scholarly journals The inhibition of lipid autoxidation by human caeruloplasmin

1977 ◽  
Vol 168 (2) ◽  
pp. 283-288 ◽  
Author(s):  
D J Al-Timimi ◽  
T L Dormandy
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Linolenic Acid ◽  
Phosphate Buffer ◽  
Brain Homogenate ◽  
Optimum Conditions ◽  
Lipid Autoxidation

1. Purified caeruloplasmin was shown to inhibit lipid autoxidation induced by ascorbic acid or inorganic iron in the following systems: (a) an emulsion of linolenic acid in water; (b) an untreated ox brain homogenate in phosphate buffer; (c) a similar homogenate whose susceptibility to autoxidation had been abolished by dialysis or by heating and then restored by the above pro-oxidants. 2. The optimum conditions for this antioxidant activity were studied. 3. Caeruloplasmin did not inhibit autoxidation by u.v. irradiation in dialysed or preheated homogenates. 4. The apoprotein (without copper) had no antioxidant activity, whereas CuSO4 alone was much less effective as an antioxidant. 5. Iron-free transferrin also had some antioxidant activity.

scholarly journals Ekstraksi dan Bioaktivitas Antioksidan Pigmen Fikoeritrin dari Rumput Laut Merah Halymenia sp.

2020 ◽  
Vol 15 (2) ◽  
pp. 115
Author(s):  
Tias Suci Lailani ◽  
Ifah Munifah ◽  
Hermanto Hermanto
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Phosphate Buffer ◽  
Extraction Time ◽  
Red Seaweed ◽  
Antioxidant Power ◽  
Extract Yield ◽  
Ferric Reducing Antioxidant Power

Fikoeritrin adalah pigmen dari rumput laut merah Halymenia sp. dengan aktivitas antioksidan yang potensial untuk dikembangkan dalam bidang nutraseutikal. Ekstraksi fikoeritrin dapat dilakuan dengan berbagai jenis pelarut. Namun, penggunaan pelarut yang tidak sesuai dapat berdampak terhadap rendemen, kemurnian, dan juga bioaktivitas ekstrak fikoeritrin. Oleh karena itu, penelitian ini bertujuan untuk mendapatkan jenis pelarut dan durasi waktu ekstraksi (secara maserasi) yang tepat sehingga menghasilkan ekstrak dengan rendemen, kemurnian, dan daya antioksidan fikoeritrin terbaik. Ekstraksi dilakukan menggunakan tiga jenis pelarut (akuabides; buffer fosfat pH 6,8; dan aseton 80%) dengan variasi waktu maserasi (24, 48, 72, dan 96 jam). Spektrofotometri Ultraviolet-Visibel (UV-Vis) dipergunakan dalam identifikasi fikoeritrin, sementara Ferric Reducing Antioxidant Power (FRAP) merupakan metode dalam telaah daya antioksidan ekstrak. Hasil penelitian menunjukkan bahwa terdapat perbedaan jumlah rendemen ekstrak (w/w segar) dari ketiga pelarut, yaitu 1,76% (akuabides); 0,91% (aseton 80%); dan 2,91% (buffer fosfat pH 6,8). Selain itu, waktu ekstraksi juga menyebabkan perbedaan jumlah rendemen, yaitu 1,72% (24 jam); 1,51% mg/mL (48 jam); 1,37% (72 jam); dan 1,43% (96 jam). Hasil ini menunjukkan bahwa pelarut buffer fosfat dengan durasi waktu maserasi 24 jam adalah metode yang terbaik untuk mendapatkan rendemen fikoeritrin tertinggi dari rumput laut merah Halymenia sp. Aktivitas antioksidan dari ekstrak buffer fosfat ini terdeteksi sebesar 3,14 mg ekuivalen asam askorbat/100 g ekstrak pada konsentrasi 10 mg/mL. ABSTRACTPhycoerythrin is a pigment from red seaweed Halymenia sp., with antioxidant activity which is prospective in nutraceutical development. There are several solvents that could be used in the extraction of phycoerythrin. However, the use of inappropriate solvents may impact the yield, purity, and bioactivity of phycoerythrin extract. Therefore, this study aimed to obtain the type of solvent and the duration of extraction (with maceration technique) to produce the highest yield, purity, and antioxidant activity of phycoerythrin extract. Extraction was carried out using three types of solvents (aquabidest, phosphate buffer pH 6.8, and acetone 80%) with variations in extraction time (24, 48, 72, and 96 hours). Spectrophotometric Ultraviolet-Visible (UV-Vis) was used to identify the phycoerythrin, and Ferric Reducing Antioxidant Power (FRAP) was applied to analyze the antioxidant activity in the extract. The results showed that there were differences in the amount of extract yield (w/w fresh) from three solvents, which was 1.77% (aquabidest), 0.91% (acetone 80%), and 2.91% (phosphate buffer pH 6.8). Moreover, extraction duration was also affecting the amount of yield, which was1.78% (24 hours), 1.51% mg/mL (48 hours), 1.37% (72 hours), and 1.43% (96 hours). These results indicated that the phosphate buffer solvent with a 24-hour extraction duration was the best method to get the highest yield of phycoerythrin from the red seaweed Halymenia sp. The antioxidant activity from the phosphate buffer extract was detected up to 3.14 mg equivalent ascorbic acid /100 g extract at a concentration of 10 mg/mL.

scholarly journals Extraction conditions of polyphenol oxidase from banana peel

2016 ◽  
Vol 13 (3) ◽  
pp. 469-474
Author(s):  
Baghdad Science Journal
Keyword(s):  
Ascorbic Acid ◽  
Enzyme Activity ◽  
Polyethylene Glycol ◽  
Polyphenol Oxidase ◽  
Phosphate Buffer ◽  
Fruits And Vegetables ◽  
Extraction Ratio ◽  
Banana Peel ◽  
Optimum Conditions ◽  
Extraction Buffer

Polyphenol oxidase (PPO) is an enzyme containing copper, presents in various fruits and vegetables. It is responsible for the browning reactions when the cells are damaged during handling. The best conditions for extraction of polyphenol oxidase from banana peel was by using an extraction buffer containing phosphate buffer (0.05 M, pH 7), 0.01 M ascorbic acid and 0.5% polyethylene glycol, with extraction ratio 1:4 (w:v) for one minute by using blender. The enzyme activity was measured spectrophotometrically at 425 nm. PPO was studied to prevent the browning of banana peel which results in the loss of their marketability. The aim of this study was to determine the optimum conditions for polyphenol oxidase extraction from banana peel.

Effect of Ethanol Treatment on Lycopene Extraction yield

2018 ◽  
Author(s):  
Nam Kyong-il ◽  
KIM rak-chon ◽  
Kang chang-hyok ◽  
Lee song-nam ◽  
Ryom sok-hun
Keyword(s):  
Antioxidant Activity ◽  
Treatment Time ◽  
Extraction Yield ◽  
Extraction Rate ◽  
Test Results ◽  
Ethanol Treatment ◽  
Optimum Conditions ◽  
Liquid Ratio ◽  
Pretreatment Method ◽  
Ethanol Pretreatment

In order to extract lycopene more effectively, this experiment focused on the optimization of ethanol pretreatment method to study the effects of ethanol treatment on the extraction rate of lycopene and its antioxidant activity. The test results show that 2 times ethanol treatment is very effective for improving lycopene yield. The optimum conditions of ethanol treatment are temperature 50 ℃, treatment time 1 time 2h, 2 times 2h, solid to liquid ratio is 1:12. The lycopene yield can be reached 20mg / 100g above.

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.

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