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Niki Mougiou, Fotini Trikka, Emmanouil Trantas, Filippos Ververidis, Antonios Makris, Anagnostis Argiriou, Konstantinos E Vlachonasios
Olive tree is one of the most valuable crops cultivated for its oil that is rich in antioxidants. The beneficial effects of oleuropein and hydroxytyrosol (HT), the most abundant and the most powerful antioxidant respectively, as well as tyrosol, HT's precursor molecule, are well studied however their biosynthetic pathways are not yet clarified. The transcriptome analysis of the young olive fruit, cultivar "Koroneiki", revealed transcripts of all the enzymes used to reconstitute the biosynthetic pathway of tyrosol and HT in other organisms...
May 5, 2018: Plant Physiology and Biochemistry: PPB
Mark B Plotnikov, Oleg I Aliev, Anastasia V Sidekhmenova, Alexander Y Shamanaev, Anna M Anishchenko, Tatiana I Fomina, Tatiana M Plotnikova, Alexander M Arkhipov
BACKGROUND: Many pathological mechanisms are involved in the development of arterial hypertension; disturbance of the rheological properties of blood and microvascular rarefaction are among those mechanisms. OBJECTIVE: The effect of p-tyrosol (Tyr) on hemorheological parameters and microvascularization in the cerebral cortex of spontaneously hypertensive rats (SHRs) at the stage of blood pressure rising (5-11 weeks) was studied. METHODS: Blood viscosity (BV), plasma viscosity (PV), hematocrit, erythrocyte aggregation and deformability, the oxygen transport capacity index (OTCI), and the capillary network in the cerebral cortex after the course of treatment of Tyr (50 mg/kg daily i...
May 6, 2018: Microvascular Research
Suryanarayan Biswal, Kalpana Kumari Barhwal, Debashree Das, Richa Dhingra, Nilima Dhingra, Tapas Chanda Nag, Sunil Kumar Hota
Chronic hypoxic stress results in deposition of lipofuscin granules in the CA3 region of hippocampal neurons which contributes to neurodegeneration and accelerated neuronal aging. Oxidative stress and mitophagy during hypoxia are crucial to cause aggregation of these lipofuscin granules in hypoxic neurons. Salidroside, a glucoside derivative of β-Tyrosol, has been reported to protect hypoxic neurons through maintenance of mitochondrial activity. The present study is aimed at investigating the potential of Salidroside in preventing mitophagy during chronic hypoxia and identification of the molecular targets and underlying signaling mechanisms...
April 30, 2018: Neurobiology of Disease
Beatriz González, Jennifer Vázquez, M Ángeles Morcillo-Parra, Albert Mas, María Jesús Torija, Gemma Beltran
Aromatic alcohols (tryptophol, phenylethanol, tyrosol) positively contribute to organoleptic characteristics of wines, and are also described as bioactive compounds and quorum sensing molecules. These alcohols are produced by yeast during alcoholic fermentation via the Erhlich pathway, although in non-Saccharomyces this production has been poorly studied. We studied how different wine yeast species modulate the synthesis patterns of aromatic alcohol production depending on glucose, nitrogen and aromatic amino acid availability...
September 2018: Food Microbiology
Beatriz González, Jennifer Vázquez, Paul J Cullen, Albert Mas, Gemma Beltran, María-Jesús Torija
Yeasts secrete a large diversity of compounds during alcoholic fermentation, which affect growth rates and developmental processes, like filamentous growth. Several compounds are produced during aromatic amino acid metabolism, including aromatic alcohols, serotonin, melatonin, and tryptamine. We evaluated the effects of these compounds on growth parameters in 16 different wine yeasts, including non- Saccharomyces wine strains, for which the effects of these compounds have not been well-defined. Serotonin, tryptamine, and tryptophol negatively influenced yeast growth, whereas phenylethanol and tyrosol specifically affected non- Saccharomyces strains...
2018: Frontiers in Microbiology
Christian Coelho, Perrine Julien, Maria Nikolantonaki, Laurence Noret, Mathilde Magne, Jordi Ballester, Régis D Gougeon
Chardonnay wines from Burgundy, obtained from musts with three levels of clarification (Low, Medium and High) during two consecutive vintages (2009 and 2010) and for two kinds of closures (screw caps and synthetic coextruded closures) were analyzed chemically and sensorially. Three bottles per turbidity level were opened in 2015 in order to assess the intensity of the reductive and/or oxidative aromas (REDOX sensory scores) by a trained sensory panel. The chemical analyses consisted in polyphenols and colloids quantification, followed by a proteomic characterization...
2018: Frontiers in Chemistry
Jingjie Jiang, Hua Yin, Shuai Wang, Yibin Zhuang, Shaowei Liu, Tao Liu, Yanhe Ma
Salidroside is an important plant-derived aromatic compound with diverse biological properties. Due to inadequate natural resources, the supply of salidroside is currently limited. In this work, we engineered the production of salidroside in yeast. First, the aromatic aldehyde synthase (AAS) from Petroselinum crispum was overexpressed in Saccharomyces cerevisiae when combined with endogenous Ehrlich pathway to produce tyrosol from tyrosine. Glucosyltransferases from different resources were tested for ideal production of salidroside in the yeast...
April 19, 2018: Journal of Agricultural and Food Chemistry
Juan Zenon Davalos, Ana C Valderrama-Negrón, Julio Barrios, Vera L S Freitas, Maria D M C Ribeiro da Silva
Theoretical and experimental studies on the energetic, structural and some other relevant physicochemical properties of the antioxidant tyrosol (1), hydroxytyrosol (1OH) molecules and the corresponding radicals 1rad• and 1Orad• are reported in this work. The experimental values of the gas-phase enthalpy of formation, (g), in kJ·mol-1, of 1 (-302.4  3.4) and 1OH (-486.3 ± 4.1) have been determined. Quantum chemical calculations, at DFT (M05-2X) and composite ab initio G3 and G4 levels of theory, provided results that served to: i/ confirm the excellent consistency of the experimental measurements performed, ii/ establish that the stabilizing effect of H-bond of hydroxyethyl chain and aromatic ring (OH••• interaction) is smaller in radicals than in parent molecules, iii/ deduce - combining experimental data in isodesmic reactions - (g) of radicals 1rad• (-152...
April 4, 2018: Journal of Physical Chemistry. A
Bi-Xia Wang, De-Hong Xu, Chao-Yang Tan, Ling-Min Jiang, Yue-Fang Luo, Lei Meng
According to the previous results from transcriptome analysis of Ligustrum quihoui, a glycosyltransferase gene(xynzUGT) was cloned by rapid amplification of cDNA ends(RACE). The full length cDNA of xynzUGT was 1 598 bp, consisting of 66 bp 5'-UTR, 1 440 bp ORF and 92 bp 3'-UTR. The ORF encoded a 480 amino-acid protein(xynzUGT) with a molecular weight of 54 826.67 Da and isoelectric point of 5.82. The structure of enzyme was analyzed by using bioinformatics method, the results showed that the primary structure contained a highly conserved PSPG box of glycosyltransferase, the secondary structure included α helix(38%), β sheet(12...
February 2018: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
Xue Liu, Xiao-Bo Li, Jianlan Jiang, Zhen-Ning Liu, Bin Qiao, Fei-Fei Li, Jing-Sheng Cheng, Xiaocui Sun, Ying-Jin Yuan, Jianjun Qiao, Guang-Rong Zhao
Synthetic microbial coculture to express heterologous biosynthetic pathway for de novo production of medicinal ingredients is an emerging strategy for metabolic engineering and synthetic biology. Here, taking efficient production of salidroside as an example of glycosides, we design and construct a syntrophic Escherichia coli-E. coli coculture composed of the aglycone (AG) strain and the glycoside (GD) strain, which convergently accommodate biosynthetic pathways of tyrosol and salidroside, respectively. To accomplish this the phenylalanine-deficient AG strain was engineered to utilize xylose preferentially and to overproduce precursor tyrosol, while the tyrosine-deficient GD strain was constructed to consume glucose exclusively and to enhance another precursor UDP-glucose availability for synthesis of salidroside...
March 26, 2018: Metabolic Engineering
Rebeca P Medina, Angela R Araujo, Raymond J Andersen, Marcos A Soares, Fabio de A Silva, Dulce H S Silva
Endophytic fungi were isolated from red alga Asparagopsis taxiformis - Falkenbergia stage, collected from the Brazilian coast, and were identified as Annulohypoxylon stygium (AT-03) and A. yungensis (AT-06) based on their macro/micromorphological and molecular features. Bioassay-guided fractionation of the EtOAc extract from laboratory cultures of both strains yielded known compounds pyrogallol from A. stygium, (3R)-scytalone and (3R,4R)-4-hydroxy-scytalone from A. yungensis. Pyrogallol was active against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli strains...
March 26, 2018: Natural Product Research
Nelly Flores, Farbod Sharif, Nael Yasri, Enric Brillas, Ignasi Sirés, Edward P L Roberts
This work compares the ability of physical and chemical treatments, namely adsorption and electrochemical advanced oxidation processes, to remove tyrosol from aqueous medium. Adsorption on graphene nanoplatelets (GNPs) performed much better than that with a graphite intercalation compound. Adsorption isotherms were found to follow the Freundlich model (R2  = 0.96), which is characteristic of a chemisorption process. Successful electrochemical regeneration enables 5 successive adsorption/regeneration cycles before corrosion of GNPs occurs...
March 7, 2018: Chemosphere
Sara Bianchi, Luca Giovannini
The mTOR pathway plays a crucial role in many human diseases, mostly associated with an over hyperactivity of the mTOR signaling, which makes its inhibitors potentially effective therapeutics. Thus, it is important to consider not only the mTOR pathway, but also all those factors that play a key role in its regulation, such as SIRT1 and AMPK. We previously demonstrated the role of some nutraceutical SIRT1 modulators in AMPK and mTOR pathway, showing the presence of a synergistic effect. Now we take further our research by evaluating the effect of berberine, quercetin, tyrosol, and ferulic acid on the mTOR/S6K1/4E-BP1 signaling, along with the existence of any synergistic effect between the following associations: berberine + tyrosol, tyrosol + ferulic acid, ferulic acid + quercetin...
April 2018: Nutrition and Cancer
Alessio Cimmino, Paola Nocera, Benedetto Teodoro Linaldeddu, Marco Masi, Marcin Gorecki, Gennaro Pescitelli, Lucio Montecchio, Lucia Maddau, Antonio Evidente
From the culture filtrates of Diaporthella cryptica, an emerging hazelnut pathogen, 2-hydroxy-3-phenylpropanoate methyl ester and its 3-(4-hydroxyphenyl) and 3-(1H-indol-3-yl) analogues, named crypticins A-C, were isolated together with the well-known tyrosol. Crypticins A-C were identified by spectroscopic (essentially NMR and HRESI MS) methods. The R absolute configuration (AC) of crypticin A was determined comparing its optical rotation power and ECD spectrum with those of papuline, the methyl ester of (-)(S)-phenyllactic acid isolated as the main phytotoxin of Pseudomonas syringae pv papulans, responsible for apple blister spot...
March 14, 2018: Journal of Agricultural and Food Chemistry
Jonathan Fusi, Sara Bianchi, Simona Daniele, Silvia Pellegrini, Claudia Martini, Fabio Galetta, Luca Giovannini, Ferdinando Franzoni
Oxidative stress arises from an imbalance between the production of free radicals and antioxidant defences. Several studies have suggested that dietary antioxidants (such as polyphenols and berberine) may counteract oxidative stress through the involvement of the Sirtuin 1/Adenosine Monophosphate-Activated Protein Kinase (SIRT1/AMPK) pathway. The aim of this study was to evaluate the direct and specific antioxidant activity of some natural compounds, as well as their ability to modulate the expression of SIRT1 and the activation of AMPK...
March 8, 2018: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Marco Masi, Paola Nocera, Angela Boari, Alessio Cimmino, Maria Chiara Zonno, Alessandro Infantino, Maurizio Vurro, Antonio Evidente
Ascochyta lentis var. lathyri has recently been reported to be the causal agent of Ascochyta blight of grass pea ( Lathyrus sativus), a disease characterized by the appearance of necrotic lesions of leaves and stems. Considering the novelty of the pathogen and the possible involvement of secondary metabolites in symptom appearance, a study was carried out to ascertain the capability of this fungus to produce bioactive metabolites. Some phytotoxic phenols were isolated from the culture filtrates of the fungus...
April 27, 2018: Journal of Natural Products
Dennis Fiorini, Maria Chiara Boarelli, Paolo Conti, Barbara Alfei, Giovanni Caprioli, Massimo Ricciutelli, Gianni Sagratini, Donatella Fedeli, Rosita Gabbianelli, Deborah Pacetti
The aim of the study was to identify new potential chemical markers of extra virgin olive oil (EVOO) quality by using a multicomponent analysis approach. Sixty-six EVOOs were purchased from the Italian market and classified according to their price as low price EVOOs (LEVOOs) and high price EVOOs (HEVOOs) costing 3.60-5.90euro/L and 7.49-29.80euro/L respectively. Sensory and chemical parameters strictly related to olive oil quality have been investigated, like volatile substances, polar phenolic substances, antioxidant activity, fatty acid composition, and α-tocopherol...
March 2018: Food Research International
Elena Fernández, Lorena Vidal, Antonio Canals
A novel approach is presented to determine hydrophilic phenols in olive oil samples, employing vortex-assisted reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) for sample preparation and screen-printed carbon electrodes for voltammetric analysis. The oxidation of oleuropein, hydroxytyrosol, caffeic acid, ferulic acid and tyrosol was investigated, being caffeic acid and tyrosol selected for quantification. A matrix-matching calibration using sunflower oil as analyte-free sample diluted with hexane was employed to compensate matrix effects...
May 1, 2018: Talanta
Pierluigi Reveglia, Sandra Savocchia, Regina Billones-Baaijens, Alessio Cimmino, Antonio Evidente
Polyphenols were characterized from Dothiorella vidmadera (DAR78993), which was isolated from a grapevine in Australia. In total, six polyphenols were isolated including a new polyphenol characterized by a spectroscopic method (essentially NMR and HR ESIMS) as 5-hydroxymethyl-2-isopropoxyphenol. Tyrosol, benzene-1,2,4-triol, resorcinol, 3-(hydroxymethyl)phenol, and protocatechuic alcohol, the latter being the main metabolite, were also isolated. Although these are already known as naturally occurring compounds in microorganisms and plants, this is the first time they have been isolated from fungal organisms involved in grapevine trunk disease...
February 28, 2018: Journal of Agricultural and Food Chemistry
Lucia Bartella, Fabio Mazzotti, Anna Napoli, Giovanni Sindona, Leonardo Di Donna
A rapid and reliable method to assay the total amount of tyrosol and hydroxytyrosol derivatives in extra virgin olive oil has been developed. The methodology intends to establish the nutritional quality of this edible oil addressing recent international health claim legislations (the European Commission Regulation No. 432/2012) and changing the classification of extra virgin olive oil to the status of nutraceutical. The method is based on the use of high-performance liquid chromatography coupled with tandem mass spectrometry and labeled internal standards preceded by a fast hydrolysis reaction step performed through the aid of microwaves under acid conditions...
March 2018: Analytical and Bioanalytical Chemistry
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