Antimicrobial Activity of Diffusible and Volatile Metabolites Emitted by Beauveria bassiana: Chemical Profile of Volatile Organic Compounds (VOCs) Using SPME-GC/MS Analysis.

The genus Beauveria includes important entomopathogenic and endophytic fungi; among them, Beauveria bassiana is the most studied species. However, there is little knowledge regarding their antimicrobial activity. The current research has been conducted to evaluate the in vitro antagonistic activity of B. bassiana and the antimicrobial efficacy of its Exo and Endo metabolites against Bacillus cereus, B. megaterium, Clavibacter michiganensis (Gram positive bacteria, G+ve), Xanthomonas campestris, Pseudomonas aeruginosa and P. fluorescence (Gram negative bacteria, G-ve). In addition, solid-phase microextraction (SPME) was coupled with Gas Chromatography-Mass Spectrometry (GC/MS) to qualitatively measure the volatile organic compounds' (VOCs) metabolic profile of the most efficient studied isolate of B. bassiana. The obtained results showed that the isolate UniB2439-3 has a promising antibacterial effect against most of the studied target bacteria. An SPME-GC/MS analysis of VOCs revealed the presence of ethanol, butanal,2-methyl, 2,4-dimethyl-1-heptene, octane, 4-methyl and ß-elemene as the dominant bioactive compounds. The results demonstrated that the efficient isolate of B. bassiana can be potentially used as a biocontrol agent against several bacteria, especially G+ve ones.

HS-SPME-GC-MS determination of the scent of Anacamptis taxa (fam. Orchidaceae) from Basilicata (Southern Italy).

The scent of Anacamptis species has been analyzed by using HS-SPME-GC-MS. The sample was collected in Basilicata (Southern Italy). Every species showed a different composition of the scent in the analyses we performed. 1,2,4-Trimethoxybenzene and methyl 4-mehoxybenzoate were the main components of that of Anacamptis coriophora subsp. fragrans. The scent of Anacamptis laxiflora was due to the presence of caryophyllene. Linear hydrocarbons but also decanal were components of the scent of Anacamptis pyramidalis. Eucalyptol was found in the scent of Anacamptis papilonacea. Finally, ß-sesquiphellandrene was the main component of the scent of Anacamptis morio.

Volatile organic compounds from Citrus australasica growing in Basilicata (Southern Italy).

SPME-GCMS analysis of vesicles of Sanguinea cultivar showed the presence of limonene (45.63%), sabinene (22.65%), and bicyclogermacrene (10.80%). The analysis of the peel showed that the main components were limonene (48.24%), sabinene (37.15%), and α-pinene (4.26%). In Pink Ice cultivar the main components of the vesicles were sabinene (31.68%), limonene (20.71%), and bicyclogermacrene (14.18%). Peel analysis showed the presence of limonene (37.68%), sabinene (33.33%), and α-pinene (5.55%). In Faustrime limonene (51.54%), γ-terpinene (10.01%), α-bergamotene (7.48%), ß-bisabolene (7.07%), and a-phellandrene (5.68%) were detected. In peel analysis limonene (27.84%), α-pinene (9.41%), γ-terpinene (10.00%), and citronellal (10.51%) were found.

Fragrance components of Gymnadenia conopsea and Gymnadenia odoratissima collected at several sites in Italy and Germany.

The SPME-GC-MS analysis of the aroma components of Gymnadenia conopsea subsp. conopsea, subsp. densiflora, var. alpina and Gymnadenia odoratissima var. odoratissima, var. idae were reported. The main components of in total 78 found in G. conopsea subsp. conopsea were elemicin, cis-9-hexadecenal, hexadecanal, isoelemicin and (Z)-11-hexadecen-1-ol acetate; in subsp. densiflora benzyl benzoate, eugenol and trans-isoeugenol; in var. alpina benzyl benzoate, methyleugenol and elemicin. In the scent of G. odoratissima var. odoratissima were found 2-phenylethyl acetate, eugenol and pentadecane, in var. idae mainly C15-C21 alkanes and C16, C18 carbonic acids and some isoprenoid-derivatives. As all tested Gymnadenia-taxa are allogamous, the differences in scent composition may play a role in pollinator attraction.

Characterization of the volatile fraction of mastic oil and mastic gum.

GC-MS of ethyl acetate solutions and HS-SPME-GC-MS of mastic oil and mastic gum showed the presence of α-pinene and ß-myrcene as main components of the mixture. In the GC-MS analysis of mastic oil 19 compounds were detected, while mastic gum allowed to detect only twelve compounds. Mastic gum showed the presence of compounds with a higher molecular weight. In HS-SPME analysis the amount of ß-myrcene increased in comparison to the results obtained in the analyses performed in solution. The relative ratio between α-pinene and ß-myrcene showed that SPME analysis induces a preferential detection for ß-myrcene (α-pinene/ß-myrcene in the mastic oil 16.18 in GC-MS analysis, and 5.06 in SPME analysis; α-pinene/ß-myrcene in mastic gum 10.64 in GC-MS analysis, and 2.25 in SPME analysis). These results can be explained considering a different absorption selectivity of these compounds on the SPME fiber.

The scent of Neotinea orchids from Basilicata (Southern Italy).

The scent of Neotinea species has been performed by using solid-phase microextraction- gas chromatography- mass spectrometry (SPME-GC-MS). The scent of Neotinea ustulata showed the presence of 9-tricosene, 1-nonadecanol and heinecosane. The analysis of the scent of Neotinea tridentata gave α-ionone as the main component. The scent of Neotinea lactea showed the presence of pentadecane, heptadecane and isopropyl palmitate. Neotinea maculata showed the presence in the scent of 1-decene and ethyl dodecanoate.

The composition of the aroma of Serapias orchids in Basilicata (Southern Italy).

The SPME-GC-MS analysis of the aroma components of Serapias cordigera, Serapias cordigera subsp. lucana, Serapias vomeracea, Serapias lingua, and Serapias parviflora were reported. The relevant components of the scent of Serapias cordigera were α-amorphene, ethyl oleate, heneicosane, heptadecane, 2-heptadecanone, ethyl elaidate, pentadecane, octadecane, farnesylacetaldehyde, nonadecane, and ethyl stearate. Serapias cordigera subsp. lucana gave α-amorphene, pentadecane, propyl undecanoate, heptadecane, ethyl elaidate and oleate, ethyl stearate, and 8-heptadecene. Serapias vomeracea showed pentadecane, 5-nonadecene, 1-nonadecene, 3-heptadecene, benzyl benzoate, 2-undecanone, and octadecane. Serapias lingua showed the presence of heptadecane, 3-heptadecene, isopropyl myristate, pentadecane, nonadecane, isopropyl palmitate, octadecane, and benzyl benzoate. Serapias parviflora gave pentadecane, pentadecene, hexadecane, heptadecane, nonadecane, and ethyl elaidate.

Aroma components of Cephalanthera orchids.

The SPME-GC-MS analysis of the aroma components of Cephalanthera damasonium, Cephalanthera rubra, and Cephalanthera longifolia were reported. The main components found in C. damasonium were pentadecane, hexadecane, heptadecane and α-farnesene. The same compounds were found in the scent of C. rubra. Although C. damasonium and C. rubra have different pollination mechanisms, their spectrum of volatile compounds surprisingly does not differ significantly. In C. longifolia pentadecane and heptadecane were found together with cis-ß-farnesene. As C. longifolia is allogamous, the differences in scent composition may play a role in pollinator attraction.

Fragrance components of Platanthera bifolia subsp. osca and Platanthera chlorantha collected in several sites in Italy.

Platanthera bifolia subsp. osca sample collected at Grisolia showed as main components linalool (17.8%), benzyl benzoate (55.8%), and benzyl 2-hydroxybenzoate (6.7%). Four samples of P. bifolia subsp. osca were collected at Pignola: the main components of the aroma are lilac derivatives (49.02-79.00%), mainly lilac alcohols B (7.41-13.52%), C (10.10-18.45%), and D (7.50-34.28%). Three samples were analyzed from the site of Marsico Nuovo. The main components of the scent found in this site were linalool (1.54-10.00%), lilac aldehydes (3.98-11.15%), and mainly lilac alcohols (50.68-61.51%). The main components of the sample collected at Palena were methyl benzoate (9.04%) and benzyl benzoate (74.72%). The analysis of the composition of the aroma of a Platanthera chlorantha plant has been performed. The main components were lilac derivatives. The reported behavior could be explained admitting an adaptive modification of the scent considering the nature of possible pollinating agents due to different habitats.

Pollination features and floral volatiles of Gymnospermium scipetarum (Berberidaceae).

The discovery of few isolated populations of Gymnospermium scipetarum (since now considered as an amphi-Adriatic endemic) in the S-Apennines prompted to investigate, also for conservation purposes, some aspects of its reproductive biology. We aim: (1) to determine if insects play an important role in pollination; (2) to describe the pollinator community; (3) to detect floral scent composition. Experiments of insect exclusion were carried out in the field using 24 flowering individuals: one raceme was capped whereas the nearest one was used as control to ascertain differences in seed set. Pollinator community was detected during the blooming phase of two consecutive flowering seasons by visual observation; insect identification was made at the highest possible taxonomic resolution with the help of digital photographs. In order to determine the chemical composition of the volatiles, we used SPME sampling of cultivated plants. Mann-Whitney U test reveals significant differences for treatment in mean seed set with very low values for capped flowers, thus clearly indicating as insects are crucial for successful pollination. During the 42 h of observations we detected 326 visitors belonging to only three guilds: 79% were Diptera, 20% Hymenoptera and 1% Coleoptera. We identified overall 36 floral organic compounds with only two compounds common to the other studied Berberidaceae. Ambrox was never identified before in the floral scents of any angiosperm. The presence in the scent of several aldehydes and one ketone (benzophenone) could be related to the detected dominance of muscoid flies as pollinators. Floral morphology and composition of the pollinators community indicate a generalist pollination behaviour probably related to its phenology and habitat preference. The possibility of being pollinated also by muscoid flies can be considered an advantage for the reproductive fitness of the species, since these Diptera are abundant in the mountain pastures surrounding the forest habitat of Gymnospermium.

Solid phase microextraction and gas chromatography mass spectrometry analysis of Zingiber officinale and Curcuma longa.

SPME analysis of Zingiber officinale Roscoe and Curcuma longa L. were performed by using a DVB/CARB/PDMS fiber. The SPME analysis of Zingiber officinale showed that the main components found were camphene (7.27%), geranial (8.37%), α-zingiberene (14.50%), α-farnesene (9.14%), ß-bisabolene (6.52%), and ß-sesquiphellandrene (9.92%). The SPME analysis of Curcuma longa showed that main components were p-cymene (12.96%) and ar-turmerone (12.08%). Other components were ß-phellandrene (7.86%), terpinolene (6.97%), ar-curcumene (8.53%), α-zingiberene (8.46%), and ß-sesquiphellandrene (7.37%).

Fragrance components of Platanthera bifolia subsp. osca.

SPME-GC-MS analysis of the scent of Platanthera bifolia subsp. osca collected during the night showed as main components lilac alcohols B, C and D and lilac aldehydes A, B and C. Other significant chemical components were linalool and caryophyllene. Some differences were found in comparison with previously reported analyses of the scent of P. bifolia and Platanthera chlorantha. The most important difference found was in the composition of the ester fraction.

In vitro study of biological activity of four strains of Burkholderia gladioli pv. agaricicola and identification of their bioactive metabolites using GC-MS.

This research was carried out to study in vitro antibacterial activity of 4 strains of Burkholderia gladioli pv. agaricicola (Bga) against G+ve Bacillus megaterium and G-ve Escherichia coli, haemolytic activity against the cell membrane of erythrocytes, the production of extracellular hydrolytic enzymes and finally, the pathogenicity against Agaricus bisporus flesh blocks. Chemical structure of bioactive substances of the most bioactive strain (ICMP 11096) was established using gas chromatography-mass spectrometry (GC-MS). All the studied Bga strains inhibited the growth of the two tested bacteria although some growing substrates negatively influenced the antimicrobial substance production. The same Bga strains showed highly haemolytic activity and were able to produce 3 hydrolytic enzymes, i.e. chitinase, glucanase and protease. In pathogenicity assays, the considered Bga strains resulted virulent for A. bisporus. The GC-MS for compounds from Bga ICMP 11096 were compatible with the structure of two bioactive fatty acids identified as methyl stearate and ethanol 2-butoxy phosphate with mass spectrum m/e 298 and 398, respectively.

Studies on volatile organic compounds of some truffles and false truffles.

Results of solid phase micro-extraction coupled to gas chromatography and mass spectrometry analyses, accomplished on sporophores of 11 species of truffles and false truffles, are reported. Volatile organic compounds (VOCs) found in Gautieria morchelliformis were dimethyl sulphide, 1,3-octadiene, 3,7-dimethyl-1,6-octadien-3-ol, amorphadiene, isoledene and cis-muurola-3,5-diene. In Hymenogaster luteus var. luteus, presence of 1,3-octadiene, 1-octen-3-ol, 3-octanone, 3-octanol and 4-acetylanisole was revealed. Two VOCs, 4-acetylanisole and ß-farnesene, constituted aroma of Hymenogaster olivaceus.Melanogaster broomeanus exhibited as components of its aroma 2-methyl-1,3-butadiene, 2-methylpropanal, 2-methylpropanol, isobutyl acetate, 3,7-dimethyl-1,6-octadien-3-ol, 3-octanone and ß-curcumene. VOC profile of Octavianina asterosperma was characterised by the presence of dimethyl sulphide, ethyl 2-methylpropanoate, methyl 2-methylbutanoate and 3-octanone. Tuber rufum var. rufum and Pachyphloeus conglomeratus showed the presence of dimethyl sulphide only.

Oxetane synthesis through the Paternò-Büchi reaction.

The Paternò-Büchi reaction is a photochemical reaction between a carbonyl compound and an alkene to give the corresponding oxetane. In this review the mechanism of the reaction is discussed. On this basis the described use in the reaction with electron rich alkenes (enolethers, enol esters, enol silyl ethers, enanines, heterocyclic compounds has been reported. The stereochemical behavior of the reaction is particularly stressed. We pointed out the reported applications of this reaction to the synthesis of naturally occuring compounds.

Volatile organic compounds of Schenella pityophilus.

Volatile organic compounds of Schenella pityophilus have been identified via solid-phase microextraction-gas chromatography-mass spectrometry analysis. Ten compounds have been identified, in which 3-methylthio-1-propene was the most significant component. Some other components were previously identified in Tuber aestivum and Tuber melanosporum.

In vitro antifungal activity of Burkholderia gladioli pv. agaricicola against some phytopathogenic fungi.

The trend to search novel microbial natural biocides has recently been increasing in order to avoid the environmental pollution from use of synthetic pesticides. Among these novel natural biocides are the bioactive secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga). The aim of this study is to determine antifungal activity of Bga strains against some phytopathogenic fungi. The fungicidal tests were carried out using cultures and cell-free culture filtrates against Botrytis cinerea, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, Sclerotinia sclerotiorum and Phytophthora cactorum. Results demonstrated that all tested strains exert antifungal activity against all studied fungi by producing diffusible metabolites which are correlated with their ability to produce extracellular hydrolytic enzymes. All strains significantly reduced the growth of studied fungi and the bacterial cells were more bioactive than bacterial filtrates. All tested Bulkholderia strains produced volatile organic compounds (VOCs), which inhibited the fungal growth and reduced the growth rate of Fusarium oxysporum and Rhizoctonia solani. GC/MS analysis of VOCs emitted by strain Bga 11096 indicated the presence of a compound that was identified as 1-methyl-4-(1-methylethenyl)-cyclohexene, a liquid hydrocarbon classified as cyclic terpene. This compound could be responsible for the antifungal activity, which is also in agreement with the work of other authors.

Studies on volatile organic compounds of Tuber borchii and T. asa-foetida.

Ascomata of two truffle species, Tuber borchii and T. asa-foetida, both naturally growing in woodlands of the Basilicata region (southern Italy), were identified on the basis of ascospore morphology and compared under a volatile organic compound profile to determine the particular volatile organic compounds that characterize each taxon. Solid-phase microextraction-gas chromatography-mass spectrometry analysis of the samples showed the presence of 1-methyl-1,3-butadiene as a primary component in both truffles. T. asa-foetida showed a compound, toluene, not present in T. borchii, which creates the penetrating "solvent" smell of the truffle.

Photochemical isomerization of aryl hydrazones of 1,2,4-oxadiazole derivatives into the corresponding triazoles.

The photochemical version of the Boulton-Katritzky reaction has been studied, examining the behaviour of the arylhydrazones of 3-benzoyl-5-X-1,2,4-oxadiazoles. The effect of several modifications of the substrates structure (the E and/or Z structures of arylhydrazones, the possible presence of substituents in the arylhydrazono moiety, and the nature of substituents at C-5 of the 1,2,4-oxadiazole ring) on the course of the photochemical rearrangement has been examined.

FT-ICR-MS analysis of lignin.

Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) of a steam-exploded lignin from wheat straw showed that fragments with a mass higher than 4534 Da cannot be obtained. Furthermore, FT-ICR-MS showed that lignin is not a completely random polymer, but shows some regularity with a difference of 44.026 m/z (C2H4O) between the peaks. The distribution of Kendrick mass defect in the function of Kendrick nominal masses showed the same behaviour. FT-ICR-MS analysis of bagasse lignin (Granit) showed that the largest value of mass found was 4347 Da. The peaks show regularities with a difference of 44.026 m/z between the peaks. The organosolv lignin showed that the polymer with the largest mass value was 3699 Da in FT-ICR-MS. The analysis of the peaks did not show regularity; however, the Kendrick diagram for this lignin showed the same slope as in the other samples, in agreement with the C2H4O regular difference between peaks.