2-O-Acyl-3-O-(1-Acyloxyalkyl) Prodrugs of 5,6-Isopropylidene-L-Ascorbic Acid and L-Ascorbic Acid: Regioselective Synthesis, Antioxidant Activity, and Ability to Permeate Silicone Membranes

2016 ◽  
Author(s):  
Kenneth Sloan
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Regioselective Synthesis ◽  
Silicone Membranes

Variation of Phytochemicals Content in Pulp and Skin of Seven Romanian Apple Cultivars

2017 ◽  
Vol 68 (3) ◽  
pp. 474-477
Author(s):  
Lacramioara Oprica ◽  
Doina Atofanei ◽  
Vladimir Poroch
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Anthocyanin Content ◽  
Colour Intensity ◽  
Total Polyphenol ◽  
Valuable Source ◽  
Golden Delicious ◽  
Apple Cultivars ◽  
Apple Fruits

The amounts of anthocyanins, flavonoids, total polyphenol and ascorbic acid in seven apple cultivars from Romania were investigated. The amounts of polyphenol and flavonoids in pulp and skin of apple cultivars ranged between 17.18�7.52 mg GAE/g DW and 20.10�11.06 mg CE/g DW as well as 3.64�1.18 mg GAE/g DW and 10.31�5.57 mg CE/g DW, respectively. The highest and smallest values of ascorbic acid both in the skin and the pulp were observed in the cultivars Mutsu and Starkrimson. The anthocyanin content is positively correlated with the colour intensity of the apple epicarp, being about three-fold higher in Prima than Golden Delicious cultivar. The better antioxidant activity provided by the content of polyphenol, ascorbic acid and flavonoids was in apple fruits of Mutsu cultivar and for this reason it should be regarded as a valuable source of antioxidants.

Composition and Antioxidant Activity of Aqueous Extracts Obtained from Herb of Tansy (Tanacetum Vulgare L.)

2018 ◽  
Vol 69 (5) ◽  
pp. 1041-1044
Author(s):  
Claudia Anca Mot ◽  
Andreea I. Lupitu ◽  
Simona Bungau ◽  
Ciprian Iovan ◽  
Dana Maria Copolovici ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Veterinary Medicine ◽  
Pharmaceutical Industry ◽  
Phenolic Content ◽  
Food Preservation ◽  
Aqueous Extracts ◽  
Tanacetum Vulgare ◽  
High Antioxidant Activity ◽  
Natural Additives

The aim of this study was to determine the phenolic content and antioxidant activity of extracts obtained from herb of Tanacetum vulgare L. (tansy) harvested in two different locations from the western part of Romania. Aqueous extracts of tansy presented high antioxidant activity that ranged between 295.77 and 653.65 mg GAE/L, and remarkable percentage of inhibition (31.82-65.05 %). The compounds quantified in the plant extracts that were determined by UHPLC are: ascorbic acid, riboflavin, pyrocatechol, rutin, quercetin, and kaempferol. Extracts obtained from tansy flowers showed higher content of phenols compared to that obtained from leaves. Similarly, the flower extracts present a high antioxidant activity that could suggest their use as natural additives in food preservation and also in pharmaceutical industry and veterinary medicine.

scholarly journals Complexes of Copper and Iron with Pyridoxamine, Ascorbic Acid, and a Model Amadori Compound: Exploring Pyridoxamine’s Secondary Antioxidant Activity

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 208
Author(s):  
Guillermo García-Díez ◽  
Roger Monreal-Corona ◽  
Nelaine Mora-Diez
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Rate Constant ◽  
Stable Complex ◽  
Aqueous Environment ◽  
Oh Radicals ◽  
Bidentate Ligands ◽  
Superoxide Radical Anion ◽  
Amadori Compound ◽  
The Stability

The thermodynamic stability of 11 complexes of Cu(II) and 26 complexes of Fe(III) is studied, comprising the ligands pyridoxamine (PM), ascorbic acid (ASC), and a model Amadori compound (AMD). In addition, the secondary antioxidant activity of PM is analyzed when chelating both Cu(II) and Fe(III), relative to the rate constant of the first step of the Haber-Weiss cycle, in the presence of the superoxide radical anion (O2•−) or ascorbate (ASC−). Calculations are performed at the M05(SMD)/6-311+G(d,p) level of theory. The aqueous environment is modeled by making use of the SMD solvation method in all calculations. This level of theory accurately reproduces the experimental data available. When put in perspective with the stability of various complexes of aminoguanidine (AG) (which we have previously studied), the following stability trends can be found for the Cu(II) and Fe(III) complexes, respectively: ASC < AG < AMD < PM and AG < ASC < AMD < PM. The most stable complex of Cu(II) with PM (with two bidentate ligands) presents a ΔGf0 value of −35.8 kcal/mol, whereas the Fe(III) complex with the highest stability (with three bidentate ligands) possesses a ΔGf0 of −58.9 kcal/mol. These complexes can significantly reduce the rate constant of the first step of the Haber-Weiss cycle with both O2•− and ASC−. In the case of the copper-containing reaction, the rates are reduced up to 9.70 × 103 and 4.09 × 1013 times, respectively. With iron, the rates become 1.78 × 103 and 4.45 × 1015 times smaller, respectively. Thus, PM presents significant secondary antioxidant activity since it is able to inhibit the production of ·OH radicals. This work concludes a series of studies on secondary antioxidant activity and allows potentially new glycation inhibitors to be investigated and compared relative to both PM and AG.

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 Capability of oxygen-scavenger sachets and modified atmosphere packaging to extend fresh barberry shelf life

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Razieh Niazmand ◽  
Samira Yeganehzad
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Phenolic Compounds ◽  
Shelf Life ◽  
Herbal Remedy ◽  
Physicochemical Characterization ◽  
Modified Atmosphere Packaging ◽  
Storage Period ◽  
Modified Atmosphere ◽  
Oxygen Scavenger

Abstract Background Barberry has long been used as an herbal remedy since ancient times which is found throughout temperate and subtropical regions of the world. Given the short harvesting season and limited shelf life of the barberry, we evaluated the possibility of using modified atmosphere packaging and oxygen-scavenger sachets to increase its storage period. For this purpose, the physicochemical characterization (antioxidant activity, anthocyanin, phenolic compounds, and ascorbic acid content, acidity, firmness, color, and decay incident) of fresh barberry samples packaged within different atmospheres was investigated over 4 weeks of storage at 4 and 25 °C. The barberries were packaged with low-density polyethylene/polyester (LDPE/PET) films under natural atmosphere (C), N2 gas (N), vacuum (V), or in the presence of an oxygen scavenger (OS). Results The results revealed that with increased storage period, the O2 and CO2 levels inside the packages decreased and increased, respectively. The antioxidant activity and amounts of anthocyanin, phenolic compounds, and ascorbic acid all decreased with increasing storage period. Among the studied atmospheres, the OS and, subsequently, V packages were most capable of maintaining the quality of fresh barberries, with the decay incidence being approximately 30 times lower inside these packages relative to the control. Increasing the storage temperature accelerated the intensity of chemical changes and decay across all samples. Conclusion The barberries inside the OS packages stored at 4 °C (and even at 25 °C) still had good sensory properties in terms of chemical properties, texture, and color after 4 weeks. Fortunately, it seems that this packaging technology makes the exportation and delayed consumption of the fresh barberry possible by maintaining its quality.

scholarly journals Implications for Degenerative Disorders: Antioxidative Activity, Total Phenols, Flavonoids, Ascorbic Acid, β-Carotene and β-Tocopherol inAloe vera

2009 ◽  
Vol 2 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Nurten Ozsoy ◽  
Eda Candoken ◽  
Nuriye Akev
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Biological Effects ◽  
Aloe Vera ◽  
Total Phenols ◽  
Beneficial Effects ◽  
Degenerative Disorders ◽  
Phosphatidylcholine Liposome ◽  
Aqueous Leaf Extract ◽  
Β Carotene

In order to demonstrate whether the known biological effects ofAloe vera(L.) Burm. fil. could correlate with the antioxidant activity of the plant, the antioxidant activity of the aqueous leaf extract was investigated. The present study demonstrated that the aqueous extract fromA. veraleaves contained naturally occuring antioxidant components, including total phenols, flavonoids, ascorbic acid, β-carotene and α-tocopherol. The extract exhibited inhibitory capacity against Fe3+/ascorbic acid induced phosphatidylcholine liposome oxidation, scavenged stable DPPH•, ABTS•+and superoxide anion radicals, and acted as reductant. In contrast, the leaf inner gel did not show any antioxidant activity. It was concluded that the known beneficial effects ofAloe veracould be attributed to its antioxidant activity and could be related to the presence of phenolic compounds and antioxidant vitamins.

VARIETAL FEATURES OF TUBERS OF JERUSALEM ARTICHOKE, GROWING IN THE KRASNODAR REGION AND THE Adygea Republic

2019 ◽  
Author(s):  
Н.Т. Шамкова ◽  
В.Ю. Токарев ◽  
А.В. Добровольская ◽  
А.З. Тодорова ◽  
А.И. ВЕРЕЩАГИНА
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Orotic Acid ◽  
Antioxidant Properties ◽  
Jerusalem Artichoke ◽  
Biotechnological Potential ◽  
Total Sugars ◽  
Krasnodar Region ◽  
Public Catering ◽  
Pectin Substances

Определен биотехнологический потенциал топинамбура сортов Новость ВИР, Скороспелка, Интерес, произрастающего в Краснодарском крае и Республике Адыгея, урожаев 2011 2018 гг. Установлено, что клубни топинамбура сорта Интерес превосходят сорта Новость ВИР и Скороспелка по содержанию, : общих сахаров на 22,41 и 14,34 инулина 41,82 и 32,99 пектиновых веществ 22,39 и 49,75 аскорбиновой кислоты 35,27 и 39,29 хлорогеновой кислоты 3,66 и 18,29 оротовой кислоты 88,89 и 84,89 соответственно. Сорт Интерес в сравнении с сортами Новость ВИР и Скороспелка содержит на 245,24 и 243,33 меньше никотиновой кислоты и на 100,0 и 108,33 кофейной кислоты соответственно. Содержание гистидина в клубнях топинамбура сортов Интерес, Новость ВИР и Скороспелка составляет 132,36 44,83 и 88,21 мг/кг аргинина 2017,2 958,56 и 460,44 мг/кг соответственно. В комплексе с аскорбиновой кислотой органические кислоты клубней топинамбура обладают выраженными антиоксидантными свойствами. Установлено, что в результате бланширования антиоксидантная активность топинамбура сорта Интерес возросла на 15,6. Таким образом, сорт Интерес наиболее перспективен для переработки в условиях предприятий общественного питания. The biotechnological potential of Jerusalem artichoke varieties Novost VIR, Skorospelka, Interes growing in the Krasnodar region and the Adygea Republic, harvest 2011 2018 has been determined. It was found that Jerusalem artichoke tubers of the Interes variety are superior to Novost VIR and Skorospelka varieties in content, : total sugars by 22,41 and 14,34 inulin 41,82 and 32,99 pectin substances 22,39 and 49,75 ascorbic acid 35,27 and 39,29 chlorogenic acid 3,66 and 18,29 orotic acid 88,89 and 84,89, respectively. Variety Interes in comparison with Novost VIR and Skorospelka varieties contains 245,24 and 243,33 less nicotinic acid and 100,00 and 108,33 coffee acid, respectively. The content of histidine in the tubers of Jerusalem artichoke varieties of Interes, Novost VIR, Skorospelka is 132,36 44,83 and 88,21 mg/kg arginine 2017,2 958,56 and 460,44 mg/kg, respectively. In a complex with ascorbic acid, organic acids of Jerusalem artichoke tubers have pronounced antioxidant properties. It was found that as a result of blanching, the antioxidant activity of Jerusalem artichoke of the Interes variety increases by 15,6. Thus, the Interes variety is most promising for processing in public catering facilities.

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