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Статті в журналах з теми "DPPH antioxidant activity":
1
Karamać, M., A. Buciński, B. Pegg R, and R. Amarowicz. "Antioxidant and antiradical activity of ferulates." Czech Journal of Food Sciences 23, No. 2 (November 15, 2011): 64–68. http://dx.doi.org/10.17221/3373-cjfs.
Анотація:
Antioxidant and antiradical activities of ferulates (i.e., ferulic acid, isoferulic acid, coniferyl aldehyde, and methyl ferulate) were investigated using a β-carotene-linoleate model system and a DPPH radical scavenging assay, respectively. Compounds so tested exhibited antioxidant and antiradical properties to varying degrees. Methyl ferulate showed the strongest antioxidant activity, whereas the parent phenolic acid was the most active ferulate to scavenge the DPPH radical (DPPH<sup>·</sup>). Isoferulic acid at concentrations ranging from 10 to 100 nmol/assay did not impart an antiradical efficacy; this may be attributed to the location of the hydroxyl group in the meta position on the aromatic ring.
2
Gulcin, İlhami, and Saleh H. Alwasel. "DPPH Radical Scavenging Assay." Processes 11, no. 8 (July 26, 2023): 2248. http://dx.doi.org/10.3390/pr11082248.
Анотація:
Today, there is an increasing interest in antioxidants, especially to prevent the known harmful effects of free radicals in human metabolism and their deterioration during processing and storage of fatty foods. In both cases, natural-source antioxidants are preferred over synthetic antioxidants. So, there has been a parallel increase in the use of assays to estimate antioxidant efficacy in human metabolism and food systems. Today, there are many bioanalytical methods that measure the antioxidant effect. Of these, the 1,1-diphenyl-2-picrylhydrazil (DPPH) removing assay is the most putative, popular, and commonly used method to determine antioxidant ability. In this review, a general approach to the DPPH radical scavenging assay has been taken. In this context, many studies, including attempts to adapt the DPPH radical scavenging method to different analytes, search for the highest antioxidant activity values, and optimize the method of measurement, have previously been performed. Therefore, it is highly important to introduce measures aimed at standardizing the conditions of the DPPH radical scavenging activity, including the various reaction media suitable for this assay. For this aim, the chemical and basic principles of DPPH free radical scavenging are defined and discussed in an outline. In addition, this study describes and defines the basic sections of DPPH free radical scavenging in food and biological systems. Additionally, some chemical, critical, and technical details of the DPPH free radical removal method are given. This is a simple assay in which the prospective compounds or herbal extracts are mixed with the DPPH solution and their absorbance is measured after a certain period. However, despite rapid advances in instrumental techniques and analysis, this method has not undergone extreme modification. This study presents detailed information about the DPPH method and an in-depth review of different developments.
3
Baliyan, Siddartha, Riya Mukherjee, Anjali Priyadarshini, Arpana Vibhuti, Archana Gupta, Ramendra Pati Pandey, and Chung-Ming Chang. "Determination of Antioxidants by DPPH Radical Scavenging Activity and Quantitative Phytochemical Analysis of Ficus religiosa." Molecules 27, no. 4 (February 16, 2022): 1326. http://dx.doi.org/10.3390/molecules27041326.
Анотація:
The use of F. religiosa might be beneficial in inflammatory illnesses and can be used for a variety of health conditions. In this article, we studied the identification of antioxidants using (DPPH) 2,2-Diphenyl-1-picrylhydrazylradical scavenging activity in Ficus religiosa, as F. religiosa is an important herbal plant, and every part of it has various medicinal properties such as antibacterial properties that can be used by the researchers in the development and design of various new drugs. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) is a popular, quick, easy, and affordable approach for the measurement of antioxidant properties that includes the use of the free radicals used for assessing the potential of substances to serve as hydrogen providers or free-radical scavengers (FRS). The technique of DPPH testing is associated with the elimination of DPPH, which would be a stabilized free radical. The free-radical DPPH interacts with an odd electron to yield a strong absorbance at 517 nm, i.e., a purple hue. An FRS antioxidant, for example, reacts to DPPH to form DPPHH, which has a lower absorbance than DPPH because of the lower amount of hydrogen. It is radical in comparison to the DPPH-H form, because it causes decolorization, or a yellow hue, as the number of electrons absorbed increases. Decolorization affects the lowering capacity significantly. As soon as the DPPH solutions are combined with the hydrogen atom source, the lower state of diphenylpicrylhydrazine is formed, shedding its violet color. To explain the processes behind the DPPH tests, as well as their applicability to Ficus religiosa (F. religiosa) in the manufacture of metal oxide nanoparticles, in particular MgO, and their influence on antioxidants, a specimen from the test was chosen for further study. According to our findings, F. religiosa has antioxidant qualities and may be useful in the treatment of disorders caused by free radicals.
4
Yamauchi, Moeka, Yukino Kitamura, Haruka Nagano, Junya Kawatsu, and Hiroaki Gotoh. "DPPH Measurements and Structure—Activity Relationship Studies on the Antioxidant Capacity of Phenols." Antioxidants 13, no. 3 (March 1, 2024): 309. http://dx.doi.org/10.3390/antiox13030309.
Анотація:
The consumption of foods that are high in antioxidant capacity is believed to contribute to good health. Moreover, the addition of highly antioxidant compounds to foods is believed to prevent food deterioration. Among the known antioxidants in food, phenols have been identified as the primary antioxidants. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay is a simple, inexpensive, and rapid method widely used to evaluate the antioxidant capacity. Although the results of the DPPH assay depend on conditions such as the reaction time and concentration, the experimental conditions have not been standardized. Further, previous research that compared the antioxidant capacity determined through the DPPH assay largely focused on the differences in the specific substructures of approximately several dozen compounds. In this study, we conducted DPPH assays on 169 phenols under the same experimental conditions and summarized the correlation between their structures and activity. This DPPH assay study is the first single-laboratory investigation of the largest number of components in terms of their Trolox equivalent antioxidant capacities. Further, the analysis method was reproduced in an interlaboratory collaborative study, enabling its application in the reproduction and comparison of measurements in other laboratories.
5
Mandic, Anamarija, Sonja Djilas, Jasna Canadanovic-Brunet, Gordana Cetkovic, and Jelena Vulic. "Antioxidant activity of white grape seed extracts on DPPH radicals." Acta Periodica Technologica, no. 40 (2009): 53–61. http://dx.doi.org/10.2298/apt0940053m.
Анотація:
Composition and antioxidant activity of grape seed extract (GSE) obtained from red grape varietes are very well documented, in contrast to the white varietes. This paper presents the results of polyphenols content of ethyl acetate extract of grape seeds, obtained from two white grape varieties, Italian Riesling and Zupljanka, and their antioxidant activity on the stable DPPH radical. The influence of the addition of GSE to raspberry juice on the DPPH radical was also examined. Content of total polyphenols in GSEs ranged between 81.6 and 82.8% (w/w), and the contetn of flavan-3-ols between 66.2 and 91.0% (w/w). HPLC results showed that the most abundant components in the extract were (+)-catechin and (-)-epicatechin for both grape varieties. All tested GSEs exhibited good antioxidant activity. IC50 values for the GSEs of Italian Riesling and Zupljanka were 0.79 and 0.95 mg sample/mg DPPH radical, respectivelly. Since the GSE of Italian Riesling possesed stronger antioxidant activity, it was used for further experiments. The IC50 value for raspberry juice was 4.18 mg raspberry juice/mg DPPH. The raspberry juice with addition of 0.60 ?g/mL of GSE showed antioxidant activity of 39.2%. The same juice with the threefold concentration of vitamin C (1.81 ?g/ml) exhibited similar antioxidant activity (33.9%). Antioxidant activity of the same amount of juice without added antioxidants was lower (15.7%). The results showed that the GSE of white varietes could be considered as a good functional food ingredient.
6
Kumar, Mishra Arvind, Kumar S. Pawan, and Gupta Satish Chand. "ANTIBACTERIAL, ANTIFUNGAL AND DPPH RADICAL SCAVENGING ACTIVITY OF ACHYRANTHES ASPERA L." International Journal of Research in Ayurveda and Pharmacy 13, no. 2 (February 28, 2022): 17–20. http://dx.doi.org/10.7897/2277-4343.130228.
Анотація:
The plant Apamarg (Achyranthes aspera L.) was tested for antibacterial (Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, Staphylococcus aureus), antifungal (Aspergillus niger and Fusarium oxysporum) activities. For extraction, methanol extract was chosen. The DPPH Radical Scavenging activity was used to test the antioxidant action. The current study reveals a link between indigenous Achyranthes aspera L. treatment and in vitro antibacterial and antifungal responses. Ascorbic acid had the lowest DPPH scavenging activity than methanolic extracts of Achyranthes aspera L., which exhibited antioxidant activity. The effects of DPPH radical scavenging are dose-dependent. The stems and roots of Achyranthes aspera L. are high in antioxidants that could be utilized as a natural supplier of antioxidants and antimicrobial components.
7
Darweesh, Majida Jummaah. "Study antioxidant activity in Thalassemia Iraqi patients." Journal of Biotechnology Research Center 8, no. 4 (December 1, 2014): 39–41. http://dx.doi.org/10.24126/jobrc.2014.8.4.379.
Анотація:
The aims of this study was to estimate the total antioxidant activity level in serum among the Thalassemia Iraq patients. We estimated total free radical scavenging activity in the120 serum of Thalassemic patients their age range from 2-27years. The DPPH activity of serum ranged from 0.1-3.11µmol/ml, the mean serum level of total antioxidants in Thalassemia patients was significantly lower than the control group, and no relation to age or sex. We concluded that DPPH is useful for evaluating the total antioxidant capacity.
8
Triadisti, Nita, and Irfan Zamzani. "Column Chromatography Fractionation and Antioxidant Activity of Passiflora foetida Leaves." Borneo Journal of Pharmacy 6, no. 1 (February 28, 2023): 22–30. http://dx.doi.org/10.33084/bjop.v6i1.1830.
Анотація:
Available synthetic antioxidants have been reported to have mutagenic and toxic effects. On the other hand, natural antioxidants show their superiority as they are not or less toxic. Passiflora foetida has the potential as an antioxidant, but the investigation of the antioxidant activity of the P. foetida chromatography column fraction has not been reported. This studied aims to investigate the antioxidant activity of the column chromatographic fractions of P. foetida leaves. An antioxidant assay using the DPPH and FRAP methods. The extraction was carried out by graded maceration, then fractionation using column chromatography. The antioxidant activity test was carried out using the DPPH and FRAP methods. Thin Layer Chromatography analysis was performed to determine the chromatogram pattern. The EC50 using DPPH method from n-hexane extract: 129.035 µg/mL, ethyl acetate extract: 206.398 µg/mL, methanol extract: 97.453 µg/mL, while the EC50 using FRAP method from n-hexane extract: 67.851 µg/mL, ethyl acetate extract : 68.981 µg/mL, and methanol extract: 58.787 µg/mL. Column chromatography fractions have antioxidant activity, with FMetPF6 as the fraction with the best activity, with percent inhibition 41.85±1.96 at concentration 25 µg/mL (DPPH), and with percent antioxidant activity 26.03±0.84 at concentration 9 µg/mL (FRAP). Passiflora foetida leaves have great potential as an antioxidant; both the extract and its fractions have antioxidant activity. The FMetPF6 has the best activity compare to other extracts and fractions. Further analysis to determine the various compounds in FMetPF6 using LC-MS/MS will facilitate the active compound's isolation.
9
Angeli, Lucrezia, Sebastian Imperiale, Yubin Ding, Matteo Scampicchio, and Ksenia Morozova. "A Novel Stoichio-Kinetic Model for the DPPH• Assay: The Importance of the Side Reaction and Application to Complex Mixtures." Antioxidants 10, no. 7 (June 24, 2021): 1019. http://dx.doi.org/10.3390/antiox10071019.
Анотація:
The 2,2-diphenyl-1-picrylhydrazyl (DPPH•) assay is widely used to determine the antioxidant activity of food products and extracts. However, the common DPPH• protocol uses a two-point measurement and does not give information about the kinetics of the reaction. A novel stoichio-kinetic model applied in this study monitors the consumption of DPPH• by common antioxidants following the second order reaction. The fitting of such decay yields the rate constant k1, which describes the main reaction between antioxidants and DPPH•, and the rate constant k2, which is attributed to a slower side reaction considering the products generated between the transient radicals (AO•) and another molecule of DPPH•. The model was first applied to antioxidant standards. Sinapic acid, Trolox and ascorbic and chlorogenic acids did not show any side reaction. Instead gallic, ferulic and caffeic acids achieved the best fitting with k2. The products of the side reaction for these compounds were confirmed and identified with high-resolution mass spectrometry. Finally, the kinetic model was applied to evaluate the antioxidant activity of eight herbal extracts. This study suggests a new kinetic approach to standardize the common DPPH• assay for the determination of antioxidant activity.
10
Sekti, Beta Herilla. "TEST OF ANTIOXIDANT CONTENT IN BLUE LOTUS (Nymphaea Stellata Wild) LEAVES WITH DPPH METHOD (1,1-Diphenyl-2-Picrylhydrazyl)." Jurnal Jamu Kusuma 1, no. 2 (December 31, 2021): 46–50. http://dx.doi.org/10.37341/jurnaljamukusuma.v1i2.10.
Анотація:
Antioxidants are compounds materials that can inhibit the rate of oxidation of other molecules or neutralize free radicals. Antioxidants can be obtained in synthetic or natural forms. Natural antioxidants can protect the human body from damage to active oxygen which can inhibit degenerative diseases and inhibit the production of fat and food. Natural antioxidants can be obtained from plants, one of which is the Blue Lotus Plant (Nymphaea Stellata Wild). To ensure the presence of antioxidants in this plant, the antioxidant activity was tested using the DPPH method. The DPPH method was used to determine the free radical scavenging activity of the Ethanol Extract of Blue Lotus Leaf (Nymphaea Stellata Wild). The positive control used was Ascorbic Acid. The IC50 value obtained for testing the antioxidant content of blue lotus leaf is 78.405 ppm ± 24.607. And Ascorbic Acid 2,238 ppm. It can be concluded that the antioxidant activity of Blue Lotus Leaf is not too different from the positive control of ascorbic acid. The antioxidant activity of blue lotus leaf was stated to be strong and ascorbic acid was stated to be very strong.
Keywords: Antioxidant, Free radicals, DPPH
Дисертації з теми "DPPH antioxidant activity":
1
Pires, Manoela Alves. "Avaliação da capacidade antioxidante de extratos comerciais de alecrim e chá verde e sua influência na estabilidade de hambúrguer de frango durante armazenamento congelado." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/74/74132/tde-06102014-110832/.
Анотація:
A atividade antioxidante de dois extratos comerciais de alecrim e chá verde foi comparada com a atividade do sintético BHA para substituição total do sintético em hambúrguer de frango. A quantificação foi determinada pelos métodos Folin-Ciocalteau, FRAP e DPPH. De acordo com as análises de atividade antioxidante, as dosagens dos extratos naturais foram determinadas, utilizando-se como base o limite de dosagem do BHA (0,01% base gordura) e aplicadas em hambúrgueres de frango: T1: Controle; T2: 0,002% BHA; T3: 0,0038% Chá Verde; T4: 0,001% Chá Verde; T5: 0,048% Alecrim; T6: 0,00186% Alecrim. Foram realizadas análises de composição centesimal e pH e análises de estabilidade no armazenamento congelado: rendimento e redução do diâmetro, índice de TBARs, cor objetiva (parâmetros L*, a* e b*) e teste sensorial de aceitação. No método Folin-Ciocalteau, das análises de atividade antioxidante, o BHA não apresentou diferença com o chá verde (p > 0,05), no método FRAP o melhor (p < 0,05) desempenho foi do BHA e no DPPH o chá verde apresentou maior atividade (p < 0,05). Os resultados de TBARS, nos hambúrgueres, mostraram diferença significativa entre as amostras e também interação amostras x tempo do armazenamento (p < 0,05), sendo que após 120 dias o teste com maior dosagem do extrato de alecrim (T5) não diferiu do sintético (T2) (0,423 e 0,369 índice de TBARs, respectivamente). No aspecto sensorial as amostras não diferiram entre si (p>0,05) nem durante todo o período de armazenamento (p > 0,05). Dentro das condições experimentais pode-se afirmar que o extrato comercial de alecrim pode substituir totalmente o antioxidante BHA em hambúrguer de frango, garantindo a mesma estabilidade oxidativa e sem interferir em sua aceitação sensorial.The antioxidant activity of two commercial extracts, rosemary and green tea, were compared with the activity of the synthetic BHA for total replacement of the synthetic in chicken burger. The spectrometric quantification was determined by UV - VIS methods: Folin - Ciocalteu , FRAP and DPPH . In the Folin-Ciocalteau method the BHA showed no difference with green tea (p > 0.05), in the FRAP method the BHA obtained better (p < 0.05) performance and for DPPH the green tea showed greater activity (p < 0.05). According to the analysis of antioxidant activity, dosages of natural extracts were determined, using as basis the limit dosage of BHA (0.01 % fat base) and applied in chicken burgers: T1: Control, T2: 0.002 % BHA, T3: 0.0038 % Green Tea, T4: 0.001 % Green Tea, T5: 0.048 % Rosemary and T6: 0.00186 % Rosemary. Chemical-physical analysis of chemical composition and pH were made, and also stability analysis: cooking loss and reducing the diameter, TBARs index, objective color (parameters L *, a * and b *) and sensory acceptance test. The results of TBARS showed a significant difference between samples and also samples interaction x storage time (p < 0.05), after 120 days the test with higher dosage of rosemary extract (T5) did not differ from synthetic (T2) (0.423 and 0.369 TBARS index, respectively), thus better performance than the other tests. The sensory evaluation results showed that the samples did not differ during the storage period (p > 0.05). According the experimental conditions can be concluded that the commercial rosemary extract can completely replace the antioxidant BHA.
2
Mothapo, Mmaphefo Patricia. "Comparative evaluation of three fundamentally different analytical methods antioxidant activity determination with reference to bush tea (anthrixia phylicoides." Thesis, University of Limpopo, 2016. http://hdl.handle.net/10386/1517.
Анотація:
Thesis (M.Sc. (Chemistry)) -- University of Limpopo, 2016In this study, antioxidant activity methodologies were evaluated in terms of analytical performances. The total antioxidant activity from Athrixia phylicoides leaves (Bush tea) determined using 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH•) method, cupric ion reducing power (CUPRAC) method and cyclic voltammetry (CV). Folin-Ciocalteu method was used to quantify total phenolic content (TPC) in Athrixia phylicoides leaves. The influence of chemical and physical parameters on the total phenolic content and antioxidant activity determination were investigated. Results from direct sample and crude sample were compared. Antioxidant activity and phenolic content from Athrixia phylicoides leaves were compared with those from commercialised green tea, black tea and rooibos tea using two chosen antioxidant capacity method with acceptable characteristics. Results from the evaluation of the methods demonstrated excellent recoveries (99 to 103%) consistently, good linearity within the calibration concentration range (R2 = 0.997) and repeatable low coefficient of variation < 5% were indicative of good precision except for CV method. The average total antioxidant activity of various extracts of Athrixia phylicoides leaves ranged from 0.039 to 0.122 mg/mL (EC50), 0.031 to 0.233 mg/mL (EC50) and 339 to 429 mV (anodic potential) for DPPH method, CUPRAC method and CV method, respectively. The total antioxidant activity values for each Athrixia phylicoides samples determined by CUPRAC method were higher than the values produced by DPPH and CV methods. The highest antioxidant activities in the DPPH and CUPRAC methods were found in water extracts (direct sample). However, concentrated samples for DPPH method and CV gave a different trend with the methanol extract (crude sample) displaying the highest antioxidant capacity. Increasing the infusion time only increased total antioxidant activity determined by CUPRAC method, whilst DPPH and CV methods had the highest antioxidant activity in the lowest infusion time (3 min). Even though the results are inconclusive with regard to the effect of solid to solvent ratio effect on the total antioxidant activity, 1:150 ratio and 1:100 ratio extracts for both CUPRAC and DPPH methods and for CV gave the highest antioxidant capacities, respectively. The total antioxidant activities in pure antioxidant standards and in the teas were ranked in the following order by both CUPRAC and DPPH methods: Quercetin > catechin > Trolox and Chinese green tea > Joko black tea > Athrixia phylicoides leaves > Laager rooibos tea, respectively. Comparative study showed the necessity of employing more than one method, as each method for the same sample yielded different results. CUPRAC and DPPH methods displayed higher sensitivity and repeatability as compared to the CV method with poor precision.
3
Křenová, Alena. "Antioxidační aktivita vybraných druhů drobného ovoce." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2015. http://www.nusl.cz/ntk/nusl-217149.
Анотація:
This diploma´s thesis deals with the determination of total antioxidant activity of red and white gooseberries and red, white and black currants. There are available information about small fruits, an overview of natural and synthetic antioxidants and a summary of the methods to determine the total antioxidant activity in the theoretical part. Frozen fruit samples were provided by Research and Breeding Institute of Pomology Holovousy Ltd. in the project QI111A141 – Research of new technologies in the cultivation of gooseberries and currants with a focus on quality and use of fetuses (Ministry of Agriculture). The total antioxidant activity of red and white gooseberries and currants was measured by spectrophotometric methods using free radicals ABTS•+ and DPPH and was expressed as a Trolox equivalent. The total antioxidant activity of black currants was measured by electron paramagnetic resonance using free radicals ABTS•+ and DPPH and expressed as a TEACABTS and a TEACDPPH. There were measured 8 species of red gooseberries, 6 species of white gooseberries, 12 species of red currants, 6 species of white currants and 8 species of black currants in this thesis. The highest values of total antioxidant activity showed species of red and white gooseberries Alan, Karmen, Pax and Invicta and species of red and white currants Rovada, Orion and Olin. Among black currants, species Ometa and Ruben had the highest values of total antioxidant activity.
4
Nocera, Anna. "Impact of an alternative ageing technology using micro-oxigenation on the wine spirit's antioxidant activity." Master's thesis, ISA, 2019. http://hdl.handle.net/10400.5/19566.
Анотація:
Mestrado em Engenharia de Viticultura e Enologia - Instituto Superior de Agronomia / Faculdade de Ciências - Universidade do PortoThe study of antioxidant activity, a quality parameter, was performed during the first year of a Lourinhã wine spirit’s ageing, through two different ageing technologies: traditional technology using 250 L barrels, and alternative technology using 1000 L stainless steel tanks with wooden staves and micro-oxygenation. In both technologies, the same types of wood were used: Limousin oak and chestnut, and mixture of them, with medium plus toasting level. The quantity of the wooden staves added to the stainless steel tanks was calculated to reproduce the surface area to volume ratio of 250 L wooden barrel, therefore, to be comparable. The tanks were provided with micro-oxygenation during the ageing period, simulating the amount of oxygen entering through the barrels. The alternative technology induced higher antioxidant activity along with faster enrichment in wood derived phenolic compounds. In addition, the antioxidant activity, the total phenolic content and the low molecular weight phenolic compounds concentrations determined by HPLC exhibited significant positive correlations. The results also showed that alternative technology can be used as a valid method of ageing wine spirits since it allowed obtaining a high quality aged beverage through a more economically and environmentally sustainable process. A synergistic effect with the chestnut wood was also observed
N/A
5
Hess, Meggan Sade. "Use of antioxidant activity and flavonoid levels to assess the quality of commercially available solid dose Sutherlandia frutescens products." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5979_1317643628.
Анотація:
The overall aims of this project were to assess the pharmaceutical quality and consistency of commercially available solid dose Sutherlandia frutescens containing products (viz. tablets & capsules) by exploring the use of monitoring the pharmaceutical presentation, flavonoid profile and antioxidant activity levels and to develop/or adapt methods and specifications that may be used for the quality control of such products.Stability tests were conducted on all of the selected SCP. The products were stored under elevated temperatures and environmental humidity conditions and total phenol, antioxidant and chromatographic analysis was conducted on these samples. Samples of each of the SCP were hydrolyzed using HCL and then analyzed using HPLC to test the stability of the flavonoids present in each product. The SCP investigated in this study physically appeared to be of quite good âpharmaceuticalâ quality, but generally lacked information on the date of manufacture and lacked package inserts, or when these were present they contained insufficient information.Based on the results obtained, it is recommended that, the manufacturers of SCP pay more attention to the information provided on the package inserts and the storage conditions for their products. Further the levels of antioxidant activity, total phenols and flavonoid (sutherlandins A to D) be used as specifications to control the quality of commercially available solid dose Sutherlandia frutescens containing preparations on an individual basis.
6
Mavundza, Edison Johannes. "Antioxidant and antibacterial activities of ethanol extract and flavonoids isolated from Athrixia phylicoides." Diss., University of Pretoria, 2010. http://hdl.handle.net/2263/25977.
Анотація:
The ethanol extract of A. phylicoides was investigated for its antioxidant activity using the DPPH scavenging method. The extract showed good antioxidant results with a EC50 value of 10.64 ± 0.0842 µ/ml. The extract was also tested for antibacterial activity against microorganisms (Staphylococcus aureus, Enterococus faecalis, Bacillus cereus, Bacillus subtilis, Bacillus pumilus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia) commonly known to pose a threat in the wellbeing of man. All tested microorganisms were significantly inhibited by the extract with the MIC values ranging from 3.13 µg/ml to 6.25 µg/ml. Folin-Ciocalteu’s reagent method was used to determine total phenolic content of dried and freshly prepared crude extract of A. phylicoides. Higher total phenolic content (28.28 ± 0.019 mg GAC/100g) and antioxidant activity (EC50, 10.64 ± 0.084 µg/ml) was observed in the dried extract compared to the fresh extract with a TPC value of 23.04 ± 0.003 mg GAC/100g and EC50 of 13.97 ± 0.066 µg/ml. Bioassay-guided fractionation of ethanolic extract from aerial parts of Athrixia phylicoides using silica and sephadex column chromatography led to the isolation of four known flavanoids, 5-hydroxy-6,7,8,3’,4’,5’-hexamethoxyflavon-3-ol (1), 3-0- demethyldigicitrin (2), 5,6,7,8,3’,4’-hexamethoxyflavone (3) and Quecertin (4). Due to the low yield, no further tests were done on compound 3. A DPPH-scavenging assay was performed to evaluate the antioxidant activity of the isolated compounds. All the tested compounds showed potent antioxidant activity with EC50 values ranging from 1.27 to 3.41 µg/ml. Compound 4 showed a higher antioxidant activity (EC50, 1.27 µg/ml) than vitamin C (EC50, 2.66 µg/ml) used as a control. The MIC values of the isolated compounds against tested microorganisms varied from 20 to more than 40 µg/ml. All the tested compounds showed no activity against S. aureus, B. pumilus, K. pneumonia and P. aeruginosa at the highest concentration tested (40 µg/ml). These compounds together with the extract were further analyzed by XTT assay on Vero cells. The extract showed a low toxicity effect on the cells at lower concentrations exhibiting EC50 value of 107.8 ± 0.129 µg/ml. Compound 4 showed minimal toxicity effect on the cells with a EC50 value of 81.38±0.331 µg/ml, compared to Compound 1 and 2 which exhibited EC50 values of 27.91 ± 0.181 µg/ml and 28.92 ± 0.118 µg/ml respectively. The results obtained from this study provide a clear rationale for the medicinal uses of Athrixia phylicoides.Dissertation (MSc)--University of Pretoria, 2011.
Plant Science
unrestricted
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Feltrin, Andrieli Cassel. "ESTUDO COMPARATIVO DE Glycyrrhiza glabra (ALCAÇUZ) E Periandra dulcis (ALCAÇUZ-DA-TERRA)." Universidade Federal de Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/5939.
Анотація:
The Fabaceae family is comprised of approximately 18 000 species in 650 genera, with wide
geographic distribution. The species Glycyrrhiza glabra (licorice) and Periandra dulcis
(licorice-of-the-earth) belong to the family Fabaceae. Licorice displays a variety of
pharmacological activities, such as antiulcer, antiinflammatory, antioxidant, antimicrobial,
among others. In ethnomedicine Brazilian, P. dulcis is used as a substitute/adulterant G.
glabra. This study aimed to differentiate plants for antioxidant activity, the HPLC
chromatographic profile and the antimicrobial activity. Plants roots were ground and
macerated using as solvent ethanol: water (70:30, v/v). Became fractionation of crude
extracts with organic solvents of increasing polarity (CH2Cl2, EtOAc, n-BuOH). The crude
extract and the fractions were investigated for the content of total polyphenols, the
antioxidant activity by DPPH and the inhibition of lipid peroxidation by TBARS method. The
content of total phenolics ranged from 70.29 ± 2.98 to 85.78 ± 1.08 mg/g for P. dulcis and
137.7 ± 1.37 to 83.26 ± 2.71 mg/g to G. glabra. In the DPPH assay, the dichloromethane
fraction was most effective in capturing free radicals in both plants. The butanol fraction of P.
dulcis showed the greatest inhibition of TBARS, with IC50 of 1.38 ± 1.22 μg/mL and better
chart the decay. In G. glabra, the dichloromethane fraction showed the best IC50 of 1.91 ±
0.73 μg/mL, but the best graphic decay was observed in the crude extract. Using the method
proposed by the Brazilian Pharmacopoeia Fourth Edition, it was possible to differentiate the
plants through the HPLC profiles. The absence of glycyrrhizin acid is evidence of falsification.
However, the method does not allow the identification of the plant adulterant. The
antimicrobial activity of the species was similar, varying only for Saccharomyces cerevisiae
and Fusarium proliferatum. The sub-fractionation of P. dulcis improved activity against
Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella pullorum.A família Fabaceae é constituída por aproximadamente 18000 espécies em 650 gêneros, com ampla distribuição geográfica. As espécies Glycyrrhiza glabra (alcaçuz) e Periandra dulcis (alcaçuz-da-terra) pertencem à família Fabaceae. Alcaçuz exibe uma variedade de atividades farmacológicas, como antiúlcera, antiinflamatória, antioxidante, antimicrobiana, entre outras. Na etnomedicina brasileira, P. dulcis é utilizado como substituto/adulterante de G. glabra. O presente trabalho objetivou a diferenciação das plantas quanto à atividade antioxidante, o perfil cromatográfico por CLAE e à atividade antimicrobiana. As raízes das plantas foram moídas e maceradas utilizando como solvente etanol:água (70:30, v/v). Fez-se fracionamento dos extratos brutos com solventes orgânicos de polaridades crescentes (CH2Cl2, AcOEt, n-BuOH). O extrato bruto e as frações foram investigados quanto ao conteúdo de polifenóis totais, atividade antioxidante pelo método do DPPH e inibição da peroxidação lipídica pelo método do TBARS. O conteúdo de fenóis totais variou de 70,29 ± 2,98 a 85,78 ± 1,08 mg/g para P. dulcis e 137,7 ± 1,37 a 83,26 ± 2,71 mg/g para G. glabra. No ensaio do DPPH, a fração diclorometano foi mais eficiente na captação de radicais livres em ambas as plantas. A fração butanólica de P. dulcis demonstrou a maior inibição dos níveis de TBARS, com IC50 de 1,38 ± 1,22 μg/mL e melhor decaimento gráfico. Em G. glabra, a fração diclorometano demonstrou o melhor IC50 de 1,91 ± 0,73 μg/mL, mas o melhor decaimento gráfico foi observado no extrato bruto. Utilizando o método proposto pela IV Edição da Farmacopéia Brasileira, foi possível diferenciar as plantas através dos perfis cromatográficos obtidos por CLAE. A ausência do ácido glicirrizínico é indício de adulteração. Contudo, o método não permite a identificação da planta adulterante. A atividade antimicrobiana das espécies foi semelhante, variando apenas para Saccharomyces cerevisiae e Fusarium proliferatum. O sub-fracionamento de P. dulcis melhorou a atividade frente à Staphylococcus aureus, Pseudomonas aeruginosa e Salmonella pullorum.
8
Co, Michelle. "Pressurised Fluid Extraction of Bioactive Species in Tree Barks : Analysis using Hyphenated Electrochemical Mass Spectrometric Detection." Doctoral thesis, Uppsala universitet, Analytisk kemi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-133264.
Анотація:
Analytical chemistry has developed throughout time to meet current needs. At present, the interest in biorefinery is growing, due to environmental awareness and the depletion of fossil resources. Biomass from agricultural and forestry industries has proven to be excellent raw material for different processes. Biorefinering valuable species such as bioactive species from biomass, without compromising the primary process of the biomass is highly desirable. Pressurised fluid extraction (PFE) using water and ethanol as a solvent was developed for extracting betulin from birch (Betula pendula) bark. Apart from betulin, stilbene glucosides such as astringin, isorhapontin and picied were also extracted from spruce (Picea abies) using PFE. PFE is an advanced technique that extracts at temperatures above the solvent’s atmospheric boiling point. The applied pressure in PFE is mainly to maintain the liquid state of the extraction solvent. Parameters such as type of solvent, temperature, and time affect the extraction selectivity and efficiency. Therefore it is necessary to comprehend these parameters in order to optimise extraction. The DPPH (1,1-diphenyl-2-picrylhydrazyl) assay was used to determine the antioxidant capacity and activity of the obtained bioactive species. The results showed high antioxidant capacity in bioactive species that were extracted at an elevated temperature, 180°C. Extraction and degradation occur simultaneously during the extraction. Hence, it is crucial to separate these two processes in order to obtain the actual value. An online hyphenated system of chromatographic separation electrochemical mass spectrometric detection was developed (LC-DAD-ECD-MS/MS). The electrochemical detector facilitates real-time monitoring of the antioxidant capacity and activity of each antioxidant and its oxidation products. This developed LC-DAD-ECD-MS/MS method enabled rapid screening of antioxidants and created a fingerprint map for their oxidation products. Characterisation and molecular elucidation of bioactive species were also performed. Degradation of bioactive species was investigated with the said online system and birch bark extract was compared with birch bark extracts that were hydrothermally treated. The obtained results showed some degradation of antioxidants at 180°C. In summary, the aim of this thesis was to develop analytical methods integrated with sustainable chemistry for extraction of bioactive species in biomass from the forestry industry. A novel online system using selective and sensitive detectors such as diode-array, electrochemical, and tandem mass spectrometry was developed to rapidly determine the antioxidant capacity and activity of antioxidants. Furthermore, tandem mass spectrometry enables identification of unknown bioactive species without the need of reference samples.Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 719
9
Ye, Liyun. "Antioxidant Activity of Ampelopsis Grossedentata Crude Extract and its Major Component Dihydromyricetin." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/76833.
Анотація:
Oxidation limits the shelf life of many food products. Adding antioxidants to foods is the most common way to solve this problem. Reports on safety issues of synthetic food additives have raised consumer interest in "all natural" foods, without added antioxidants or with synthetic replaced with natural antioxidants. The natural antioxidants now in use are much more expensive and less potent than the synthetic antioxidants. Thus, effective and economical natural antioxidants are of great interest to researchers. Teng Cha is a type of herbal tea found in China that has reported high levels of antioxidants. Antioxidant activity of Teng Cha extract and its major component dihydromyricetin has been reported, but no studies have provided clear evidence for the antioxidant effectiveness of Tech Cha extracts. The goal of this study was to measure the antioxidant activity of Teng Cha extract and dihydromyricetin (DHM), a major component of Tech Cha extract. The DPPH assay was conducted and antioxidant activities of the crude extract and dihydromyricetin were evaluated in soybean oil based on the peroxide value, anisidine value, Totox value, headspace volatiles and headspace oxygen. Antioxidant effectiveness was also evaluated in a cooked beef model system. DHM was more potent than BHA in preventing soybean oil oxidation. The crude extract was not as effective as BHA and DHM, possibly because it contained transition metals. In cooked beef, DHM and the crude extract showed lower activity than BHA, possibly due to their low solubility. Overall, Teng Cha extract and DHM are potential natural food antioxidants for future applications.Master of Science in Life Sciences
10
Ribeiro, Vera Lúcia Meireles Carpinteiro. "Estudo de compostos bioativos presentes em Adansonia digitata e o seu potencial fitoquímico na indústria farmacêutica." Master's thesis, [s.n.], 2012. http://hdl.handle.net/10284/3734.
Анотація:
Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas.O género Adansonia digitata, comumente conhecido como baobab compreende oito espécies das quais seis são endémicas da ilha de Madagáscar (A. fony, A. za, A. madagascariensis, A. suarezensis e A. perrieri), uma de África (A. digitata) e uma da Austrália (A. gregorii). Entre as espécies supracitadas, a que tem merecido particular atenção é a A. digitata possivelmente devido à sua frequente utilização na medicina tradicional. O stresse oxidativo produzido no organismo relaciona-se com o aparecimento e/ou desenvolvimento de uma série de doenças crónicas não transmissíveis. Os compostos bioativos, presentes nos frutos, são capazes de neutralizar as estruturas radicalares formadas no metabolismo humano, diminuindo o risco do aparecimento de doenças crónicas, nomeadamente do foro cardiovascular e carcinogénico. As frutas são caracterizadas como fontes naturais de energia, hidratos de carbono, vitaminas e minerais, bem como, pelo seu contributo na aquisição de compostos bioativos que apresentam benefícios para a promoção da saúde em geral. A dietoterapia e a fitoterapia são duas vias terapêuticas de recurso natural em franca ascensão, relacionando o conceito de alimentos funcionais com a ação farmacológica uma vez que a ação antioxidante dos compostos bioativos depende, não só, das suas estruturas químicas como também das suas concentrações. Atualmente, o recurso e o interesse no conhecimento da composição nutricional e fitoquímica dos frutos exóticos têm aumentado, não só pelo fácil acesso a estes recursos naturais como pelo interesse económico que os mesmos podem potenciar a economia nacional dos países em desenvolvimento. O presente trabalho teve como objetivo a análise quantitativa dos compostos bioativos mais representativos da polpa do fruto da árvore Adansonia digitata, de Angola, cidade de Benguela, local de onde são provenientes os frutos estudados. Foi avaliada a atividade antioxidante pelo método espetrofotométrico do radical livre DPPH•. Os resultados obtidos mostram que o fruto do baobab angolano possui teores elevados de vitamina C e de fenólicos totais, o que explica a sua elevada capacidade antioxidante. Os teores de carotenóides apresentaram teores pouco significativos para a matriz estudada, uma vez que a coloração da polpa do fruto carece de pigmentação. Este estudo, embora preliminar, indicou por meio de uma abordagem fitoquímica in vitro, a presença de compostos com propriedades bioativas, visando o seu interesse para a sua aplicação numa vertente tanto alimentar como farmacêutica para a elaboração de suplementos naturais com atividade farmacológica e terapêutica. The Adansonia digitata genus, commonly known as baobab comprises eight species, which six are endemic from Madagascar island (A. fony, A. za, A. madagascariensis, A. suarezensis and A. perrieri), one of Africa (A. digitata ) and one from Australian (A. gregorii). Among the above species, the one who has received particular attention is the A. digitata, possibly due to its frequent use in traditional medicine. The oxidative stress produced in live organisms is related to the appearance and/or development of a series of non-transmissible chronic diseases. Phenolic compounds present in fruits are able to neutralize these substances, thus reducing the risk of development of free radicals associated to several pathologies, such as cardiovascular disease and cancer. Fruits are characterized as natural sources of energy, carbohydrates, vitamins and minerals as well as for their contribution in the contribution of bioactive compounds that exhibit high benefits for the health promotion. The dietotherapy and the phytotherapy are two therapeutic natural resources in great ascension, relating the concept of functional foods with the pharmacological action. The antioxidant activity of bioactive compounds depends, not only on their chemical structures as well as their concentrations in fruits. Currently, the knowledge and the interest in the nutritional and phytochemical composition of exotic fruits have been increasing, not only because of theirs easy access to the natural resources as the economic interest that they can boost the national economy of developing countries. The aimed of the present study was to evaluate the characterization of bioactive compounds more representative of the fruit pulp of Adansonia digitata tree, from Angola, more exactly from Benguela city place where fruits studied come from. Results showed that the Angolan baobab fruit has high levels of vitamin C and phenolic compounds, which explains its high antioxidant capacity. The carotenoids content were underrepresented in this studied, what was expected, once the fruit pulp lacks of pigmentation. This study, although considered as a preliminary and incomplete work indicated an in vitro phytochemical approach and the presence of compounds with bioactive properties, aiming the interest for its application, not only in the food diet as well as a natural resource for pharmaceutical industry, particularly in developing natural supplements with therapeutic and pharmacological activities.
Частини книг з теми "DPPH antioxidant activity":
1
Rubab, Momna, Ramachandran Chelliah, and Deog-Hwan Oh. "Screening for Antioxidant Activity: Diphenylpicrylhydrazine (DPPH) Assay." In Methods in Actinobacteriology, 453–54. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-1728-1_61.
2
Nenadis, Nikolaos, and Maria Z. Tsimidou. "DPPH (2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl) radical scavenging mixed-mode colorimetric assay(s)." In Measurement of Antioxidant Activity & Capacity, 141–64. Chichester, UK: John Wiley & Sons, Ltd, 2017. http://dx.doi.org/10.1002/9781119135388.ch8.
3
Londonkar, Ramesh, and Maithilee Kesralikar. "In Vitro Anticancer Screening of Methanolic Extract of Stachytarpheta Mutabilis." In Proceedings of the Conference BioSangam 2022: Emerging Trends in Biotechnology (BIOSANGAM 2022), 188–204. Dordrecht: Atlantis Press International BV, 2022. http://dx.doi.org/10.2991/978-94-6463-020-6_19.
Анотація:
AbstractIn therapeutic plants, phytochemicals are found in abundance. A family of verbena known as vervain (verbenaceae) consists of over 100 genera and nearly 2600 species. Among the Verbenaceae family is Stachytarpheta, a green perennial herb. The species is being examined in this study for its phytochemical, antioxidant, and anti-inflammatory properties. Stachytarpheta mutabilis methanol extracts were studied for their phytochemical screening, antimicrobial, anti-inflammatory, and anticancerous effects in the current study. Phytochemical study revealed the presence of alkaloids, flavonoids, glycosides, steroids, tannins, carbohydrates, and saponins, among other phytoconstituents. One fungus, Aspergillus niger, Staphylococcus aureus, and Bacillus subtilis, as well as four-gram (+) pathogens, including Staphylococcus aureus and Bacillus subtilis, and two gram (-) pathogens, including Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae, were disc diffusion tested for antibacterial activity. The nitric oxide scavenging assay was used to test for anti-inflammatory efficacy in vitro. DPPH, ABTS, and total antioxidant tests were used to evaluate antioxidant activity. Analyses such as TLC, GC-MS, and were performed as per common procedure. A nitric oxide scavenging experiment was utilised to determine the anti-inflammatory properties of the drug in vitro. Tests for antioxidant activity were conducted using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), and total antioxidant tests. MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) analysis has been used to do anticancer screening. Extracts from Stachytarpheta mutabilis were found to include flavonoids, tannins and phenolic compounds as well as terpenoids and steroids in their phytochemical analysis. Squalene, octadecanal, and butan-1-one were found in the GC-MS study as were thirty other bioactive chemicals such as 4-isopropylcinnamic acid and octadecanoic acid. The methanolic fractions of plant extracts were shown to be effective against all bacteria. Anti-inflammatory and antioxidant experiments performed in the lab revealed the compounds’ potent inhibition activity. Analysis of the GC-MS data revealed the existence of thirty distinct components. MTT assay on the extract revealed anticancer activity. The data shows that the methanolic extract has a significant properties. Stachytarpheta mutabilis has therapeutic value and other pharmaceutical qualities may be assessed as a result of these results, which support the traditional usage of folk medicine as well.
4
Chen, Yong, Nanqun Zhu, and Chi-Tang Ho. "Identification of Antioxidants from Du-Zhong (Eucommia ulmoidesOliver) Directed by DPPH Free Radical-Scavenging Activity." In ACS Symposium Series, 224–31. Washington, DC: American Chemical Society, 2003. http://dx.doi.org/10.1021/bk-2003-0859.ch016.
5
Gorbachev, Mikhail, Natalia Gorinchoy, Iolanta Balan, and Ion Arsene. "Electronic Structure-Antioxidant Action Relationships for Chemical Compounds." In Fundamental and Biomedical Aspects of Redox Processes, 143–58. IGI Global, 2023. http://dx.doi.org/10.4018/978-1-6684-7198-2.ch006.
Анотація:
The relationships between electronic structure particularities and antioxidant activity of some chemical compounds are considered on the basis of the density functional theory (DFT) calculations of reactions between some natural phenolic antioxidants (gallic, caffeic, p-coumaric, and other acids), as well as dihydroxyfumaric acid, and the stable radicals ABTS•+ and DPPH• in water, ethanol, and methanol. Particular attention is paid to the processes of the primary proton transfer between neutral molecules of the above antioxidants and molecules of these solvents. The important factors are also considered: the formation of the charge transfer complexes (CTC) between the anionic forms of these antioxidants and the radicals, and possible tautomeric effects essentially changing the pre-reactional structures of the investigated antioxidant molecules and their anions. The quantitative relationships between the electronic structure parameters and the antioxidant activity of some short chain n-alkanes with radicals OH• and NO3• are also discussed.
6
Ayembilla, Jacob Apibilla, Phyllis Naa Yarley Otu, Eunice A. Dotse, Abigail Aning, Emmanuel Kweku Ofori, Regina Appiah-Opong, and Henry Asare-Annane. "Antioxidant and Anticancer Potential of Natural Cocoa Extract." In Technological Innovation Driving Sustainable Entrepreneurial Growth in Developing Nations, 156–75. IGI Global, 2023. http://dx.doi.org/10.4018/978-1-6684-9843-9.ch007.
Анотація:
The aim of this study was to investigate antioxidant and anticancer potentials of natural cocoa extracts. Antioxidant properties of the extracts were evaluated by DPPH assay, total phenolic content by Folin-Ciocalteau and reduced glutathione content by O-phthalaldehyde assays. Antiproliferative activity was also evaluated on leukaemia and prostate cancer cell lines using MTT assay. The hydroethanolic extracts of cocoa roots and beans and aqueous cocoa leaves showed high total antioxidant activities with the root extract having the strongest scavenging effect on DPPH and the highest total phenolics content. The hydroethanolic cocoa bean crude extract showed the highest anticancer activity against LNCaP cells, whiles the ethyl acetate fraction of hydroethanolic cocoa leaf exhibited the highest anticancer against PC3. Jurkat and PC3 cells had similar susceptibilities to the natural cocoa extracts. Thus, cocoa has antioxidant and anticancer activity, and the specific bioactive compounds responsible for these activities need to be elucidated in future research.
7
Zhang, Mengling, Xuewen Bao, Xin Huang, Haigang Li, Yanhui Li, and Meihua Bao. "Optimization of the Extraction Strategy for Polyphenols from Pieris Japonica and Evaluation of Its Antioxidant Activity." In Studies in Health Technology and Informatics. IOS Press, 2023. http://dx.doi.org/10.3233/shti230819.
Анотація:
Pieris Japonica, belonging to the Rhododendron family, is known for its anti-insect and analgesic properties. Despite previous research, the components and antioxidant activity of Pieris Japonica extract remain unclear. This study aims to identify the optimal extraction process for Pieris Japonica, determine its components, and evaluate its antioxidant capacity. An L9 (34) orthogonal method was employed to optimize the Pieris Japonica extraction process, with the polyphenol content serving as the extraction efficiency index. The extracted components were identified by high-performance liquid chromatography-mass spectrometry (HPLC/MS-MS). Antioxidant activity was assessed via the DPPH test, ABTS radical scavenging test, and FRAP reduction ability test. The optimal extraction process involved soaking Pieris Japonica powder in 60% ethanol with a weight-to-volume ratio of 1:20 (g/mL), followed by eight hours of reflux at 50°C. Under these conditions, the total polyphenol content was 11.2 ± 0.6 mg/g. HPLC/MS-MS revealed that flavonoids were the primary components in the Pieris Japonica extract. The FRAP method determined the total antioxidant capacity to be 1.00 ± 0.05 μmol/mL, while the DPPH method showed a radical scavenging rate of 42.21 ± 4.02%, and the ABTS method yielded a 85.74% scavenging rate, indicating a strong antioxidant activity. The primary components of Pieris Japonica extract were flavonoids, and the extracted plant material exhibited potent antioxidant activity.
8
Lobo, Patrícia Teixeira Damasceno, Elisa Teshima, and Sandra Aparecida de Assis. "Antioxidant and prebiotic activity of (1→3)-β-D-glucan obtained from Rhodotorula mucilaginosa." In UNITING KNOWLEDGE INTEGRATED SCIENTIFIC RESEARCH FOR GLOBAL DEVELOPMENT. Seven Editora, 2023. http://dx.doi.org/10.56238/uniknowindevolp-053.
Анотація:
The β-Glucans has high biotechnological potential application in several industrial sectors. Then, the antioxidant and prebiotic activity of (1→3)-β-D-glucan obtained from the cell wall of R. Mucilaginosa yeast was evaluated. The strains tested Bifidobacterium Lactis and Bifidobacterium longum showed a comparable result with the commercially inulin. The digestibility of glucan was investigated in vitro by exposing them to artificial human gastric juice. The results show that not occurred hydrolysis of (1→3)-β-D-glucan under the studied conditions and the glucan remain undigested in 100%. Antioxidant capacity was evaluated by ABTS, DPPH and total antioxidant capacity test. The results of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity showed a maximum inhibition percentage of 51.00% and the test of total antioxidant capacity showed that 10 mg/mL of (1→3)-β-D-glucan shows the same result as the use of the 222.27 ± 4.3 µg/mL ascorbic acid. The obtained results show that the (1→3)-β-D-glucan extracted from the cell wall of R. mucilaginosa has the potential to be explored as a food ingredient with functional capacity.
9
Florin Danet, Andrei. "Recent Advances in Antioxidant Capacity Assays." In Antioxidants - Benefits, Sources, Mechanisms of Action. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96654.
Анотація:
This work presents a survey of the important antioxidant capacity/activity assays applied for a diversity of samples including plant extracts, foods, biological material, etc. The published materials are critically discussed, emphasizing the recent findings in the field. New and emergent antioxidant capacity assays, such as nanoparticles-based assay, are also presented. The discussion includes chemical-based methods as well as biochemical and cellular assays. Chemical methods detailed are radical/ROS-based scavenging assays (the trolox equivalent antioxidant capacity (TEAC/ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC) assays, chemiluminescence methods, total radical-trapping antioxidant parameter (TRAP), total oxy radical scavenging capacity (TOSC), and β-carotene bleaching assays), non-radical redox potential-based assays (ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), nanoparticle-based methods and electrochemical methods), metal chelation capacity and total phenolic content tests. The biochemical-based assays and in vivo assays discussed include the oxidation of low density lipoprotein (LDL), the thiobarbituric acid reactive substances (TBARS) and the cellular antioxidant activity (CAA) assays. While a direct link between the antioxidant capacity and health benefits is still a matter of debate, the antioxidant testing methodologies presented in this chapter remain valuable for the high efficiency and cost-effective evaluation of antioxidants, from compound discovery to quality control.
10
Huaraca Aparco, Rosa, María del Carmen Delgado Laime, Fidelia Tapia Tadeo, Henrry Wilfredo Agreda Cerna, Edwin Mescco Cáceres, Juan Alarcón Camacho, Hans Yuri Godoy Medina, et al. "Bioactive Compounds and Antioxidant Activity of Essential Oil of Species of the Genus Tagetes." In Recent Developments in Antioxidants From Natural Sources [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.109254.
Анотація:
This study investigated the bioactive compounds and antioxidant activity of the essential oil of two species of the genus Tagetes (Tagetes minuta L. and Tagetes elliptica Sm). The essential oil was obtained by steam distillation, and its extraction performance, relative density, refractive index, and solubility in ethanol (70% v/v) were determined. The chemical components were evaluated by gas chromatography coupled to mass spectrometry (GC-MS). Antioxidant activity was determined by the free radical 2,2-diphenyl-1-picrylhydrocyl (DPPH) method and the trapping capacity of the ABTS*+ radical cation. In the essential oils of the species Tagetes, it was possible to identify 26 chemical components for the species Tagetes elliptica Sm. and 16 for Tagetes minuta L., both species presented as main components monoterpenes (61%) and sesquiterpenes (44%). The compounds found were β-myrcene, trans-tagetone, β-trans-ocimene, and β-caryophyllene. Essential oils showed a variation in extraction yields and density. The refractive index was higher in the species Tagetes elliptica Sm., finding a high solubility in both species. A variation was found between 1.77 and 2.56 mg/mL of antioxidant activity by the DPPH method and 21.02–41.06 mg/mL for ABTS*+. The essential oils of the species Tagetes elliptica Sm.y and Tagetes minuta L. have bioactive components with antimicrobial and antioxidant potentialities for use for food preservatives.
Тези доповідей конференцій з теми "DPPH antioxidant activity":
1
Sovrlić, Miroslav, Nedeljko Manojlović, Marijana Kosanić, Aleksandar Kočović, Jovica Tomović, and Perica Vasiljević. "Lichenochemical analysis and in vitro antioxidant activity of extracts and gyrophoric acid from lichen Umbilicaria grisea." In 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.515s.
Анотація:
This research investigates the chemical composition, total phenolic and flavonoid content, and antioxidant activity of acetone, methanol, and ethanol extracts of the lichen Umbilicaria grisea, and its major secondary metabolite, gyrophoric acid. The extracts were analyzed using high-performance liquid chromatography (HPLC-UV) and spectrophotometric assays. The results showed significant levels of phenolic compounds and flavonoids, which contribute to the lichen’s antioxidant potential. The antioxidant activity was evaluated using in vitro assays such as DPPH and ABTS radical scavenging activity. The extracts demonstrated potent antioxidant activity, suggesting their potential as natural antioxidants. The identification of bioactive compounds, high phenolic and flavonoid content, and significant antioxidant activity support the potential use of U. grisea as a natural source of therapeutic agents. Further studies are needed to elucidate the underlying mechanisms responsible for these biological activities and evaluate the efficacy and safety of these extracts for potential pharmaceutical applications.
2
Rodríguez-Ramírez, Juan, Irene Chaparro-Hernández, Lilia L. Méndez-Lagunas, and Luis Gerardo Barriada-Bernal. "Effect of spray drying conditions on antioxidants activity, flavonoids and total phenolic compounds of stevia rebaudiana." In 21st International Drying Symposium. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7518.
Анотація:
In this work the spray drying of the fresh stevia leaves aqueous extract without encapsulating agents was carried out. The effect of the inlet air temperature (160-200 ºC) and the feed flow rate (2-3 kg/h) on the total phenolic content, the total flavonoid content and the antioxidant capacity were evaluated using Folin-Ciocalteau, aluminum chloride and DPPH methods respectively. The inlet air temperature had a significant effect on all parameters evaluated that showed a decrease when increasing the inlet air temperature, the feed flow rate had a significant effect on total flavonoids content and the antioxidant capacity, by increasing the feed flow rate the inhibition of the DPPH radical decreased and the total flavonoid content increased. The treatment at 160 ºC and 3 kg/h retained highest total flavonoid content and the antioxidant capacity. Keywords: Phenolic compounds, stevia, spray drying, antioxidant capacity
3
Som, Ayub Md, Norizan Ahmat, Hairul Amani Abdul Hamid, Siti Raihanah Abdul Rahman, Nurul Amirrah Rahimudin, Nur Amira Zainidi, and Adilah Amirah Ayub. "Phytochemical Screening and Antioxidant Activity of <i>Hylocereus undatus</i> Foliage: Effects of Using Different Drying and Assays Methods." In 5th International Conference on Global Sustainability and Chemical Engineering 2021 (ICGSCE2021). Switzerland: Trans Tech Publications Ltd, 2023. http://dx.doi.org/10.4028/p-m2r02u.
Анотація:
Phytochemical screening was conducted on Hylocereusundatus foliage to determine the presence of alkaloids, flavonoids, tannins, and saponins using methanol and chloroform solvents via oven-dried and open air-dried methods. As for the antioxidant activity, powdered Hylocereusundatus foliage were extracted using both solvents through Ferric Reduction Antioxidant Power (FRAP) assay; and the findings were then compared to 2,2-Diphenyl-1-Ipicrylhydrazyl (DPPH) assay from previous studies. Results revealed that for both methods in phytochemical screening, flavonoids were present only in methanol extract; however, saponins were present in both extracts. No alkaloid and tannins were present in both extracts using both methods. Antioxidant activity results revealed that the methanol extract (59.05%) and chloroform extract (20.58%) using the FRAP assay were comparable to that of DPPH assay in which methanol extract (88.81%) and chloroform extract (38.30%) were obtained. It concludes that Hylocereusundatus has comparable phytochemical constituents and antioxidant activity based on the different drying and assay methods.
4
Todorović, Jovana D., Aleksandra D. Vesić, Nevena N. Petrović, and Marijana M. Kosanić. "Edible mushrooms as promising antioxidants." In 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.300t.
Анотація:
Antioxidant activity of the acetone extracts of the mushrooms Macrolepiota procera and Chlorophyllum rhacodes has been screened in vitro by using different methods (DPPH radical scavenging and reducing power assay), and also it has been determined the total phenolic compounds as total flavonoid content. The research findings indicate that the acetone extract of M. procera demonstrated superior antioxidant activities when compared to C. rhacodes. Similarly, the mushroom M. procera displayed a more pronounced effect on reducing power. In addition, the total content of phenol and flavonoid in extracts were determined as pyrocatechol equivalent, and as rutin equivalent, respectively. A higher content of total phenols and flavonoids was detected in the extract of M. procera. The strong relationships between total phenolic and flavonoid contents and the antioxidative activities of tested extracts imply that these compounds have a significant impact on antioxidant activity. The present study highlights that the tested mushroom species exhibit potent antioxidant properties and can be regarded as valuable sources of natural antioxidants.
5
Petrović, Aleksandar, Ivana Plavšić-Janjatović, Nikolina Lisov, Maria Čebela, Uroš Čakar, Ivan Stanković, and Brižita Đorđević. "ANTIOXIDANT PROPERTIES AND BIOLOGICAL ACTIVITY OF FRUIT WINES." In 1st International Symposium on Biotechnology. University of Kragujevac, Faculty of Agronomy, 2023. http://dx.doi.org/10.46793/sbt28.405p.
Анотація:
The fruit wines from blueberry were made by microvinification procedure. Wines were produced in the absence or presence of sugar and/or enzymatic preparation glycosidase (EPG). Selected phenolic acids were quantified using UPLC/MS-MS analysis. Total phenolic content (TPC) was determined by the Folin-Ciocalteu method. Also, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing ability of plasma (FRAP) methods were applied. The α-glucosidase inhibitory activity of blueberry wines was also investigated. Wines made with addition of sugar and EPG showed the best results. Phenolic profile and biological activity of blueberry wine depended from microvinification procedure which was used in the production.
6
Marković, Violeta R., Jovana M. Muškinja, and Tamara Lj Todorović. "Synthesis and antioxidant activity of novel vanillin-based ferrocenyl chalcones." In 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.547m.
Анотація:
A small series of new ferrocenyl chalcones was prepared, starting from the corresponding aldehydes and monoacetyl ferrocene. Di-derivatives of vanillin and ethylvanillin were prepared and used as aldehydes for this synthesis. All new compounds were characterized by IR and NMR spectroscopy and physical data. The antioxidant potential of new compounds was evaluated using the DPPH test and the results showed moderate activity in vitro.
7
Muškinja, Jovana M., Jelena S. Katanić Stanković, and Zoran R. Ratković. "SYNTHESIS AND ANTIOXIDANT ACTIVITY OF SOME NEW SULFONAMIDE DERIVATIVES." In 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac, 2021. http://dx.doi.org/10.46793/iccbi21.351m.
Анотація:
Sulfonamide derivatives are a very important class of compounds with pronounced biological activities and, for this reason, they have very useful pharmaceutical applications. They are the basis of several groups of drugs and are known as sulfa-drugs. From this point of view, the present study focuses on the synthesis of some novel structural hybrids incorporating two very important groups, sulfonamide, and pyrazoline. The new sulfonamide-based pyrazolines were synthesized in very good yields. The structures of the sulfonamide compounds were confirmed by IR and NMR methods. Synthesized compounds were tested for their antioxidant activities using two different methods, DPPH radical and ABTS radical cation scavenging assays. The results showed relatively good in vitro antioxidant activity.
8
"Determination of Antioxidant Property, Total Phenolics Content, and α-Glucosidase Inhibitory Activity of Different Solvent Extracts of Defatted and Non-Defatted Peanut Skins". У 4th International Conference on Biological & Health Sciences (CIC-BIOHS’2022). Cihan University, 2022. http://dx.doi.org/10.24086/biohs2022/paper.781.
Анотація:
Peanut skins are by-product with little economic value. The effect of different solvents, on the total phenolic content (TPC), antioxidant property and in vitro antidiabetic activity of defatted and non-defatted peanut skins was determined. TPC was estimated using Folin-Ciocalteau reagent. Antioxidant property was evaluated using ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1- picrylhydrazyl (DPPH) radical scavenging capacity methods, α-glucosidase inhibition was evaluated using 4- nitrophenyl α-D-glucopyranoside (pNPG) method. Peanut skin of the defatted extracted with ethanol had the much of the content of total phenolics (391.76 mg/g GAE). Highest DPPH scavenging property was found in the methanolic extract of defatted peanut skins with IC50 value of 15.00 ± 1.00 μg/mL, while highest FRAP value was found in the aqueous extract of non-defatted extracts. Aqueous extracts demonstrated stronger inhibitory property against α-glucosidase and had IC50 of 16.33 ± 1.15 and 16.33 ± 8.50 μg/mL for defatted and non-defatted extracts, respectively. The finding of the present shows that peanut skins are important by-product for utilization as natural antioxidant and α-glucosidase inhibitors.
9
Keke, Anete, and Ingmars Cinkmanis. "Total phenolic content and antioxidant activity of honey powders." In Research for Rural Development 2021 : annual 27th International scientific conference proceedings. Latvia University of Life Sciences and Technologies, 2021. http://dx.doi.org/10.22616/rrd.27.2021.015.
Анотація:
Honey powders could be an innovative and attractive substitutes to liquid honey. The production of honey powders would allow to expand honey’s usage in food industry, cosmetics and pharmaceutics. In this research, freeze drying method was performed to obtain honey powder samples. Overall, 4 different formulations were prepared to obtain the powder samples. The aim of the research was to determine the total phenolic content and antiradical activity of the freeze-dried honey powder samples by spectrophotometric method. The content of total phenolics in the samples ranged from 92 to 146 mg GAE 100 g-1 of dry matter. Antiradical activity was measured with DPPH radical scavengers, and the IC50 results ranged from 6 to 12 mg mL-1.
10
Borompichaichartkul, Chaleeda, Desi Sakawulan, and Richard Archer. "Enhancing antioxidant property of instant coffee by microencapsulation via spray drying." In 21st International Drying Symposium. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7520.
Анотація:
This study is aimed to improve the antioxidant property of instant coffee by using microencapsulation technique and spray drying. Concentrated coffee extract was mixed with Konjac glucomannan hydrolysate (KGMH) and Maltodextrin (MD). The mixture of coating material and coffee extract was then spray dried at 160 - 180 °C inlet air temperature and at 85-90 °C outlet air temperature. KGMH can preserve retention of phenolic compounds, DPPH scavenging activity and antioxidant activity of FRAP (p<0.05 of instrant coffee better than other treatment. Keywords: Hydrolysed Konjac Glucomannan; Spray Drying; Microencapsulation; Instant Coffee, Antioxidant