ABTS Scavenging Activity Research Articles

Phytochemical analysis using GC-FID, FPLC fingerprinting, antioxidant, antimicrobial, anti- inflammatory activities analysis of traditionally used Eucalyptus globulus essential oil

Eucalyptus globules is an widely distributed in tropical and subtropical regions. It has been widely used as folk medicine, and folk cosmetic owing to its antioxidant values. Despite its importance, phytochemical and pharmacological studies remain infancy. This study was aimed at extraction of essential oil by steam-distillation and evaluation of bioactive components, antioxidant, antimicrobial, anti-inflammatory activities along with analysis by UV-VIS, FT-IR and Fluorescent techniques. Fast protein liquid chromatography (FPLC) was used to confirm the presence of polyphenols. Different antioxidant activities like DPPH., ABTS.+, .OH, superoxide, nitric oxide and reducing power of the essential oil. Essential oil was analyzed by UV-VIS, FT-IR and Fluorescent techniques. In vitro antimicrobial activity was also monitored. FT-IR fingerprint qualitative analysis was performed using commercial standards. Considerable amount of flavonoids were detected in essential oil. Oil exhibited considerable scavenging activities of ABTS.+, .OH, superoxide, nitric oxide and reducing power. UV-VIS, FT-IR analysis revealed the presence of polyphenolics in essential oil. Fluorescent spectroscopy revealed the presence of fluorophores in essential oil. FPLC and FT-IR fingerprint analysis revealed the presence of bioactive constituents like rutin, tannic acid, vanillic acid and ascorbic acid in the essential oil. A strong anti-inflammatory activity of oil was observed using fluorescent spectroscopy. An appreciable in vitro antibacterial activity against gram-negative bacteria like Acetobacter aceti and Pseudomonas aeruginosa was detected. The data provides the scientific support to the use of essential oil from Eucalyptus globules as a potent herbal source of bioactive compounds possessing natural antioxidant activities in food and pharmaceutical industries.

Evaluation of The Antioxidant, Antidiabetic and Immunomodulatory Activity of Cydonia oblonga Fruit Extract

Dietary natural antioxidant consumption can protect the human body from several diseases induced by free radicals. The aim of this study was to evaluate the antioxidant, antidiabetic and immunomodulatory properties of Cydonia oblonga fruit. For this; hydroethanolic extract of Cydonia oblonga fruit (HECO) was examined for antioxidant activity using DPPH free radical sc avenging, ABTS cation radical decolorization, Cupric reducing antioxidant capacity (CUPRAC), and Metal Chelating on ferrous ions activities. The inhibitory activity of the extract against α-glucosidase enzyme was also investigated. HECO was tested in vivo for the immunomodulatory activity on non-specific immunity by the carbon clearance test. The content of the nonenzymatic antioxidant reduced glutathione (GSH) in liver tissue of used mice was estimated. in vitro studies revealed that the HECO has an inhibitory concentration (IC50) value of 249.26 ± 3.75μg/mL, 117.34 ± 1.41 μg/ml for DPPH and ABTS scavenging activity respectively. As well as the ability to reduce cupric (167.17 ± 1.15μg/mL) and iron (Fe) (417.98 ± 48.82μg/mL). The extract showed antidiabetic activity as evidenced by its capacity to inhibit the α-glucosidase enzyme (IC50: 326.48 ± 18.56 µg/mL) near the acarbose (IC50: 275.98 ± 1.57 µg/mL) used as a positive control. In addition, our results showed that HECO at the concentration of 50 and 100 mg/kg significantly increased the clearance rate of carbon from the bloodstream concomitant with increased liberation of GSH from liver cells. This study demonstrates that HECO is effective in scavenging free radicals and can serve as potent antioxidants that provide potential treatment and prevention for diabetes with benefits on the innate defense system. Keywords: Antidiabetic, Antioxidant, Cydonia oblonga, Hydroethanolic extract, Phagocytic activity

Optimization of Ultrasonic Cellulase-Assisted Extraction and Antioxidant Activity of Natural Polyphenols from Passion Fruit.

In this paper, ultrasonic cellulase extraction (UCE) was applied to extract polyphenols from passion fruit. The extraction conditions for total phenol content (TPC) and antioxidant activity were optimized using response surface methodology (RSM) coupled with a Box-Behnken design (BBD). The results showed that the liquid-to-solid ratio (X2) was the most significant single factor and had a positive effect on all responses. The ANOVA analysis indicated quadratic models fitted well as TPC with R2 = 0.903, DPPH scavenging activity with R2 = 0.979, and ABTS scavenging activity with R2 = 0.981. The optimal extraction parameters of passion fruit were as follows: pH value of 5 at 30 °C for extraction temperature, 50:1 (w/v) liquid-to-solid ratio with extraction time for 47 min, the experimental values were found matched with those predicted. Infrared spectroscopy suggested that the extract contained the structure of polyphenols. Furthermore, three main polyphenols were identified and quantified by HPLC. The results showed the content of phenolic compounds and antioxidant activity of the optimized UCE were 1.5~2 times higher than that determined by the single extraction method and the Soxhlet extraction method, which indicates UCE is a competitive and effective extraction technique for natural passion fruit polyphenols.

Effect of different drying methods and storage conditions on physical, nutritional, bioactive compounds and antioxidant properties of doum (Hyphaene thebaica) fruits

The present study reports effect of various drying and storage conditions on physical, bioactive compounds, and antioxidant properties of doum (H. thebaica) fruit for the first time. Three types of fruit are used such as fresh, dried from tree, and dried fruits purchased from local market. Pulp of fresh fruit was dried using sun, shade and oven at different temperatures and stored under different conditions for three months. Samples were analysed before and after drying and storage. The results showed significantly (p < 0.01) higher dry matter (98.73 g/100g), pH (7.09), tannins (27.64 mg/g), flavonoids (19.90 mg/g) and total polyphenols (7.13 mg/g) contents in pericarp than other parts of fruit. The pulp without pericarp exhibited higher ash, amino acids, proteins and vitamin C contents, however pulp of whole fresh fruit had higher Ca (1.67 mg/g), Na (640.26 mg/g) and Zn (11.63 μg/g). Pulp of fruit purchased from local market showed significantly stronger antioxidant activities (DPPH and ABTS). All parameters evaluated were significantly (p < 0.01) affected in comparison with pulp of fresh fruit but varied with respect to drying methods and storage conditions. The shade-dried samples showed higher proteins, amino acids, vitamin C, ash, fibres and acidity contents than other drying methods. Polyphenols and antioxidant activities are higher in oven-dried samples at low temperature (40 °C) as compared to others. The highest DPPH and ABTS scavenging activities are observed after drying and storage conditions for three months. Significant and positive (p < 0.01) correlations are found between antioxidant compounds and antioxidant activities. Thus, drying methods and storage conditions can preserve pulp of doum fruit with high physicochemical, bioactive compounds and antioxidant capacities for human well-being up to three months, however shade-drying followed by oven-drying are highly promising process that must be considered as suitable drying methods for doum fruits.

Study to Evaluate the Effectiveness and Quality of Products of The Process of Extracting Codonopsis javanica Extract at Pilot Scale

The Codonopsis javanica, also known as “Đảng sâm” in Vietnamese, is a medicinal plant of high economic value. In this study, we further extended the previously reported process to produce C. javanica root extract by examining the concentrating stage to produce dried extract. Afterwards, effects of storage conditions on were evaluated and the pilot scale extraction process was compared with the lab-scale process. These processes were investigated with respect to different extract quality parameters including total polyphenol content (TPC), total flavonoid content (TFC), DPPH and ABTS scavenging activity. Best conditions for the concentration process included time of 120 minutes, temperature of 60°C. The efficiency of extracting C. javanica extract at pilot scale shows a difference of about 20% and this dried extract will retain the best quality when stored at 5°.

English

Ulvan is a water-soluble polysaccharide that is extracted from the algae Ulva pertusa (Chlorophyta). In this study, ulvan-calcium derivative (U-calcium) was prepared and calcium content was 5.2%. Ulvan-calcium could effectively scavenge on 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2&rsquo;-azino-bis (3-ethyl-benzothiazolie-6-sulfonic acid) (ABTS), hydroxyl, and superoxide radicals. The inhibition rate on superoxide radicals (&bull;O2-) was 83.14% at 0.2 mg/mL, and the scavenging activity of ABTS and hydroxyl radical (&bull;OH) at 3.0 mg/mL was 58.45 and 43.65%, and that of DPPH radicals at 8.0 mg/mL was 57.37%. All results showed that the antioxidant activity of ulvan-calcium was stronger than that of ulvan. The ulvan-calcium maybe used as an antioxidant to remove ROS and resist excessive oxidative stress. Key words: Ulvan-calcium, Ulva pertusa, antioxidant activity.

Antioxidant, and enhanced flexible nano porous scaffolds for bone tissue engineering applications

AbstractThree‐dimensional bioactive, antioxidant, and porous nanocomposite scaffolds are inevitable to avoid dependency and disability in the life cycle. Herein, we develop a facile fabrication protocol of nano porous zinc doped hydroxyapatite (Zn‐HAp) scaffold enhanced by polysaccharide polymeric structure for bone tissue engineering applications. The bioactive nano scaffold exhibit opens porous assembly that sustains its flexible and robust nature and promotes efficient linking capability. Moreover, nano scaffold geometry and its porosity were controlled efficiently in various concentrations of zinc doped hydroxyapatite (Zn‐HAp) nanoparticles. Indeed, the composite scaffolds are retained in a dry shape with a suitable load‐bearing strength adjacent to the cancellous bone. The presence of zinc doped hydroxyapatite in the polymeric matrix of nano scaffold regulates its antibacterial response against different bacterial strains owing to its oxidative stress nature. The antioxidant and biocompatibility of nano‐scaffolds were investigated by DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) scavenging behavior, the scavenging activity of ABTS (2,2‐azino‐bis‐3‐ethylbenzthiazoline‐ 6‐sulphonic acid) radical, and iron‐chelating potential. The observed results reveal that polysaccharide‐dependent porous geometry possesses adequate biocompatibility, radical scavenging behavior, and excellent antibacterial properties that validate it as a suitable candidate material for bone tissue implantation. The unprecedented radical scavenging and antioxidant bioactive nanocomposite scaffold are all set to reshape the future bone tissue implantation.

Antioxidant Activity and Biocompatibility of Fructo-Polysaccharides Extracted from a Wild Species of Ornithogalum from Lebanon.

The present study aims to investigate the properties of biopolymers extracted from a Lebanese onion non edible plant. The extraction was performed under mild conditions by varying the percentage of ultra-sound (US) treatment duration to a total extraction time of 30 min (0, 50, 100% US). The extracts were characterized using FTIR, SEC, GC-MS, TGA, and DSC analyses. The composition of the extracts was determined from the total carbohydrate content and protein content measurements. The thermal analyses indicate that all samples have high thermal stability. The antioxidant activities of the extracts were investigated, using β-carotene bleaching, scavenging activity of ABTS, metal chelating ability, and total antioxidant activity tests. The results indicate that the 50% US treatment leads to the best antioxidant activity. Biocompatibility of the extracts was evaluated using hemolysis and cytotoxicity assays. The results showed that 0 and 50% US samples are not toxic to human cells, in contrary to 100% US.

Standardization of Juniperus macrocarpa Sibt. & Sm. and Juniperus excelsa M. Bieb. Extracts with Carbohydrate Digestive Enzyme Inhibitory and Antioxidant Activities.

Juniperus species growing in Turkey are used for various medicinal purposes in traditional folk medicine. We aimed to evaluate in-vitro antidiabetic (α-glucosidase and α-amylase inhibition assays), antiobesity (pancreatic lipase inhibition assay), and antioxidant (ABTS and DPPH radical scavenging activities, ferric reducing activity, metal chelating activity, and phosphomolybdenum assay) activities of the extracts obtained from branches, leaves, and fruits of Juniperus macrocarpa and Juniperus excelsa. The branch (IC50 = 67.1 ± 1.7 µg/mL) and leaf ethyl acetate extracts (IC50 = 83.4 ± 0.8 µg/mL) of J. macrocarpa exhibited the strongest activity on the α-glucosidase enzyme. Besides that, J. excelsa leaf methanol extract exerted remarkable α-amylase inhibitory activity (IC50 = 950.1 ± 3.5 µg/mL). Only J. macrocarpa branch and J. excelsa leaf ethyl acetate extract slightly inhibited pancreatic lipase enzyme with 2963.3 ± 736.4 and 2343 ± 557.8 µg/mL IC50 values, respectively. The RP-HPLC-DAD analysis results demonstrated that the more active J. macrocarpa extracts are richer in agathisflavone, amentoflavone, and umbelliferone than J. excelsa extracts. With this study, it is concluded that J. macrocarpa branch and leaf ethyl acetate extracts may be a new source of α-glucosidase enzyme inhibitory activity and agathisflavone, amentoflavone can be used in the standardization of the extracts.

Studies on Polyphenol content, flavonoid content, and antioxidant activity of Graviola tea pulp (Annona muricata L.)

Tea is the most commonly consumed beverage worldwide due to promote health and prevention of some human diseases. Soursop tea pulp is well-known for containing a significant content of ascorbic acid (TAA), polyphenols (TPC) and flavonoids (TFC). In the present study, different pulp tea samples with varying dates of production were checked for TAA, TPC, TFC, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging activities, followed by sensory evaluation. There is a difference in TAA between sample (1) and (4), achieved 7.43 ± 0.04 mg/g DM and 12.21 ± 0.04 mg/g DM, respectively. TFC content ranged between 0.13 and 0.18. The phenolics group in tea is high and there are differences between the 3 recent production samples with (1): 3.81mg QC/g DM fluctuation. In sample 1, the antioxidant activity of the ethanol extract of Soursop was correlated with total phenolic and flavonoid content with values of 0.26 mgAA / g DM, 2.61 mgAA / g DM for DPPH and ABTS scavenging activity, respectively. Moreover, the CIE Lab* color space of the soursop tea is measured in the dark area, the L * difference achieved at 30.82 ± 1.24 (2) lowest and the highest 37.42 ± 4.77 (1). Consumer sensory evaluation is performed with results based on a 5-point scale describing: flavor, aroma, color, and favorite. The results showed sensory acceptance of all four samples and neligible difference in scores.

Solvent effect on phenolics and antioxidant activity of Huangshan Gongju (Dendranthema morifolium (Ramat) Tzvel. cv. Gongju) extract

Huangshan Gongju was extracted with organic solvents (ethanol, methanol and acetone) of different concentrations (0–90%), and the extracts’ phenolic content and antioxidant activity, as well as the correlations between them were examined. With the increasing concentration of organic solvent, the total phenolic compound (TPC) increased continuously and met its maximum at 70% acetone, whereas the total flavonoid compound (TFC) and most individual phenolics met their maximums at 70% ethanol. Similar changes occurred to the antioxidant activity, including DPPH and ABTS scavenging activities, and their maximums were respectively found at 50% acetone and 70% ethanol. The antioxidant activity correlated strongly with TPC/TFC (r > 0.954, p < 0.01) and individual phenolics (r > 0.886, p < 0.05), and the strongest correlations between them were mainly given by luteolin-7-O-glucoside (r > 0.975, p < 0.001). These results suggested that high content organic solvent (50–70%) was beneficial to obtain Huangshan Gongju extracts of higher phenolic content and antioxidant activity, and 70% ethanol may be the promising solvent. Besides, phenolics were found to be the main antioxidants of Huangshan Gongju extracts, and flavonoids especially luteolin-7-O-glucoside may play more important roles in the antioxidant activity.

Preparation, characterization and antioxidant activity of astaxanthin esters with different molecular structures.

Astaxanthin (Asta) is widely used in the nutraceutical and food industry because of its strong antioxidant properties. However, natural Asta mainly exists in the esterified form with various fatty acid chains, making it difficult to understand the particular molecular structure of astaxanthin esters (Asta-Es) that have better antioxidant capacity. In this study, Asta-Es with different molecular structures was systematically prepared, and identified by using thin-layer chromatography (TLC), ultraviolet-visible (UV-visible), high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and proton nuclear magnetic resonance (1 H-NMR). In addition, their antioxidant properties were evaluated by 2,2'-diphenylpicrylhydrazyl (DPPH) and ABTS scavenging activity. Fourteen Asta-Es with different molecular structures were systematically synthesized. This study used a simple and efficient method for the separation and purification of astaxanthin monoester (Asta-ME) and astaxanthin diester (Asta-DE) with high purity (86%-94%) by silica gel column chromatography. 13-cis-Asta-E and 9-cis-Asta-E were firstly identified from Asta-E. The DPPH clearance rates and ABTS scavenging rates of Asta-C4:0, Asta-C8:0, Asta-C12:0, and Asta-C18:0 were relatively close, but the DPPH and ABTS scavenging rates of Asta-C18:0, Asta-C18:1, Asta-C18:2, and Asta-C22:6 increased gradually. Among all Asta-Es, Asta-C22:6/C22:6 showed the highest antioxidant capacity, with the DPPH and ABTS scavenging rates of 77.22 ± 3.29% and 51.84 ± 1.65%, respectively. In this study, it was concluded that chemically synthesized Asta-Es contained cis-astaxanthin ester and polyunsaturated fatty acid chain increased the antioxidant activity of Asta, showing less effect of the length of fatty acid chain. These results provide useful information for the production and use of highly efficient Asta-E as functional food and pharmaceutical ingredients. © 2020 Society of Chemical Industry.

Isolation of endophytic bacteria from the leaves of Anredera cordifolia CIX1 for metabolites and their biological activities

BackgroundEndophytes, especially those that are found from ethnopharmacologically noteworthy medicinal plants have attracted attention due to their diverse bioactive metabolites of pharmacological importance.MethodsThis study aimed at isolating endophytic bacterium from the leaves of Anredera cordifolia CIX1 for its bioactive metabolites. The endophytic isolates were identified by 16S rRNA sequence and investigated for antibiotic sensitivity using different antibiotics. The secondary metabolites were evaluated for antibacterial activity against four bacterial strains. The 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azinobis (3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were used to assess their scavenging activities. The chemical components were analysed by gas chromatography-mass spectrometry (GC-MS).ResultsOut of 13 isolates, Isolate 1 was identified as Pseudomonas aeruginosa CP043328.1. It was resistant to clindamycin, ertapenem, penicillin G, amoxicillin, cephalothin and kanamycin but sensitive to imipenem, meropenem, and gentamycin. Its extract demonstrated antibacterial activity with minimum inhibitory concentration value of 0.098 against Bacillus cereus (ATCC 10102) and Staphylococcus aureus (ATCC 25925) and 0.391 mg/ml against Escherichia coli (ATCC 25922) and Proteus mirabilis (ATCC 25933). The extract revealed DPPH and ABTS scavenging activities with half maximal inhibitory concentration value of 0.650 mg/ml and 0.15 mg/ml, respectively. The GC-MS revealed a total of 15 compounds with diisooctyl phthalate (50.51%) and [1, 2, 4] oxadiazole, 5-benzyl-3 (10.44%) as major components.ConclusionsP. aeruginosa CP043328.1 produced secondary metabolites with antibacterial and antioxidant activities.

Chitosan nanoparticles as edible surface coating agent to preserve the fresh-cut bell pepper (Capsicum annuum L. var. grossum (L.) Sendt)

This work synthesized chitosan nanoparticles (CSNPs) by ionic gelation method using sodium tripolyphosphate pentabasic (STPP) and applied as nano-coating agent to extend the shelf life of fresh cut bell pepper (FCP) by preventing the microbial contaminations. The CSNPs were spherical shaped and 22.55 ± 1.69 d.nm sized with ζ-potential of 45.10 ± 1.42 mV confirmed by UHR-SEM, FE-TEM, and ζ-potential size analyses. The crystallinity and functional group changes were determined by XRD and FT-IR analyses respectivelly. The antioxidant activity of CSNPs was determined in terms of DPPH and ABTS scavenging activities. The 1% and 3% of CSNPs were found to be minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) respectively against all tested bacteria. The MBC of CSNPs was exhibited the promising anti-biofilm activity. Therefore, the 3% of CSNPs was used to prepare the chitosan nano-coating (CSNC), and applied on surface of FCP to prevent the microbial contaminations such as fungi, bacteria including Listeria monocytogenes and Salmonella enterica. The experimental results showed that the application of CSNC was maintained the FCP for 12 days at 5 °C without loss of weight, and sensory quality.

Impact of Ocimum Tenuiflorum Mediated Green Synthesis of Silver Nanoparticles on In-Vitro Antioxidant and Antibacterial Activities

The leaf extract of O. tenuiflorum was used to synthesize silver nanoparticles (AgNPs) and evaluated for its antioxidant and antibacterial properties. The silver nanoparticle was characterized using the UV-Vis spectrophotometer, SEM, FTIR, and XRD. The total phenolic and total flavonoid contents were determined for both leaf extract and synthesized silver nanoparticles. Antioxidant activities before and after synthesis of silver nanoparticles was assessed by DPPH, ABTS, iron chelating, and NO radical scavenging methods. The antibacterial activity of the leaf extract and AgNP were tested against Escherichia coli and Staphylococcus aureus. Statistical analysis was carried out to establish possible relations between the antioxidant, antibacterial and antioxidant activities. The formation of a dark brown solution mixture confirms the formation of silver nanoparticles at a wavelength of 450 nm. The AgNPs synthesized were spherical, with the size between 14 to 33 nm. Functional groups such as alcohol, aldehyde, nitrile, primary amines, carbonyl, and aromatic groups were confirmed by FTIR and XRD. Total phenol was higher in leaf extract, while total flavonoids were higher in the AgNps. Silver nanoparticles exhibited strong NO scavenging activity while leaf extract showed better ABTS scavenging activity. Silver nanoparticles inhibited E. coli better compared to S. aureus bacteria. It can be coined that the leaf extract of Ocimum tenuiflorum mediated the green synthesis of silver nanoparticles and possess strong antioxidant and antibacterial potentials that can find application in various biomedical areas.

Safety and biological activity evaluation of Uncaria rhynchophylla ethanolic extract

Uncaria rhynchophylla (UR) belongs to the Rubiaceae family, and its dried hooks are usually used in traditional medicine. It is effective in treating diseases related to the central nervous system. This study aimed to evaluate the safety of UR extract, investigate its antimutagenic and antioxidative activities, and elucidate its active components. Extraction and fractionation of the UR extract resulted in yields of 6.71%, 0.037%, 0.042%, 0.152%, 0.332%, and 5.132%, for hexane, ether, DCM, EtOAC, and aqueous fractions, respectively. The four indole alkaloids, total phenolic content (TPC), and total flavonoid content (TFC) of UR extract and its subfractions were measured. Alkaloid content was highest in the UR extract. TPC was the highest in the EtOAC fraction (373.7 ± 20.9 mg gallic acid equivalent (GAE)/g), whereas TFC was the highest in the UR extract (33.5 ± 2.4 mg quercetin equivalent (QE)/g). To assess the safety of UR extract mutagenicity, cytotoxicity, and oxidative stress inducibility assays were performed. The UR extract (2000 µg/plate) showed excellent antimutagenic activity (above 90%) against BaP in both TA98 and TA100 strains. The UR extract exhibited efficient DPPH (RC50 239.2 ± 16.5 µg/mL) and ABTS scavenging activity (RC50 458.7 ± 25.0 µg/mL). The UR extract (150 µg/mL) showed cytoprotective activity (65.6% ± 9.2%) against t-BHP. Among the subfractions, the EtOAC fraction possessed the strongest activities, overall. UR generally showed excellent biological activity at nontoxic concentrations (determined in vitro in current work), although the chemical composition of UR requires further investigation prior to its potential future use.

Physicochemical and functional properties of Maillard reaction products derived from cod (Gadus morhua L.) skin collagen peptides and xylose

To improve the utilization of cod skin collagen peptides (CSCP), we heated them with xylose at 80 °C, 100 °C, and 120 °C for up to 150 min to prepare xylose-CSCP Maillard reaction products (MRPs), and then investigated their physicochemical and functional properties. The results showed that Arg, Lys, Phe, and Asp were the major amino acids involved in the Maillard reaction. After being heated at 120 °C for 150 min, the ABTS scavenging activity and reducing power of xylose-CSCP MRPs were 99.59% and 0.887 absorbance units, respectively. Xylose-CSCP MRPs had better emulsifying properties and foaming properties than CSCP. Furthermore, 26 volatile compounds, including 2,5-dimethyl-pyrazine and 2-ethyl-3,5-dimethylpyrazine, were identified from xylose-CSCP MRPs by gas chromatography-ion mobility spectrometry. Newly formed heterocyclic compounds might be responsible for the flavor and antioxidant capacity of xylose-CSCP MRPs. These results suggest the potential for xylose-CSCP MRPs to serve as functional food ingredients.

Antioxidant Activity of Flavonoids from the Leaves of Tapinanthus pentagonia (Loranthaceae)

Phytochemical investigation of the crude methanolic extract of the leaves of Tapinanthus pentagonia (Loranthaceae) resulted in the isolation of four known flavonoids namely, quercetin 4’-methylether (1), 4’-methoxy-3’,5,7-trihydroxyflavone (2), quercetin-3-O-rhamnoside (3) and quercetin 3-O-rhamnoside4’- methylether (4). The structures of the isolated compounds were elucidated based on their 1D and 2D-NMR data. This is the first phytochemical study of that plant. The DPPH(2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, ABTS scavenging activity and ferric reducing antioxidant power (FRAP) were used to assess the antioxidant activities of the crude extract and three of the isolated compounds using catechin, ascorbic acid and gallic acid as standards, respectively. Results of the findings revealed that compound 3 exhibited the highest antioxidant activity in the three tests based on its IC50values followed by compound 4. Its IC50 value was 0.024 mg/ml comparable to that of catechin (0.015 mg/ml) for the radical scavenging activity. In summary, compounds 1, 3 and 4 exhibited good antioxidant properties and reducing power compared to the crude methanolic extract.

Antioxidative and anti-diabetic potentials of tigernut (Cyperus esculentus) sedge beverages fortified with Vernonia amygdalina and Momordica charantia

The utilization of tigernut is growing by the day due mainly to the myriads of health benefits attributed to it. Value addition is anticipated to further enhance the economic value and utilization of this sedge family crop. This study examined the physicochemical, antioxidant, anti-diabetic, and sensory properties of tigernut beverages fortified with extracts of Vernonia amygdalina and Momordica charantia with date and honey as sweeteners. Folin–Ciocalteau method was used to measure the total phenolic content while the ferric reducing antioxidant potential (FRAP), 2,2-diphenyl-1-picryhydrazyl (DPPH) and 2,2-azinobis (3-ethylbenzothiazoline-6-Sulfonate) (ABTS) were used to determine the in-vitro antioxidant activities. The inhibitory action of the beverages on α-amylase and α-glucosidase was used to assess the anti-diabetic potential. The DPPH, FRAP and ABTS scavenging activities were significantly higher in all the beverages with vegetable extracts. The inhibitory activity on α-glucosidase and α-amlyase are 38.82–75.54% and 20.59–60.14%, respectively. The sweeteners were able to significantly mask the bitter taste from the vegetable extracts thus improving consumer acceptability. The inhibitory effect of the beverages on diabetic related enzymes and the antioxidant activities suggest the formulation could be used as functional beverages with antidiabetic potential.

Metabolomic Analysis, Fast Isolation of Phenolic Compounds, and Evaluation of Biological Activities of the Bark From Weinmannia trichosperma Cav. (Cunoniaceae).

Weinmannia trichosperma Cav. (Cunoniaceae) (local name, tineo; Mapuche names, madén, mëdehue) is an endemic species of Chile and Argentina used in Mapuche traditional medicine in the treatment of chronic diarrhea, inflammation, and wound healing. This study focused on the isolation, analysis, and characterization of the biological activity of compounds and bark extracts from this plant for the first time. The infusion and tincture of the bark were characterized regarding antioxidant and important enzyme inhibitory activities, phenolics, and flavonoids content and UHPLC-ESI-OT-MS metabolite profiling. Twenty-five metabolites were detected in the medicinal infusion of W. trichosperma, three flavonols were isolated: isoastilbin, neoisoastilbin, and neoastilbin ((2R,3S)-, (2S,3R)-, and (2S,3S)-dihydroquercetin 3-O-alpha-l-rhamnoside) by countercurrent chromatography, and the isomers were quantified in the bark using a validated analytical HPLC methodology. The antioxidant properties were measured by ABTS, DPPH, FRAP, ORAC, and TEAC methods. The infusion displayed a strong DPPH and ABTS scavenging activity (IC50 = 20.58 and 3.070 µg ml−1, respectively) while a moderated effect was observed in the FRAP, ORAC, and ABTS assays. The infusion showed a content of phenolic and flavonoid compounds of 442.1 mg GAE g−1 and 15.54 mg QE g−1, respectively. Furthermore, the infusion showed a good and promissory inhibitory activity (33.80%, 33.12%, and 82.86% for AChE, BuChE, and 5-hLOX, respectively) and isoastilbin (51.70%, 50.10%, and 34.29–80.71% for AChE, BuChE, and 5-hLOX, respectively). The biomolecules identified in this study support the traditional uses of this bark and the potential industrial interest from this Valdivian plant species.