87 research outputs found

    Antifungal activity of selected Malassezia indolic compounds detected in culture

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    Background: Malassezia yeasts produce bioactive indolic substances when grown on L‐tryptophan agar. A panel of these substances was tested against commensal and opportunistic fungi, the Minimum Inhibitory Concentration (MIC) was determined and the potential for in loco antifungal activity on the skin was assessed. Materials and Methods: Eight indoles were included (malassezin, pityriacitrin, indirubin, indolo[3,2‐b]carbazole, 6‐formylindolo[3,2‐b]carbazole, tryptanthrin, 6‐hydroxymethylindolo[3,2‐b]carbazole and 6‐methylindolo[3,2‐b]carbazole) and were tested against 40 fungal strains [yeasts: Malassezia spp.(N = 9); Cryptococcus spp.(N = 10); Candida spp.(N = 7); Yarrowia lipolytica(N = 1); Exophialla dermatitidis (N = 2); moulds: Aspergillus spp.(N = 7); Fusarium spp.(N = 2); Rhizopus oryzae(N = 2)]. The concentration of 5/8 of the tested indoles on diseased skin was calculated from published data. Kruskal‐Wallis and Mann‐Whitney U tests were employed for group susceptibility evaluation in 33 strains. Results: The MIC range was 0.125‐32 μg/mL, and the median log2MIC was four. Indirubin was the most potent antifungal agent and differed significantly from the others. The highest median MIC was found for FICZ. Malassezia with Candida strains were more susceptible compared to Cryptococcus and Aspergillus, and this inhibitory activity was predicted to be valid also on human skin. Conclusions: Malassezia yeasts produce indolic species that inhibit an array of clinically significant yeasts and moulds

    Cyber Insurance: recent advances, good practices & challenges

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    The aim of this ENISA report is to raise awareness for the most impact to market advances, by shortly identifying the most significant cyber insurance developments for the past four years – during 2012 to 2016 – and to capture the good practices and challenges during the early stages of the cyber insurance lifecycle, i.e. before an actual policy is signed, laying the ground for future work in the area

    Chemical analysis of Greek pollen - Antioxidant, antimicrobial and proteasome activation properties

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    <p>Abstract</p> <p>Background</p> <p>Pollen is a bee-product known for its medical properties from ancient times. In our days is increasingly used as health food supplement and especially as a tonic primarily with appeal to the elderly to ameliorate the effects of ageing. In order to evaluate the chemical composition and the biological activity of Greek pollen which has never been studied before, one sample with identified botanical origin from sixteen different common plant taxa of Greece has been evaluated.</p> <p>Results</p> <p>Three different extracts of the studied sample of Greek pollen, have been tested, in whether could induce proteasome activities in human fibroblasts. The water extract was found to induce a highly proteasome activity, showing interesting antioxidant properties. Due to this activity the aqueous extract was further subjected to chemical analysis and seven flavonoids have been isolated and identified by modern spectral means. From the methanolic extract, sugars, lipid acids, phenolic acids and their esters have been also identified, which mainly participate to the biosynthetic pathway of pollen phenolics. The total phenolics were estimated with the Folin-Ciocalteau reagent and the total antioxidant activity was determined by the DPPH method while the extracts and the isolated compounds were also tested for their antimicrobial activity by the dilution technique.</p> <p>Conclusions</p> <p>The Greek pollen is rich in flavonoids and phenolic acids which indicate the observed free radical scavenging activity, the effects of pollen on human fibroblasts and the interesting antimicrobial profile.</p

    Chemical analysis and antimicrobial activity of Greek propolis

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    One new 2,3-dihydroflavone derivative, 7-0-prenylstrobopinin, and 25 known diterpenes and phenolic compounds were identified from the n-butanol extract of Greek propolis. This is the first time that diterpenes have been isolated from propolis of European origin, while six of the known compounds are reported as propolis constituents for the first time. The structures of the isolated compounds were determined by spectroscopic methods, mainly by the concerted application of 1D, 2D NMR techniques (HMQC, HMBC, NOESY) and mass spectrometry. The studied sample and the isolated compounds were tested for their antimicrobial activity against Gram (±) bacteria and fungi and five of them exhibited strong activities

    Chemical constituents of selected unifloral Greek bee-honeys with antimicrobial activity

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    (±)-3-Hydroxy-4-phenyl-2-butanone (1) and (+)-8-hydroxylinalool (2) were isolated from Greek honey samples and their structures were determined by spectroscopic and mass spectrometry methods. The enantiomeric ratio of 1 and 2 was determined using chiral GC-MS. Compound 1 has recently been proposed as a possible chemical marker of thyme honey, but although 1, in our hands, was identified only in monofloral thyme honey amongst the honey samples, it was not found in all studied thyme honey samples and additionally its origin was not directly associated with thyme, proving that compound 1 should not be considered as an unambiguous marker of thyme honey. Compound 2 was isolated and identified as the (+)-6S isomer only in monofloral citrus honey. The combination of (+)-8-hydroxylinalool with methyl anthranilate and caffeine could be proposed as a fingerprint marker for the description of citrus honey. All studied honey extracts and the isolated compounds were also tested for their antimicrobial activity. © 2011 Elsevier Ltd. All rights reserved

    Chemistry and bioactivity of royal jelly from Greece

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    Twenty-five compounds were identified from the dichloromethane and methanol extracts of royal jelly from Greece. Among them, 16 compounds are reported for the first time as royal jelly constituents, whereas 7 of them are isolated for the first time as natural products. The 7 new compounds were fatty acid derivatives: 10-acetoxydecanoic acid (1), trans-10-acetoxydec-2-enoic acid (2), 11-oxododecanoic acid (3), (11S)-hydroxydodecanoic acid (4), (10R, 11R)-dihydroxydodecanoic acid (5), 3,11-dihydroxydodecanoic acid (6), and (11S), 12-dihydroxydodecanoic acid (7). The structures of the isolated compounds were determined by spectroscopic methods, mainly by the concerted application of 1D and 2D NMR techniques (HMQC, HMBC) and mass spectrometry. The studied sample and the isolated compounds were tested for their antimicrobial activity against Gram-positive and Gram-negative bacteria and fungi and exhibited interesting activities. © 2005 American Chemical Society

    Isolation of megaritolactones and other bioactive metabolites from &apos;Megaritiki&apos; table olives and debittering water

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    &apos;Megaritiki&apos; is an olive cultivar widely used in Greece for the production of low polyphenol olive oil and table olives. To investigate possible metabolic differentiation in comparison with other varieties, the composition of &apos;Megaritiki&apos; olive fruits and wastewaters from the debittering procedure was studied. Moreover, the recovery of bioactive metabolites from wastewater using adsorption resin was studied to exploit this byproduct. Metabolites in fruits and wastewaters were monitored using NMR spectroscopy. The major constituents of wastewater were hydroxytyrosol-4-O-glucoside, 11-methyl-oleoside, hydroxytyrosol, and tyrosol but not oleuropein. Furthermore, wastewater afforded rengyoxide and rengyoside B, which are for the first time isolated from olives. The final edible olives, besides hydroxytyrosol and tyrosol, contained rengyoxide and cleroindicin C, which are the first isolated from the species, haleridone for the first time isolated from edible olives, and four metabolites, which are the first reported as natural products, megaritodilactone, megaritolactonic acid, methyl ester of megaritolactonic acid B, and megaritolactonol. © 2014 American Chemical Society

    Volatile constituents of propolis from various regions of Greece - Antimicrobial activity

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    The volatiles of five samples of Greek propolis from various geographic origin (A-E) were analyzed by capillary gas chromatography, using flame ionization GC and mass spectrometric detection. Ninety-four components were identified from the oils. The major components from each sample were found to be: junipene (11.7%), α-pinene (7.9%), manoyl oxide (7.1%) (sample A), α-pinene (45.8%), trans-β-terpineol (6.6%) (sample B), α-pinene (17.7%), α-eudesmol (12.1%), n-decanal (6.2%), guaiol (5.0%) (sample C), α-pinene (18.2%), δ-cadinene (8.4%) and α-muurolene (5.0%) (sample D), α-pinene (10.9%), n-decanal (10.3%), cedrol (6.3%), n-nonanal (5.4%), and manool (5.2%) (sample E). The total profile of the volatile constituents of all samples reveals the predominance of terpenoids, especially of α-pinene. The in vitro antimicrobial activity of the volatiles from all five studied samples against six bacteria and three fungi is also assayed and reported. © 2006 Elsevier Ltd. All rights reserved

    Composition of the essential oil of verbascum undulatum from Greece

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    The essential oil of the aerial parts of Verbascum undulatum Lam. was analyzed by GC and GC/MS. Thirty-six compounds were identified and the major components were 1-octen-3-ol (22.5%), α-bisabolol (10.6%) and nonanal (9.0%). © 2007, Taylor &amp; Francis Group, LLC. All rights reserved
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