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Background: There are ongoing efforts to identify the chemical composition of plants used as food or medicines in other to correlate their components with the numerous claims of their medicinal usefulness in folklore. Objective: This work is aimed at profiling the phytochemical composition of Spondias purpurea using GC-MS, as well as to determine the total phenolic content, total flavonoid content and the antioxidant capacity by DPPH radical scavenging assay. Methods: Whole fruit and stem bark of Spondias purpurea were collected, dried, extracted with methanol and concentrated in vacou before assessing them for their total phenolic content by Folin-Ciocalteu's phenol reagent method; total flavonoid content and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activities. The whole fruit and stem bark extracts were partitioned into n-hexane, dichloromethane, ethyl acetate and aqueous fractions. The n-hexane fraction of the stem bark and whole fruit were analyzed on GC-MS. Results: The stem bark had the highest phenolic content of 29.81 ± 1.18 GAE mg/g. Similarly, free radical scavenging activities assay showed the stem bark to be most active with IC50 of 6.20 ± 1.51µg/ml, better than the standard, ascorbic acid with IC50 of 11.51 ± 0.3µg/ml. The n-hexane partitioned fractions of the fruit and stem bark on GC-MS analysis showed 9 prominent compounds including 9,17-Octadecadienal (5.43%), 3-((4Z,7Z)-Heptadeca-4,7-dien-1-yl) phenol(12%), (Z)-3-(Heptadec-10-en-1-yl) phenol (11.76%), n-Hexadecanoic acid (7.07%) and 13 compounds including 9,17-Octadecadienal (20.51%),trans-13-Octadecenoic acid (12.61%), Pentadecanoic acid (8.3%), n-Hexadecanoic acid(15.24%). Conclusions: This study provides justification for some of the folkloric use of Spondias purpurea. [ABSTRACT FROM AUTHOR]

A series of new di- and polyamine-caffeine analogues were synthesised and characterised by NMR, FT-IR, and MS spectroscopic methods. To access the stability of the investigated caffeine analogues, molecular dynamic simulations were performed in NAMD 2.9 assuming CHARMM36 force field. To evaluate the antioxidant capacity of new compounds, three different antioxidant assays were used, namely 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH•) scavenging activity, ferrous ions (Fe2+) chelating activity, and Fe3+→Fe2+reducing ability. In vitro, the ability of new derivatives to protect human erythrocytes against oxidative haemolysis induced by free radical from 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH) was estimated. The cytotoxic activity was tested using MCF-7 breast cancer cells and human erythrocytes. All compounds showed the antioxidant capacity depending mostly on their ferrous ions chelating activity. In the presence of AAPH, some derivatives were able to effectively inhibit the oxidative haemolysis. Two derivatives, namely 8-(methyl(2-(methylamino)ethyl)-amino)caffeine and 8-(methyl(3-(methylamino)propyl)amino)caffeine, showed cytotoxic activity against MCF-7 breast cancer cells but not against human erythrocytes. Therefore, it is concluded that the selected di- and polyamine caffeine analogues, depending on their chemical structure, were able to minimise the oxidative stress and to inhibit the tumour cell growth. The confirmed antioxidant and cytotoxic properties of some caffeine derivatives make them attractive for potential applications in food or pharmaceutical industries. [ABSTRACT FROM AUTHOR]

In this study we determined contents of dry matter, ash, total protein, total sugars, lipids, B-group vitamins and vitamin C, polyphenolic compounds, and flavonoids, as well as active acidity, pH value, and antioxidant activity against ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)), DPPH ( 1,1-Diphenyl-2-picrylhydrazyl radical, 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) radicals, FRAP (ferric ion reducing antioxidant power) in fresh and lacto-fermented white asparagus stored for 1 and 3 months. In addition, we analyzed the microbiological quality of fermented asparagus. The nutritional value and contents of biologically-active compounds were affected by both the fermentation process and the storage of fermented products. Fermentation had no significant effect on dry matter, total protein and fat contents, but contributed to an increase in ash content and a decrease in total sugars content. Fermentation caused a significant decrease in contents of B-group vitamins, polyphenolic compounds, and dehydroascorbic acid, whereas enhanced ability to reduce iron ions and decreased vitamin content were determined in fermented white asparagus during storage. Fermentation and storage did not affect the radical scavenging ability against DPPH and ABTS nor contents of total polyphenols and total flavonoids. [ABSTRACT FROM AUTHOR]

Abstract: A detailed kinetic study was performed for the reaction of the aroxyl radical (ArO•) with eight vegetable oils 1–8, which contain different concentrations of α‐, β‐, γ‐, and δ‐tocopherols and ‐tocotrienols (‐Tocs and ‐Toc‐3s). The second‐order rate constants (ks) and aroxyl radical absorption capacity (ARAC) values for the reaction of ArO• with vegetable oils 1–8 (rice bran 1, perilla 2, rapeseed 3, safflower 4, grape seed 5, sesame 6, extra virgin olive 7, and olive oils 8) were measured in ethanol/chloroform/D2O (50:50:1, v/v/v) solution at 25 °C using stopped‐flow spectrophotometry. The ks value (16.1 × 10−3 L g−1 s−1) of rice bran oil 1 with the highest activity was 8.0 times larger than that (2.02 × 10−3) of olive oil 8 with the lowest activity. The concentrations (in mg 100 g−1) of α‐, β‐, γ‐, and δ‐Tocs and ‐Toc‐3s contained in the vegetable oils 1–8 were determined using high performance liquid chromatography‐mass spectrometry/mass spectrometry (HPLC‐MS/MS). From these results, it was clarified that the ArO•‐scavenging rates (ks) (i.e., the relative ARAC value) obtained for the vegetable oils 1–8 may be well explained as the sum of the product ∑ k s AOH ‐ i AOH ‐ i / 10 5 of the rate constant ( k s AOH ‐ i) and the concentration ([AOH‐i]/105) of AOH‐i (Tocs and Toc‐3s) included in vegetable oils. The results suggest that the ARAC assay method might be used in the evaluation of antioxidant activity of general food extracts. [ABSTRACT FROM AUTHOR]

A comprehensive study on the composition and antioxidant properties of black tea samples with a chemometric approach was performed via LC-ESI-Q-TOF-MS, DPPH radical scavenging assay, and Folin-Ciocalteu assay (TPC). Marked differences between the teas from seven different countries (China, India, Iran, Japan, Kenya, Nepal, Sri Lanka) were shown. The Indian samples demonstrated the highest total catechin content (184.8 mg/100 mL), the largest TPC and DPPH scavenging potential (58.2 mg/100 mL and 84.5%, respectively). The applied principal component analysis (PCA) and ANOVA revealed several correlations between the level of catechins in tea infusions. EC (epicatechin), ECG (epicatechin gallate), EGC (epigallocatechin), and EGCG (epigallocatechin-3-gallate) content was not correlated with DPPH, gallic acid, and TPC; however, a strong correlation of EC and ECG between themselves and a negative correlation of these two catechins with EGCG and EGC was noted. Interestingly, simple catechins were not found to be responsible for antioxidant properties of the black teas. The samples collected in the higher altitudes were similar. [ABSTRACT FROM AUTHOR]

BACKGROUND Lunasin is a novel cancer-preventive peptide that has been detected in various plants. However, the presence and bioactivity of lunasin in quinoa have not been demonstrated. RESULTS Lunasin was detected in quinoa using ultrahigh-pressure liquid chromatography-electrosparay ionization-mass spectrometry. The content in 15 quinoa samples ranged from 1.01 × 10−3 g kg−1 dry seed to 4.89 × 10−3 g kg−1 dry seed. Significant differences ( P < 0.05) in lunasin content among different cultivars (yy22, xsg86, xsg59, yy30 and yy19) from the same area and the same cultivar from different areas (Hainan, Hebei and Shanxi provinces) were observed. The lunasin isolated and purified from quinoa ( QLP) exhibited a weak DPPH radical scavenging activity (no IC50 value), but a strong ABTS+ radical scavenging activity ( IC50 value, 1.45 g L−1) and oxygen radical scavenging activity (40.06 µmol L−1 Trolox equivalents/g QLP when the concentration was 3.20 g L−1). In addition, QLP inhibited the production of nitric oxide ( NO), tumor necrosis factor-α and interleukin-6 on lipopolysaccharide-stimulated RAW264.7 macrophages by up to 44.77%, 39.81% and 33.50%, respectively, at a concentration of 0.40 g L−1. CONCLUSION Taken together, these findings indicate that lunasin presents in quinoa and is bioactive, which strengthens the recommendations for the development of quinoa-based functional foods. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Scavenging activities of isoliquiritigenin (ISO) and liquiritigenin (LIQ) toward hydroxyl (•OH) and hydroperoxyl (•OOH) radicals were studied using the density functional theory (DFT). Two representative reaction mechanisms, hydrogen atom transfer (HAT) and radical adduct formation (RAF), were investigated. In order to identify the scavenging activity of each active site of ISO and LIQ, the thermodynamic and kinetic parameters of all channels involved in two mechanisms were calculated in both gas and water phases. We found that RAF is the major mechanism of ISO scavenging •OH and •OOH. In the whole reaction of LIQ with •OH/•OOH, B′4-OH group in LIQ is always the most active site, meaning that HAT is the main mechanism of LIQ scavenging •OH/•OOH. For scavenging both radicals, ISO has a much higher activity than LIQ, which is probably due to the nearly planar conjugated conformation of ISO. The calculation results are valuable for designing high-activity scavengers against radicals. [ABSTRACT FROM AUTHOR]

A kinetic approach was used to determine the radical scavenging activities of sinapic acid and its derivatives: sinapine, 4-vinylsyringol, syringic acid, syringaldehyde, and ethyl, propyl and butyl sinapate. The responses were expressed as rates of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·) scavenging (RS), superoxide radical (O2·-) scavenging (RFF), and β-carotene bleaching in the emulsion system (RB). For RS and RB, the esters of sinapic acid showed the highest responses while, for RFF, this was seen for syringic acid. The effectiveness of the selected compounds for scavenging these free radicals was also determined at a fixed endpoint. The early response parameters were demonstrated to be good discriminators in assessing differences for antioxidants with comparable fixed endpoint activity. The primary feature that ranks the kinetic data and the endpoint determinations is interpreted in terms of the mechanisms of the reactions involved in each of the assays conducted. [ABSTRACT FROM AUTHOR]

The antioxidant properties of trans -aconitic acid (TAA) alone or in the presence of usual antioxidants were assessed by DPPH assay. The IC 50 value equal to 70 mM was very high compared to usual antioxidants (vitamin C and trolox). A joint experimental/theoretical study suggested that hydrogen atom abstraction in TAA by DPPH was located on –CH 2 – methylene bridge because the corresponding radical was more stabilized than COO · and C C · radicals. In combination with antioxidants (vitamin C, gallic acid, caffeic acid, trolox), synergy or additivity effects were noticed. The magnitude of the synergistic effect varied between 1.06 and 1.24 depending on the type and concentration of antioxidant for a concentration of TAA equal to 22.3 mM. Especially, the addition of TAA at a concentration below 32 mM to a solution containing 20 μM of vitamin C had a synergy effect. Beyond this concentration, TAA showed an additive effect. [ABSTRACT FROM AUTHOR]

To increase the utilization of rice cake as a traditional food and encourage healthy consumption of rice cakes, rice cakes with greater functionality are required. This can be achieved by adding medicinal plants to rice cakes. This study aimed to improve the functionality of rice cake by addition of the medicinal plant Codonopsis lanceolata. An experiment was conducted on the quality, functionality, and physiochemical properties of rice cake containing C. lanceolata powder. We confirmed the antioxidant activity of rice cake containing C. lanceolata powder by evaluating the DPPH(1-diphenyl-2-picrylhydrazyl) radical scavenging activity. We also confirmed the physiochemical properties of rice cake in a basic analysis experiment to determine the pH, glucose amount, and total flavonoid content. This experiment showed that rice cake with C. lanceolata powder contains higher values in all five (pH, moisture, crude protein, crude fat, and total flavonoids) physical and chemical characteristics tested, compared to the control group. When measuring 100 mg/ml, the antioxidant activity in the control group was only IC50 = 844.26 mg/ml, whereas rice cake with C. lanceolata powder had activity of IC50 = 119.01 mg/ml. In this study, we obtained meaningful results confirming that rice cake containing C. lanceolata powder has high marketability and functionality. Consequently, we expect to increase the demand for traditional rice cakes, to enhance the value of rice cake as a healthy food and to contribute to the production of various rice cakes containing a medicinal plant. [ABSTRACT FROM AUTHOR]

Consumption of banana flower as a vegetable is popular among many countries in Southeast Asia. In this study, banana flowers of six different Malaysian cultivars namely, pisang Abu (Musa balbisiana cv P. Abu), pisang Berangan (Musa acuminata cv P. Berangan), pisang Nipah (Musa balbisiana cv P. Nipah), pisang Susu (Musa acuminata cv P. Susu), pisang Mas (Musa acuminate cv P. Mas) and pisang Rastali (Musa paradisiaca cv P. Rastali) were investigated for their antioxidant and anti-hyperglyemic properties. The total poly phenolic content and antioxidant activities, the α-amylase and α-glucosidase inhibitory potentials of the banana flower extracts were studied in vitro using relevant assays. Among the six cultivars, cultivar Susu was found to have the highest phenolic content (80.13 ± 4.64 mg of GAE/g of extract) and displayed the highest ABTS+ and DPPH radical scavenging activities (24.73 ± 0.04 and 25.10 ± 0.15 μmole of Trolox equivalent/g of extract). The anti-amylase and antiglucosidase activity of the banana flowers extracts were in the range of 47.31-62.58% and 74.98-91.62%, respectively. All banana flower extracts inhibited the activity of α-glucosidase better than α-amylase at the concentration of 200 μg/ml. This study concluded that the extracts of Malaysian banana flowers were potent sources of natural antioxidants, which can be used as postprandial hyperglycemia regulators. [ABSTRACT FROM AUTHOR]

Okra is a common vegetable in most regions of Turkey and available all year-round, with a peak season during the summer months. In this study, first the chemical composition and physical properties of mature okra seeds were investigated. Then, the unroasted okra seed flour (OSF)and roasted okra seeds flour (ROSF) (40 min at 160°C) were analyzed for total phenolic contents and 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity. The results of flour samples showed that the values of phenolics in OSF (157.80 mg GAE 100 g-1 flour) and ROSF (232.19 mg GAE 100 g-1 flour). The concentration that provided 50% radical scavenging (IC50) was determined as 360.25 ± 2.01 mg ml-1 and 452.39 ± 12.27 mg ml-1 for roasted and unroasted okra seed flour, respectively. Regarding physical and chemical composition, okra seeds and their flour could be recommended for a good source of protein, fat, mineral and phenolic acid, which can be help remove the stigma of "starvation food" for people and promote them as a healthy food source. [ABSTRACT FROM AUTHOR]

New polyhydroxylated flavon-3-ols and 3-hydroxy-2-styrylchromones were prepared and assessed as reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavengers. The synthetic strategy involved the preparation of 2′-hydroxychalcones and 2′-hydroxycinnamylidenoacetophenones from base-catalyzed aldol reaction of appropriate 2′-hydroxyacetophenones and benzaldehydes/cinnamaldehydes, followed by an Algar-Flynn-Oyamada (AFO) reaction to give the polyalkoxy(flavon-3-ols and 3-hydroxy-2-styrylchromones). The last step of this synthetic route consisted in the cleavage of the protecting groups affording the expected polyhydroxylated derivatives. The present work consisted in the study of the in vitro scavenging activities of the synthetized compounds against the most physiologically relevant ROS [superoxide radical (O 2 - ), hydrogen peroxide (H 2 O 2 ), hypochlorous acid (HOCl), singlet oxygen ( 1 O 2 ) and peroxyl radical (ROO )] and RNS [nitric oxide ( NO) and peroxynitrite anion (ONOO − )]. Generally, all the tested new polyhydroxylated flavon-3-ols and 3-hydroxy-2-styrylchromones exhibited scavenging effects dependent on the concentration, and with IC 50 values found within the micromolar range. This work allowed the establishment of new structure-activity relationships and brought the knowledge about the selective choice of a structure depending on the targeted reactive species. [ABSTRACT FROM AUTHOR]

[Objective] To determine chemical components of volatile oils from leaves of Artemisia argyi and study their antioxidant activities in vitro. [Methods] Volatile oils were extracted from leaves of Artemisia argyi by the steam distillation (SD) method and chemical components were analyzed and identified by gas chromatography-mass spectrometry (GC-MS) method. Through the method of scavenging DPPH (1,1-diphenyl-2-picrylhydrazyl) organic free radicals, functions of volatile oils scavenging free radicals were studied. Ultraviolet-Visible Spectrophotometry was applied to determine and compare the clearance rate of volatile oils, antioxidant BHT (2,6-Di-tert-butyl-4-methylphenol) and Ve (Vitamin E). [Results] 40 chemical compounds were detected in volatile oils of leaves of Artemisia argyi. 27 of them were preliminarily identified, accounting for 89.12% of total volatile compounds. Major compounds were thujone (25.17%), eucalyptol (23.42%) and alcanfor (8.58%), α-Thujone (7.76%), terpinen-4-ol (4.7%), and borneol (3.34%). Antioxidant activity in vitro experiment indicated that the ability of scavenging DPPH free radicals is BHT > volatile oils of Artemisia argyi > Ve. [Conclusion] Volatile oils of Artemisia argyi mainly consist of ketones and terpenes, which have excellent in vitro antioxidant activity. [ABSTRACT FROM AUTHOR]

Grape seed and green tea extracts are reported to produce antioxidant scavenging activities against free radical toxicity. This study aimed to investigate the hypothesis that a specific combination of these extracts presents a synergistic antioxidant scavenging activities. The extracts of grape seed, green tea and their mixtures were characterized by phytochemical studies and tested for phenolics and flavonoids. In vitro antioxidant activity for individual extract and its mixtures was determined by DPPH, hydroxyl and superoxide free radical scavenging methods. The amount of total phenolics varied among the different extracts and ranged from 43.74 to 67.68 mg of gallic acid equivalents (GAE) / g dry weight, whereas total flavonoids content ranged from 4.25 to 11.66 mg of quercetin equivalents (QU)/g dry weight. The present results suggest that both extracts reported a highly contents of total phenolic and flavonoids compounds, also the mixtures of these extracts can synergistically enhance antioxidant activity. Antioxidant potential from mixture 2 (grape seed extract 200 mg: green tea extract 100 mg) was comparable to that of standard. HPLC results showed that the most abundant components in the mixture 2 extract were epigallocatechingallate while the lowest was the procyanidine. [ABSTRACT FROM AUTHOR]

In this study, we examined a possible use of a surface-deacetylated chitin nano-fiber (SDCH-NF) and hyaluronic acid (HA) interpolymer complex (IPC) tablet as a potential antioxidative compound in extended-release matrix tablets. The antioxidant properties of untreated chitin (UCH), SDCH-NF, and HA were examined using N-centered radicals derived from 1,1'-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). SDCH-NF and HA had acceptable scavenging abilities and were relatively efficient radical scavengers, but UCH was much less effective. The results suggest that SDCH-NF and HA could serve as scavengers of compounds related to the development of oxidative stress. An SDCH-NF/HA IPC tablet was prepared and evaluated as an extended-release tablet matrix using famotidine (FMT) as a model drug. The release of FMT from the IPC tablet (DCF-NF:HA = 1:1) was slower than that from a SDCH-NF only tablet. Turbidity measurements and X-ray diffraction (XRD) data also indicated that the optimum complexation ratiofor IPC between SDCH-NF/HA is 1/1, resulting in a good relationship between turbidity or XRD of the complex and the release ratio of FMT. These results suggest that an SDCH-NF/HA tablet has the potential for use in an extended-release IPC tablet with a high antioxidant activity. [ABSTRACT FROM AUTHOR]

Highlights: [•] Antioxidant activity of the extracts of 10 legumes were studied. [•] The relationship between antioxidant activity and phenolic content were evaluated. [•] Significant differences were observed in antioxidant activity of various legume extracts. [•] Lentil extracts have the highest total antioxidant activity, and DPPH• scavenging activity. [Copyright &y& Elsevier]

Highlights: [•] We investigated 62 commonly consumed Korean beverages. [•] The physicochemical properties and antioxidant activities were assessed. [•] Total phenolic content and ORAC values were highest in the pomegranate beverage. [•] DPPH radical and nitrite scavenging activities were highest in the vitamin beverage. [•] This research helps in the development of accurate method to determine antioxidant activities of commercial products. [Copyright &y& Elsevier]

Highlights: [•] W-HNP and A-HNP from P. tuber-regium present significant antioxidant activity. [•] Both W-HNP and A-HNP can effectively scavenge . [•] Scavenging activity to of W-HNP were stronger than that of A-HNP. [•] A-HNP was stronger than W-HNP in other four antioxidant activities. [Copyright &y& Elsevier]

This study characterised and evaluated the phenolic composition and antioxidant activity of the red wine grape Vranac (Vitis vinifera L.) from the southern Serbian vineyard region during grape ripening. Polyphenol composition at different harvest dates was determined by HPLC-DAD analysis. Antioxidant activity was estimated by DPPH assay. The study demonstrates that the Vranac variety represents important sources of dietary antioxidants. The results show that (+)-catechin, (-)-epicatechin and procyanidin dimer B2 were the most prevalent in the seeds, and quercetin and malvidin glucosides in the grape skins. All grape extracts were shown to have high radical-scavenging activity. Strong correlations between radical-scavenging activity and polyphenols suggest that the phenolic composition of the Vranac variety contributes significantly to the antioxidant capacities of grape extracts. During grape ripening there were significant changes in physiological properties and phenolic content, and it is important to determine optimal harvest time, which will ensure grapes with very good quality parameters (in our study at the 30th day after véraison). [ABSTRACT FROM AUTHOR]

[Objective] To investigate the effective component content and the antioxidant activity of the peels of Poria cocos (Schw.) Wolf, and to provide references for the application of P. cocos peels in the processing of high-value health food. [Methods] With the triterpenes methanol extracts of P. cocos peels as the research materials and ursolic acid as the reference substances, the antioxidant activity in vitro was evaluated by colorimetric method and chemiluminescence method. [Results] The percentage content of triterpenes in P. cocos peels was 1.58%. Triterpenes in P. cocas peels could effectively remove the superoxide anion free radicals(02- *), hydroxyl free radicals ( · OH) and hydrogen peroxide (H2O2). And their IC50 values were 1.01, 0.91 and 0.87 mg/mL. respectively. There were certain dose dependence relationship between scavenging rate and concentration. In vitro antioxidant test showed that triterpenes in P. cocos peels could restrict the erythrocyte hemolysis of chicken and had good scavenging effects on the MDA generation during the lipid peroxidation of mice liver. [Conclusions] The antioxidant activity of crude triterpenes in P. cocos peels was comprehensively evaluated. It was verified that the triterpenes had significant antioxidant activity. Effects of the triterpenes treatment groups were superior to the effects of ursolic acid methanol solution. Among them, 1.58 mg/mL triterpenes methanol solution had the most significant inhibitory effects. [ABSTRACT FROM AUTHOR]

[Objective] This study aimed to analyze the low-polar components and antioxidant activities of Vernonia divergens. [Method] After extraction, the relative contents of various components were calculated with peak area normalization method. In addition, V divergens were extracted with n-hexane, ethyl acetate and n-butanol, respectively; DPPH scavenging capacity and reducing capacity of these three extracts were analyzed and compared with that of vitamin C. [Result] A total of 29 compounds were identified that accounted for 88. 30% of the total amount of low-polar chemical components. The results indicated that n-butanol extract exhibited higher DPPH scavenging capacity and reducing capacity than ethyl acetate extract and n-hexane extract. [Conclusion] This study provided a theoretical basis for the development and utilization of V divergens. [ABSTRACT FROM AUTHOR]