Volatiles from seven truffle species (Tuber spp.) wild-growing in Greece

In the framework of our phytochemical studies on mushrooms, we report herein, our analyses of seven selected species of Tuber (T. aestivum, T. melanosporum, T. mesentericum, T. magnatum, T. borchii, T. brumale and T. uncinatum), wild-growing in Northern Greece. Truffles are the fruiting bodies of mycorrhizal filamentous fungi well-known and part of the human diet, since antiquity [1] due to their unique and peculiar aroma. The aim of this study was to qualify and semi-quantify their aroma profile, as well as, to evaluate their total phenolic content, to the best of our knowledge for the first time on Greek truffles. The volatile organic compounds (VOCs) were analyzed by Headspace Solid-Phase Microextraction (HS-SPME) with two different polarity fibers (PDMS and CAR-PDMS) and led to the identification of more than fifty (50) VOCs. T. magnatum’s profile was characterized by aldehydes and other secondary metabolites, including its marker compound 2,4-dithiapentane [2]. In addition to this, amines and other nitrogen-containing derivatives were identified, leading to a distinction between the studied species. T. mesentericum was dominated by aromatic compounds, such as 3-methylanisole, previously referred to as its most characteristic chemical marker [3]. T. melanosporum and T. brumale were mainly characterized by aldehydes and T. uncinatum, T. aestivum and T. borchii showed an abundant presence of ketones and alcohols. Differing from all other studied samples, T. borchii was shown to emit the highest concentration of sulfur-containing derivatives, in accordance with the existing literature [4]. Moreover, all studied truffles were evaluated regarding their total phenolic content; T. mesentericum and T. borchii were the richest sources of phenolics (7.8 and 7.4 mg GAE (gallic acid equivalents)/g of the samples, respectively), followed by T. aestivum > T. uncinatum > T. melanosporum > T. magnatum > T. brumale

Chemical analyses of truffle flavored (Tuber spp.) olive oils on the Greek market with HS-SPME

Truffles are subterranean edible fungi of the genus Tuber (Ascomycota, Pezizales), with a high commercial interest and economic value due to their unique aroma [1]. There are a number of foods flavored with truffles, such as oils etc. The aroma profile of such flavored foods has been studied thoroughly during the last decades. In the framework of this study, 5 truffle olive oils from the Greek market were investigated, coming from white (T. magnatum) and black (T. melanosporum) truffles. All samples were analyzed by Headspace Solid-Phase Micro-Extraction (HS-SPME) coupled with Gas Chromatography-Mass Spectrometry (GC-MS) and a total of 31 metabolites were identified, including a variety of sulfur-containing volatiles. 2,4-Dithiapentane, well known as a volatile chemical marker of white truffles [2], was detected in high concentrations in both white and black truffle olive oils, however, probably as the main constituent of synthetic flavor additives. Furthermore, other artificial sulfur-containing compounds were identified in the oils available in the market, e.g. 1-propanethiol, diallyl sulfide, and allyl isothiocyanate, which have not been detected previously in other truffle olive oils but have been reported among the volatiles of Allium spp. [3,4] and Brassica nigra [5], respectively. In conclusion, this study confirmed that all studied truffle olive oils from the Greek market are produced by the addition of synthetic aroma compounds. These flavors are of low cost, highly effective olfactorily [6], and of low toxicity, used widely according to European regulations in order to imitate the aroma of truffles

Kainari, a Unique Greek Traditional Herbal Tea, from the Island of Lesvos: Chemical Analysis and Antioxidant and Antimicrobial Properties

The chemical composition, as well as the total phenolic content (TPC) and the potential antioxidant and antimicrobial activity, of three Kainari-herbal tea samples from different areas of Lesvos Island (Greece) was evaluated. The rich aroma of the mixtures was studied through GC-MS, as well as through Headspace Solid-Phase Microextraction (HS-SPME)/GC-MS analyses. Cinnamon, clove, nutmeg, pepper, and ginger were identified as main ingredients, while, throughout the chemical analysis of the volatiles of one selected sample, several secondary metabolites have been isolated and identified on the basis of GC-MS as well as spectral evidence as eugenol, cinnamic aldehyde and myristicin, cinnamyl alcohol, alpha-terpinyl acetate, and β-caryophyllene. Furthermore, two food dyes, azorubine and amaranth, were also isolated and identified from the infusions. The total phenolic content was estimated and the free radical scavenging activity was determined by DPPH and ABTS assays and the antimicrobial activity of the extracts was tested showing a very interesting profile against all the assayed microorganisms. Due to its very pleasant aroma and taste properties as well as to its bioactivities, Kainari-herbal tea could be further proposed as functional beverage

Chemical Composition and Antimicrobial Activity of Geniosporum rotundifolium Briq and Haumaniastrum villosum (Bene) AJ Paton (Lamiaceae) Essential Oils from Tanzania

Purpose: To determine the chemical composition and antimicrobial potential of essential oils from two aromatic plants of Tanzania, Geniosporum rotundifolium Briq. and Haumaniastrum villosum (Benè) A.J. Paton (Lamiaceae).Method: Essential oils from the aerial parts of the plants were extracted by hydro-distillation for 3 h using a Clevenger type of apparatus. The constituents were analyzed by gas chromatography – mass spectrometry (GC/MS).The minimum inhibitory concentrations of the essential oils were determined for eight bacterial strains and three pathogenic fungi using agar dilution method.Results: The constituents of G. rotundifolium oil were mainly oxygenated derivatives of mono- and sesquiterpenes; spathulenol (12.46 %), α-terpineol (4.65 %) and germacrene-D (3.71 %) were the most abundant. Those of H. villosum oil were predominantly sesquiterpenes (72.61 %) with caryophyllene oxide (19.01 %), humulene epoxide II (11.95 %), β-bourbonene (5.7 %), α-humulene (5.63 %) and β- caryophyllene (5.39 %) being more abundant. The oil of G. rotundifolium exhibited weak to moderate activity against the bacterial species but showed no activity against the test fungi. However, H. villosum oil showed very promising activity against all the test microorganisms (MIC 0.08 – 10.34 mg/mL).Conclusion: The major components of G. rotundifolium essential oil were oxygenated derivatives of mono- and sesquiterpenes whereas those of H. villosum were sesquiterpenes. All tested microorganisms were susceptible to H. villosum oil.Keywords: Geniosporum rotundifolium, Haumaniastrum villosum, Essential oils, Chemical composition, Antimicrobial activit

Phytochemical analysis and biological evaluation of three selected Cordia species from Panama

The aim of the present study was the phytochemical analysis of the leaves from three not previously studied tropical species Cordia bicolor, Cordia megalantha and Cordia dentata (Boraginaceae) collected from Panama. The genus Cordia is one of the major and most important of the family and involves a wide range of therapeutic uses in traditional medicine. Eleven known compounds allantoin (1), rosmarinic acid (2), caffeic acid (3), isoquercetin (4), rutin (5), quercetin-3-Ο-β-D-neohesperidoside (6), kaempferol 3-Ο-β-D-neohesperidoside (7), helichrysoside (8), kaempferol 3-O-(2″-O-α-L-rhamnosyl-6″trans-p-coumaroyl)-β-D-glucoside (9), quercetin 3-O-(6″ trans-p-coumaroyl)-β-D-galactoside (10), 4-hydroxyphenyl lactic acid (11), have been isolated and structurally elucidated. Compounds 6 and 7 have been isolated for the first time in Cordia genus, compounds 8-10 are reported for the first time in the Boraginaceae family, while secondary metabolite 9 is isolated as natural product for the second time. The methanolic extracts of the plants have been assayed for their antioxidant properties by free radical scavenging, reducing power, phosphomolybdenum and metal chelating assay. Enzyme inhibitory activity has been also evaluated against cholinesterases, α-amylase and α-glucosidase. C. megalantha exhibited the strongest antioxidant activity compared to the other studied Cordia species and a high inhibitory activity against α-glucosidase, which suggests that this herbal material could be used for further studies as a potential source for therapeutic applications

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

<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

Assessment of Antioxidant and Antimicrobial Properties of Selected Greek Propolis Samples (North East Aegean Region Islands)

Propolis is a bee-produced substance rich in bioactive compounds, which has been utilized widely in folk medicine, in food supplement and cosmetology areas because of its biological properties, (antibacterial, antiviral, antioxidant, anti-inflammatory, etc.). The subject of this study is associated with the chemical analysis and the biological evaluation of 16 propolis samples from the northeast Aegean region Greek islands, a well-recognized geographic area and the homeland of rich flora as a crossroads between Europe and Asia. Our study resulted in the detection of a significant percentage of diterpenes by gas chromatography&ndash;mass spectrometry (GC-MS), while flavonoids were identified in low percentages among studied samples. Furthermore, the DPPH assay highlighted that eight of the samples (Lesvos and Lemnos origin) demonstrated a promising antioxidant profile, further verified by their total phenolic content (TPC). Additionally, the propolis samples most rich in diterpenes showed significant antibacterial and fungicidal properties against human pathogenic microorganisms, proving them to be a very interesting and promising crude material for further applications, concluding that floral diversity is the most responsible for the bioactivity of the propolis samples

Coumarins from Angelica lucida L.- Antibacterial Activities

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Chemical Analyses of Volatiles from Kumquat Species Grown in Greece—A Study of Antimicrobial Activity

The volatiles of different aerial parts of three kumquat species (Fortunella margarita Swingle–Nagami, Fortunella japonica Swingle–Marumi, and Fortunella crassifolia Swingle–Meiwa) growing in Greece were analyzed via GC-MS and evaluated for their antimicrobial properties against nine human pathogenic microorganisms. A total number of 23 compounds were identified in the peel, 38 in the leaves, and 30 in the flowers of the examined species. Limonene was the dominant metabolite in the peels of all three species, germacrene-D was present in the leaves of Nagami and Marumi kumquats, while limonene was the most abundant in the flower of Marumi and Meiwa kumquat but with significant differences in the composition of the total fracture of the essential oil, since compounds with high antimicrobial activity were only present in the flower of Meiwa kumquat. The essential oils from the leaf and peel of the three kumquat species were either inactive or showed weak antimicrobial activity, respectively, against Gram-positive and Gram-negative bacterial strains and pathogenic fungi. Only the essential oil from the flower of F. crassifolia Swingle (Meiwa) showed a stronger effect (MIC values 3.5–7.48 mg/mL) against all the assayed microorganisms. Furthermore, through multivariate statistical analysis, we studied the relationships between the samples regarding their origin (species and plant part), as well as between the chemical composition of the corresponding essential oils and their antimicrobial activity. Considering its chemical profile and antimicrobial activity, the Greek Meiwa flowers’ essential oil seemed a promising essential oil for further exploitation in the food and/or medicinal industry