scholarly journals UV-effects on antioxidant activity of selected carotenoids in the presence of lecithin estimated by DPPH test

2008 ◽  
Vol 73 (11) ◽  
pp. 1051-1061 ◽  
Author(s):  
Dragan Cvetkovic ◽  
Dejan Markovic
Keyword(s):  
Antioxidant Activity ◽  
Ultraviolet Radiation ◽  
Energy Input ◽  
High Energy ◽  
Antioxidant Action ◽  
Dpph Radical ◽  
Dpph Test ◽  
Uv Photons

The effects of ultraviolet radiation (UV) on the antioxidant action of three selected carotenoids (?-carotene, lycopene and lutein) in the presence of a lipoidal lecithin mixture were studied by the DPPH (1,1-diphenyl-2-picrylhydrazyl) test. The test is based on the measurement of the decrease of the free DPPH radical absorbance at 517 nm caused by the antioxidant action of carotenoids, which appeared to be strongly affected by UV-action. The high-energy input of the involved UV-photons plays a major governing role.

scholarly journals UV-induced change in quercetin antioxidant activity toward benzophenone initiated lipid peroxidation

2012 ◽  
Vol 77 (11) ◽  
pp. 1571-1588 ◽  
Author(s):  
Jelena Zvezdanovic ◽  
Dejan Markovic ◽  
Dragan Cvetkovic ◽  
Jelena Stanojevic
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Uv Irradiation ◽  
Energy Input ◽  
Incident Light ◽  
Methanol Solution ◽  
Suppression Effect ◽  
Peroxidation Processes ◽  
Uv Photons ◽  
Uv C

The aim of this work is to estimate the degradation and change in antioxidant activity of quercetin in the presence of two different mixtures of phospholipids in methanol solution, under continuous UV-irradiation from three different sub-ranges (UV-A, UV-B and UV-C), in the presence and in the absence of selected UV-absorbing photosensitizer, benzophenone. Quercetin is employed to control lipid peroxidation process generated by UV-irradiation, by absorbing part of the UV-incident light, or/and by scavenging the involved, created free radicals. The results show that quercetin undergoes to irreversible destruction, highly dependent on UV-photons energy input, more expressed in the presence than in the absence of benzophenone. In the same time quercetin expresses suppression effect on lipid peroxidation processes in UV-irradiated phospholipid mixtures in both cases - absence or presence of benzophenone (more or less effective, respectively). In UV-C-irradiated mixtures, benzophenone photosensitizing function is significantly reduced due to its strong absorption in the same UV-C spectral range, therefore affecting less antioxidant activity of the remained quercetin.

scholarly journals Effects of continuous UV-irradiation on the antioxidant activities of quercetin and rutin in solution in the presence of lecithin as the protective target

2011 ◽  
Vol 76 (7) ◽  
pp. 973-985 ◽  
Author(s):  
Dragan Cvetkovic ◽  
Dejan Markovic ◽  
Dragana Cvetkovic ◽  
Blaga Radovanovic
Keyword(s):  
Lipid Peroxidation ◽  
Uv Irradiation ◽  
Energy Input ◽  
Antioxidant Activities ◽  
Antioxidant Action ◽  
First Order ◽  
First Order Kinetics ◽  
Uv Photons ◽  
Uv C

The stabilities and antioxidant action of two selected flavonoids, quercetin and rutin, dissolved in methanol and water, toward continuous UV-irradiation from three different sub-ranges (UV-A, UV-B and UV-C) were studied. The flavonoids underwent degradation (bleaching) following first-order kinetics. The bleaching rates were highly dependent on the energy input of the involved UV-photons. The antioxidant activities of the two flavonoids on UV-induced lecithin lipid peroxidation were studied by the TBA-MDA test, and appeared to be also affected by the continuous UV irradiation. The energy input of the incident UV-photons again played a major governing role, but an impact of the flavonoids structures cannot be neglected.

Uşak İli’nden Toplanan Taxus Baccata (L) Türünün Metanol Ekstresinin Yaprak, Dal ve Meyvesinde Biyolojik Aktivitenin Belirlenmesi

2019 ◽  
Vol 7 (10) ◽  
pp. 1533
Author(s):  
Yasemin Karafakıoglu
Keyword(s):  
Antioxidant Activity ◽  
Methanol Extract ◽  
Phenolic Content ◽  
Maximum Amount ◽  
Chemical Components ◽  
Taxus Baccata ◽  
Dpph Radical ◽  
Flavonoid Content ◽  
Future Studies ◽  
Different Parts

Taxus species in different parts of the world prevent the formation of hepatoprotective, anticoagulant, antiulcerogenic, anti-coagulant, antifungal and tumour cells. In this study, biological activity studies were performed on the leaves, branches and fruits of the methanol extract of Taxus baccata L. species collected from Sivaslı district of Uşak province. The methanol extract of the T.baccata species, the total amount of phenolic content of the sample was found to be 14.76 mg GAEQ/1g dry sample in the highest leaves. In T.baccata methanol extract, the maximum amount of flavonoid content was 0.468±mg QE/g dry sample. Antioxidant activity value as DPPH radical; % inhibition value was found as 93.21%. Based on the results; It can be concluded that the leaves of T.baccata have higher antioxidant activity than fruits and branches. Future studies need to explore the chemical components contained in the T.baccata species to determine and investigate in further detail.

Phenolic Imidazole Derivatives with Dual Antioxidant/Antifungal Activity: Synthesis and Structure-Activity Relationship

2019 ◽  
Vol 15 (4) ◽  
pp. 341-351 ◽  
Author(s):  
Ana P. Bettencourt ◽  
Marián Castro ◽  
João P. Silva ◽  
Francisco Fernandes ◽  
Olga P. Coutinho ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antifungal Activity ◽  
Organic Molecules ◽  
Inhibitory Concentration ◽  
Yeast Species ◽  
Dpph Radical ◽  
Dpph Assay ◽  
Gram Negative ◽  
Structure Activity ◽  
Deoxyribose Degradation

Background: Previous publications show that the addition of a phenolic antioxidant to an antifungal agent, considerably enhances the antifungal activity. Objective: Synthesis of novel compounds combining phenolic units with linear or cyclic nitrogencontaining organic molecules with antioxidant/antifungal activity using methodologies previously developed in the group. Methods: Several N- [1,2-dicyano-2- (arylidenamino) vinyl]-O-alkylformamidoximes 3 were synthesized and cyclized to 4,5-dicyano-N- (N´-alcoxyformimidoyl)-2-arylimidazoles 4 upon reflux in DMF, in the presence of manganese dioxide or to 6-cyano-8-arylpurines 5 when the reagent was refluxed in acetonitrile with an excess of triethylamine. These compounds were tested for their antioxidant activity by cyclic voltammetry, DPPH radical (DPPH•) assay and deoxyribose degradation assay. The minimum inhibitory concentration (MIC) of all compounds was evaluated against two yeast species, Saccharomyces cerevisiae and Candida albicans, and against bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram negative). Their cytotoxicity was evaluated in fibroblasts. Results: Among the synthetised compounds, five presented higher antioxidant activity than reference antioxidant Trolox and from these compounds, four presented antifungal activity without toxic effects in fibroblasts and bacteria. Conclusion: Four novel compounds presented dual antioxidant/antifungal activity at concentrations that are not toxic to bacteria and fibroblasts. The active molecules can be used as an inspiration for further studies in this area.

scholarly journals Phytochemical, antioxidant and antimicrobial properties of Litsea angulata extracts

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1839
Author(s):  
Harlinda Kuspradini ◽  
Indah Wulandari ◽  
Agmi Sinta Putri ◽  
Sabeti Yulis Tiya ◽  
Irawan Wijaya Kusuma
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Antimicrobial Properties ◽  
Phytochemical Analysis ◽  
Dpph Radical ◽  
Free Radical Formation ◽  
Dpph Radical Scavenging ◽  
Phytochemical Constituent ◽  
Microdilution Broth

Background: Litsea angulata is a plant species belonging to Lauraceae family that is distributed throughout Indonesia, Malaysia, and New Guinea. The seeds have been traditionally used by local people in Kalimantan, Indonesia for the treatment of boils; however, there is no information about the potency of its branch, bark and leaves yet. This study aimed to determine the antioxidant, antimicrobial activity as well as the phytochemical constituent of Litsea angulata branch, bark, and leaves. Methods: Extraction was performed by successive maceration method using n-hexane, ethyl acetate, and ethanol solvent. Antioxidant activity was evaluated by DPPH radical scavenging assay. The antimicrobial activity using the 96 well-plate microdilution broth method against Staphylococcus aureus and Streptococcus mutans. Results: Based on the phytochemical analysis, it showed that extract of L. angulata contains alkaloids, flavonoids, tannins, terpenoids, and coumarin. The results showed that all extracts of plant samples displayed the ability to inhibit DPPH free radical formation and all tested microorganisms. Conclusions: L. angulata contains secondary metabolites such as alkaloids, flavonoids, tannins, terpenoids, carotenoids, and coumarin. The antioxidant activity on different plant extracts was a range as very strong to weak capacity. All extracts in this study could inhibit the growth of S. aureus and S. mutans.

scholarly journals Antiglycation and Antioxidant Properties of Ficus deltoidea Varieties

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Nur Sumirah Mohd Dom ◽  
Nurshieren Yahaya ◽  
Zainah Adam ◽  
Nik Mohd Afizan Nik Abd. Rahman ◽  
Muhajir Hamid
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Protein Carbonyl ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Dpph Radical Scavenging Activity ◽  
Ficus Deltoidea ◽  
Dpph Radical Scavenging

The present study aimed to evaluate the potential of standardized methanolic extracts from seven Ficus deltoidea varieties in inhibiting the formation of AGEs, protein oxidation, and their antioxidant effects. The antiglycation activity was analyzed based on the inhibition of AGEs, fructosamine, and thiol groups level followed by the inhibition of protein carbonyl formation. The antioxidant activity (DPPH radical scavenging activity and reducing power assay) and total phenolic contents were evaluated. After 28 days of induction, all varieties of Ficus deltoidea extracts significantly restrained the formation of fluorescence AGEs by 4.55–5.14 fold. The extracts also reduced the fructosamine levels by 47.0–86.5%, increased the thiol group levels by 64.3–83.7%, and inhibited the formation of protein carbonyl by 1.36–1.76 fold. DPPH radical scavenging activity showed an IC50 value of 66.81–288.04 μg/ml and reducing power activity depicted at 0.02–0.24 μg/ml. The extent of phenolic compounds present in the extracts ranged from 70.90 to 299.78 mg·GAE/g. Apart from that, correlation studies between the activities were observed. This study revealed that seven varieties of Ficus deltoidea have the potential to inhibit AGEs formation and possess antioxidant activity that might be attributed to the presence of phenolic compounds.

scholarly journals Bleaching of chlorophylls by UV irradiation in vitro: The effects on chlorophyll organization in acetone and n-hexane

2008 ◽  
Vol 73 (3) ◽  
pp. 271-282 ◽  
Author(s):  
Jelena Zvezdanovic ◽  
Dejan Markovic
Keyword(s):  
Uv Irradiation ◽  
Photosynthetic Pigments ◽  
Energy Input ◽  
First Order ◽  
First Order Kinetics ◽  
Uv Photons ◽  
The Stability ◽  
Major Factors

The stability of chlorophylls toward UV irradiation was studied by Vis spectrophotometry in extracts containing mixtures of photosynthetic pigments in acetone and n-hexane. The chlorophylls underwent destruction (bleaching) obeying first-order kinetics. The bleaching was governed by three major factors: the energy input of the UV photons, the concentration of the chlorophylls and the polarity of the solvent, implying different molecular organizations of the chlorophylls in the two solvents.

scholarly journals Antioxidant, Antimicrobial and Cytotoxic Activities of Samanea saman (Jacq.) Merr.

1970 ◽  
Vol 3 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Afia Ferdous ◽  
Mohammad Zafar Imam ◽  
Tajnin Ahmed
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Carbon Tetrachloride ◽  
Brine Shrimp ◽  
Dpph Radical ◽  
Cytotoxic Potential ◽  
Ic50 Value ◽  
Total Antioxidant ◽  
Samanea Saman ◽  
Soluble Fractions

In the present investigation the n-hexane, carbon tetrachloride and choloroform soluble fractions of crude methanolic extract of Samanea saman bark were tested for antioxidant, antimicrobial and cytotoxic potential. Antioxidant activity of the extracts was evaluated by DPPH radical scavenging assay and total antioxidant activity test. Antimicrobial activity was tested using disc diffusion method against thirteen bacteria and three fungi and cytotoxicity was tested by brine shrimp lethality bioassay. Chloroform and hexane soluble fraction showed IC50 value of 12μg/ml and 14μg/ml respectively in scavenging DPPH radical while the reference Butylated hydroxytoluene showed an IC50 value of 10μg/ml. The carbon tetrachloride fraction showed the highest total antioxidant capacity. The carbon tetrachloride fraction was also found to possess mild to moderate microbial growth inhibitory capacity. In the brine shrimp lethality bioassay, the n-hexane, carbon tetrachloride, chloroform soluble fractions showed LC50 value of 14.94μg/ml, 0.831μg/ml and 3.288μg/ml respectively. The results suggest good antioxidant and cytotoxic potential of chloroform and hexane soluble fractions and antimicrobial activity of carbon tetrachloride fraction of Samanea saman bark extract. Key Words: Samanea saman; Leguminoseae; Cytotoxicity; Antimicrobial; Antioxidant; Total antioxidant capacity. DOI: 10.3329/sjps.v3i1.6792S. J. Pharm. Sci. 3(1): 11-17

Aktywność biologiczna ekstraktów z propolisu

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Magdalena Woźniak ◽  
Anna Kwiatkowska ◽  
Elżbieta Hołderna-Kędzia ◽  
Katarzyna Sosnowska ◽  
Lucyna Mrówczyńska ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Biological Activity ◽  
Phenolic Compounds ◽  
Propylene Glycol ◽  
Ethyl Alcohol ◽  
Antiradical Activity ◽  
Colorimetric Method ◽  
Biological Properties ◽  
Bioactive Substances ◽  
Dpph Test

Introduction. Propolis, also known as bee glue, is a resinous material collected by honeybees with numerous biological properties, including antibacterial, antifungal, antioxidant and anticancer effects. Due to its health-promoting properties, propolis is a component of many products, including dietary supplements, cosmetics and healthy food. Aim. The aim of the study was to determine the antibacterial, antifungal and antioxidant activity of propolis extracts, as well as to compare the biological activity of propolis extracts, depending on the solvent used – ethyl alcohol or propylene glycol. Material and methods. Two propolis extracts were used in the research – the first was prepared in ethyl alcohol, and the second in propylene glycol. The antimicrobial activity of the examined extracts was determined against S. aureus, E. coli and C. albicans. The antioxidant activity was determined on the basis of the evaluation of their antiradical activity in the DPPH· test and Fe2+ chelating activity. Moreover, the total content of phenolic compounds and flavonoids in the tested extracts was determined using the colorimetric method. Results. The tested propolis extracts, regardless of the solvent used (ethyl alcohol or propylene glycol), showed high antibacterial (against S. aureus), antifungal (against C. albicans) and antioxidant (antiradical activity in the DPPH· test and ferrous iron chelating potency in the ferrozine test) activity. Moreover, both tested extracts were characterized by a high and similar content of bioactive compounds – phenolic compounds and flavonoids. Conclusions. The results of the conducted tests showed that the solvent used did not affect determined biological activity and the content of bioactive substances in the tested propolis extracts.

DPPH Radical Scavenging Activity of Kaempferol

2013 ◽  
Vol 781-784 ◽  
pp. 1294-1297 ◽  
Author(s):  
Ping Liu ◽  
Yun Tao Gao ◽  
Jiao Jiao Yu ◽  
Jia Wei Cha ◽  
Dong Mei Zhao ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Absorption Spectrum ◽  
Reaction Time ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Dpph Radical Scavenging Activity ◽  
Dpph Radical Scavenging

The UV-Vis absorption spectrum of kaempferol and DPPH was investigated, the optimum determination wavelength and reaction time for determining the DPPH radical scavenging activity of kaempferol was 517 nm and 30 min, respectively. Kaempferol exhibited strong DPPH radical scavenging activity with a IC50 value of 0.004349 mg·mL-1, which is smaller than that of rutin, indicating that kaempferol has a stronger antioxidant activity than rutin.

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