scholarly journals Characteristics of antioxidant activity for certain fractions of polyphenols from seagrass of genus Zostera

2021 ◽  
Vol 201 (2) ◽  
pp. 505-515
Author(s):  
N. M. Aminina ◽  
V. M. Ostapenko ◽  
E. P. Karaulova
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Heterogeneous Systems ◽  
Total Content ◽  
Japan Sea ◽  
Size Exclusion ◽  
Quantitative Composition ◽  
Aniva Bay ◽  
Exclusion Chromatography ◽  
Layer Chromatography

Some components of alcohol extracts from seagrass of genus Zostera were fractioned in the column filled with sorbent Sephadex LH-20 using the methods of size exclusion chromatography. Content of polyphenols in the fractions and their antioxidant activity were determined. The total content of polyphenols in the extracts from Zostera asiatica collected in the Rudnaya Bay (Japan Sea) and Zostera marina from the Aniva Bay (Okhotsk Sea) was 2.10 and 2.15 mg/mL, or 0.4 and 1.8 mg/g DW, respectively. The antioxidant activity varied by fractions in the range 19.1–118.0 μg of ascorbic acid per mL for Z. asiatica and 96.2–213.9 μg of ascorbic acid per mL for Z. marina, in dependence on qualitative and quantitative composition of the fractions. The alcohol extracts of Zostera were heterogeneous systems with different polyphenol components and included protein substances covalently bound with polysaccharides and/or polyphenols, that was confirmed by UV spectrometry and thin-layer chromatography. Phenolic acids, flavones and flavonols were presented in the extracts.

scholarly journals Berries and Leaves of Actinidia kolomikta (Rupr. & Maxim.) Maxim.: A Source of Phenolic Compounds

Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 147
Author(s):  
Laima Česonienė ◽  
Paulina Štreimikytė ◽  
Mindaugas Liaudanskas ◽  
Vaidotas Žvikas ◽  
Pranas Viškelis ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Phenolic Compounds ◽  
Radical Scavenging ◽  
Total Content ◽  
Ascorbic Acid Content ◽  
Free Radical Scavenging ◽  
Raw Material ◽  
Quantitative Composition ◽  
Pharmaceutical Industries

Berries of Actinidia kolomikta (A. kolomikta) are known for high ascorbic acid content, but the diversity of phenolic compounds has been little studied. The present research aimed to investigate phenolic compounds and antioxidant activity in berries and leaves of twelve A. kolomikta cultivars. The UHPLC-ESI-MS/MS technique was used to determine differences among cultivars in the quantitative composition of individual phenolic compounds. Antioxidant activity was determined by DPPH• free radical scavenging and CUPRAC methods. In the present study, 13 phenolic compounds were detected in berries, whereas leaves contained 17 phenolic compounds. Flavonols were the primary class found in both berries and leaves; other identified phenolic compounds were flavan-3-ols, flavones and, phenolic acids; and dihydrochalcone phloridzin was identified in the leaves. The amount and variety of phenolic compounds in berries and leaves and antioxidant activity were found to be cultivar-dependent. The highest total content of phenolic compounds was found in the leaves of the cultivar ‘Aromatnaja’ and in the berries of the cultivar ‘VIR-2’. Results of this study have confirmed that berries and leaves of A. kolomikta could be a valuable raw material for both food and pharmaceutical industries.

scholarly journals 68Ga-Labeling: Laying the Foundation for an Anti-Radiolytic Formulation for NOTA-sdAb PET Tracers

2021 ◽  
Vol 14 (5) ◽  
pp. 448
Author(s):  
Henri Baudhuin ◽  
Julie Cousaert ◽  
Philippe Vanwolleghem ◽  
Geert Raes ◽  
Vicky Caveliers ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Room Temperature ◽  
Radiochemical Purity ◽  
Negative Impact ◽  
Size Exclusion ◽  
Single Domain Antibody ◽  
Domain Antibody ◽  
Exclusion Chromatography ◽  
Optimal Mix ◽  
Layer Chromatography

During the preparation of [68Ga]Ga-NOTA-sdAb at high activity, degradation of the tracers was observed, impacting the radiochemical purity (RCP). Increasing starting activities in radiolabelings is often paired with increased degradation of the tracer due to the formation of free radical species, a process known as radiolysis. Radical scavengers and antioxidants can act as radioprotectant due to their fast interaction with formed radicals and can therefore reduce the degree of radiolysis. This study aims to optimize a formulation to prevent radiolysis during the labeling of NOTA derivatized single domain antibody (sdAbs) with 68Ga. Gentisic acid, ascorbic acid, ethanol and polyvinylpyrrolidone were tested individually or in combination to find an optimal mix able to prevent radiolysis without adversely influencing the radiochemical purity (RCP) or the functionality of the tracer. RCP and degree of radiolysis were assessed via thin layer chromatography and size exclusion chromatography for up to three hours after radiolabeling. Individually, the radioprotectants showed insufficient efficacy in reducing radiolysis when using high activities of 68Ga, while being limited in amount due to negative impact on radiolabeling of the tracer. A combination of 20% ethanol (VEtOH/VBuffer%) and 5 mg ascorbic acid proved successful in preventing radiolysis during labeling with starting activities up to 1–1.2 GBq of 68Ga, and is able to keep the tracer stable for up to at least 3 h after labeling at room temperature. The prevention of radiolysis by the combination of ethanol and ascorbic acid potentially allows radiolabeling compatibility of NOTA-sdAbs with all currently available 68Ge/68Ga generators. Additionally, a design is proposed to allow the incorporation of the radioprotectant in an ongoing diagnostic kit development for 68Ga labeling of NOTA-sdAbs.

scholarly journals (−)-Epicatechin—An Important Contributor to the Antioxidant Activity of Japanese Knotweed Rhizome Bark Extract as Determined by Antioxidant Activity-Guided Fractionation

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 133
Author(s):  
Urška Jug ◽  
Katerina Naumoska ◽  
Irena Vovk
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
High Performance ◽  
Radical Scavenging ◽  
Size Exclusion ◽  
Solvent Mixtures ◽  
Japanese Knotweed ◽  
Compound Identification ◽  
Rp Hplc ◽  
Ic50 Value

The antioxidant activities of Japanese knotweed rhizome bark extracts, prepared with eight different solvents or solvent mixtures (water, methanol, 80% methanol(aq), acetone, 70% acetone(aq), ethanol, 70% ethanol(aq), and 90% ethyl acetate(aq)), were determined using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay. Low half maximal inhibitory concentration (IC50) values (2.632–3.720 µg mL−1) for all the extracts were in the range of the IC50 value of the known antioxidant ascorbic acid at t0 (3.115 µg mL−1). Due to the highest extraction yield (~44%), 70% ethanol(aq) was selected for the preparation of the extract for further investigations. The IC50 value calculated for its antioxidant activity remained stable for at least 14 days, while the IC50 of ascorbic acid increased over time. The stability study showed that the container material was of great importance for the light-protected storage of the ascorbic acid(aq) solution in a refrigerator. Size exclusion–high-performance liquid chromatography (SEC-HPLC)–UV and reversed phase (RP)-HPLC-UV coupled with multistage mass spectrometry (MSn) were developed for fractionation of the 70% ethanol(aq) extract and for further compound identification, respectively. In the most potent antioxidant SEC fraction, determined using an on-line post-column SEC-HPLC-DPPH assay, epicatechin, resveratrol malonyl hexoside, and its in-source fragments (resveratrol and resveratrol acetyl hexoside) were tentatively identified by RP-HPLC-MSn. Moreover, epicatechin was additionally confirmed by two orthogonal methods, SEC-HPLC-UV and high-performance thin-layer chromatography (HPTLC) coupled with densitometry. Finally, the latter technique enabled the identification of (−)-epicatechin. (−)-Epicatechin demonstrated potent and stable time-dependent antioxidant activity (IC50 value ~1.5 µg mL−1) for at least 14 days.

scholarly journals Synthesis, Characterization and Antioxidant Activity of 2-Aryl Benzimidazole Derivatives

2020 ◽  
Vol 8 (2) ◽  
pp. 35-44
Author(s):  
Vineet Kumar Singh ◽  
Amrita Parle
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Radical Scavenging ◽  
Aromatic Aldehydes ◽  
Benzimidazole Derivatives ◽  
Benzoic Acids ◽  
Antioxidant Assay ◽  
Layer Chromatography

Objective: To synthesize benzimidazole derivatives, characterize them by 1HNMR and ATIR techniques and evaluate their antioxidant activity. Methods: In the present study 19 benzimidazole derivatives were synthesized by reacting O-phenylenediamine as the primary reactant with different aromatic aldehydes and benzoic acids. Reactions were monitored using thin layer chromatography technique, and the newly synthesized derivatives were characterized by ATIR and 1HNMR techniques. The antioxidant assay was performed using ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)] method and DPPH [2,2-diphenyl-1-picrylhydrazyl] method. Results: Compounds BNZ-1, BNZ-2, BNZ-3, BNZ-9, and BNZ-10 showed comparable antioxidant activity to ascorbic acid at higher dose. Conclusion: The synthesized benzimidazole derivatives have significant radical scavenging potential.    

scholarly journals Characterization and Antioxidant Activity of Products Derived from Xylose–Bovine Casein Hydrolysate Maillard Reaction: Impact of Reaction Time

Foods ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 242 ◽  
Author(s):  
Kun Chen ◽  
Jiajia Zhao ◽  
Xiaohan Shi ◽  
Qayum Abdul ◽  
Zhanmei Jiang
Keyword(s):  
Antioxidant Activity ◽  
Reaction Time ◽  
Maillard Reaction ◽  
Radical Scavenging ◽  
Casein Hydrolysate ◽  
Size Exclusion ◽  
Maillard Reaction Products ◽  
Reaction Products ◽  
Exclusion Chromatography ◽  
Initial Ph

The characterization and antioxidant activity on Maillard reaction products (MRPs) derived from xylose and bovine casein hydrolysate (BCH) was investigated at 100 °C and initial pH 8.0 as a function of reaction time. The pH values and free amino groups contents of xylose–BCH MRPs remarkably decreased with the reaction time up to 8 h, whereas their browning intensities significantly increased (p < 0.05). After 4 h of heat treatment, the fluorescence properties of xylose–BCH MRPs reached the maximum. There was a production of higher and smaller molecular substances in xylose–BCH MRPs with an increased reaction time, as analyzed by size exclusion chromatography. The 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging capacity and ferrous reducing activity of xylose-BCH MRPs gradually increased with the reaction time extended from 0 to 8 h.

scholarly journals Screening and Bioguided Fractionation of Mimosa pigra L. Bee Pollen with Antioxidant and Anti-Tyrosinase Activities

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Phanthiwa Khongkarat ◽  
Rico Ramadhan ◽  
Preecha Phuwapraisirisan ◽  
Chanpen Chanchao
Keyword(s):  
Antioxidant Activity ◽  
Silica Gel ◽  
Column Chromatography ◽  
Size Exclusion ◽  
Tyrosinase Inhibition ◽  
Chiang Mai ◽  
Bee Pollen ◽  
Mimosa Pigra ◽  
Exclusion Chromatography ◽  
Chiang Mai Province

AbstractBee pollen, one of the economic bee products, is widely known as a nutritional food with many bioactivities that depend on many such factors as bee species, plant source and biogeography. For this study, bee pollen was collected from Apis mellifera, harvested from the flowers of mimosa (Mimosa pigra L.) in the Chiang Mai province, Thailand. The sample was extracted in methanol (MeOH) and then sequentially partitioned with hexane, dichloromethane (DCM) and MeOH in order to isolate compounds depending on their polarities. The obtained extracts were then tested for their antioxidant and anti-tyrosinase activities through 1,1-diphyenyl-2-picrylhydrazyl (DPPH) assay and for/through inhibition of mushroom tyrosinase extract, respectively. The DCM partitioned extract of mimosa flower bee pollen (DCMMBP) provided the highest antioxidant activity, with an effective concentration at 50% (EC50) of 192.1 μg/mL, and was further fractionated by silica gel 60 column chromatography and Sephadex LH20 size exclusion chromatography. All fractions were tested for their antioxidant activity and analyzed for the chemical structure through nuclear magnetic resonance (NMR). The most active fraction (EC50 of 121.3 μg/mL) was a mixture of compounds, but the isolated flavonoid, naringenin, had a negligible antioxidant activity. In contrast, all three partitioned extracts and pooled fractions after silica gel 60 column chromatography provided no anti-tyrosinase activity (IC50 of > 500 μg/mL) and a very low percentage of tyrosinase inhibition (0–2.99 ± 3.18%), compared to kojic acid (IC50 of 8.58 μg/mL and tyrosinase inhibition of 74.2 ± 1.25%).

scholarly journals Antioxidant potentials of different potato genotypes

2018 ◽  
Vol 43 (3) ◽  
pp. 369-381
Author(s):  
SMZ Al Meraj ◽  
TK Ghosh ◽  
AKMA Islam ◽  
M Mohi Ud Din
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Food Security ◽  
Significant Variation ◽  
Antioxidant Properties ◽  
Total Content ◽  
Antioxidant Potential ◽  
Total Antioxidant Activity ◽  
Total Carotenoids ◽  
Total Antioxidant

The present investigation was undertaken to analyze the antioxidant potential of sixteen different potato genotypes. Eleven yellow fleshed potato genotypes namely Forza, Courage, Laura, Rosa Gold, Lady Rosetta, Cumbica, Asterix, Coronada, Granola, Cardinal and Diamant and five purple fleshed potato genotypes namely Jam Alu, KAC 10063, KAC 10064, KAC 10069, KAC 10097 were used as experimental materials. Total carotenoids, anthocyanin, phenolics, flavonoids, ascorbic acid and antioxidant activity in the above mentioned genotypes were determined to compare the antioxidant potentials of the genotypes. Analysis of above mentioned parameters resulted significant variation in their contents in both yellow and purple fleshed genotypes. The results indicate the purple fleshed genotypes showed significantly higher carotenoids, anthocyanin, flavonoids and total antioxidant activity than those of yellow fleshed genotypes. The findings also suggested the antioxidant activity of the genotypes positively correlates to the total content of carotenoids, anthocyanin and flavonoids. Since, purple fleshed genotypes showed higher antioxidant properties, the results of this study claim that the purple fleshed genotypes would be suitable for direct consumption as vegetables which might increase the health and food security of human beings.Bangladesh J. Agril. Res. 43(3): 369-381, June 2018

scholarly journals Composition and Antioxidant Activity of Phenolic Compounds in Fruit of the Genus Rosa L.

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 545
Author(s):  
Mindaugas Liaudanskas ◽  
Irena Noreikienė ◽  
Kristina Zymonė ◽  
Rugilė Juodytė ◽  
Vaidotas Žvikas ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Radical Scavenging ◽  
Total Content ◽  
Quantitative Composition ◽  
Rosa Multiflora ◽  
Epicatechin Gallate ◽  
Qualitative And Quantitative ◽  
Fruit Samples

We investigated the qualitative and quantitative composition of phenolic compounds in the fruit of Rosa L. cultivars grown in Lithuania. The highest total content of phenolic compounds (50.13 ± 4.17 mg GAE/g, p < 0.05) was determined in fruit samples of Rosa pimpinellifolia L. cultivar “Single Cherry”. The highest levels of hydroxycinnamic acid derivatives were determined in fruit samples of Rosa rugosa Thunb. cultivars “Dart’s Defender” and “Adam Chodun”. The highest flavonoid content was determined in fruit samples of Rosa multiflora Thunb. cultivar “Nana” and R. multiflora species. The strongest antioxidant activity evaluated by applying DPPH and FRAP assays was determined in fruit extracts of R. pimpinellifolia cultivar “Single Cherry” and R. rugosa cultivar “Adam Chodun”. Qualitative and quantitative analysis of phenolic compounds in Rosa L. fruit was performed by applying UHPLC. The following phenolic compounds were identified in fruit samples: caffeic acid, chlorogenic acid, quercetin, quercitrin, (+)-catechin, (−)-epicatechin, (−)-epicatechin gallate, rutin, phloridzin, and kaempferol-3-O-glycoside. A strong correlation was determined between the total amount of phenolic compounds determined in extracts of the fruit samples of Rosa L. cultivars and the radical scavenging and reducing activity of their extracts in vitro (R = 0.767 and 0.727, respectively, p < 0.05).

Analysis of extractives from Pinus halepensis and Eucalyptus camaldulensis as predominant trees in Algeria

Holzforschung ◽  
2018 ◽  
Vol 72 (2) ◽  
pp. 97-104 ◽  
Author(s):  
Nacera Benouadah ◽  
Andrey Pranovich ◽  
Djamel Aliouche ◽  
Jarl Hemming ◽  
Annika Smeds ◽  
...  
Keyword(s):  
High Performance ◽  
Pinus Halepensis ◽  
Eucalyptus Camaldulensis ◽  
Total Content ◽  
Resin Acids ◽  
Size Exclusion ◽  
Steryl Esters ◽  
Flame Ionization ◽  
The North ◽  
Exclusion Chromatography

AbstractThe lipophilic and hydrophilic extractives in the sapwood (sW) and heartwood (hW) of stems fromPinus halepensisMill andEucalyptus camaldulensisDehnh trees grown in the north of Algeria were analyzed. The extraction of dried samples was carried out in an accelerated solvent extractor (ASE). The lipophilic substances were first extracted withn-hexane and then the hydrophilic ones with acetone/water. The extractives were analyzed by gas chromatography-flame ionization detection (GC-FID), GC-mass spectroscopy (MS) and high-performance size-exclusion chromatography (HPSEC). The largest amount of lipophilic extractives (≈13.4 mg g−1) was observed in the hW ofP. halepensis, while the hW ofE. camaldulensiscontained the largest amount of hydrophilic extractives (≈116.3 mg g−1). Lipophilic extractives are mainly composed of oleoresins (resin acids, terpenes), fats (fatty acids, glycerides, steryl esters, sterols) and waxes (fatty alcohols). Hydrophilic extractives are composed of polyphenols (stilbenes, flavanols), sugars (monosaccharides) and sugar alcohols (cyclic polyols). The main identified lipophilic extractives are resin acids in pine and glycerides in eucalypt. The main identified hydrophilic extractives are cyclic polyols in pine and flavanols and monosaccharides in eucalypt. The total content of extractives is higher in hW than in sW.

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