scholarly journals Extraction, Enrichment, and Quantification of Main Antioxidant Aglycones of Flavonoids and Tannins from Melastoma Dodecandrum Lour.: Guided by UPLC-ESI-MS/MS

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Yingpeng Tong ◽  
Yu Jiang ◽  
Xubo Chen ◽  
Xiaonan Li ◽  
Ping Wang ◽  
...  

The objective of this work was to determine the main antioxidant aglycones of flavonoids and tannins in antioxidant extracts from Melastoma dodecandrum Lour. (MD), based on its extraction and purification process optimization and component identification by UPLC-ESI-MS/MS. Firstly, the ultrasound-assisted extraction (UAE) process for antioxidants was established by using single factor tests and response surface optimization. Evaluating by DPPH radical scavenging assay, the antioxidant capacity of MD could reach 2742.27 ± 93.86 (μmol Trolox/g) under the optimized conditions including methanol concentration (61%, v/v), extraction time (45 min), liquid-solid ratio (0.46 ml/mg), and extraction temperature (25°C). Then, the antioxidants in the solution were enriched by using macroporous resins. Because of the highest adsorption capacity and desorption ratio, HPD 500 was selected out of 14 macroporous resins for further study based on the static adsorption and desorption tests. The adsorption mechanism of the HPD 500 resin presented that pseudo-first-order kinetics model and Freundlich isotherm model could adequately explain the adsorption process. After the antioxidants were dynamically saturated by HPD 500, the column was eluted with different concentrations of ethanol (0, 25, 50, 75, and 100%, v/v). Among the above five ethanol fractions, 50% ethanol fraction showed the strongest antioxidant activity and more than 95% antioxidants adsorbed in HPD500 could be eluted by 75% ethanol. Guided by analysis results of UPLC-ESI-MS/MS, main antioxidant aglycones of flavonoids and tannins in each ethanol elution fraction were quantitatively detected. Finally, according to the correlation analysis between the antioxidant capacity of each ethanol elution fraction and its content of 10 main flavonoids and phenolic acids, the antioxidant activities of MD could mainly contribute to tannins containing phenolic units such as ellagic acid and/or gallic acid. The results of this work would provide useful information for the production of antioxidants from MD. Thus, the analysis methods could also be a quality control tool for material or products related with MD.

Author(s):  
Khoa Van Tran ◽  
Hieu Trung Le ◽  
Son Lam Le ◽  
Vu Xuan Anh Ho ◽  
Kiet Tam Trinh ◽  
...  

<p>The objective of the work reported in this paper was to evaluated effects of temperatures extraction on <em>in vitro</em> antioxidant activities of polysaccharides from the <em>Ophiocordyceps sobolifera. </em>The antioxidant capacity of <em>Ophiocordyceps sobolifera </em>polysaccharide was evaluated to use  2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and total antioxidant activity methods. From this study, it could be concluded that the highest antioxidant activity of the polysaccharides could be obtained from extraction temperature 80 <sup>o</sup>C. Total antioxidant capacity of polysaccharides from <em>Ophiocordyceps sobolifera </em>  contained from 0.1183 ± 0.0011 to 0.1454 ± 0.0021 mg GA/g or from 0.1105 ± 0.0004 to 0.1215 ± 0.0006 μmol AS/g. Polysaccharides has the most potential antioxidant activity with the lowest half maximal inhibitory concentration (IC<sub>50</sub>) value range 0.97 mg/mL to 1.06 mg/mL.</p><p> </p>


2014 ◽  
Vol 12 (8) ◽  
pp. 858-867 ◽  
Author(s):  
Christina Zălaru ◽  
Claudia Crişan ◽  
Ioan Călinescu ◽  
Zenovia Moldovan ◽  
Isabela Ţârcomnicu ◽  
...  

AbstractThe aim of this research was to investigate the chemical composition of Coreopsis tinctoria Nutt. fruits extract, to highlight the potential of ultrasound assisted extraction in the fast preparation of extracts rich in polyphenols using different solvents (55%, 78% and 96% hydrous ethanol) and to evaluate the antioxidant potential of formulated extracts. LC-MS/MS was used to characterize the ethanolic extract from Coreopsis tinctoria Nutt. dried fruits. The extract contains different flavonoids (marein, flavanomarein, quercetagetin-7-O-glucoside, okanin aurone, leptosidin, luteolin, apigenin) and phenolic acids (chlorogenic acid, caffeic acid). Several parameters that could affect extraction efficiency were evaluated. Finally, this study focused on determination of plant extracts total phenolic content and their antioxidant capacity. The experimental results allowed the selection of the optimum operating parameters leading to the highest total polyphenolic content, expressed as gallic acid equivalents, and avoiding the degradation of phenolic compounds (ethanol 55%; extraction temperature 323.15 K, extraction time 30 min, liquid/solid ratio 20/1). A good relationship between total phenolic content and antioxidant capacity was obtained.


2017 ◽  
Vol 6 (2) ◽  
pp. 24 ◽  
Author(s):  
V. Nyau ◽  
S. Prakash ◽  
J. Rodrigues ◽  
J. Farrant

Processing of legumes before consumption has several effects on micronutrients, macronutrients and phytonutrients. This study was undertaken to investigate the effect of domestic processing on antioxidant activities and phenolic phytochemicals of the red bambara groundnuts and red beans. The study employed in vitro antioxidant assays (DPPH and FRAP) to screen for antioxidant properties, HPLC-PDA-ESI-MS and Folin Ciocalteu assay to screen for phenolic phytochemical profiles. Domestic cooking displayed positive effects on the antioxidant activity and phenolic phytochemical profiles of the two legumes. The free radical scavenging speed increased 10-fold in the methanolic extract from cooked red bambara groundnuts compared to uncooked. By contrast, the free radical scavenging speed increased 20-fold in the methanolic extract from cooked red beans compared to uncooked. HPLC-PDA-ESI-MS profiles of the cooked red bambara groundnuts and red beans revealed a number of emergent phenolic compounds, mainly flavonoids. These data indicate that cooking appear to enhance the nutraceutical profiles of the legumes investigated.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Nor Adila Mhd Omar ◽  
Noorlidah Abdullah ◽  
Umah Rani Kuppusamy ◽  
Mahmood Ameen Abdulla ◽  
Vikineswary Sabaratnam

Water extract ofLentinus squarrosulusmycelia was analysed for nutritional content, antioxidant capacity, and antiulcer ability. The extract contains high protein (57.6 g/100 g) and low total fat (0.5 g/100 g) and is rich in magnesium (0.4 g/100 g), potassium (3.8 g/100 g), vitamins B1(1.42 mg/100 g), and B3(194.29 mg/100 g) with total phenolic content of 39.16 mg/100 g. The cupric reducing antioxidant capacity and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of the extract were A450of 0.20 ± 0.03 at 0.5 mg/ml and IC50of 14.29 mg/ml, respectively. Oral feeding ofL. squarrosulusextract (250 mg/kg) offered significant gastric mucosal protection of Sprague-Dawley rats compared to cimetidine (50 mg/kg). The ulcer healing rate of ulcerated rats after 24, 48, and 72 hours of treatment was 82%, 90%, and 100%, respectively. The IL-1β level in the serum and the NF-κB level in the tissues indicate that the healing potential was associated with attenuation of proinflammatory cytokines.


2016 ◽  
Vol 12 (5) ◽  
pp. 439-449 ◽  
Author(s):  
Fan Hou ◽  
Yanwen Wu ◽  
Lina Kan ◽  
Qian Li ◽  
Shuangshuang Xie ◽  
...  

Abstract A comparison of chestnut polysaccharide extraction using ultrasound-assisted extraction (UAE) and hot water extraction (HWE) demonstrated that UAE is superior to HWE due to its higher extraction efficiency. Scanning electron microscopy (SEM), thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) and Fourier-transform infrared spectroscopy (FTIR) were used to characterize the ultrasound-assisted-extracted polysaccharide (UAEP) and hot water-extracted polysaccharide (HWEP). SEM images revealed that the UAEP and chestnut residue were crushed, with particle sizes that were smaller than those of the HWEP, which was related to the breakage of long-chain polysaccharides. TGA-DSC showed a higher transition temperature and enthalpy value for the UAEP than the HWEP, and the FTIR spectrum revealed typical characteristics of polysaccharides, with some differences between the UAEP and HWEP. The evaluation of antioxidant activities showed that the UAEP had stronger antioxidant capacities than the HWEP, regardless of the reducing power and DPPH-, ABTS- and hydroxyl radical-scavenging activities, suggesting that ultrasound is an optimal method to rapidly extract chestnut polysaccharide, a potential natural antioxidant.


Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 257 ◽  
Author(s):  
Marco Garcia-Vaquero ◽  
Gaurav Rajauria ◽  
Brijesh Tiwari ◽  
Torres Sweeney ◽  
John O’Doherty

The objectives of this study were to employ response surface methodology (RSM) to investigate and optimize the effect of ultrasound-assisted extraction (UAE) variables, temperature, time and amplitude on the yields of polysaccharides (fucose and total glucans) and antioxidant activities (ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity (DPPH)) from Laminaria digitata, and to explore the suitability of applying the optimum UAE conditions for L. digitata to other brown macroalgae (L. hyperborea and Ascophyllum nodosum). The RSM with three-factor, four-level Box-Behnken Design (BBD) was used to study and optimize the extraction variables. A second order polynomial model fitted well to the experimental data with R2 values of 0.79, 0.66, 0.64, 0.73 for fucose, total glucans, FRAP and DPPH, respectively. The UAE parameters studied had a significant influence on the levels of fucose, FRAP and DPPH. The optimised UAE conditions (temperature = 76 °C, time = 10 min and amplitude = 100%) achieved yields of fucose (1060.7 ± 70.6 mg/100 g dried seaweed (ds)), total glucans (968.6 ± 13.3 mg/100 g ds), FRAP (8.7 ± 0.5 µM trolox/mg freeze-dried extract (fde)) and DPPH (11.0 ± 0.2%) in L. digitata. Polysaccharide rich extracts were also attained from L. hyperborea and A. nodosum with variable results when utilizing the optimum UAE conditions for L. digitata.


Author(s):  
Israa Mahmud ◽  
Mohamed E. S. Mirghani ◽  
Faridah Yusof ◽  
Ma'an Al-khatib

Dietary polyphenols exist in two forms; extractable polyphenols (EPP) or compounds solubilised by aqueous/organic solvents, and non-extractable polyphenols (NEPP) or compounds remain in the corresponding residues after the extraction. At present, most researchers focus on EEP fractions, while NEPP is neglected. Thus, this study aimed to release NEPP from the remaining powder residue of Barhi date palm kernels (BDPK) with acid hydrolysis. The related extraction conditions were determined and optimised using response surface methodology (RSM) for maximisation of NEPP with highest cytotoxic and antioxidant activities. The face-centred central composite design (FCCCD) was used to establish treatments based on three independent variables, namely; extraction temperature, time, and solvent/sample ratio. Under the optimal conditions, the experimental values for DPPH radical-scavenging capacity of NEPP (IC50=57.52µg/mL), and cytotoxicity of NEPP against A549 and HT29 cells were IC50=17.4 µg/mL and 31.4µg/mL, respectively. The experimental values were in agreement with those predicted by RSM models, confirming the suitability of the model employed and the success of RSM for optimisation of the extraction conditions for NEPP from BDPK. These results indicate that NEPP from industrial date fruit waste could be a promising candidate as natural antioxidants with significant antiproliferation effect against A549 and HT29 cancer cells in-vitro.


2018 ◽  
Vol 9 (4) ◽  
pp. 375-381 ◽  
Author(s):  
Mahmoud Al‐Refai ◽  
Mohammad Ibrahim ◽  
Abdullah Al‐Fawwaz ◽  
Armin Geyer

A new series of furo[2,3-b]pyridine derivatives bearing aryl substituents were synthesized in two steps, where, the cyano-(2H)-pyridones (1a-l) were converted to the corresponding nicotinonitriles (2a-l), followed by the Thorpe-Ziegler ring cyclization to the furo[2,3-b]pyridine derivatives (3a-l). All new compounds were characterized by 1D-NMR experiments (1H and 13C) and 2D-NMR experiments (COSY, HMBC and HSQC), as well as ESI-MS and HR-ESI-MS data. The new compounds were screened for their antioxidant activities by 2,2-diphenyl-1-picryl-hydrazylhydrate (DPPH) free radical assay. The highest radical scavenging effect was observed for nicotinonitriles 2d, 2h and 2l and furo[2,3-b]pyridines 3b, 3f and 3j by methanolic solvent at 4.0 mg/mL concentration. Remarkably, all nicotinonitriles and furo[2,3-b]pyridine exhibited a significant radical scavenging activity after 24 and 48 hours compared with 0.5 hour.


2018 ◽  
Vol 43 (3) ◽  
pp. 19
Author(s):  
Juliana Metzner Franco ◽  
Silvana Marina Piccoli Pugine ◽  
Antônio Márcio Scatoline ◽  
Mariza Pires De Melo

The aim of the present study was to evaluate in vitro antioxidant capacity of Melissa extract (ME) (Melissa officinalis L.) and its protective effect on peroxyl radical-induced oxidative damage in erythrocytes. ME used in present study was obtained by rota-evaporation of the crude extract (ethanol:water/dried leaves). Total phenolic and flavonoids contend determination, 176.8 ± 13.2 mg GAE/g dw and  26.2 ± 3.2 mg QE/g dw, respectively).  Total equivalent antioxidant activities, TEAC in mg TE/g dw, were 61.4 ± 5.5 and 512.4 ± 77.2 for respective FRAP assay and DPPH• radical-scavenging. The ME acts as an antioxidant on NO and O2•-, when ME exerted a higher antioxidant action on NO scavenging to compared to the ascorbic acid (1.9 times), however, the antioxidant capacity of ME on O2•- was lower than ascorbic acid (5.6 times). The values of hemolysis inhibition from ME (IC50, 2.0 ± 0.5 mg/mL) were higher than ascorbic acid (IC50, 7.1 ± 1.8 mg/mL). Extract of Melissa was able to eliminate biological free radicals, suggesting a potential to prevent oxidative damage in vivo. In fact, the ME exerted protective action on cell membrane lysis in situ.


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