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Wyszukujesz frazę "Polyphenol" wg kryterium: Temat


Tytuł:
Polyphenol oxidase from wheat bran is a serpin
Autorzy:
Yamasaki, Yoshiki
Konno, Haruyoshi
Noda, Kazuhiko
Powiązania:
https://bibliotekanauki.pl/articles/1040750.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
polyphenol oxidase
serpin
wheat bran
Opis:
Polyphenol oxidase (PPO; EC 1.10.3.2) was isolated from wheat bran by a procedure that included ammonium sulfate fractionation, batch adsorption by DEAE-cellulofine, CM-cellulofine column chromatography, DEAE-cellulofine column chromatography, preparative isoelectric focusing, adsorption on the membrane of a Vivapure Q Maxi H spin column, and heat treatment. These procedures led to 150-fold purification with 4.2% recovery. The PPO was homogeneous by SDS/PAGE. The relative molecular weight of the PPO was estimated to be 37000 based on its mobility in SDS/PAGE. The isoelectric point of the PPO was 4.4. The Km values of the PPO for caffeic acid, chlorogenic acid, pyrocatechol, 4-methyl catechol and l-DOPA as substrates were 0.077, 0.198, 1.176, 1.667 and 4.545 mM. The PPO was strongly inhibited by tropolone. The Ki value for tropolone is 2.2 × 10-7 M. The sequence of the 15 N-terminal amino-acid residues was determined to be ATDVRLSIAHQTRFA, which was identical to those of serpin from Triticum aestivum and protein Z from Hordeum vulgare. The PPO strongly inhibited the activity of trypsin, which is an enzyme of serine proteases; 50% inhibition was observed with 1.5 × 10-7 M PPO. The Ki value for PPO is 2.3 × 10-8 M. The wheat bran PPO should be a very important protein for protecting wheat against disease, virus, insect and herbivore damages by both the activities of PPO and protease inhibitor.
Źródło:
Acta Biochimica Polonica; 2008, 55, 2; 325-328
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sprouts as potential sources of dietary antioxidants in human nutrition
Autorzy:
Zujko, M.E.
Terlikowska, K.M.
Zujko, K.
Paruk, A.
Witkowska, A.M.
Powiązania:
https://bibliotekanauki.pl/articles/1918350.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Medyczny w Białymstoku
Tematy:
Antioxidant potential
polyphenol
flavonoid
sprouts
Opis:
Purpose: The present study evaluates antioxidant activity, as well as polyphenol and flavonoid contents in common sprouts, available on the Polish market. The aim of this study was to extend our already published food databases. Materials and methods: Ten seed species from four plant families were analysed. Total polyphenol content of sprout extracts was determined using the Folin-Ciocalteau method. Total flavonoid content was assessed by the aluminium chloride colorimetric method. Total antioxidant status was measured using FRAP and ABTS methods. Results: The FRAP antioxidant potential was 0.60- 2.53 mmol TE (trolox equivalents)/100 g FM (fresh mass), and arranged in descending order it was: white mustard>cress>radish>broccoli>chickpea> sunflower>mung bean>wheat>green lentil>alfalfa), while the ABTS potential was 3.92-16.19 mmol TE/100 g FM (according to decreasing value: white mustard>green lentil>chickpea>sunflower>mung bean>cress> alfalfa>wheat> broccoli> radish). The polyphenol content was 160-774 mg GAE (gallic acid equivalents)/100 g FM, and flavonoid content 15-53 mg QE (quercetin equivalents)/100 g FM. Conclusion: Our results suggest that sprouts in comparison to other foods, despite small weight can be powerful sources of antioxidants. Special attention in human nutrition should be paid to white mustard sprouts as they are excellent source of polyphenol and flavonoid and are characterized by tremendous antioxidant activity.
Źródło:
Progress in Health Sciences; 2016, 6(2); 77-83
2083-1617
Pojawia się w:
Progress in Health Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Curcumin Prevents Free Fatty Acid-Induced Lipid Accumulation via Targeting the miR-22-3p/CRLS1 Pathway in HepG2 Cells
Autorzy:
Mei, Yuanyuan
Sun, Xiaoting
Huang, Shi-Ying
Wu, Xiaowen
Ho, Kuo-Ting
Lu, Liming
Chen, Chaoxiang
Li, Jian
Liu, Jingwen
Li, Guiling
Powiązania:
https://bibliotekanauki.pl/articles/28408450.pdf
Data publikacji:
2024-02-13
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
polyphenol
epigenetics
liver
steatosis
mitochondria
Opis:
Dysregulated lipid metabolism in liver is an important hallmark of non-alcoholic fatty liver disease (NAFLD), which may be modulated by dietary polyphenols or microRNAs (miRNAs). However, the underlying epigenetic regulatory mechanism of polyphenols remain unclear. The current study aimed to address how miRNA mediates hepatic lipid metabolic control of curcumin, a polyphenolic food supplement. The results showed that 24 h treatment with 5 - 20 μM curcumin prevented free fatty acid-induced lipid accumulation by around 10 ~ 50% in HepG2 cells, which was attenuated by pre-transfection with 40 nM miR-22-3p mimic for 48 h. In consequence, transfection with 40 nM miR-22-3p inhibitor for 48 h significantly reduced lipid accumulation by around 10%. And 48 h overexpression of miR-22-3p targeting cardiolipin synthase 1 (CRLS1) gene, which encodes a mitochondrial phospholipid synthase, showed a similar regulatory effect. Thus, miR-22-3p and CRLS1 showed opposite effects in modulating lipid metabolism, which probably involved mitochondrial control. In summary, this study demonstrated that curcumin improved hepatic lipid metabolism via targeting the miR-22-3p/CRLS1 pathway. Identification of the epigenetic regulatory mechanism underlying lipid metabolism may thereby facilitate alleviation of metabolic disorders by natural polyphenols.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2024, 74, 1; 59-68
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metal Detoxification in Nature and Its Translation into Functional Adsorbent Materials
Autorzy:
Permana, Rega
Ihsan, Yudi Nurul
Powiązania:
https://bibliotekanauki.pl/articles/1030803.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
adsorbent
bioinspired
heavy metal
polyphenol
Opis:
Nature has a remarkable strategies to overcome the unfavoring environmental condition by producing a unique chemical compounds, including polyphenol. Polyphenol residues in many living organism have been documented to express numerous biological function ranging from antioxidant, mechanical reinforcement as well as metal anchoring substances. This gave us insight of how nature converts toxic metal compound and deposits it into a harmless form. This review will discuss some natural strategies of living organism to metabolize metal in a safe manner so that the metal no longer harmful to them. Example taken from aluminum accumulating plants, vanadium accumulating marine tunicate and iron-reinforced mussel byssus, which all three utilized phenol derivative compound to chelate the metal. Advances made by incorporating cutting edge characterization tools allowed us to understand the exact mechanism of metal chelation at the atomic level. A comprehensive discussion of molecular mechanism governing the complexion between the phenolic compound and metal will be beneficial for further study to fabricate functional materials, for example adsorbent, to remediate contaminated water. Translating these natural strategies into an engineered polyphenol based adsorbent materials will be prospective to be further applied as a remediation agent as it is easily found in nature, cost effective and highly efficient.
Źródło:
World Scientific News; 2020, 145; 144-155
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of polyphenols on Bifidobacterium growth
Autorzy:
Gwiazdowska, Daniela
Juś, Krzysztof
Jasnowska-Małecka, Joanna
Kluczyńska, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/1038940.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
dietary polyphenol
probiotic
inhibition
stimulation
Opis:
Polyphenols are a common group of plant based bioactive compounds, that can affect human health because of their antioxidant and antimicrobial properties as well as free-radical scavenging activity. An increasing interest is observed in the interaction between polyphenols and microbiota occurring in food and the human gut. The aim of the work presented here, was to evaluate the effect of some polyphenolic compounds on the growth of two strains of Bifidobacterium: B. adolescentis and B. bifidum. The influence of some flavonoids: naringinin, hesperidin, rutin, quercetin as well as phenolic acids: gallic, caffeic, p-coumaric, ferulic, chlorogenic, vanillic and sinapic was determined by a 96-well microtiter plate assay. In the experiments the effect of three different concentrations of polyphenols: 2, 20 and 100 µg/ml on the growth of Bifidobacterium strains was investigated. All tested compounds influenced the growth of the examined bacteria. Both stimulatory and inhibitory effects were observed in comparison to the positive control. The strongest impact on the growth of bifidobacteria was observed during the first hours of incubation. The constant inhibitory effect was observed for hesperidin and quercetin addition and was dose-dependent. B. bifidum showed a stronger dependence on phenolic acids content in the medium than B. adolescentis during the first hours of incubation.
Źródło:
Acta Biochimica Polonica; 2015, 62, 4; 895-901
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antioxidant Enzyme Mechanism of Cluster Bean (Cyamopsis tetragonaloba (L.) Taub). Under Cobalt Stress
Autorzy:
Jayakumar, Kaliyamoorthy
Powiązania:
https://bibliotekanauki.pl/articles/1076708.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Catalase
Cobalt
Cyamopsis tetragonaloba
Peroxidasa
Polyphenol oxidase
Opis:
The research work has been carried out to estimate the low level cobalt application enhance antioxidant enzyme activities of cluster bean plants. The experiments were conducted in earthen pots containing 3 kg of air dried soil. The inner surface of pots was lined with polythene sheet. Cluster bean plants were raised in soil amended with different concentration of cobalt (0, 50, 100, 150, 200 and 250 mg/kg). The antioxidant enzyme activities were analysed at 30, 60, and 90 days after sowing (DAS). There found a significant enhance antioxidant enzyme activities at 50 mg/kg cobalt application in the soil in all the sampling days when compared to control. Further increase in the cobalt level (100-250 mg/kg) in the soil decreased antioxidant enzyme activities of cluster bean plants in all the sampling days.
Źródło:
World News of Natural Sciences; 2019, 24; 64-70
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Polyphenol on Visual Fatigue Caused by VDT Work
Autorzy:
Yoshihara, A.
Yamanaka, K.
Kawakami, M.
Powiązania:
https://bibliotekanauki.pl/articles/89982.pdf
Data publikacji:
2009
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
polyphenol
VDT work
visual fatigue
accommodative function
Opis:
Visual fatigue of VDT (visual display terminal) operators poses a serious problem for corporations where VDT work is a major part of operations. In this study, an investigation in a corporation was carried out to examine the effect of polyphenol on recovery from visual fatigue of the visual function caused by working at a VDT. Three kinds of parameters were used for evaluating the effect of polyphenol. As a subjective evaluation, the first was a questionnaire to ascertain subjective feelings of fatigue. As aspects of a physiological evaluation, the second and third parameters were the accommodative function and the flicker value.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2009, 15, 3; 339-343
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Facile Electrochemical Analysis to Determine Antioxidant Activity of Bee Pollen
Autorzy:
Rebiai, A.
Lanez, T.
Powiązania:
https://bibliotekanauki.pl/articles/412330.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Bee pollen
Antioxidant
Polyphenol
Flavonoids
voltammetry
Opis:
The aim of this study was to determine the phenolic and flavonoid content, and antioxidant properties of tow samples of bee pollen harvested from Algeria. The content of total polyphenolic compounds, flavonoids, and antioxidant activity by the cyclic voltammetry method were determined. The contents of polyphenolic compounds was 22.68 mg/g for the pollen from Blida and 21,9 mg/g for Tipaza pollen. High antioxidant activities were found for the cyclic voltammetry method, with values that ranged from 22,3 to 27,63 mg of AAE•g–1 pollen. The bee pollen of Blida showed high antioxidant activity probably due to the high content of polyphenolic compounds present in pollen.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 9, 1; 31-38
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antioxidant activity of rye bread enriched with milled buckwheat groats fractions
Autorzy:
Zmijewski, M.
Sokol-Letowska, A.
Pejcz, E.
Orzel, D.
Powiązania:
https://bibliotekanauki.pl/articles/876671.pdf
Data publikacji:
2015
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
antioxidant activity
rye bread
buckwheat
flavonoids
rutin
quercetin
polyphenol
Opis:
Background. Buckwheat, despite its broad nutritional benefits, is still not widely appreciated grain. It contains a protein with preferred amino acid composition and it is a valuable source of micronutrients and vitamins of the B group and vitamin E. Moreover, buckwheat groats have a high amount of polyphenols, including flavonoids and flavones. Eating rye bread is beneficial due to its high content of dietary fiber, phenolic acids and characteristic taste and aroma. Therefore, the use of rye flour and buckwheat mill products for bread may allow obtaining a product of high nutritional value and flavor. Objective. The aim of the study was to evaluate the influence of buckwheat products addition and baking process on the antioxidant properties of rye-buckwheat blends and breads. Material and methods. Experimental material was rye flour type 580 and buckwheat flour, wholegrain flour and bran obtained by grinding buckwheat groats. Buckwheat products share was 20 and 35%. The control was the rye flour. In the rye-buckwheat blends and bread loaves, the contents of selected flavonoids by HPLC method, total polyphenols content by Folin-Ciocalteu method and the antioxidant activity by the DPPH˙ radical scavenging method were determined. Results. Buckwheat bran was significantly richer in total polyphenols, rutin, quercetin, orientin and isoorientin than other buckwheat products and rye flour. Bread after baking contained similar amount of total polyphenols and quercetin and have a comparable ability to scavenge 1,1diphenyl-2-picrylhydrazyl radicals (DPPH˙) than the corresponding blends. Baking process negatively affected the amount of rutin, orientin and isoorientin. Conclusions. The use of buckwheat bran as a replacement for wheat flour in bread significantly increases its nutritional value. The process of baking unequally affects the content of particular groups of antioxidant compounds.
Wprowadzenie. Gryka mimo swoich wszechstronnych właściwości prozdrowotnych, nie jest jeszcze wystarczająco docenionym zbożem. Zawiera ona między innymi białko o bardzo korzystnym składzie aminokwasowym, jest również cennym źródłem mikroelementów i witamin z grupy B oraz witaminy E. Ponadto orzeszki gryczane wyróżniają się dużą ilością polifenoli, wśród nich flawonoidów i flawonów. Spożywanie pieczywa żytniego jest natomiast korzystne ze względu na wysoką zawartość w nim błonnika pokarmowego i kwasów fenolowych oraz charakterystyczny smak i aromat. Dlatego też wykorzystanie do wypieku pieczywa zarówno z mąki żytniej, jak i produktów przemiału gryki może pozwolić uzyskać produkt o wysokiej wartości smakowej i odżywczej. Cel badań. Celem badań była ocena wpływu dodatków gryczanych i procesu wypieku na wartość prozdrowotną mieszanek i pieczywa żytnio-gryczanego. Materiał i metody. Materiał badawczy stanowiła mąka żytnia typ 580 oraz mąka, śruta i otręby gryczane, które otrzymano w wyniku przemiału kaszy gryczanej nieprażonej. Produkty gryczane dodawano do mąki żytniej w ilości 20 i 35%. Próbę kontrolną stanowiła mąka żytnia typ 580. W mieszankach żytnio-gryczanych i wypieczonym z nich pieczywie oznaczono zawartość wybranych flawonoidów metodą HPLC, polifenoli ogółem metodą Folina-Ciocalteu, oraz oznaczono aktywność przeciwutleniającą z wykorzystaniem rodników 1,1difenyl-2-pikrylohydrazylowych (DPPH). Wyniki. Wykazano, że otręby gryczane były znacznie bogatsze w polifenole ogółem, rutynę, kwercetynę, orientynę i izoorientynę niż inne produkty gryczane i mąka żytnia. Po obróbce cieplnej, jaką jest wypiek, chleb zawierał więcej polifenoli ogółem i kwercetyny oraz miał większą siłę gaszenia rodników DPPH niż mieszanki, z których go wypieczono. Proces wypieku niekorzystnie wpływał na ilość rutyny, orientyny i izoorientyny. Wnioski. Zastosowanie otrąb gryczanych, jako zamiennika mąki żytniej w pieczywie znacznie zwiększa jego walory żywieniowe. Proces wypieku wpływa niejednakowo na zawartość poszczególnych grup związków przeciwutleniających.
Źródło:
Roczniki Państwowego Zakładu Higieny; 2015, 66, 2
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular cloning and characterization of pearl millet polyphenol oxidase and its role in defense against downy mildew
Autorzy:
Niranjan-Raj, S.
Lavanya, S.N.
Nayaka, S.C.
Powiązania:
https://bibliotekanauki.pl/articles/2084674.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
downy mildew
plant defense
Pennisetum glaucum
polyphenol oxidase
Opis:
Polyphenol oxidase partial gene PG-PPO was cloned and characterized from Pennisetum glaucum (pearl millet) which showed 42% identity to a PPO sequence isolated from wheat at the region of Copper B with a score of 40 and e-value of 2.8. Multiple sequence alignment results revealed similarity to polyphenol oxidase (PPO) sequences from wheat, trifolium, lettuce, apricot, tobacco, tomato, pokeweed, apple, grape and poplar especially at the Copper B region of PPO. The 395 bp pearl millet PPO sequence was AT rich (53.3%) and contained the highly conserved amino acids of histidine-rich copper binding sites similar to PPO sequences from other crops. Results also indicated that PPO in pearl millet exists in multi copy. The role of the isolated PPO gene during pearl millet-downy mildew interaction was analyzed and the results showed significantly higher and rapid accumulation of PPO mRNAs in resistant pearl millet seedlings inoculated with Sclerospora graminicola in comparison to the susceptible control, demonstrating that the PPO plays a prominent role in pearl millet defense against pathogens, particularly downy mildew pathogen.
Źródło:
Journal of Plant Protection Research; 2019, 59, 3; 423-427
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Losses of essential oils and antioxidants during the drying of herbs and spices. A review
Straty olejków eterycznych oraz związków o właściwościach przeciwutleniających podczas suszenia ziół i przypraw. Przegląd
Autorzy:
Prusinowska, R.
Smigielski, K.
Powiązania:
https://bibliotekanauki.pl/articles/5330.pdf
Data publikacji:
2015
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
essential oil
antioxidant
polyphenol
loss
drying
herb
spice
Opis:
Drying is the most common and also the simplest method of preserving fresh plant materials. This process greatly extends the life of the product by the removal of water, which decreases the rate of chemical and enzymatic reactions, or even inhibits them. The drying step can cause a change in appearance, taste, color and consistency, as well as reduce the quantity of essential oils, polyphenols, pigments and vitamins. These changes can be significantly reduced by using suitable drying techniques, depending on the material. The choice of the technique should be based on knowledge of the biological, physical and chemical characteristics of the raw material. The paper presents the effects of drying on the quantitative loss of essential oils and compounds with antioxidant properties, as well as changes in the antioxidant properties of selected herbs and spices dried by different methods. Both, the food industry and the cosmetics or pharmaceuticals industry generates a demand for high-quality raw materials, and hence research is being conducted both on preservation methods and on their impact on the quality of the obtained material. It seems that the new technology of drying material in a fluidized bed, greatly reduces or even eliminates the disadvantages of current procedures.
Suszenie jest najczęściej stosowaną i zarazem najprostszą metodą konserwacji świeżych surowców roślinnych. Proces ten znacznie przedłuża trwałość produktu, poprzez usunięcie wody, co zmniejsza szybkość bądź nawet hamuje reakcje chemiczne i enzymatyczne. Etap suszenia może powodować zmiany w wyglądzie, smaku, kolorze czy konsystencji, jak również obniżać ilość olejków eterycznych, polifenoli, barwników czy witamin. Zmiany te można w znacznym stopniu ograniczyć, stosując odpowiednie techniki suszenia w zależności od suszonego materiału, których dobór powinien wynikać ze znajomości biologicznych, fizycznych i chemicznych właściwości surowca. W pracy przedstawiono wpływ suszenia na straty olejków eterycznych i związków o właściwościach przeciwutleniających oraz zmiany właściwości antyoksydacyjnych wybranych ziół i przypraw, suszonych różnymi metodami. Zarówno przemysł spożywczy jak i kosmetyczny czy farmaceutyczny, wykazuje zapotrzebowanie na surowce wysokiej jakości, i stąd wskazane jest prowadzenie badań zarówno nad metodami utrwalania jak i nad określeniem ich wpływu na jakość uzyskanego surowca. Wydaje się, że nowa technologia suszenia surowców w złożu fluidalnym w znacznym stopniu ogranicza a nawet eliminuje wady obecnie stosowanych procedur.
Źródło:
Nauki Inżynierskie i Technologie; 2015, 2(17)
2449-9773
2080-5985
Pojawia się w:
Nauki Inżynierskie i Technologie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical composition, antioxidant and antimicrobial activities of Moroccan species of Psidium guajava extracts
Autorzy:
Lahlou, J.
Amraoui, B.E.
El-Wahidi, M.
Bamhaoud, T.
Powiązania:
https://bibliotekanauki.pl/articles/2082864.pdf
Data publikacji:
2022
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
antibacterial activity
antifungal activity
polyphenol
medicinal plant
essential oil
Opis:
Background. During the recent years, appropriate attention has been paid to the oxidative stress which damages the body’s cells, proteins, and DNA. Therefore, the need of antioxidants becomes a therapeutic and preventive priority. In addition, microbial infections also constitute a public health problem. Objective. To find efficient, reliable and safe alternatives sources to synthetic antioxidants, antibiotics and antifungals drugs. Materials and methods. Extract and essential oil of Psidium guajava were screened for their antioxidant and antimicrobial activities against gram positive bacteria (Enterococcus faecalis and Staphylococcus aureus), gram negative bacteria (Citrobacter freundii, Escherichia coli and Pseudomonas sp) and fungi (Candida albicans,Candida tropicalis and Cryptococcus neoformans), as well as to determine the functional groups of phytochemicals present in the essential oil by Fourier transform infrared spectroscopy (FTIR). Results. The results indicate that P. guajava leaves extract demonstrated very high antioxidant activity and P.guajava essential oil showed the highest polyphenols content. The antioxidant capacity showed a significant negative linear correlation to total polyphenolic content (TPC) with Pearson’s correlation coefficients. P. guajava essential oil shows high antibacterial and antifungal activity against all the studied bacteria and fungi.The FTIR analysis of P. guajava essential oil showed the presence of several functional groups (ethers, esters, ketones, terpenes, alkanes, aldehydes, aromatic hydrocarbons, alcohols, and phenols). The relationship between the chemical composition and antimicrobial activity of P.guajava essential oil suggests that the attribution of its antimicrobial activity to a particular compound or a synergistic effects between its different constituents remains difficult. Conclusions. The present study demonstrated that Psidium guajava is a valuable source of active compounds with anti- oxidant and antimicrobial activities. This finding suggests the new use of the fruits and the leaves extracts of this plant in the treatment of bacterial and fungal infections, as well as for the extraction of new antioxidants. Therefore, it is necessary to be carried out in another study to identify the active(s) compound(s) in P.guajava essential oil with respect to their mechanisms and synergistic actions.
Źródło:
Roczniki Państwowego Zakładu Higieny; 2022, 73, 1; 65-77
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Properties, various functions and application of bacterial melanins – some properties and possible application of melanin produced by Azotobacter chroococcum
Autorzy:
Kozieł, Monika
Powiązania:
https://bibliotekanauki.pl/articles/2163439.pdf
Data publikacji:
2023-01-31
Wydawca:
Instytut Uprawy Nawożenia i Gleboznawstwa – Państwowy Instytut Badawczy
Tematy:
bacterial melanin
polyphenol oxidase
stress protection
biosynthesis
Azotobacter chroococcum
Opis:
Melanins are a group of macromolecular pigments formed as a result of oxidative polymerization of phenolic and indole compounds. They are considered the most common, heterogeneous, resistant and evolutionarily oldest pigments found in nature. Melanins occurrred very early in the evolution of various groups of organisms. They have already been found in dinosaur, bird and primitive cephalopod fossils. Today, melanins are found in every kingdom of living organisms and play an important role in the processes of reproduction, thermoregulation, chemoprotection and camouflage. In addition to the important functions they perform in organisms, they exhibit a different chemical structure and are characterized by a wide range of colors, from black-brown to yellow-red. Differences in chemical structure have become the criterion for dividing melanins into four groups, i.e. eumelanin, allomelanin, pheomelanin and neuromelanin. Production of melanins is characteristic for many microorganisms, including free-living Azotobacter bacteria. The genus Azotobacter comprises eight species and only Azotobacter bryophylli does not produce pigments. Azotobacter chroococcum, the most abundant in soils all over the world, produces a dark brown melanin pigment non-diffusible into the substrate. Melanins synthesized by this species of bacteria increased the growth of some plants and detoxification of soils and waters polluted with heavy metals. In addition, the method of obtaining melanin produced by A. chroococcum is simple and relatively cheap compared to the cost of obtaining synthetic melanins, which gives the opportunity to conduct further research on the use of this pigment in biotechnology and molecular biology. In work it was describe the physicochemical properties, various functions and possible applications of bacterial melanins in various industries. The publication also summarizes the current knowledge on some properties and the possibility of use in bioremediation of soils and waters contaminated with heavy metals melanins synthesized by Azotobacter chroococcum.
Źródło:
Polish Journal of Agronomy; 2022, 51; 46-54
2081-2787
Pojawia się w:
Polish Journal of Agronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The mechanism of azide activation of polyphenol oxidase II from tobacco.
Autorzy:
Shi, Chunhua
Liu, Qingliang
Dai, Ya
Xie, Yongshu
Xu, Xiaolong
Powiązania:
https://bibliotekanauki.pl/articles/1043711.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
polyphenol oxidase (PPO)
azide activation
peroxide activation
superoxide activation
copper proteins
Opis:
So far, azide has been consistently reported to act as an inhibitor of metal enzymes, especially copper proteins. The present work shows that azide can also act as an activator of polyphenol oxidase II (PPO II) from tobacco leaves. From0 the square-wave voltammetry of native PPO II, peroxide-PPO II complex and azide-PPO II complex, the reduction of nitro blue tetrazolium by the enzymes and activation of PPO II by peroxide it follows that the binding of azide to PPO II induces the formation of CuO(2)(2-)Cu in the active site of PPO II from CuO(2)(-)Cu in native PPO II. The reason for azide acting as an activator can be attributed to azide complexing with PPO II, thus inducing the formation of CuO(2)(2-)Cu, which is the active site of the peroxide-PPO II complex in which peroxide plays the role of activator.
Źródło:
Acta Biochimica Polonica; 2002, 49, 4; 1029-1035
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antioxidant activities and polyphenolics content of Flammulina velutipes mushroom extracts
Czynniki wpływające na właściwości przeciwutleniające i ogólną zawartość związków polifenolowych w ekstraktach z grzyba Flammulina velutipes
Autorzy:
Slawinska, A.
Radzki, W.
Kalbarczyk, J.
Powiązania:
https://bibliotekanauki.pl/articles/71449.pdf
Data publikacji:
2013
Wydawca:
Instytut Włókien Naturalnych i Roślin Zielarskich
Tematy:
antioxidant activity
polyphenol content
Flammulina velutipes
mushroom extract
total phenol content
Opis:
A study was conducted in order to determine the content of phenolic compounds and antioxidative activity of extracts from Flammulina velutipes. Water and ethanolic, methanolic, acetone (70% v/v) extracts were prepared from lyophilized fruiting bodies of mushrooms. Different extraction techniques were used: ultrasonication and stirring by a rotary shaker at ambient temperature and at 50oC, and at boiling point for each solvent. Next, total phenolics by Folin-Ciocalteu method, antioxidant capacity (EC) by ferric reducing antioxidant power assay (FRAP) and scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals were analysed in these extracts. It was observed that the extraction method and the kind of solvent influenced the antioxidant activity and concentration of total phenolics in the extracts. The highest concentration of phenolic compounds (7.58±0.17 mg GAE/g extract) were observed for water extract prepared with use of ultrasonification method (at 50oC for 1h). Results showed that water extracts possessed high equivalent capacity (EC) for all applied extraction methods. The highest EC value (9.2±0.18 mM Fe2+/g extract) was observed in water extract prepared by stirring at ambient temperature for 1 h. This extract was characterized by high level of total phenolics. The acetone extracts, prepared by ultrasonic extraction at 50oC for 1 h, at 10 mg/ml showed the highest scavenging activity (57.53±1.18%), although, the value was lower than that of ascorbic acid at 10 mg/ml (60.50±1.32%).
Praca miała na celu określenie ogólnej zawartości związków polifenolowych i właściwości przeciwutleniających ekstraktów z grzyba Flammulina velutipes. Z liofilizowanych owocników F. velutipes przygotowano ekstrakty wodne, etanolowe (70% v/v), metanolowe (70% v/v) i acetonowe (70% v/v). Zastosowano różne techniki ekstrakcji: wytrząsanie i ekstrakcję przy użyciu łaźni ultradźwiękowej w temperaturze pokojowej i w 50oC oraz ekstrakcję we wrzącym rozpuszczalniku. W otrzymanych ekstraktach zbadano ogólną zawartość związków polifenolowych metodą Folin-Ciocalteu i ich właściwości przeciwutleniające (EC – equivalent capacity) metodą FRAP (ferric reducing antioxidant power assay) oraz zdolność do neutralizacji wolnych rodników z użyciem DPPH (1,1-diphenyl-2-picrylhydrazyl). Zaobserwowano, że takie czynniki jak warunki ekstrakcji czy rodzaj użytego rozpuszczalnika mają wpływ na właściwości przeciwutleniające i ogólną zawartość związków polifenolowych w otrzymanych ekstraktach. Najwyższą ilość związków polifenolowych uzyskano w wodnych ekstraktach otrzymanych z użyciem łaźni ultradźwiękowej w 50oC (7,58±0,17 mg GAE/g ekstraktu). Wyniki pokazują, że wodne ekstrakty, otrzymane wszystkimi zastosowanymi metodami ekstrakcji, posiadają wysokie właściwości przeciwutleniające. Najwyższą wartość EC (9.2±0.18 mM Fe2+/g ekstraktu) zaobserwowano dla wodnych ekstraktów przygotowanych w pokojowej temperaturze z użyciem wytrząsarki. Te ekstrakty charakteryzowały się również wysoką zawartością związków polifenolowych. Ekstrakty acetonowe otrzymane poprzez zastosowanie łaźni ultradźwiękowej w 50oC przy stężeniu 10 mg/ml wykazywały najwyższą zdolność do redukcji wolego rodnika DPPH (57,53±1,18%) ale niższą niż kwas askorbinowy przy takim samym stężeniu (60,50±1,32%).
Źródło:
Herba Polonica; 2013, 59, 3
0018-0599
Pojawia się w:
Herba Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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