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Publication
Journal: Journal of Agricultural and Food Chemistry
June/29/2011
Abstract
The isolation and identification of a phytocomplex from olive mill waste waters (OMWW) was achieved. The isolated phytocomplex is made up of the following three phenolic compounds: hydroxytyrosol (3,4-DHPEA), tyrosol (p-HPEA) and the dialdehydic form of decarboxymethyl elenolic acid, linked with (3,4-dihydroxyphenyl)ethanol (3,4-DHPEA-EDA). The purification of this phytocomplex was reached by partial dehydration of the OMWW, followed by liquid-liquid extraction with ethyl acetate and middle pressure liquid chromatography (MPLC) on a Sephadex LH-20 column. The phytocomplex accounted for 6% of the total phenolic content of the OMWW. The phytocomplex and individual compounds were tested for antioxidant capacity by the oxygen radical absorbance capacity (ORAC) method. The ORAC phytocomplex produced 10,000 ORAC units/g dry weight, whereas the cellular antioxidant activity, measured by the cellular antioxidant activity in red blood cell (CAA-RBC) method, demonstrated that the phytocomplex and all of the components are able to permeate the cell membrane thus exhibiting antioxidant activity inside the red blood cells. Our phytocomplex could be employed in the formulation of fortified foods and nutraceuticals, with the goal to obtain substantial health protective effects due to the suitable combination of the component molecules.
Publication
Journal: Pharmaceutical Biology
October/14/2019
Abstract
Context:Kochia scoparia (L.) Schrad (Amaranthaceae), known as a traditional medicine in China, Japan and Korea, is reported to have various biological activities. However, K. scoparia seed extract (KSE) functional roles on angiogenesis and prostate cancer inhibition have not been elucidated. Objective: This study elucidates the effects of KSE on vascular endothelial growth factor (VEGF)-induced angiogenesis in human umbilical vein endothelial cells (HUVECs) and inhibition of proliferation in prostate cancer cells. Materials and methods: HUVECs were treated with 10-20 µg/mL of KSE and 20-50 ng/mL of VEGF for 12-72 h. Anti-angiogenesis properties of KSE were determined by wound healing, trans-well, tube formation, rat aortic ring assay and western blotting. Prostate cancer and normal cells were incubated with 10-250 µg/mL of KSE for 24 h, and cell viability was measured by SRB assay. Phenolic compounds in KSE were analyzed using a HPLC-PDA system. Results: IC50 for cell viability of HUVECs, LNCaP, PC-3, RC-58T and RWPE-1 by KSE were 30.64, 89.25, 123.41, 141.62 and >250 µg/mL, respectively. Treatment with KSE (20 µg/mL) significantly suppressed VEGF-induced migration, invasion and capillary-like structure formation of HUVECs and microvessel sprouting from rat aortic rings. In addition, KSE down-regulated PI3K/AKT/mTOR levels and phosphorylation of VEGF receptor 2 in HUVECs. 3-OH-tyrosol (1.63 mg/g) and morin hydrate (0.17 mg/g) were identified in KSE. Conclusions: KSE inhibits angiogenesis in HUVECs as well as proliferation in human prostate cancer cells, suggesting KSE may be useful herbal medicine for preventing progression of prostate cancer and angiogenesis.
Publication
Journal: 3 Biotech
August/15/2017
Abstract
Endophytic fungi associated with rhizomes of four cultivars of Zingiber officinale were identified by molecular and morphological methods and evaluated for their activity against soft rot pathogen Pythium myriotylum and clinical pathogens. The volatile bioactive metabolites produced by these isolates were identified by GC-MS analysis of the fungal crude extracts. Understanding of the metabolites produced by endophytes is also important in the context of raw consumption of ginger as medicine and spice. A total of fifteen isolates were identified from the four varieties studied. The various genera identified were Acremonium sp., Gliocladiopsis sp., Fusarium sp., Colletotrichum sp., Aspergillus sp., Phlebia sp., Earliella sp., and Pseudolagarobasidium sp. The endophytic community was unique to each variety, which could be due to the varying host genotype. Fungi from phylum Basidiomycota were identified for the first time from ginger. Seven isolates showed activity against Pythium, while only two showed antibacterial activity. The bioactive metabolites identified in the fungal crude extracts include tyrosol, benzene acetic acid, ergone, dehydromevalonic lactone, N-aminopyrrolidine, and many bioactive fatty acids and their derivatives which included linoleic acid, oleic acid, myristic acid, n-hexadecanoic acid, palmitic acid methyl ester, and methyl linoleate. The presence of these varying bioactive endophytic fungi may be one of the reasons for the differences in the performance of the different ginger varieties.
Publication
Journal: Applied and Environmental Microbiology
August/10/2019
Abstract
Tyrosol plays a key role in fungal morphogenesis and biofilm development. Also, it has a remarkable antifungal effect at supraphysiological concentrations. However, the background of the antifungal effect remains unknown, especially in the case of non-albicans Candida species such as Candida parapsilosis We examined the effect of tyrosol on growth, adhesion, redox homeostasis, virulence, as well as fluconazole susceptibility. To gain further insights into the physiological consequences of tyrosol treatment, we also determined genome-wide gene expression changes using transcriptome sequencing (RNA-Seq). A concentration of 15 mM tyrosol caused significant growth inhibition within 2 h of the addition of tyrosol, while the adhesion of yeast cells was not affected. Tyrosol increased the production of reactive oxygen species remarkably, as revealed by a dichlorofluorescein test, and it was associated with elevated superoxide dismutase, glutathione peroxidase, and catalase activities. The interaction between fluconazole and tyrosol was antagonistic. Tyrosol exposure resulted in 261 and 181 differentially expressed genes with at least a 1.5-fold increase or decrease in expression, respectively, which were selected for further study. Genes involved in ribosome biogenesis showed downregulation, while genes related to the oxidative stress response and ethanol fermentation were upregulated. In addition, tyrosol treatment upregulated the expression of efflux pump genes, including MDR1 and CDR1, and downregulated the expression of the FAD2 and FAD3 virulence genes involved in desaturated fatty acid formation. Our data demonstrate that exogenous tyrosol significantly affects the physiology and gene expression of C. parapsilosis, which could contribute to the development of treatments targeting quorum sensing in the future.IMPORTANCECandida-secreted quorum-sensing molecules (i.e., farnesol and tyrosol) are key regulators in fungal physiology, which induce phenotypic adaptations, including morphological changes, altered biofilm formation, and synchronized expression of virulence factors. Moreover, they have a remarkable antifungal activity at supraphysiological concentrations. Limited data are available concerning the tyrosol-induced molecular and physiological effects on non-albicans Candida species such as C. parapsilosis In addition, the background of the previously observed antifungal effect caused by tyrosol remains unknown. This study reveals that tyrosol exposure enhanced the oxidative stress response and the expression of efflux pump genes, while it inhibited growth and ribosome biogenesis as well as several virulence-related genes. Metabolism was changed toward glycolysis and ethanol fermentation. Furthermore, the initial adherence was not influenced significantly in the presence of tyrosol. Our results provide several potential explanations for the previously observed antifungal effect.
Publication
Journal: Bioorganic Chemistry
August/2/2019
Abstract
An ethyl acetate extracts isolated from a marine fungal strain, Penicillium chrysogenum DXY-1, obtained from marine sediments surrounding the East Sea, was found to exhibit anti-quorum sensing (anti-QS) activity. Interestingly, a novel active compound was identified as tyrosol by the purification and structural characterization. At a concentration of 0.5 mg/mL, tyrosol decreased QS-regulated violacein production in Chromobacterium violaceum CV026 by 53.5% and decreased QS-regulated pyocyanin production, elastase activity and proteolytic activity in Pseudomonas aeruginosa PA01 by 63.3%, 57.8% and 9.9%, respectively. SEM images showed that tyrosol inhibited biofilm formation in P. aeruginosa PA01 without having any effect on bacterial growth. Molecular docking results revealed that the natural signal molecule C6HSL and tyrosol bound to different receptor pockets of CviR, and tyrosol inhibited the QS activity of CviR in C. violaceum by binding to the DNA-binding domain and blocking pathogenic gene expression. All the data suggest that tyrosol may act as a potential inhibitor of the QS systems to solve the looming crisis of bacterial resistance. We believe that there are other active compounds with relatively high anti-QS activity or synergistic inhibitory effects on QS in the crude extract, which warrants further research.
Publication
Journal: Food Microbiology
November/16/2015
Abstract
The technological characteristics of five oleuropeinolytic strains of the Lactobacillus plantarum group selected within 135 isolates from table olives were investigated. The metabolism of phenolic compounds during elaboration of green (cv. Chalkidikis) and black (cv. Kalamata) olives under reduced salt conditions was evaluated. Olives of both cultivars were fermented in two different kinds of brine (Brine A containing 2.3% NaCl, 32.3 mM Ca-acetate and 33.9 mM Ca-lactate and Brine B containing 4% NaCl, pH 5.0 in both brines) by five selected strains of L. plantarum group. After 60 days of fermentation, the analysis of phenolic compounds was performed by HPLC and nine compounds were identified and quantified: oleuropein, hydroxytyrosol, tyrosol and vanillin and the phenolic acids protocatechuic, caffeic, p-hydroxybenzoic, vanillic and p-coumaric acid. The study can lead to the development of starter culture potentially active in biological debittering of olives during fermentation in order to unify the debittering and fermentation process during elaboration of table olives.
Publication
Journal: Nutrition and Cancer
April/3/2018
Abstract
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. Our results indicate the existence of an important relationship between the substances tested and the pathway of mTOR/S6K1/4E-BP1, a report corroborated by the bond of mTOR with SIRT1/AMPK pathways and by their reciprocal regulation.
Publication
Journal: Medicinski Glasnik
August/22/2012
Abstract
Olea europea, the olive tree, is an ancient tree that originates from the Mediterranean environment of Asia Minor. The edible olive fruit is also used for its oil, gained by the process of pressing, a nutrient with proven beneficial effects. Virgin olive oil is the natural juice of the olive fruit, which plays a major role in the healthy Mediterranean diet. The source of its health effects are the biophenols and squalenes (oleocanthal, tyrosol, hydroxytyrosol, oleuropein) it contains. They provide an exceptional antioxidative activity, removing harmful compounds from the body. Oxidants are essential in the genesis of many diseases and conditions, such as cardiovascular disorders, cancer, osteoporosis, Alzheimer disease, and premenstrual syndrome. Oleic acid, an unsaturated fatty acid, has demonstrated a significant effect in the prevention of malignant diseases such as colon cancer and breast cancer. Biophenols from olive oil successfully suppress the synthesis of LDL, a protein that is crucial in the development of cardiovascular disease, by reducing blood pressure and the development of atherosclerotic plaques. In addition, there is strong evidence of the antimicrobic effect of the biphenols from olive oil that successfully destroy colonies of microorganisms which may cause respiratory tract, intestinal, and genital tract infections.
Publication
Journal: Die Pharmazie
October/17/2010
Abstract
Roseroot, Rhodiola rosea, is a perennial herbaceous plant of the family Crassulaceae. The rhizomes of 95 roseroot clones in the Norwegian germplasm collection were analysed and quantified for their content of the bioactive compounds rosavin, salidroside, rosin, cinnamyl alcohol and tyrosol using HPLC analysis. All five bioactive compounds were detected in all 95 roseroot clones but in highly variable quantities. The ranges observed for the different compounds were for rosavin 2.90-85.95 mg g(-1), salidroside 0.03-12.85 mg g(-1), rosin 0.08-4.75 mg g(-1), tyrosol 0.04-2.15 mg g(-1) and cinnamyl alcohol 0.02-1.18 mg g(-1). The frequency distribution of the chemical content of each clone did not reflect a certain geographic region of origin or the gender of the plant. Significant correlations were found for the contents of several of these bioactive compounds in individual roseroot clones. A low, but not significant correlation was found between AFLP markers previously used to study the genetic diversity of the roseroot clones and their production of the chemical compounds. The maximum level of rosavin, rosin and salidroside observed were higher than for any roseroot plant previously reported in literature, and the roseroot clones characterized in this study might therefore prove to be of high pharmacological value.
Publication
Journal: Yao xue xue bao = Acta pharmaceutica Sinica
October/28/1992
Abstract
Six chemical components I-IV were isolated from the roots of Rhodiola crenulata (Crassulaceae). Five (I-V) of them were identified as known salidroside (I), p-tyrosol(II), pyrogallol, gallic acid, and beta-sitosterol, based on comparison of its Rf(TLC), mmp and spectral data with those of authentic samples. The sixth component was found to be a new delta 1-isopentenyl-3-O-beta-D-glucopyranoside and named crenulatin(VI). Its structure was confirmed on the basis of its spectral data (IR, MS, 1H- and 13C-NMR).
Publication
Journal: Journal of Agricultural and Food Chemistry
June/20/2001
Abstract
Two new phytotoxic polyketides, tagetolone (1) and tagetenolone (2), in addition to tyrosol and p-hydroxybenzoic acid, have been isolated from the organic crude extract of culture filtrates from the fungal pathogen Alternaria tagetica. Complete characterization of all structures was carried out following a careful analysis of their spectroscopic data (IR, MS, (1)H and (13)C NMR, and 2D NMR experiments).
Publication
Journal: Frontiers in Pharmacology
September/2/2019
Abstract
As one of the most severe manifestations of diabetes, vascular complications are the main causes of diabetes-related morbidity and mortality. Hyperglycemia induces systemic abnormalities, including impaired angiogenesis, causing diabetic patients to be highly susceptible in suffering hindlimb ischemia (HLI). Despite its severe prognosis, there is currently no effective treatment for diabetic HLI. Skeletal muscle cells secrete multiple angiogenic factors, hence, recently are reported to be critical for angiogenesis; however, hyperglycemia disrupted the paracrine function in skeletal muscle cells, leading to the impaired angiogenesis potential observed in diabetic patients. The present study showed that tyrosol, a phenylethanoid compound, suppresses accumulation of intracellular reactive oxygen species (ROS) caused by hyperglycemia, most plausibly by promoting heme oxygenase-1 (HO-1) expression in skeletal muscle cells. Consequently, tyrosol exerts cytoprotective function against hyperglycemia-induced oxidative stress in skeletal muscle cells, increases their proliferation vigorously, and simultaneously suppresses apoptosis. Furthermore, tyrosol grossly increases the secretion of vascular endothelial growth factor-A (VEGF-A) and platelet-derived growth factor-BB (PDGF-BB) from skeletal muscle cells. This leads to enhanced proliferation and migration capabilities of vascular endothelial and smooth muscle cells, two types of cells that are responsible in forming blood vessels, through cell-cell communication. Finally, in vivo experiment using the diabetic HLI mouse model showed that tyrosol injection into the gastrocnemius muscle of the ischemic hindlimb significantly enhances the formation of functional blood vessels and subsequently leads to significant recovery of blood perfusion. Overall, our findings highlight the potential of the pharmacological application of tyrosol as a small molecule drug for therapeutic angiogenesis in diabetic HLI patients.
Publication
Journal: Journal of Natural Products
January/29/2013
Abstract
Two isolates of Neofusicoccum australe belonging to ITS haplotypes H4 and H1 and associated with grapevine cordon dieback and branch dieback of Phoenicean juniper, respectively, have been shown to produce in vitro structurally different secondary metabolites. From the strain BOT48 of N. australe (haplotype H4) a new cyclohexenone oxide, namely, cyclobotryoxide, was isolated together with 3-methylcatechol and tyrosol. Cyclobotryoxide was characterized as (1S,5R,6S)-5-hydroxy-3-methoxy-4-methyl-7-oxabicyclo[4.1.0]hept-3-en-2-one by spectroscopic, optical, and chemical methods. The strain BL24 (haplotype H1) produced tyrosol along with botryosphaerone D and (3S,4S)-3,4,8-trihydroxy-6-methoxy-3,4-dihydro-1(2H)-naphthalenone. The metabolites obtained from both strains were tested at four concentrations on leaves of grapevine cv. Cannonau, holm oak, and cork oak by the leaf puncture assay. Cyclobotryoxide proved to be the most phytotoxic compound. Tyrosol and cyclobotryoxide were also tested on detached grapevine leaves at concentrations of 0.25 and 0.5 mg/mL. Only cyclobotryoxide was found to be active in this bioassay.
Publication
Journal: Frontiers in Microbiology
November/13/2018
Abstract
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. The effects of the aromatic alcohols were observed at concentrations commonly found in wines, suggesting a possible role in microbial interaction during wine fermentation. Additionally, we demonstrated that aromatic alcohols and ethanol are able to affect invasive and pseudohyphal growth in a manner dependent on nutrient availability. Some of these compounds showed strain-specific effects. These findings add to the understanding of the fermentation process and illustrate the diversity of metabolic communication that may occur among related species during metabolic processes.
Publication
Journal: Food Chemistry
November/7/2017
Abstract
Changes in phenolic profiles and color parameters can help to differentiate between extra virgin olive oils (EVOOs) with protected designation of origin (PDO). Phenolic profile characterization and CIELAB parameters determination of 9 PDO EVOOs from Spain were developed. Both properties of EVOOs are very relevant to their commercialization and increase the product value. The Serrana de Espadán olive cultivar was characterized for the first time and showed the highest pinoresinol concentrations and clarities in these olive oils, which are important values for the product image. To detect fraudulent instrumental work and implement quality control, principal component analysis (PCA) and linear discriminant analysis (LDA) were performed. EVOO geographical origin and cultivar distributions were achieved with cumulative variances of 93.4% and 92.4%, respectively. A categorization of PDO EVOOs was proposed using the following 7 phenolic compounds: phenolic alcohols (tyrosol and hydroxytyrosol), 3,4-DHPEA-EDA, 3,4-DHPEA-EA, p-HPEA-EDA, pinoresinol and total phenolic compounds.
Publication
Journal: Antioxidants and Redox Signaling
June/24/2014
Abstract
OBJECTIVE
While much data exist for the effects of flavonoid-rich foods on spatial memory in rodents, there are no such data for foods/beverages predominantly containing hydroxycinnamates and phenolic acids. To address this, we investigated the effects of moderate Champagne wine intake, which is rich in these components, on spatial memory and related mechanisms relative to the alcohol- and energy-matched controls.
RESULTS
In contrast to the isocaloric and alcohol-matched controls, supplementation with Champagne wine (1.78 ml/kg BW, alcohol 12.5% vol.) for 6 weeks led to an improvement in spatial working memory in aged rodents. Targeted protein arrays indicated that these behavioral effects were paralleled by the differential expression of a number of hippocampal and cortical proteins (relative to the isocaloric control group), including those involved in signal transduction, neuroplasticity, apoptosis, and cell cycle regulation. Western immunoblotting confirmed the differential modulation of brain-derived neurotrophic factor, cAMP response-element-binding protein (CREB), p38, dystrophin, 2',3'-cyclic-nucleotide 3'-phosphodiesterase, mammalian target of rapamycin (mTOR), and Bcl-xL in response to Champagne supplementation compared to the control drink, and the modulation of mTOR, Bcl-xL, and CREB in response to alcohol supplementation.
METHODS
Our data suggest that smaller phenolics such as gallic acid, protocatechuic acid, tyrosol, caftaric acid, and caffeic acid, in addition to flavonoids, are capable of exerting improvements in spatial memory via the modulation in hippocampal signaling and protein expression.
CONCLUSIONS
Changes in spatial working memory induced by the Champagne supplementation are linked to the effects of absorbed phenolics on cytoskeletal proteins, neurotrophin expression, and the effects of alcohol on the regulation of apoptotic events in the hippocampus and cortex.
Publication
Journal: Oral Diseases
April/20/2017
Abstract
OBJECTIVE
This study assessed the effect of tyrosol and chlorhexidine gluconate in combination against Candida albicans, Candida glabrata, and Streptococcus mutans in the planktonic state or forming biofilms in vitro.
METHODS
Checkerboard assays were performed for determination of minimum inhibitory concentration. Biofilms were cultivated during 24 h on specimens of acrylic resin and hydroxyapatite and treated with the drugs alone or in combination twice a day for 1 min, during 3 days. The antibiofilm effect was determined by quantification of the metabolic activity and cultivable cells. The drug combination was also applied on C. albicans to investigate its action on the number of hyphae. Data were statistically examined by two-way ANOVA and Holm-Sidak test (P < 0.05).
RESULTS
The effect of drug combination on planktonic cells was classified as antagonistic for C. albicans and indifferent for the other strains. Also, the drugs were ineffective against the tested biofilms. However, the drug combination showed a synergistic effect in reducing the number of hyphae by C. albicans.
CONCLUSIONS
The combination of tyrosol with chlorhexidine gluconate was only effective in reducing the number of hyphae by C. albicans, a relevant virulence factor of this species.
Publication
Journal: Antioxidants
August/10/2019
Abstract
Pentacyclic triterpenes and phenols are two types of bioactive molecules found in olive trees that have important activities related to health and disease prevention. Triterpenes, including oleanolic acid, maslinic acid, erythrodiol and uvaol, show antitumoral activities, and phenols such as oleuropein, tyrosol, and hydroxytyrosol are natural antioxidants. The concentration of these metabolites is considered a marker of the quality of olives and olive oil. In recent years, a lack of rain water has caused important economic losses relating to olive trees grown in Jaén, Spain. In this work, we investigated the effect of water stress by drought on the concentration of pentacyclic triterpenes and phenols in the fruits, leaves, stems and roots of cv. Picual olive trees, by comparing the concentration found in water-stressed versus irrigated plants. We used HPLC-UV/Vis and HPLC-MS to identify and determine the concentration of each individual compound. Our results showed that important changes in the concentration of these compounds are produced in response to water stress in different organs. The total content of most of these compounds in the fruits was significantly reduced, affecting their quality and production.
Publication
Journal: Journal of Separation Science
August/12/2015
Abstract
A new ultra high performance liquid chromatography coupled with tandem mass spectrometry method for a fast and sensitive determination of eight polyphenols (hydroxytyrosol, catechin, epicatechin, epigallocatechin gallate, oleuropein, quercetin, rutin, tyrosol) and panthotenic acid in extra-virgin olive oil was developed. The method does not require long sample pre-treatment and presents the lowest limit of detection and limit of quantitation values present in literature. Inter- and intra-day variability, linear dynamic range of the calibration curve, recovery and matrix effect were also determined and investigated. The method was applied to several oil samples of different type and origin. Given its accuracy, precision and rapidity, the method is characterized by an interestingly high throughput, reliability, and sensitivity.
Publication
Journal: Journal of Agricultural and Food Chemistry
June/18/2000
Abstract
Industries aim to ensure extra virgin olive oil (EVOO) stability especially during commercial activities up to use by end consumers. The objective of this work was to set up predictive models of EVOO stability during commercial activities. Stability was studied on five lots of a batch of Tuscan virgin olive oil to simulate different commercial activities. Chemical, physical, and sensory analyses were carried out on EVOO samples. Experimental data were processed by multivariate analyses to select significant parameters and by regression analyses to set up kinetic models. A few parameters were found to be significant: hydroxytyrosol and tyrosol contents, carotenoid absorbance at 475 and 448 nm, alpha-tocopherol content, Rancimat induction time, and K(232). It was also shown that the stability of this EVOO was not significantly influenced by different uncontrolled bottling, transport, and storage conditions in supermarkets. Empirical models were set up to predict the time to reach a reference value for K(232).
Publication
Journal: FEMS Yeast Research
February/21/2016
Abstract
Tyrosol is a quorum-sensing molecule of Candida albicans able to induce hyphal development in the early and intermediate stages of biofilm growth. In the present study, we evaluated the effect of high concentrations of exogenous tyrosol on planktonic cells and biofilms of C. albicans (n = 10) and C. tropicalis (n = 10), and investigated whether tyrosol could be synergic to antifungals that target cellular ergosterol. Antifungal susceptibility and drug interaction against planktonic cells were investigated by the broth microdilution method. Tyrosol was able to inhibit planktonic cells, with MIC values ranging from 2.5 to 5.0 mM for both species. Synergism was observed between tyrosol/amphotericin B (11/20 strains), tyrosol/itraconazole (18/20 strains) and tyrosol/fluconazole (18/20 strains). Exogenous tyrosol alone or combined with antifungals at both 10 × MIC and 50 × MIC were able to reduce biofilm of both Candida species. Mature biofilms were susceptible to tyrosol alone at 50 × MIC or combined with amphotericin at both 10 × MIC and 50 × MIC. On the other hand, tyrosol plus azoles at both 10 × MIC and 50 × MIC enhanced biofilm growth.
Publication
Journal: Frontiers in Chemistry
November/13/2018
Abstract
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. For the two vintages, the REDOX sensory scores appeared to be driven both by the type of closure and to a lesser extent by the level of must clarification. Vintages and must racking prefermentative operations were also distinguished by chemical analyses. All white wines from the lowest must turbidity had the lowest REDOX sensory scores. Such wines exhibited lower concentrations in tyrosol and grape reaction product and higher concentrations in colloids with relatively low molecular weights. Among these macromolecules, grape proteins were also quantified, two of them exhibiting concentrations in bottled wines, which were statistically correlated to oxidative evolution in white wines.
Publication
Journal: Natural Product Research
May/30/2018
Abstract
From the green alga Cladophora sp. collected in Italy, the marine fungal strain A12 of Trichoderma citrinoviride was isolated, identified and characterized. LC-MS qTOF analysis was applied to perform a metabolic profile of the fungal culture. Chromatographic techniques and spectroscopic methods were used to isolate and characterize the major secondary metabolites produced by this strain in liquid culture. In particular, four known sorbicillinoids (trichodermanone C, spirosorbicillinol A, vertinolide and sorbicillin) were purified and identified, together with 2-phenylethanol and tyrosol. Moreover, metabolomic analysis allowed to detect small amounts of trichodimerol, rezishanone A, 2',3'-dihydrosorbicillin and bisvertinol. For the first time a significant inhibitory effect on nitrite levels has been shown for trichodermanone C in lipopolysaccharide-stimulated J774A.1 macrophages.
Publication
Journal: Journal of Applied Microbiology
March/12/2019
Abstract
Cells limit the cell number of dense biofilms by releasing self-inhibitory molecules. Here, we aim to assess the effectiveness of yeast quorum sensing (QS) molecules and the antifungal agent natamycin against yeast biofilms of strains commonly isolated from fruit juice ultrafiltration membranes.

METHODS AND RESULTS
Yeast QS molecules, such as tyrosol, 2-phenylethanol and farnesol, were detected by solvent extraction and HS-SPME GC-MS in Candida tropicalis cultures. The effect of QS molecules on mono- and multispecies biofilms formed by Rhodotorula mucilaginosa, C. tropicalis, Candida krusei and Candida kefyr was evaluated by plate count and epifluorescence microscopy. Farnesol caused a decrease in cell number and disrupted mono- and multispecies yeast biofilms during adhesion (0·6 mmol l-1 ). 2-phenyl ethanol 1·2 mmol l-1 stimulated biofilm density and increased cell number in both mono- and multispecies biofilms, while tyrosol did not show effects when tested against C. tropicalis biofilms (0·05-1·2 mmol l-1 ). Natamycin caused a strong decrease in cell number and disruption of biofilm structure in C. tropicalis biofilms at high concentrations (0·3-1·2 mmol l-1 ). The combination of farnesol 0·6 mmol l-1 and natamycin at 0·01 mmol l-1 , the maximum concentration of natamycin accepted for direct addition into fruit juices, effectively reduced cell counts and disrupted the structure of C. tropicalis biofilms.

CONCLUSION
Farnesol 0·6 mmol l-1 significantly increased the inhibition exerted by natamycin 0·01 mmol l-1 (~5 ppm) reducing biofilm development from juice on stainless steel surfaces.

These results support the use of QS molecules as biofilm inhibitors in beverages and would certainly inspire the design of novel preservative and cleaning products for the food industry based on combinatory approaches.
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