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.

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.

Novel imazethapyr detoxification applying advanced oxidation processes.

Different degradation methods have been applied to assess the suitability of advanced oxidation process (AOPs) to promote mineralization of imazethapyr [(RS)-5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid], a widely used imidazolinone class herbicide, the persistence of which has been demonstrated in surface and ground waters destined to human uses. Independent of the oxidation process assessed, the decomposition of imazethapyr always followed a pseudo-first order kinetic. The direct UV-irradiation (UV) of the herbicide as well as its oxidation with ozone (O3), and hydrogen peroxide tied to UV-irradiation (H2O2/UV) were sufficiently slow to permit the identification of intermediate products, the formation pathway of which has been proposed. Ozonation joined to UV-irradiation (O3/UV), ozonation joined to titanium dioxide photo-catalysis (TiO2/UV+O3), sole photo-catalysis (TiO2/UV), and photo-catalysis reinforced with hydrogen peroxide-oxidation (TiO2/UV+H2O2) were characterized by a faster degradation and rapid formation of a lot of small molecules, which were quickly degraded to complete mineralization. The most effective oxidation methods were those using titanium dioxide photo-catalysis enhanced either by ozonation or hydrogen peroxide. Most of all, these last processes were useful to avoid the development of dangerous by-products.

Photodegradation of crude oil on a solid support.

The modifications of crude oil after absorption on silica, montmorillonite, and zeolite were studied. Solid-phase microextraction gas chromatography-mass spectrometry analysis showed that some compounds are kept better by the solid support than other ones. The modifications that occurred were studied considering the relative amount of different classes of compounds, the number of compounds in function of the number of carbon atoms, and the relative amount in function of the number of carbon atoms for different classes of compounds (linear alkanes, branched alkanes, cyclic alkanes, aromatic hydrocarbons, and alkenes). The modifications which occurred after irradiation with a 125 W high pressure mercury arc towards Pyrex were studied. A global index of the modifications which occurred was proposed. All of the solids prevent photodegradation. Zeolite was the worst, while the most preservative effect was showed by montmorillonite.

Photochemical degradation of crude oil: Comparison between direct irradiation, photocatalysis, and photocatalysis on zeolite.

Direct irradiation for 100h of crude oil from Basilicata (Southern Italy) gave in the case of linear and branched alkanes a reduction of 9 and 5%, respectively. On the contrary, cyclic alkanes decreased for 54% while aromatic hydrocarbons showed a reduction of 37%. These results are in agreement with a prevalent electron transfer mechanism. Photocatalysis (100h) gave extensive degradation of crude oil: linear alkanes were degraded for 98.66%, branched alkanes were reduced for 97.31%, cyclic alkanes for 96.04%, while aromatic compounds and alkenes were reduced for 99.54 and 98.38%, respectively. These results are in agreement with a prevalent hydrogen abstraction mechanism. When photocatalysis is performed in the presence of zeolite linear alkanes were degraded for 79.85%, branched alkanes were reduced for 45.38%, cyclic alkanes for 58.10%, while aromatic compounds were reduced for 91.85%. In this case, an increase of the relative amount of alkenes (42.05%) was observed.

Paternò-Büchi reaction between aromatic carbonyl compounds and 1-(3-furyl)alkanols.

The photochemical reaction between aromatic carbonyl compounds and 3-furylmethanol derivatives occurs with high regioselectivity. In most of the experiments formation of oxetanes occurs at the hydroxyalkylated double bond. With chiral 1-(3-furyl)alkanols the reaction occurs with good-high stereoselectivity. In the case of 1-(3-furyl)-benzyl alcohol the stereoselectivity can be explained on the basis of the conformers of the reagent, assuming the formation of a complex between the carbonyl compound and the hydroxyl group.

[Prevalence of hearing loss in elderly individuals over 65 years of age: a pilot study in Lombardia (Italy)]. / Prevalenza della sordità in soggetti di età superiore ai 65 anni. Studio pilota in un campione di popolazione Lombarda.

A cross sectional study was performed to determine the prevalence of hearing loss in individuals over age 65 years presenting to a medical centre in Lombardia (Italy). The aim was to assess the feasibility of performing a survey to evaluate the prevalence of hearing loss in the entire region. Audiometric testing was performed in each enrolled subject, to reveal losses in hearing levels at 250 to 8000 Hz; hearing levels were measured in decibels. Prevalences of mild, moderate, severe, and profound hearing impairment were found to be 39%, 17.4%, 2.9% and 0.6% respectively when using the WHO classification, and 59.9%, 25.6%, 2.9%, and 0.6% respectively when using the classification of the Bureau International d'Audiophonologie (BIAP).This study has shown that a relevant part of the study population is affected by hearing impairment and has served as a pilot study for a larger-scale study to be performed in the Lombardia region.

The stereoselectivity of the Paternò-Büchi reaction between tertiary 2-furylmethanol derivatives and aromatic carbonyl compounds: on the nature of the hydroxy directing effect.

The photochemical reaction of 1-(2-furyl)-1-phenylethanol with benzaldehyde gave a mixture of regioisomeric products. The adduct obtained on the more hindered side of the molecule was obtained with complete diastereoselectivity. The same substrate with benzophenone gave only one product with a diastereoisomeric excess of 48%. The reaction of 2-(2-furyl)-3,3-dimethylbutan-2-ol with benzaldehyde and benzophenone gave the corresponding adducts on the more hindered side of the molecule with diastereoisomeric excesses of 42 and 71%, respectively. These results, and also those obtained using 2-furylphenylmethanol with benzophenone and acetone (complete diastereoselectivity and absence of diastereoselectivity, respectively), were explained assuming the attack of the excited carbonyl compound on the same side as the hydroxy group, through the formation of a hydrogen bond or of a complex. This type of attack gave the biradical intermediate in preferential conformations. The relative energies of these conformers account for the observed diastereoselectivity.

On the Paternò-Büchi reaction of chiral phenylglyoxylate esters with furan derivatives.

The reaction of (S)-1-methylpropylbenzoylformate with furan gave (1'S)-1'-methylpropyl (1S,5R,6R)-6alpha-phenyl-2,7-dioxabicyclo[3.2.0]hept-3-en-6beta-carboxylate with de = 15%. The reaction of (S)-2-methylbutyl benzoylformate with furan gave (2'S)-2-methylbutyl (1SR,5RS,6RS)-6alpha-phenyl-2,7-dioxabicyclo[3.2.0]hept-3-en-6beta-carboxylate as a mixture of stereoisomers. (1R,2S,5R)-5-Methyl-2-(1-methylphenylethyl)cyclohexyl benzoylformate gave (1R,2S,5R)-5-methyl-2-(1-methylphenylethyl)cyclohexyl (1R,5S,6S)-6alpha-phenyl-2,7-dioxabicyclo[3.2.0]hept-3-en-6beta-carboxylate with de = 95%. The stereochemical behaviour can be explained considering the energy gap between the biradical intermediates in the coupling reaction. When the reaction was performed in the presence of zeolite, the diastereoisomeric excess increased (37, 18 and 98%, respectively). The reaction of (S)-1-methylpropylbenzoylformate with 2-methylfuran gave (1'S)-1'-methylpropyl (1S,5R,6R)-1-methyl-6alpha-phenyl-2,7-dioxabicyclo[3.2.0]hept-3-en-6beta-carboxylate (yield: 12%) with de = 94%. The main product was (1'S)-1'-methylpropyl (1SR,5RS,6RS)-3-methyl-6alpha-phenyl-2,7-dioxabicyclo[3.2.0]hept-3-en-6beta-carboxylate as a mixture of diastereoisomers. The reaction of (S)-2-methylbutyl benzoylformate with 2-methylfuran gave (2'S)-2-methylbutyl (1S,5R,6R)-1-methyl-6alpha-phenyl-2,7-dioxabicyclo[3.2.0]hept-3-en-6beta-carboxylate (yield: 9%) with de = 10%. The main product was (2'S)-2-methylbutyl (1SR,5RS,6RS)-3-methyl-6alpha-phenyl-2,7-dioxabicyclo[3.2.0]hept-3-en-6beta-carboxylate as a mixture of stereoisomers. The stereochemical behaviour can be explained on the basis of the energy gap between the possible biradical intermediates. The reaction of (S)-1-methylpropylbenzoylformate and (S)-2-methylbutyl benzoylformate with 2-furylmethanol gave the corresponding adducts as a mixture of diastereoisomers. The reaction of (S)-1-methylpropylbenzoylformate and (S)-2-methylbutyl benzoylformate with 2-furylphenylmethanol gave the corresponding adducts with high diastereoselectivity. In this case, the stereochemical behaviour is determined by the presence of the hydroxy group in a molecule with a preferntial conformation.