scholarly journals Synthesis and Structure of Novel Copper(II) Complexes with N,O- or N,N-Donors as Radical Scavengers and a Functional Model of the Active Sites in Metalloenzymes

2021 ◽  
Vol 22 (14) ◽  
pp. 7286
Author(s):  
Joanna Masternak ◽  
Małgorzata Zienkiewicz-Machnik ◽  
Iwona Łakomska ◽  
Maciej Hodorowicz ◽  
Katarzyna Kazimierczuk ◽  
...  
Keyword(s):  
Self Assembly ◽  
Active Sites ◽  
Radical Scavenging Activity ◽  
Functional Model ◽  
Radical Scavenging ◽  
Water Soluble ◽  
Activity Levels ◽  
X Ray Diffraction ◽  
Assembly Method ◽  
Enzyme Mimetics

To evaluate the antioxidant activity of potential synthetic enzyme mimetics, we prepared new five copper(II) complexes via a self-assembly method and named them [Cu(2-(HOCH2)py)3](ClO4)2 (1), [Cu(2-(HOCH2)py)2(H2O)2]SiF6 (2), [Cu2(2-(HOCH2CH2)py)2(2-(OCH2CH2)py)2](ClO4)2 (3), [Cu(pyBIm)3](BF4)2·1.5H2O (4) and [Cu(py2C(OH)2)2](ClO4)2 (5). The synthetic protocol involved N,O- or N,N-donors: 2-(hydroxymethyl)pyridine (2-(HOCH2)py), 2-(hydroxyethyl)pyridine (2-(HOCH2CH2)py), 2-(2-pyridyl)benzimidazole (pyBIm), di(2-pyridyl)ketone (py2CO). The obtained Cu(II) complexes were fully characterised by elemental analysis, FTIR, EPR, UV-Vis, single-crystal X-ray diffraction and Hirshfeld surface analysis. Crystallographic and spectroscopic analyses confirmed chromophores of both monomeric ({CuN3O3} (1), {CuN2O4} (2), {CuN6} (4), {CuN4O2} (5)) and dimeric complex ({CuN2O3} (3)). Most of the obtained species possessed a distorted octahedral environment, except dimer 3, which consisted of two copper centres with square pyramidal geometries. The water-soluble compounds (1, 3 and 5) were selected for biological testing. The results of the study revealed that complex 1 in solutions displayed better radical scavenging activity than complexes 3, 5 and free ligands. Therefore, complex 1 has been selected for further studies to test its activity as an enzyme mimetic. The chosen compound was tested on the erythrocyte lysate of two groups of patients after undergoing chemotherapy and chemoradiotherapy. The effect of the tested compound (1) on enzyme activity levels (TAS, SOD and CAT) suggests that the selected complex can be treated as a functional mimetic of the enzymes.

Preparation and Characterization of Polyaniline Nanotubes Doped with Different Acid

2013 ◽  
Vol 401-403 ◽  
pp. 663-666
Author(s):  
Xue Lian Bai ◽  
Jian Ting Mei ◽  
Zhong Guo Mu ◽  
Yun Bai
Keyword(s):  
Acetic Acid ◽  
Self Assembly ◽  
Ammonium Persulfate ◽  
Tetraacetic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Property ◽  
Assembly Method ◽  
Polyaniline Nanotubes

Polyaniline (PANI) nanotubes were synthesized separately using amino acetic acid (AA), ethylenediamine tetraacetic acid (EDTA), oxalic acid (OA) as dopant and ammonium persulfate (APS) as oxidant by a self-assembly method. SEM, TEM,FTIR and X-ray diffraction (XRD) and applying the 4 probes method characterized the morphology, structure and property of the product. It was found that nanotubes morphology were synthesized when the [Aci/[A ratio is 1:2.The room template conductivity of the products were studied.

scholarly journals Purification, Characterization, Prebiotic Preparations and Antioxidant Activity of Oligosaccharides from Mulberries

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2329 ◽  
Author(s):  
Erna Li ◽  
Shiyuan Yang ◽  
Yuxiao Zou ◽  
Weiwei Cheng ◽  
Bing Li ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Average Molecular Weight ◽  
Radical Scavenging ◽  
Lactobacillus Rhamnosus ◽  
Gel Permeation Chromatography ◽  
Water Soluble ◽  
Gas Chromatography Mass Spectrometry ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Antioxidant Power

A water-soluble oligosaccharide termed EMOS-1a was prepared by enzymatic hydrolysis of polysaccharides purified from mulberries by column chromatography. The chemical structure of the purified fraction was investigated by ultraviolet spectroscopy, Fourier-transform infrared spectroscopy, and gas chromatography–mass spectrometry, which indicated that galactose was the main constituent of EMOS-1a. Chemical analyses showed that the uronic acid and sulfate content of EMOS-1a were 5.6% and 8.35%, respectively, while gel permeation chromatography showed that EMOS-1a had an average molecular weight of 987 Da. The antioxidant activities of EMOS-1a were next investigated, and EMOS-1a exhibited concentration-dependent 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, Trolox equivalent antioxidant capacity, and ferric reducing antioxidant power. The level of proliferation of Lactobacillus rhamnosus reached 1420 ± 16% when 4% (w/v) EMOS-1a was added, where the number of colonies in MRS (de Man, Rogosa, and Sharpe) medium with no added oligosaccharide was defined as 100% proliferation. These results indicate that the oligosaccharide EMOS-1a could be used as a natural antioxidant in prebiotic preparations.

scholarly journals Changes in Metabolisms of Antioxidant and Cell Wall in Three Pummelo Cultivars during Postharvest Storage

Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 319 ◽  
Author(s):  
Liu ◽  
Liang ◽  
Jiang ◽  
Chen
Keyword(s):  
Cell Wall ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Pectate Lyase ◽  
Water Soluble ◽  
Scavenging Activity ◽  
Total Phenols ◽  
Postharvest Storage ◽  
Total Antioxidant ◽  
Juice Sacs

The juice sacs of pummelo fruit is susceptible to softening during storage at 25 °C, which causes quality deterioration and flavor loss during postharvest pummelo storage. This study investigated the changes in metabolisms of antioxidant and cell wall in juice sacs of three pummelo cultivars—Hongroumiyou (HR), Bairoumiyou (BR) and Huangroumiyou (HuR)—during postharvest storage. The results revealed that, with the extension of storage, the juice sacs of three pummelo cultivars exhibited a decrease in total antioxidant capacity (TAC), DPPH and ABTS radical scavenging activity; a decline in total phenols (TP) content and an increase firstly then a decrease in total ascorbic acid (TAA) content; and a decrease in lipoxygenase (LOX) activity and a rise initially, but a decline in activities of ascorbate peroxidase (APX) and glutathione peroxidase (GPX). Additionally, increased water-soluble pectin (WSP), but declined propectin, ionic-soluble pectin (ISP) and chelator-soluble pectin (CSP); as well as an increase from 0 d to 60 d then followed by a decline in activities of pectinesterase (PE), polygalacturonase (PG) and pectate lyase (PL) were observed. These results suggested that the metabolisms of antioxidant and cell wall could result in softening and senescence of pummelo fruit.

Preparation and Chromatic Properties of Encapsulated Carbon Black Pigment via Layer-by-Layer Self-Assembly Method

2015 ◽  
Vol 1104 ◽  
pp. 15-20 ◽  
Author(s):  
Xiao Jun Zhang ◽  
Ting Chen ◽  
Wei Hui Jiang ◽  
Jian Min Liu ◽  
Tong Qing Zhou
Keyword(s):  
Carbon Black ◽  
Self Assembly ◽  
Black Pigment ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Assembly Method ◽  
Transmission Electron ◽  
Color System ◽  
Chromatic Properties ◽  
Cie Color System

Encapsulated carbon black pigment was prepared by layer-by-layer self-assembly method. The RX8002 carbon black particles were well coated by a SiO2 layer, which makes it has good connection with ZrSiO4 layer. Meanwhile, dense ZrSiO4 layer was coated on the C@SiO2 particles surface to prevent the corrosive effects of glaze. The structure and morphology of samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The chromatic value of the pigments was measured by the CIE color system. The results show that the carbon black particles can be well coated by SiO2 and ZrSiO4 layer. When the TEOS/H2O ratio is 0.002 and the ZrSiO4/C ratio is 0.71, the chromatic value of the encapsulated carbon black pigment is 42.55, and the pigment has a good stability in glaze.

In Vitro Antioxidant Activities of Polysaccharides from Auricularia auriada

2011 ◽  
Vol 183-185 ◽  
pp. 104-109
Author(s):  
Ning Zhang ◽  
Zhen Yu Wang ◽  
Hua Zhang ◽  
Jian Ren ◽  
Xiu Mei Hao
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Water Soluble ◽  
Peroxide Radical ◽  
Scavenging Effect ◽  
Radical Scavenging Effect ◽  
Chelating Ability

This study aims to evaluate the antioxidative activities of water and alkaline solution pH=8, 50% ethanolic (APP1 or SAPP1), 75% ethanolic (APP2 or SAPP2) and 100% ethanolic (APP3 or SAPP3) extracts of A. auricular. The antioxidant activities, including the ABTS, superoxide anion radical-scavenging effect, hydrogen peroxide radical-scavenging effect and chelating ability on ferrous ions were studied in vitro. A comparison of the 50% effective concentration (EC50) values of different antioxidative reactions revealed that SAPP3 was more effective in scavenging ABTS, hydrogen peroxide and chelating ability on ferrous ions.SAPP2 showed a higher superoxide radical-scavenging activity. The alkali-soluble polysaccharides extracts showed higher radical-scavenging effect than water-soluble polysaccharides.

scholarly journals Synthesis of a novel green carbon dots as a bioimaging agent and a drug delivery system for enhanced antioxidant and antibacterial efficacy

2020 ◽  
Author(s):  
Neeraj Tejwan ◽  
Mousumi Kundu ◽  
Anirudh Sharma ◽  
Joydeep Das ◽  
Parames C Sil
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Carbon Dots ◽  
Radical Scavenging Activity ◽  
Drug Loading ◽  
Radical Scavenging ◽  
Water Soluble ◽  
Root Extract ◽  
Scavenging Activity

Abstract Background Now-a-days, synthesis of carbon dots (CDs) from renewable sources has attracted considerable attention due to their wide spread availability, lower cost, higher aqueous solubility and more biocompatibility. Here, we have synthesized water soluble CDs from the root extract of red Korean ginseng via simple microwave irradiation. The CDs were further loaded with a natural flavonoid, rutin, to check its efficacy as a drug delivery system. Result The CDs showed a size distribution between 1–4 nm and excitation-dependent fluorescence emission, and could be used as a bio-imaging agent.The CDs showed a drug loading content of 14% and a sustained drug release behavior at physiological conditions. CDs showed excellent free radical scavenging activity both in cell free systems and intra-cellular conditions. Besides, loading with the drug further improved the intra-cellular radical scavenging activity. The CDs and the nanohybrids also showed very little toxicity upto the concentration of 100 µg/mL in normal kidney epithelial cells. The CDs and the nanohybrids also showed a dose-dependent antibacterial effect against both gram negative as well as gram positive bacteria. Conclusion Our synthesized green CDs can be considered as a promising candidate for the biomedical applications due to its facile synthesis, low cytotoxicity, excellent fluorescent properties and potential as drug delivery systems.

scholarly journals Bioactive chemical constituents, acute toxicity and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of Polyalthia longifolia root

2021 ◽  
Vol 14 (1) ◽  
pp. 018-026
Author(s):  
Charles Akhadelor Unuigbe ◽  
Chinem Fumi Unula ◽  
Anthony Aiwonegbe ◽  
Jeremiah Ogboma Uadia ◽  
Isaac Akhigbe ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Ethyl Acetate ◽  
Methanol Extract ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Water Soluble ◽  
Total Phenolic ◽  
Scavenging Activity ◽  
Polyalthia Longifolia ◽  
Crude Methanol Extract

Polyalthia longifolia (masquerade tree) is a plant which is believed to possess varied pharmacological and therapeutic values among different populations. The present report investigated the phytochemical composition, proximate, acute toxicity and antioxidant potential of P. longfolia root. All analyses were carried out using established methods; the antioxidant activity of the crude methanol extract and its fractions (n-hexane and ethyl acetate) were examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay while the total phenolic and flavonoid contents were assessed using the Folin-Ciocalteu and the aluminum chloride calibration methods respectively. The phytochemical analysis revealed the presence of alkaloids, carbohydrate, reducing sugars, tannins, saponins, flavonoids, phenolic compounds and protein in aqueous extract. The proximate analysis showed moisture content, total ash, alcohol extractive value, water extractive value, acid insoluble ash and water soluble ash at 8.80, 9.35, 3.28, 3.29, 2.27 and 7.29% respectively. The ethyl acetate fraction showed the highest antioxidant property compared to the n-hexane fraction and crude methanol extract in all assays conducted. Also, the methanol fraction was found to have the highest flavonoids and phenolic content among the extract and fractions. Oral administration of crude methanol extract of P. longifolia to Swiss mice was relatively non-toxic at a maximum dose of 5000 mg/kg. The root extract and fractions of P. longifolia indicated moderately high level of some phytochemicals with outstanding radical scavenging activity, and therefore substantiate its use as a conventional and comparatively non-toxic plant antioxidant.

scholarly journals Determination of Flavonoid and Proanthocyanidin Profile of Hungarian Sour Cherry

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3278 ◽  
Author(s):  
Andrea Nemes ◽  
Erzsébet Szőllősi ◽  
László Stündl ◽  
Attila Biró ◽  
Judit Homoki ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Sour Cherry ◽  
Fresh Fruit ◽  
Water Soluble ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenolic ◽  
Antioxidant Power ◽  
Trolox Equivalent

Hungarian sour cherries (SC) are excellent source of anthocyanin (concentrations (100–300 mg in 100 g fresh fruit) and melatonin (0.15 mg in 100 g fresh fruit), but other flavonoid derivatives also can be isolated by aqueous alcoholic extraction. We have developed a new process for extracting non-extractable procyanidines bound to the membrane, proteins, and fibers. These compounds were seperated with UHPLC-MS methods, and the structure of individual components were identified on the basis of their mass fragmentation spectra. The antioxidant capacity of soluble and non-soluble antioxidants were measured with ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (DPPH), trolox equivalent antioxidant capacity (TEAC) assays, and compared to the new measurement methods of water-soluble antioxidant capacity (ACW), lipid-soluble antioxidant capacity (ACL). Furthermore, total phenolic content (TPC) and total procyanidin content (PAC) were determinated. As a result of our investigation, we found that the solvent combination, where in the first step is water–ethanol (1:1), then 100% ethanol were suitable for the extraction of the extractable antioxidants. However, the chemiluminescence method that is based on the elimination of the superoxide radical is more accurate than other colorimetric methods which measure antioxidant capacity.

Synthesis and Characterization of Polyaniline Nanotubes Doped with Amino Acetic Acid

2012 ◽  
Vol 184-185 ◽  
pp. 1285-1288 ◽  
Author(s):  
Xue Lian Bai ◽  
Jian Ting Mei ◽  
Yun Bai ◽  
Zhong Guo Mu
Keyword(s):  
Acetic Acid ◽  
Self Assembly ◽  
Ammonium Persulfate ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Property ◽  
Assembly Method ◽  
Doped Polyaniline

Doped polyaniline (PANI) nanostructure has been prepared at room temperature using amino acetic acid (AA) as dopant and ammonium persulfate (APS) as oxidant by a self-assembly method. The structure and property of polyaniline nanostructure were characterized by SEM, TEM，IR and X-ray diffraction (XRD) and applying the 4 probes method. The results showed the production was PANI. The effect of molar ratio of AA to An affected the morphology of the product and room template conductivity of the products were studied.

Phenolic Compound Profile and Functionality of Aqueous Overripe Tempe Extracts

2019 ◽  
Vol 7 (2) ◽  
pp. 382-392
Author(s):  
Zatil Afrah Athaillah ◽  
Dian Muzdalifah ◽  
Asri Lestari ◽  
Anastasia Fitria Devi ◽  
Linar Zalinar Udin ◽  
...  
Keyword(s):  
Cytotoxic Activity ◽  
Cancer Cell ◽  
Radical Scavenging Activity ◽  
Health Benefits ◽  
Radical Scavenging ◽  
Water Extract ◽  
Cancer Cell Line ◽  
Water Soluble ◽  
Total Phenols ◽  
Fermentation Time

Tempe is a soy fermentation product and has been associated with many health benefits. It is usually consumed after 48 hours of fermentation; however extended fermentation is sometimes favoured. Since cooking involves water, it is of interest to study the health benefits of tempe water extract. In this study, we focused our study on total phenols, total flavonoids, DPPH free radical scavenging activity, cytotoxic activity, and identification of the main flavonoids. Our findings demonstrated that concentration of water-soluble flavonoids in tempe increased as fermentation time was prolonged. Fermentation for 60 hr resulted in extracts with very noticeable cytotoxic activity against MCF-7 cancer cell line (IC50 of 8.70 µg/ml). The cytotoxic activity of the extracts was fermentation time-dependent following non-linear relationship. The activity showed strong inverse correlation with total phenols and flavonoids in the extracts. LC-MS/MS data suggested that extracts from control and 24-hr fermented tempe demonstrated the highest responses for genistein, genistin, daidzein, daidzin, and glycitein, compared to those of other treatments and therefore suggested that excessive amount of the isoflavones, particularly genistein, induced cancer cell proliferation but lesser yet optimum concentration (observed at 60 hr-fermentation) contributed to otherwise effect.

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