determined. The content of total phenolics in the fractions ranged from 54 mg/g (fraction I) to 927 mg/g (fraction VI). Condensed tannins were detected in fractions II–VI. Total antioxidant activity (TAA) of phenolic fractions of <I>Mallotus philipinensis</I> bark extract ranged from 0.58 mmol Trolox/g (fraction I) to 6.82 mmol Trolox/g (fraction IV). Fraction IV also showed the strongest antiradical activity against DPPH<sup>•</sup> and reducing power. Several phenolic constituents in the fractions were detected by RP-HPLC using a gradient solvent system with UV-DAD detection.

scholarly journals Antioxidant Activity and Phenolic Composition of a Red Bean (Phasoelus vulgaris) Extract and its Fractions

2017 ◽  
Vol 12 (4) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Ryszard Amarowicz ◽  
Magdalena Karamać ◽  
Montserrat Dueñas ◽  
Ronald B. Pegg
Keyword(s):  
Antioxidant Activity ◽  
Total Phenolics ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
In Vitro Assays ◽  
Total Antioxidant ◽  
Red Bean ◽  
Fraction I

The activities of the crude acetonic extract of red bean and its two fractions were determined using a β-carotene-linoleate model system as well as the total antioxidant activity (TAA), the total phenolics content (TPC), the DPPH radical-scavenging activity, and the reducing power assays. Results from the in vitro assays showed the highest values when tannins (fraction II) were tested. Specifically, the TAA of the tannins fraction was 4.37 mmol Trolox eq./g fraction; whereas, the crude extract and fraction I were 0.481 and 0.093 μmol Trolox eq./mg extract or fraction, respectively. The content of total phenolics in fraction II was the utmost (612 mg/g); the tannins content, assayed by the vanillin method and expressed as absorbance units at 500 nm per 1 g, was 938. RP-HPLC-PAD-MS profiling revealed the presence of 33 compounds: quercetin arabinoglucoside, quercetin rutinoside, quercetin, p-hydroxybenzoic acid, and kaempferol rutinoside were the most abundant phenolics in the extract.

scholarly journals Variation in antioxidant activity at two ripening stages of wild mango, Spondias pinnata (L.f.) Kurz., an underutilized fruit

2020 ◽  
Vol 7 (4) ◽  
Author(s):  
Bince Mani ◽  
Sinjumol Thomas
Keyword(s):  
Nitric Oxide ◽  
Hydrogen Peroxide ◽  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Total Phenolic ◽  
Total Antioxidant Activity ◽  
Plant Origin ◽  
Nitric Oxide Radical ◽  
Total Antioxidant

Antioxidant compounds play a significant role in preventing and scavenging free-radicals by reducing oxidative stress and providing protection to humans against degenerative diseases and infections. Obviously, antioxidant molecules of plant origin are pivotal to combat the oxidative harm in cells. Present work intended to evaluate the antioxidant capacity of the fruits of Spondias pinnata. Methanol extracts of the fruits at two stages of maturity were prepared and investigated by various antioxidants analyses such as total antioxidant activity, reducing power and radical scavenging assays (DPPH, nitric oxide and hydrogen peroxide). Its total phenol, flavonoid and tannin contents were also determined. Spondias pinnata fruit extracts exhibited effective antioxidant activity and its IC50 values of the unripe fruits were 65, 66, 72.23, 83.25, 66.75 ?g/ml and ripe fruits were 124.24, 92.50, 97.66, 144.10, 72.25 ?g/ml, for total antioxidant activity, reducing power, DPPH radical scavenging, nitric oxide radical scavenging and hydrogen peroxide scavenging assays respectively. The extracts, especially unripe fruit extract had good amounts of total phenolic and flavonoid contents which might contribute the antioxidant activities considerably. It is evident from the study that the fruits of S. pinnata possessed potent antioxidant activity and it can be considered as a good dietary choice among the underutilized fruits as well as common fruits. Therefore, wild mango may be a good choice of antioxidants of plant origin for dietary and pharmaceutical uses.

scholarly journals Synthesis, Characterization, and Antioxidant Activity of 8-Hydroxygenistein

2020 ◽  
Vol 15 (1) ◽  
pp. 1934578X2090139 ◽  
Author(s):  
Jin Shao ◽  
Tong Zhao ◽  
Hui-Ping Ma ◽  
Zheng-Ping Jia ◽  
Lin-Lin Jing
Keyword(s):  
Antioxidant Activity ◽  
High Performance ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Positive Control ◽  
Raw Material ◽  
Biochanin A ◽  
Total Antioxidant Activity ◽  
Nitric Oxide Radical ◽  
Total Antioxidant

It was reported that 8-hydroxygenistein (8-OHG) was synthesized by methylation, bromination, methoxylation, and demethylation using cheap and readily available biochanin A as raw material. All synthesized products were structurally confirmed by ultra-high-performance liquid chromatography (UHPLC), infrared spectroscopy, mass spectrometry, 1H-nuclear magnetic resonance (NMR), and 13C-NMR. In addition, we examined the antioxidant capacity of 8-OHG using 6 different methods such as 1,1-diphenyl-2-picrylhydrazyl radical scavenging, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical (ABTS) scavenging, nitric oxide radical (NO) scavenging, superoxide radical (O2 −•) scavenging, reducing power assay, and total antioxidant activity using ascorbic acid (VC) as a positive control. Compared with VC, 8-OHG exhibited higher total antioxidant activity and stronger scavenging activity on ABTS, NO, and O2 −•. These results indicate that 8-OHG is an excellent antioxidant agent and may be effective in preventing damage induced by free radical.

scholarly journals Examining the Performance of Two Extraction Solvent Systems on Phenolic Constituents from U.S. Southeastern Blackberries

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4001
Author(s):  
Xiaoxi Liao ◽  
Phillip Greenspan ◽  
Ronald B. Pegg
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Capacity ◽  
Total Phenolics ◽  
Antioxidant Properties ◽  
Solvent System ◽  
Antioxidant Power ◽  
Extraction Solvent ◽  
Phenolic Constituents ◽  
Ferric Reducing Antioxidant Power ◽  
Solvent Systems

Two common extraction solvent systems, namely acidified aqueous methanol and acidified aqueous acetone, were used to extract blackberry phenolics, and the antioxidant properties of the recovered extracts were compared. The crude extracts were fractionated into low- and high-molecular-weight phenolics by Sephadex LH-20 column chromatography. The hydrophilic-oxygen radical absorbance capacity (H-ORACFL), ferric reducing antioxidant power (FRAP), and the cellular antioxidant activity (CAA) assays were employed as indices to assess antioxidant capacity of the extracts and their respective fractions. The methanolic solvent system displayed a greater efficiency at extracting anthocyanin and flavonol constituents from the blackberries, while the acetonic solvent system was better at extracting flavan-3-ols and tannins. Anthocyanins were the dominant phenolic class found in the blackberries with 138.7 ± 9.8 mg C3G eq./100 g f.w. when using methanol as the extractant and 114.6 ± 3.4 mg C3G eq./100 g f.w. when using acetone. In terms of overall antioxidant capacity of blackberry phenolics, the acetonic solvent system was superior. Though present only as a small percentage of the total phenolics in each crude extract, the flavan-3-ols (42.37 ± 2.44 and 51.44 ± 3.15 mg/100 g f.w. in MLF and ALF, respectively) and ellagitannins (5.15 ± 0.78 and 9.31 ± 0.63 mg/100 g f.w. in MHF and AHF, respectively) appear to account for the differences in the observed antioxidant activity between the two solvent systems.

Inactivation of Listeria monocytogenes on Frozen Red Raspberries by Using UV-C Light

2017 ◽  
Vol 80 (4) ◽  
pp. 545-550 ◽  
Author(s):  
Yen-Te Liao ◽  
Roopesh M. Syamaladevi ◽  
Hongchao Zhang ◽  
Karen Killinger ◽  
Shyam Sablani
Keyword(s):  
Antioxidant Activity ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Total Phenolics ◽  
Total Antioxidant Activity ◽  
Frozen Food ◽  
E Coli ◽  
Total Antioxidant ◽  
Total Anthocyanins ◽  
Uv C

ABSTRACTIn this study, the efficacy of UV-C treatment was determined on the reduction of foodborne pathogens on artificially contaminated frozen food surfaces. At first, the UV-C inactivation rates on 100 μl of the respective cocktails of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes covered underneath 0.5-cm-thick ice were examined. Simultaneously, the energy percentage of UV-C transmitted through the ice was determined. The experiments showed that more than 65% of the UV-C light energy passed through the ice and that UV-C susceptibility was in the descending order of E. coli O157:H7, Salmonella, and L. monocytogenes. L. monocytogenes, the most UV-C–resistant strain, was then selected to test on frozen raspberries. The UV-C inactivation kinetic data of L. monocytogenes were well described using the Weibull equation. During 720 s of UV-C exposure, with a total dose of 7.8 × 102 mJ/cm2, a 1.5-log CFU/g reduction of L. monocytogenes population on the surface of frozen red raspberries was noted. No significant differences in total anthocyanins, total phenolics, and total antioxidant activity were observed between UV-C–treated and untreated frozen berries immediately after treatment. At the end of 9 months of storage at −35°C, UV-C–treated berries had statistically lower total phenolics, higher total anthocyanins, and similar total antioxidant activity compared with untreated berries. This study shows that UV-C light can be used to reduce the L. monocytogenes population on frozen raspberries.

scholarly journals Optimization of Total Phenolics Content and Total Antioxidant Activity of Black Tea Using Response Surface Methodology

2017 ◽  
Vol 9 (3) ◽  
pp. 29 ◽  
Author(s):  
Tah Clovis Tiku ◽  
Feumba Dibanda Romelle ◽  
Yadang Germaine ◽  
Nyobe Emillienne Carine ◽  
Achegui Nestor ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Total Phenolics ◽  
Black Tea ◽  
Total Antioxidant Activity ◽  
Fermentation Time ◽  
Fermentation Conditions ◽  
Total Antioxidant ◽  
Phenolics Content

Response surface methodology was used to optimize the fermentation conditions for the total phenolics content and antioxidant activity of black tea (Camellia sinensis). Fresh tea leaves were fermented following a rotatable central composite design of eleven experiments replicated thrice. The minimum and maximum fermentation time and temperature were respectively of 1 - 3 h and 30 - 40 °C. The results demonstrated that fermentation time and temperature significantly affect the total phenolics content and antioxidant activity of black tea. The optimum fermentation conditions for the present study were at 36 °C for 35 min which the values for total phenolics content and total antioxidant activity were 38.99 g GAE/100 g dw and 19.74 mg VitC Eq/100 g dw, respectively. Antioxidant activity was strongly correlated with total phenolics content of black tea.

scholarly journals Acetylcholinesterase Inhibitory and Antioxidant Activity of the Compounds Isolated from Vanda roxburghii

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Salim Ahammed ◽  
Rejina Afrin ◽  
Nasim Uddin ◽  
Yusuf Al-Amin ◽  
Kamrul Hasan ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Nervous System ◽  
Antioxidant Activities ◽  
Reducing Power ◽  
Chloroform Fraction ◽  
Total Antioxidant Activity ◽  
Traditional Use ◽  
Phytochemical Investigation ◽  
Total Antioxidant ◽  
First Time

Vanda roxburghii has been used in traditional medicine to treat nervous system disorders including Alzheimer’s disease (AD). We reported earlier a high acetylcholinesterase inhibitory and antioxidant activity in the chloroform fraction of this plant. Therefore, this study was designed to explore the compounds with acetylcholinesterase inhibitory and antioxidant activities from the chloroform fraction of Vanda roxburghii. Phytochemical investigation led to the isolation for the first time of a fatty acid ester: methyl linoleate (1), and three phenolics: syringaldehyde (2), vanillin (3), and dihydroconiferyl dihydro-p-coumarate (4) along with the previously reported compound gigantol (5). Among the isolates, vanillin (3) and dihydroconiferyl dihydro-p-coumarate (4) were found to significantly inhibit the activity of acetylcholinesterase, scavenge the free radicals, exhibit the reducing power and total antioxidant activity, and effectively reduce the peroxidation of lipid. Gigantol (5) and syringaldehyde (2), despite lacking the activity against acetylcholinesterase, exhibited antioxidant activity. Among the compounds, gigantol (5) appeared to be the most potent antioxidant. These findings revealed that V. roxburghii contained compounds with potential acetylcholinesterase inhibitory and antioxidant activity, which support its traditional use in the treatment of AD.

scholarly journals An Evaluation of the Antioxidant Activity of a Methanolic Extract of Cucumis melo L. Fruit (F1 Hybrid)

Separations ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 123
Author(s):  
R. S. Rajasree ◽  
Sibi P. Ittiyavirah ◽  
Punnoth Poonkuzhi Naseef ◽  
Mohamed Saheer Kuruniyan ◽  
G. S. Anisree ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Antioxidant Activity ◽  
Cucumis Melo ◽  
Methanolic Extract ◽  
Antioxidant Activities ◽  
Reducing Power ◽  
Total Antioxidant Activity ◽  
F1 Hybrid ◽  
Total Antioxidant ◽  
Cucumis Melo L

Cucumis melo L. (C. melo) is a fruit with many medicinal properties and is consumed in various countries. It is utilised for chronic eczema and to treat minor burns and scrapes. The present study was conducted to evaluate the antioxidant activity of a methanolic extract of Cucumis melo Linn (MECM). A coarse powder prepared from the fruit and seeds was extracted with methanol (absolute) by a hot continuous percolation process in accordance with the standard protocols. All the extracts were estimated for potential antioxidant activities with tests such as an estimation of total antioxidant activity, hydroxyl radical and nitric oxide scavenging activity and reducing power ability. The qualitative analysis of the methanolic extract of C. melo fruit showed the presence of various phytochemical constituents such as carbohydrates, alkaloids, sterols, phenolic compounds, terpenes and flavonoids. The total antioxidant activity of concentrations of 50, 100 and 200 µg were tested and observed to be 3.3 ± 0.1732, 6.867 ± 0.5457 and 13.63 ± 0.8295 µg of ascorbic acid, respectively. The results also showed significant nitric oxide and DPPH scavenging activities as well as a reducing power activity of MECM. Thus, our results suggest that MECM may serve as a putative source of natural antioxidants for therapeutic and nutraceutical applications.

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