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https://www.readbyqxmd.com/read/29136554/separation-and-purification-of-four-phenolic-compounds-from-persimmon-by-high-speed-counter-current-chromatography
#1
Jinming Peng, Kaikai Li, Wei Zhu, Xiangyi Deng, Chunmei Li
An efficient method was established by high-speed counter-current chromatography (HSCCC) for preparation of four phenolic compounds from the depolymerization products of persimmon tannin. Using the two solvent systems of n-hexane/ethyl acetate/water (3:17:20, v/v/v) and ethyl acetate/methanol/water (50:1:50, v/v/v), the preparative isolation was successfully performed by a two-step separation. The yields of one run (150mg crude sample) for gallic acid, methyl gallate, and epigallocatechin-3-gallate-(4β→8, 2β→O→7)-epigallocatechin-3-gallate dimer (A-type EGCG dimer) were 4...
November 7, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/29136076/enhancing-the-photostability-of-poly-phenylene-ethynylene-for-single-particle-studies
#2
C F Calver, B A Lago, K S Schanze, G Cosa
Single molecule fluorescence (SMF) studies on conjugated polymers yield enhanced information on exciton dynamics and on the interplay between polymer conformation/morphology and photophysical behavior. SMF studies, however, demand good signal stability, excellent photostability, and high photon yields (a measure of both photostability and brightness) and thus the development of strategies to help conjugated polymers (CPs) meet these requirements is a topic of great interest. Here, we evaluate the effect of a number of triplet quencher additives on the photostability of a 49-mer long poly(phenylene-ethynylene) conjugated polymer bearing carboxylate side groups (PPE-CO2-49) that is deposited onto 100 nm diameter SiO2 nanoparticles (NPs)...
November 14, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/29128698/seminal-plasma-antioxidants-are-directly-involved-in-boar-sperm-cryotolerance
#3
Junwei Li, Isabel Barranco, Asta Tvarijonaviciute, Manuel F Molina, Emilio A Martinez, Heriberto Rodriguez-Martinez, Inmaculada Parrilla, Jordi Roca
Boar ejaculates are ejected in fractions with a specific composition in terms of sperm numbers and seminal plasma (SP), which is reflected in the varying sperm cryotolerance observed among different fractions. As boar sperm are particularly sensitive to oxidative stress, this study evaluated the role of SP antioxidants in the observed differences in sperm cryotolerance among ejaculate fractions. Ten ejaculates from five boars were manually collected in fractions: the first 10 mL of the sperm-rich fraction (SRF), the rest of the SRF and the post-SRF...
October 31, 2017: Theriogenology
https://www.readbyqxmd.com/read/29124681/synergistic-toxicity-of-the-neurometabolites-quinolinic-acid-and-homocysteine-in-cortical-neurons-and-astrocytes-implications-in-alzheimer-s-disease
#4
Paula Pierozan, Helena Biasibetti-Brendler, Felipe Schmitz, Fernanda Ferreira, Carlos Alexandre Netto, Angela T S Wyse
The brain of patients affected by Alzheimer's disease (AD) develops progressive neurodegeneration linked to the formation of proteins aggregates. However, their single actions cannot explain the extent of brain damage observed in this disorder, and the characterization of co-adjuvant involved in the early toxic processes evoked in AD is essential. In this line, quinolinic acid (QUIN) and homocysteine (Hcy) appear to be involved in the AD neuropathogenesis. Herein, we investigate the effects of QUIN and Hcy on early toxic events in cortical neurons and astrocytes...
November 9, 2017: Neurotoxicity Research
https://www.readbyqxmd.com/read/29107744/detection-and-inhibition-of-lipid-derived-radicals-in-low-density-lipoprotein
#5
Yuma Ishida, Yuka Okamoto, Yuta Matsuoka, Arisa Tada, Jindaporn Janprasit, Mayumi Yamato, Noppawan Phumala Morales, Ken-Ichi Yamada
Oxidized low density lipoprotein (Ox-LDL) is implicated in a variety of oxidative diseases. To clarify the mechanisms involved and facilitate the investigation of therapeutics, we previously developed a detection method for lipid-derived radicals using the fluorescent probe 2,2,6-trimethyl-6-pentyl-4-(4-nitrobenzo[1,2,5]oxadiazol-7-ylamino)piperidine-1-oxyl (NBD-Pen). In this study, NBD-Pen was used to detect lipid-derived radicals in Ox-LDL from in vitro and in vivo samples using an iron overloaded mouse model...
October 28, 2017: Free Radical Biology & Medicine
https://www.readbyqxmd.com/read/29106995/azacoccones-a-e-five-new-aza-epicoccone-derivatives-from-aspergillus-flavipes
#6
Shupeng Zou, Zhongbo Wang, Jing Wang, Guangzheng Wei, Wenjing Wang, Yi Zang, Fanrong Zeng, Keliang Chen, Junjun Liu, Jianping Wang, Zengwei Luo, Yongbo Xue, Hucheng Zhu, Chunping Yin, Chunmei Chen, Yonghui Zhang
Azacoccones A-E (1-5), five new aza-epicoccone derivatives, were isolated from the culture of Aspergillus flavipes. Their structures were determined by extensive NMR spectroscopic analyses and the absolute configuration of 5 was determined by electronic circular dichroism (ECD) calculation. Compounds 1-5 are proposed to be generated via a Pictet-Spengler reaction-based biosynthetic route starting from the precursor flavipin. Pictet-Spengler reaction is rarely found in the fungal kingdom, which indicated the distinctive nature of 1-5...
October 26, 2017: Fitoterapia
https://www.readbyqxmd.com/read/29102637/assessment-of-reactive-oxygen-species-generated-by-electronic-cigarettes-using-acellular-and-cellular-approaches
#7
Jiayuan Zhao, Yipei Zhang, Jennifer D Sisler, Justine Shaffer, Stephen S Leonard, Anna M Morris, Yong Qian, Dhimiter Bello, Philip Demokritou
Electronic cigarettes (e-cigs) have fast increased in popularity but the physico-chemical properties and toxicity of the generated emission remain unclear. Reactive oxygen species (ROS) are likely present in e-cig emission and can play an important role in e-cig toxicity. However, e-cig ROS generation is poorly documented. Here, we generated e-cig exposures using a recently developed versatile exposure platform and performed systematic ROS characterization on e-cig emissions using complementary acellular and cellular techniques: 1) a novel acellular Trolox-based mass spectrometry method for total ROS and hydrogen peroxide (H2O2) detection, 2) electron spin resonance (ESR) for hydroxyl radical detection in an acellular and cellular systems and 3) in vitro ROS detection in small airway epithelial cells (SAEC) using the dihydroethidium (DHE) assay...
October 29, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/29101646/s-adenosylmethionine-promotes-oxidative-stress-and-decreases-na-k-atpase-activity-in-cerebral-cortex-supernatants-of-adolescent-rats-implications-for-the-pathogenesis-of-s-adenosylhomocysteine-hydrolase-deficiency
#8
Ângela Zanatta, Cristiane Cecatto, Rafael Teixeira Ribeiro, Alexandre Umpierrez Amaral, Angela Ts Wyse, Guilhian Leipnitz, Moacir Wajner
S-Adenosylmethionine (AdoMet) concentrations are highly elevated in tissues and biological fluids of patients affected by S-adenosylhomocysteine hydrolase deficiency, who are clinically characterized by cerebral symptoms whose pathogenesis is still unknown. In the present work, we investigated the effects of AdoMet on redox homeostasis and on the activity of Na(+), K(+)-ATPase in the cerebral cortex of young rats. AdoMet caused lipid peroxidation (increase of malondialdehyde concentrations) and protein oxidation (increase of carbonyl formation and decrease of sulfhydryl content)...
November 3, 2017: Molecular Neurobiology
https://www.readbyqxmd.com/read/29100946/the-interaction-of-phospholipase-a2-with-oxidized-phospholipids-at-the-lipid-water-surface-with-different-structural-organization
#9
N M Litvinko, L A Skorostetskaya, D O Gerlovsky
Phospholipase A2 (PLA2 IB) activity towards UV-irradiated (λ=180-400nm) phospholipids in comparison to non-irradiated ones was investigated using phosphatidylcholine (PC) liposomes and mixed micelles of phosphatidylcholine and sodium deoxycholate as a membrane model. PLA2 activity, determined by spectral changes of hemoglobin (Hb) under the interaction with fatty acids (product of the phospholipolysis), correlated well with the phospholipid peroxidation degree. The present work is the first study that determines the degree of oxidation of non-fragmented OxPCs, on the base of PLA2 activity...
October 31, 2017: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/29100878/n-acetyl-l-cysteine-and-mn-2-attenuate-cd-2-induced-disturbance-of-the-intracellular-free-calcium-homeostasis-in-cultured-cerebellar-granule-neurons
#10
Nickolay K Isaev, Svetlana Avilkina, Sergey A Golyshev, Elisaveta E Genrikhs, Olga P Alexandrova, Marina R Kapkaeva, Elena V Stelmashook
Cadmium is a highly toxic heavy metal that is capable of accumulating in the body via direct exposure or through the alimentary and respiratory tract, leading to neurodegeneration. In this article, we show that the application of CdCl2 (0.001-0.005mM) for 48h induced high dose-dependent death rate of cultured cerebellar granule neurons (CGNs). Unlike Trolox or vitamin E, antioxidant N-acetyl-l-cysteine (NAC, 1mM) and Mn(2+) (0.0025-0.005mM) significantly protected CGNs from this toxic effect. Using Fluo-4 AM, measurements of intracellular calcium ions demonstrated that 24h-exposure to Cd(2+) induced intensive increase of Fluo-4 fluorescence in neurons accompanied by mitochondria swelling...
October 31, 2017: Toxicology
https://www.readbyqxmd.com/read/29099074/5-alkylresorcinol-derivatives-from-the-bryozoan-schizomavella-mamillata-isolation-synthesis-and-antioxidant-activity
#11
María J Ortega, Juan J Pantoja, Carolina de Los Reyes, Eva Zubía
The chemical study of the bryozoan Schizomavella mamillata has led to the isolation of six new 5-alkylresorcinol derivatives, schizols A-F (1-6), whose structures were established by spectrocospic means. Schizol A (1) exhibits a (E)-6-phenylnon-5-enyl moiety linked to the C-5 of a resorcinol ring, while in schizol B (2) the substituent at C-5 contains an unusual 1,2-dihydrocyclobutabenzene moiety. Schizols C (3) and D (4) have been characterized as the 1-sulfate derivatives of 1 and 2, respectively, and schizols E (5) and F (6) are the corresponding 1,3-disulfates...
November 2, 2017: Marine Drugs
https://www.readbyqxmd.com/read/29095492/antioxidant-stability-study-of-oregano-essential-oil-microcapsules-prepared-by-spray-drying
#12
Claudia M Asensio, Alejandro J Paredes, Maria P Martin, Daniel A Allemandi, Valeria Nepote, Nelson R Grosso
Release kinetics of the volatile compounds of oregano EO microcapsules and the relation with the antioxidant activity were studied. Different wall material (WM) to core (C) ratios (1:1 and 2:1; WM:C), addition of colloidal silicon dioxide (CSD); and different storage conditions: 23 °C (room temperature; R) and 4 °C (fridge temperature; F) were evaluated for 90 d. Volatile compounds, total phenolic content (TPC), free radical scavenging activity (FRSA), and Trolox equivalent antioxidant capacity (TEAC) were measured...
November 2, 2017: Journal of Food Science
https://www.readbyqxmd.com/read/29072399/free-radical-scavenging-properties-of-annona-squamosa
#13
Biba Vikas, S Akhil B, Remani P, K Sujathan
Annona squamosa has extensively been used in the traditional and folkloric medicine and found to possess many biological activities. Different solvents, petroleum ether, chloroform, ethyl acetate and methanol extracts of Annona squamosa seeds (ASPE, ASCH, ASEA, ASME) have been used to prepare plant extracts. The present investigations dealt with the free radical scavenging activity of four extracts using various techniques such as total reducing power estimation, total phenolic count, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging effect, evaluation of ABTS cation decolorisation capacity, FRAP assay, hdroxyl radical scavenging assay, super oxide assay and Nitric oxide radical scavenging assay of the extracts...
October 26, 2017: Asian Pacific Journal of Cancer Prevention: APJCP
https://www.readbyqxmd.com/read/29051668/culture-broth-of-ganoderma-lucidum-exhibited-antioxidant-antibacterial-and-%C3%AE-amylase-inhibitory-activities
#14
Rakrudee Sarnthima, Saranyu Khammaung, Piyawan Sa-Ard
Culture broth of Ganoderma lucidum was determined for antioxidant, antibacterial and α-amylase inhibitory activities. The culture broth contained protein as determined by Bradford method equaled to 0.2 mg/ml and total phenol content as 0.078 mg GAE/mg protein (0.557 mg GAE/g extract). It exhibited radicals scavenging activities against ABTS(+·) and DPPH(·) radicals with a half maximal inhibitory concentration (IC50) less than 1.70 ± 0.02 and 2.28 ± 0.02 µg protein/ml, respectively and reducing power equaled to 4...
October 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/29026707/nadph-oxidase-mediates-%C3%AE-amyloid-peptide-induced-neuronal-death-in-mouse-cortical-cultures
#15
Kee-Oh Chay, Kyoung Young Nam Koong, Shinae Hwang, Jong-Keun Kim, Choon Sang Bae
β-Amyloid peptide (Aβ) is the main component of senile plaques in patients with Alzheimer's disease, and is known to be a main pathogenic factor of the disease. Recent evidence indicates that activation of NADPH oxidase (NOX) in microglia or astrocytes may be a source of Aβ-induced reactive oxygen species (ROS). We investigated the role of neuronal NOX in Aβ-induced neuronal death in mouse mixed cortical cultures. Cell death was assessed by measuring lactate dehydrogenase efflux to bathing media 24 or 48 hr after exposure to Aβ25-35, a fragment of Aβ with an equivalent neurotoxic effect...
September 2017: Chonnam Medical Journal
https://www.readbyqxmd.com/read/29017787/dual-antioxidant-structures-with-potent-anti-inflammatory-hypolipidemic-and-cytoprotective-properties
#16
Panagiotis Theodosis-Nobelos, Chrysoula Athanasekou, Eleni A Rekka
Novel amide derivatives of trolox, 3,5-di-tert-butyl-4-hydroxybenzoic acid, (E)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylic acid and cinnamic acid with cysteamine and l-cysteine ethyl ester were synthesised. In four cases, the disulfide derivatives were also isolated and tested. All compounds were examined for antioxidant activity, expressed as their ability to inhibit lipid peroxidation and to scavenge free radicals. They were found to demonstrate up to 17-fold better activity than that of the parent antioxidant acids...
September 28, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/28994714/inhibition-of-5%C3%AE-reductase-il-6-secretion-and-oxidation-process-of-equisetum-debile-roxb-ex-vaucher-extract-as-functional-food-and-nutraceuticals-ingredients
#17
Wantida Chaiyana, Chanun Punyoyai, Suvimol Somwongin, Pimporn Leelapornpisid, Kornkanok Ingkaninan, Neti Waranuch, Jukkarin Srivilai, Natthawut Thitipramote, Wudtichai Wisuitiprot, Roswitha Schuster, Helmut Viernstein, Monika Mueller
This study aims to investigate the biological activities related to hair loss of Equisetum debile extracts, including 5α-reductase inhibition, interleukin-6 (IL-6) secretion reduction, and anti-oxidation. E. debile extracts were obtained by maceration in various solvents. Crude extract (CE) was obtained by maceration in 95% ethanol. Chlorophyll-free extract (CF) was the CE which of the chlorophyll has been removed by electrocoagulation. Hexane extract (HE), ethyl acetate extract (EA), and ethanolic extract (ET) were fraction extracts obtained from maceration in hexane, ethyl acetate, and 95% ethanol, respectively...
October 10, 2017: Nutrients
https://www.readbyqxmd.com/read/28993239/regulation-of-nadph-oxidase-nox4-by-delta-iodolactone-il-%C3%AE-in-thyroid-cancer-cells
#18
Thomasz Lisa, Romina Oglio, Leonardo Salvarredi, Marina Perona, Luciano Rossich, Silvia Copelli, Mario Pisarev, Guillermo Juvenal
INTRODUCTION: Iodine is not used only by the thyroid to synthesize thyroid hormones but also directly influences a number of thyroid parameters such as thyroid proliferation and function. Several iodinated lipids, biosynthesized by the thyroid, were postulated as intermediaries in the action of iodide. Among these, iodolactone (IL-δ) and 2-iodohexadecanal (2-IHDA) have shown to inhibit several thyroid parameters. The antiproliferative effect of IL-δ is not restricted to the thyroid gland...
October 7, 2017: Molecular and Cellular Endocrinology
https://www.readbyqxmd.com/read/28992569/4-alkyliden-azetidinones-modified-with-plant-derived-polyphenols-antibacterial-and-antioxidant-properties
#19
Daria Giacomini, Rosario Musumeci, Paola Galletti, Giulia Martelli, Lorenzo Assennato, Gianni Sacchetti, Alessandra Guerrini, Enrico Calaresu, Marianna Martinelli, Clementina Cocuzza
Antimicrobial resistance is one of the major and growing concerns in hospital- and community acquired infections, and new antimicrobial agents are therefore urgently required. It was reported that oxidative stress could contribute to the selection of resistant bacterial strains, since reactive oxygen species (ROS) revealed to be an essential driving force. In the present work 4-alkylidene-azetidinones, a new class of antibacterial agents, were functionalized with phytochemical polyphenolic acids such as protocatechuic, piperonyl, caffeic, ferulic, or sinapic acids and investigated as dual target antibacterial-antioxidant compounds...
September 23, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28988627/design-synthesis-and-evaluation-of-salicyladimine-derivatives-as-multitarget-directed-ligands-against-alzheimer-s-disease
#20
Hua-Li Yang, Pei Cai, Qiao-Hong Liu, Xue-Lian Yang, Si-Qiang Fang, Yan-Wei Tang, Cheng Wang, Xiao-Bing Wang, Ling-Yi Kong
A series of salicyladimine derivatives were designed, synthesized and evaluated as multi-target-directed ligands for the treatment of Alzheimer's disease (AD). Biological activity results demonstrated that some derivatives possessed significant inhibitory activities against amyloid-β (Aβ) aggregation and human monoamine oxidase B (hMAO-B) as well as remarkable antioxidant effects and low cell toxicity. The optimal compound, 5, exhibited excellent potency for inhibition of self-induced Aβ1-42 aggregation (91...
November 1, 2017: Bioorganic & Medicinal Chemistry
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