ABTS Radical Scavenging Capacity Research Articles

Extraction Process, Component Analysis, and In Vitro Antioxidant, Antibacterial, and Anti-Inflammatory Activities of Total Flavonoid Extracts from Abutilon theophrasti Medic. Leaves.

The flavonoid fraction was extracted from the leaves of Abutilon theophrasti Medic., which are usually used as a traditional Chinese herbal medicine for the treatment of inflammation and joint pain. The current study focused on the extraction process, component analysis, and in vitro antioxidant, antibacterial, and anti-inflammatory activities of the flavonoid fraction as a part of ongoing research on bioactive substances from natural plant sources. This study evaluated the antioxidant activities via assays of DPPH radical scavenging capacity, ABTS radical scavenging capacity, and reducing power and investigated inhibitory activities against Escherichia coli, Salmonella, Staphylococcus aureus, and Streptococcus. Moreover, the inflammatory activity of the flavonoid fraction was estimated by measurement of the content of tumor necrosis factor alpha, interleukin-1-beta, interleukin-6, interleukin-10, nitric oxide, and cyclooxygenase-2 and the gene expression levels of several inflammation markers, such as inducible nitric oxide synthase and cyclooxygenase-2, in RAW 264.7 macrophages after LPS treatment. In addition, the underlying anti-inflammatory mechanisms, that is, the activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, were also revealed from the gene and protein expression levels. Taken together, these results suggested that the flavonoid fraction might exert in vitro antioxidant, antibacterial, and anti-inflammatory effects on LPS-stimulated RAW 264.7 macrophages and will be potentially useful as an adjuvant treatment for oxidative stress and bacterial and inflammatory diseases.

Stability of the potent antioxidant peptide SNAAC identified from Spanish dry-cured ham

Antioxidant peptides positively regulate oxidative stress in the human body as well as delay, retard or prevent protein and lipid oxidation in food products. Spanish dry-cured ham has been reported as a good source of bioactive peptides, being SNAAC the most active antioxidant peptide identified to date. In this work, the stability of this peptide against in vitro digestion, heat treatments and different salt concentrations was evaluated using three methods for measuring antioxidant activity: β-carotene bleaching assay, ABTS radical scavenging capacity and ORAC assay. The results evidenced a marked decrease in the antioxidant activity of SNAAC after gastrointestinal digestion, and the MALDI-ToF MS analysis revealed the degradation of the peptide after the process, the generation of the fragment SNAA and the presence of a peptide dimer throughout the in vitro digestion. On the other hand, the peptide SNAAC showed good heat stability after exposure to different temperatures (50°C, 72°C, and 90°C), but its antioxidant activity evaluated by ORAC assay decreased substantially when exposed to 100°C as compared with the control at 37°C. SNAAC remained stable in the presence of salt at concentrations ranging from 0 to 8% NaCl as well as it was able to inhibit about 40% of lipid oxidation in an emulsion system. These results reported the stability of the antioxidant peptide SNAAC to several conditions used in meat industry for the processing of dry-cured hams and ham-derived products and its effectiveness to partially prevent the lipid oxidation in these products. However, some strategies would be needed in order to increase the stability of the peptide during gastrointestinal digestion and thus improve its bioavailability to be used as functional food ingredient.

Inhibitory Effects of Siegesbeckia orientalis Extracts on Advanced Glycation End Product Formation and Key Enzymes Related to Metabolic Syndrome.

Metabolic syndrome typically includes Type 2 diabetes associated with hyperglycemia, central obesity, dyslipidemia and hypertension. It is highly related to oxidative stress, formation of advanced glycated end products (AGEs) and key enzymes, such as carbohydrate digesting enzymes like pancreatic α-amylase and intestinal α-glucosidase, pancreatic lipase and angiotensin I-converting enzyme (ACE). This study used an in vitro approach to assess the potential of four extracts of Siegesbeckia orientalis linne on key enzymes relevant to metabolic syndrome. In this research, S. orientailis was firstly extracted by ethanol. The ethanol extract (SE) was then partitioned sequentially with hexane, ethyl acetate and methanol, and these extracts were named SE-Hex, SE-EA and SE-MeOH, respectively. The experimental results showed that SE-EA had the highest total phenolic content (TPC, 76.9 ± 1.8 mg/g) and the total flavonoids content (TFC, 5.3 ± 0.3 mg/g). This extract exhibited the most significant antioxidant activities, including DPPH radical-scavenging capacity (IC50 = 161.8 ± 2.4 μg/mL), ABTS radical-scavenging capacity (IC50 = 13.9 ± 1.5 μg/mL) and reducing power. For anti-glycation activities, SE-EA showed the best results in the inhibition of AGEs, as well as inhibitory activities against α-glucosidase (IC50 = 362.3 ± 9.2 μg/mL) and α-amylase (IC50 = 119.0 ± 17.7 μg/mL). For anti-obesity activities, SE-EA indicated the highest suppression effect on pancreatic lipase (IC50 = 3.67 ± 0.52 mg/mL). Finally, for anti-hypertension activity, SE-EA also demonstrated the strongest inhibitory activity on ACE (IC50 = 626.6 ± 15.0 μg/mL). Close relationships were observed among the parameters of TPC, antioxidant activities, inhibitory activities on α-amylase, α-glucosidase, lipase and ACE (R > 0.9). Moderate correlations were found among the parameters of TFC, antioxidant activities, and suppression of dicarbonyl compounds formation (R = 0.5–0.9). Taken together these in vitro studies reveal the therapeutic potential of SE-EA extract in the prevention and treatment of metabolic disorders.

Antibacterial and antioxidant properties of grape stem extract applied as disinfectant in fresh leafy vegetables.

In the present study total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity and antimicrobial properties of grape (Vitis vinifera var. Red Globe) stem extract is reported. Also, the identification of main phenolic compounds was carried out by UPLC-PAD analysis. TPC and TFC of extract were 37.25gGAEkg-1 and 98.07gQEkg-1, respectively. Extract showed an antioxidant capacity of 132.60 and 317g TEkg-1 for DPPH and ABTS radical scavenging capacity, respectively. The main phenolic compounds identified were rutin, gallic acid, chlorogenic acid, caffeic acid, catechin and ferulic acid. Extract inhibited the growth of Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Typhimurium, and Escherichia coli O157: H7 at MIC range 16-18gL-1. Extract affected the different phases of bacterial growth. In addition, application of Extract (25g L-1) as a sanitizer was effective to reduce the populations of all bacteria inoculated in lettuce (0.859-1.884 log reduction) and spinach (0.843-2.605 log reduction). This study emphasizes the potential of grape processing byproducts as an emergent and attractive source of bioactive compounds with antioxidant properties and antimicrobial activity against important foodborne pathogens. The study demonstrated that stem extract could be used to control the presence of human pathogenic bacteria in fresh leafy vegetables.

Anacardium microcarpum extract and fractions protect against paraquat-induced toxicity in Drosophila melanogaster.

Anacardium microcarpum Ducke (Anacardiaceae) is a native species of Brazil used in folk medicine for the treatment of several illnesses although its antioxidant activity has been reported in vitro, there is no evidence of this effect in an in vivo model. Here, we investigated the potential protective effect of hydroalcoholic extract (AMHE), methanol (AMMF) and acetate (AMAF) fraction of A. microcarpum against paraquat toxicity on survivorship, locomotor performance, antioxidant enzymes activity and reactive species using Drosophila melanogaster. Flies were exposed to the extract or fractions (1 and 10 mg/ml) in the presence or absence of paraquat (5 mM) in sucrose solution for 72 h. In addition, total phenolic content of extract and fractions was evaluated as well as ABTS radical scavenging capacity. Our results demonstrated that AMAF presented higher content of phenols and ABTS chelating potential. Treatment of flies with the extract or fractions did not alter the survivorship, locomotor ability, and acetylcholinesterase (AchE) activity per se. Paraquat caused 85 % mortality of flies and 30 % increase in reactive species generation, which were significantly attenuated by AMHE and AMMF. AAMF increased catalase activity (from 66.77 ± 6.64 to 223.94 ± 25.92 mU/mg of protein), while AMAF increased GST activity (from 477.76 ± 92 to 770.19 ± 147.92 mU/mg of protein) and catalase activity (from 66.77 ± 6.64 to 220.54 ± 26.63 mU/mg of protein). AMHE and AMMF were more effective in protecting against paraquat toxicity. Taken together, the data indicate the potential of this plant in acting as a protective and antioxidant agent in vivo.

Chemical compositions, chromatographic fingerprints and antioxidant activities of Citri Exocarpium Rubrum (Juhong)

BackgroundCitri Exocarpium Rubrum (CER), which is known as Juhong in Chinese, is the dried exocarp of Citrus reticulata Blanco and its cultivars (Fam. Rutaceae) and is currently used in Chinese medicine to protect the stomach and eliminate dampness and phlegm. The main aim of this study was to develop a high-performance liquid chromatography ultraviolet mass spectrometry (HPLC-UV-MS) method for determining the chemical compositions and fingerprint of CER. We also evaluated the antioxidant properties of CER based on its 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, ferric ion reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays.MethodsTen CER samples were collected from Hong Kong and mainland China. Each CER sample was extracted using an ultrasonic extraction method. Chromatographic separation was achieved using a conventional Dikma Inspire C18 column with photo diode array detection (190–400 nm). Hesperidin, nobiletin and tangeretin were quantified based on the UV signal observed at 330 nm. The column was eluted with a mobile phase consisting of water and acetonitrile (15–55%) over 55 min. Fingerprints combined with similarity and principal component analyses were used to classify the herbs. The DPPH free radical scavenging activity, FRAP and ABTS properties of the different CER samples were assayed. Bivariate correlation analysis was performed to investigate the correlation between the characteristic peaks and their antioxidant capacities.ResultsLimit of detection (LOD), limit of quantification (LOQ), linearity, inter-day precision, intra-day precision, repeatability, stability and recovery of the developed method were validated, and the method was subsequently used to determine the contents of hesperidin, nobiletin and tangeretin, and to acquire the fingerprints of the CER samples. Seventeen characteristic peaks were found in the fingerprints, and eleven of them were identified. Bivariate correlation analysis revealed correlations between the characteristic peaks and the antioxidant activities of the samples.ConclusionAn HPLC-UV-MS method was developed and validated after a detailed investigation on extraction of chemical compounds from CER using different solvents and extraction times. None of the peaks was correlated with the DPPH free radical scavenging activity or ferric reducing capacity. Most of the peaks were correlated well with the ABTS radical scavenging capacity.

Bioactive compounds and antioxidant activity evolution during the ripening process of 12 Opuntia spp. fruit accessions

Opuntia spp. is easily adaptable to arid and semiarid climates, and represents a valuable alternative for the agricultural development in dry regions. Twelve accessions of Opuntia spp. fruits were characterized to know the evolution of their bioactive compounds concentration such as phenolics, flavonoids and pigments (Isobetanins, betanins, indicaxanthins and total betalains) during their ripening process. DPPH and ABTS radical scavenging capacity were determined and correlated with pigments and bioactive compounds concentration. Bioactive compounds and pigments concentration increased along ripening. Higher concentration of total betalains were found in ripe ꞌBondaꞌ (O. guerrana Griffiths) and ꞌRojo Tolucaꞌ (Opuntia robusta var. Larreyi) accessions, being of 78.96 ± 0.54 mg 100 g-1 DW and 69.87 ± 0.29 mg 100 g-1 DW respectively. Findings in this work can help to select Opuntia spp. accessions with high potential to be established as a valuable crop in the arid zones of Mexico.

Microwave-Assisted Extraction for Saponins and Antioxidant Capacity from Xao Tam Phan (Paramignya trimera) Root

The aim of this study was to determine the optimal microwave-assisted extraction (MAE) parameters for saponins and antioxidant capacity from the P. trimera root. The optimal MAE parameters were found to be 100% methanol, extraction time of 40 min and ratio of solvent to sample of 100 mL/g. Saponin content, saponin extraction efficiency, ABTS radical scavenging capacity, DPPH radical scavenging capacity, cupric ion reducing antioxidant capacity, and ferric reducing antioxidant power of the P. trimera root achieved under these parameters were 520.5 mg escin equivalents (EE)/g dried sample, 62.6%, 215.3, 93.2, 24.7, 121.7 mg trolox equivalents (TE)/g dried sample, respectively, which were higher than predicted values (488.8 mg EE/g dried sample, 58.8%, 213.7, 89.5, 24.0, 115.8 mg TE/g dried sample, respectively). Therefore, the optimal MAE parameters of 100% methanol, 40 min and 100 mL/g are recommended for obtaining saponin-enriched extracts from the P. trimera root for potential application in the food industry. Practical Application This study indicated that methanol concentration had the highest effect on the extractability of saponins and antioxidant capacity from P. trimera root, followed by ratio of solvent to sample and extraction time. Therefore, the application of the optimized MAE parameters allows obtaining the highest saponin yield as well as the greatest antioxidant capacity from P. trimera root for further investigation and application.

Antioxidant dietary fibre recovery from Brazilian Pinot noir grape pomace

Brazilian grape pomace was extracted in hot water, and a factorial experiment was used to evaluate polysaccharide recovery. The dependent variables were the temperature, particle size and solute:solvent ratio. Polysaccharide yields varied from 3% to 10%, and the highest sugar content was observed when extraction was carried out at 100°C from finely sized particles (⩽249μm) in a 1:12 solute:solvent ratio. The monosaccharide composition of extracts obtained from flours were, on average, Rha:Ara:Xyl:Man:Gal:Glc:GalA in a 3:32:2:13:11:20:19M ratio, with varying Glc:GalA ratios. 13C NMR and HSQC spectra confirmed the presence of pectic- and glucose-based polysaccharides in the extracts. Phenolic compounds were found after pomace extraction, and catechin, gallic acid and epicatechin were the principal compounds identified. The extracts also had ABTS radical scavenging capacity (from 8.00 to 46.60mMol Trolox/100g pomace). These findings indicate that these grape pomace flours are rich in antioxidant dietary fibre and have a potential use as food ingredients.

Phenolic Content and Antioxidant Capacity of Selected Cucurbit Fruits Extracted with Different Solvents

Cucurbits are major economically important species of plants; particularly those with edible fruits having nutritional significance. The present work was to investigate the polyphenolic content and antioxidant capacity of peels and pulps of four cucurbit fruits, namely pumpkin, ash gourd, watermelon and muskmelon. The solvent systems used were methanol, ethanol and acetone at three different concentrations in distilled water (50, 70, and 100%) and 100% distilled water. The extracts were analyzed for their total phenolic content, total flavonoid content and antioxidant activities using Ferric Reducing Antioxidant Power assay (FRAP assay), DPPH free radical-scavenging assay and ABTS radical scavenging capacity. The result showed that the highest extraction was by 50% acetone in case of peels and 50% ethanol in case of pulp. The best solvent was 50% acetone as it gave highest yield as well as showed highest correlation between various assays. The polyphenolic content and the antioxidant activity were high in peels than pulps. The muskmelon fruit extracts (peel and pulp) showed highest antioxidant activity. High polyphenolic content showed significant correlation with high antioxidant activity. The result indicated that these cucurbit fruit are good source of natural antioxidants which can be utilized as an ingredient to functional foods.

Antioxidant potential of rice bran oil prepared from red and white rice

The focus of the present study was to determine the total phenolic content (TPC) and antioxidant potential of Rice Bran Oil (RBO). The bran of two rice varieties was obtained and stabilized and subsequently RBO was extracted into hexanes. The phenolic fraction of the oil was extracted into methanol by passing the oil through a glass column packed with silica (60 A, pore diameter). TPC was determined and expressed as mg gallic acid equivalents (GAE) per gram extract. The antioxidant potential of the oil extracts was evaluated using DPPH and ABTS radical scavenging assays and β-carotene/linoleate model system. DPPH and ABTS radical scavenging capacities were expressed as IC50 values and inhibition of linoleic acid induced oxidation of β-carotene was expressed as percent inhibition. The TPC of the two extracts was not significantly different (p>0.05). However, the extract obtained from red rice variety exhibited significantly high (p Tropical Agricultural Research Vol. 26 (1): 1 – 11 (2014)

Identification of the anthocyanins from the purple leaf coloured tea cultivar Zijuan (Camellia sinensis var. assamica) and characterization of their antioxidant activities

Zijuan (Camellia sinensis var. assamica) is the most well-known representative of purple leaf coloured anthocyanin-rich tea cultivars in China. Herein, its anthocyanin composition has been investigated for the first time. Eight anthocyanins, pelargonidin-3,5-diglucoside, cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, delphinidin, cyanidin, pelargonidin, peonidin, and malvidin were identified using HPLC and LC–MS and by comparison of their retention times, elution order and MS spectra to authentic standards. Cyanidin-3-O-galactoside was found to be the most abundant. Anthocyanins are generally enriched in tender Zijuan tea leaves, and the green tea processing, especially roasted green tea, can effectively retain the vast majority of the anthocyanins originally present in the fresh leaves compared with those for Oolong tea and black tea. The antioxidant activities of tea infusions made from different kinds of Zijuan tea products were determined by measuring their DPPH radical scavenging capacity, ABTS radical scavenging capacity, ferric reducing antioxidant power (FRAP), and cellular antioxidant activity (CAA). Generally Zijuan green tea has stronger antioxidant activity than Zijuan Oolong tea and Zijuan black tea. Moreover, a significant positive correlation was observed between the total anthocyanins and antioxidant activity as measured by DPPH. (r = 0.896), ABTS.+ (r = 0.933), FRAP (r = 0.907) and CAA (r = 0.967) assays, suggesting that anthocyanins contribute greatly to the antioxidant activity of Zijuan tea products. This study provides a foundation for further basic research of anthocyanins and the exploitation of the health benefits of natural anthocyanins in Zijuan tea cultivar.

Antiglycation activity of lipophilized epigallocatechin gallate (EGCG) derivatives

Lipophilized EGCG derivatives were synthesized by esterification of EGCG with aliphatic fatty acids and demonstrated to possess many advantages, such as higher lipophilicity and apparent health benefits over the parent EGCG. This study used a total of seven lipophilized EGCG derivatives with fatty acids of different chain lengths attached and examined the impact of lipophilization on EGCG’s antiglycation activity in vitro. The length of fatty acid chain was found to be an important factor, which positively correlated with ABTS radical scavenging capacity but long chain bulky substitutes prevented methylglyoxal (MGO) trapping. Except docosahexaenoic acid (DHA), lipophilization generally showed no interference with EGCG’s in vitro inhibitory activity of advanced glycation endproducts (AGEs) formation. Therefore, the lipophilized EGCG derivatives are promising candidates worthy of further exploration for preventing AGEs accumulation in vivo and hence treating AGEs-associated diseases.

Effect of in vitro digestion on bioactive compounds and antioxidant activity of common bean seed coats

The effects of gastrointestinal digestion on black bean (BB) and small red bean (SRB) seed coats were evaluated in treated and untreated extracts with an in vitro digestion process. The total phenols (TPs), total flavonoids (TFs), condensed tannins (CTs), monomeric anthocyanins (MAs), ABTS radical-scavenging capacity and oxygen radical absorbance capacity (ORAC) were evaluated in both groups. Anthocyanins, which appeared at 10-fold higher levels in BB than SRB (0.83mg and 0.08mg cyanidin 3-glucoside equivalents/g of bean, respectively) were undetectable in either extract after digestion. The results indicate that the in vitro digestion process was responsible for a reduction of the TPs, CTs and MAs in both the BB and SRB seed coats, and of TFs in the BB seed coats. However, the antioxidant activity was maintained for both groups, and even significantly increased in the BB group when measured with an ORAC assay.

ABTS radical scavenging capacity in green and roasted coffee extracts

The impact of two parameters (temperature and duration) on the radical scavenging capacity of individual compounds, and total extracts found in coffee was investigated. Phenolic coffee extracts of light (200 °C), medium (225 °C) and dark (235 °C) roasted coffees in a range of 0–30 min were analyzed by an on-line RP-HLPC-ABTS•+ decolourization assay. This study revealed a general decrease of radical scavenging capacity related to native phenolic compounds. Processing coffee beans leads to generation of up to 10 new radical scavengers. The roasting process influences not only color and taste in coffees, but also the radical scavenging capacity of coffee as well. Phenolic content in roasted coffee and green coffee is very different. Six compounds identified as caffeoylquinic acids and dicaffeoylquinic acids, endowed with radical scavenging capacity were found in green coffee, whereas depending on the roasting process, roasted coffees can present up to 16 different radical scavengers. The compounds formed during the roast are most likely chlorogenic acids derivatives, of which 4 could be clearly identified as two feruloylquinic acids and two caffeoylquinides. In longer roasting durations, these molecules are subjected to auto-degradation, thus total radical scavenging capacity in coffee decline along with roasting (duration and temperature).

Antioxidant and anticancer activities from leaf extracts of four Combretum species from northern Thailand

Four Combretum species (Combretaceae) from northern Thailand (Combretum deciduum, Combretum griffithii, Combretum latifolium and Combretum quadrangulare) were tested for antioxidant and anticancer activities. Antioxidant activities were assessed by ABTS and DPPH radical scavenging capacity methods. Anticancer activity was tested against three cancerous human cell lines (KB, MCF7 and NCI-H187). All methanolic leaf extracts showed antioxidant activities with the ABTS and DPPH methods. The methanolic leaf extracts of C. deciduum inhibited KB-oral cavity and MCF7-breast cancer cell lines, C. latifolium inhibited MCF7-breast cancer cell line and C. quadrangulare inhibited KB-oral cavity and NCI-H187-small cell lung cancer cell lines. However, the methanolic leaf extracts of C. griffithii were inactive against all three cell lines. All methanolic leaf extracts exhibited non-cytotoxicity to Vero cell lines.

Nutritional compositions and antioxidative capacity of the silk obtained from immature and mature corn

The silks of immature and mature corn were evaluated for their variations in nutritional compositions, mineral content and antioxidant capacity. Both immature and mature silks were good source of nutritional compositions. Immature silks contained significantly higher moisture (89.31%) (fresh basis), lipid (1.27%) and protein (12.96%) content than the mature silk. Mature silks contained higher composition of ash (5.51%), carbohydrate (29.74%) and total dietary fiber (51.25g/100g), than the immature silk, but the difference was not significant. In mineral determination, immature silk was rich source of Ca (1087.08μg/g), Mg (1219.17μg/g), Cu (5.60μg/g) and Zn (46.37μg/g) than the mature silks. In contrast, other minerals such as K (35671.67μg/g), Na (266.67μg/g), Fe (4.50μg/g) and Mn (35.57μg/g) were found higher in the mature silk. The silks were extracted with ethyl acetate, ethanol and water using the Soxhlet extraction method to determine the polyphenol and ABTS radical scavenging capacity. From this study, the highest content of total polyphenol of immature silks was exhibited by ethanol extract (92.21mgGAE/g) while water extract (64.22mgGAE/g) had the highest polyphenol content among mature silk extracts. Total flavonoid content of both immature and mature silks was higher in the water extract at 8.40mgCAE/g and 2.31mgCAE/g, respectively. In the ABTS free radical assay method, all immature silk extracts had higher percentage of inhibition compared to the mature silks. Among all three crude extracts, the ethanol extract of immature (EC50=0.478mg/ml) and mature silk (EC50=0.799mg/ml) exhibited the strongest antioxidant capacity followed by the water and ethyl acetate extract.

Antimicrobial and antioxidant chitosan solutions enriched with active shrimp (Litopenaeus vannamei) waste materials

Several shrimp active materials, including protein concentrates, protein hydrolysates and a carotenoid extract, were recovered from shrimp (Litopenaeus vannamei) processing residues (head and exoskeleton) and characterized in terms of chemical composition and antioxidative properties (Ferric ion reducing power and ABTS radical scavenging capacity). Different coating solutions were prepared by solubilizing chitosan, which was obtained from the residual chitinous material, in lactic acid and blending it with the various recovered materials. Chitosan-based solutions were tested for their viscosity and their antioxidative and antimicrobial properties against 26 selected microbial strains. All blend solutions showed higher antioxidant capacity and reduced viscosity as compared to the base chitosan solution. The incorporation of an astaxanthin-rich protein concentrate increased the antimicrobial capacity of the blend solution, but no further effect was observed after extra addition of the carotenoid extract.

Antioxidant capacity of anthocyanins from Rhodomyrtus tomentosa (Ait.) and identification of the major anthocyanins

The anthocyanins in the fruits of Rhodomyrtus tomentosa (ACN) were extracted by 1% TFA in methanol, and then purified by X-5 resin column and C18 (SPE) cartridges. The purified anthocyanin extract (ART) from the fruits of R. tomentosa showed strong antioxidant activities, including DPPH radical-scavenging capacity, ABTS radical scavenging capacity, reducing power and oxygen radical absorbance capacity (ORAC). The purified anthocyanin extract was analyzed by high performance liquid chromatography (HPLC). The major anthocyanins were purified by semi-preparative HPLC and Sephadex LH-20 column chromatography, and were identified as cyanidin-3-O-glucoside, peonidin-3-O-glucoside, malvidin-3-O-glucoside, petunidin-3-O-glucoside, delphinidin-3-O-glucoside and pelargonidin-3-glucoside by HPLC–ESI/MS and nuclear magnetic resonance spectroscopy (NMR). Cyanidin-3-O-glucoside was considered as the most abundant anthocyanin, which was 29.4mg/100g dry weight of R. tomentosa fruits. Additionally, all the major anthocyanins were identified from R. tomentosa fruit for the first time.

Anti-Oxidant Activity of Anthocyanins of Black Soybean <i>In Vitro</i>

The aim of the work was to research antioxidant activity of the anthoyanins extracts of black soybean. The whole soybean through defatted, were to determine the phenolic and anthocyanin contents in black soybean extracts and to examine antioxidant activity of extract against DPPH and ABTS assays, and Ferric Reducing Antioxidant Power (FRAP), and superoxide anion radical scavenging activity. The defatted sample was extracted using ethanol by ultrasonic. The optimum DPPH and ABTS radical scavenging capacity (%) were 68.34% and 70.12%, VC was 59.76% and 95.23%, respectively, and contains high levels of reducing power and superoxide anion radical scavenging activity. The present results indicate that the anthoyanins extract from black soybean has greater anti-oxidative and is useful in functional food and other applications.