Fragmentation study of major spirosolane-type glycoalkaloids by collision-induced dissociation linear ion trap and infrared multiphoton dissociation Fourier transform ion cyclotron resonance mass spectrometry.

RATIONALE: Glycoalkaloids play a key role in the plant protection system against phytopathogens including fungi, viruses, bacteria, insects and worms. They can be toxic to humans if consumed in high concentrations causing gastrointestinal disturbances. METHODS: The structural characterization of the major spirosolane glycoalkaloids, solasonine, solamargine, α-tomatine and dehydrotomatine, were investigated by positive electrospray ionization (ESI) coupled with a hybrid linear ion trap (LIT) and Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Tandem mass spectrometric analysis of spirosolane glycoalkaloids was performed by both collision-induced dissociation (CID) within the LIT and infrared multiphoton dissociation (IRMPD) in conjunction with the FTICR cell. RESULTS: Several common product ions were observed, generated by losses of the sugar moiety or aglycone fragmentation in the B- or E-ring, that can provide information on the accurate mass of aglycone and the primary sequence and branching of the oligosaccharide chains. Thanks to the multistage CID it was possible to understand the fragmentation pathways and thanks to the high resolution of IRMPD-FTICR the elemental compositions of product ions were obtained. CONCLUSIONS: Because the investigated tandem mass spectra data were acquired with high mass accuracy, unambiguous interpretation and determination of the chemical compositions for the majority of detected fragment ions were feasible. From these data, generalized fragmentation pathways were proposed, providing guidance for the characterization of unknown glycoalkaloids in plants. Copyright © John Wiley & Sons, Ltd.

Secondary metabolites: applications on cultural heritage.

Biological sciences and related bio-technology play a very important role in research projects concerning protection and preservation of cultural heritage for future generations. In this work secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga) ICMP 11096 strain and crude extract of glycoalkaloids from Solanaceae plants, were tested against a panel of microorganisms isolated from calcarenite stones of two historical bridges located in Potenza and in Campomaggiore (Southern Italy). The isolated bacteria belong to Bacillus cereus and Arthrobacter agilis species, while fungi belong to Aspergillus, Penicillium, Coprinellus, Fusarium, Rhizoctonio and Stemphylium genera. Bga broth (unfiltered) and glycoalkaloids extracts were able to inhibit the growth of all bacterial isolates. Bga culture was active against fungal colonies, while Solanaceae extract exerted bio-activity against Fusarium and Rhizoctonia genera.

Morphological and molecular characterisation of fungal populations possibly involved in the biological alteration of stones in historical buildings.

The deterioration process of historical building is progressive and irreversible, and the timing and mode of impact are different depending on the characteristics of building materials used, local microclimate, air pollution, presence of specific flora and fauna. The chemical and microbiological characterisation of building materials is mandatory in preventing and eventually recovering degradation effects. Ideally, the analysis of structural stones should be complete, efficient, rapid, and non destructive when dealing with a precious or unique construction. The investigation has been performed on a private historical building made using calcarenite stones and sited between the archaeological site of Lavello, a little town located in the Basilicata Region (South Italy), and the industrial area surrounding this town. To study in progress the degradation of stone materials, a new building sample (ca. 1 m3) was constructed by using the same stones (33 x 15cm), collected from a local quarry. The intact calcarenite stone was characterised by using different methods of surface analysis (XRD, XPS, SEM), and exposed to outdoor conditions. The analyses of the stone material were repeated after three and six months to early evaluate the progression of alterations and the forward modifications of calcarenite structure. After only three months of the new building sample exposure, the adopted analytical methods were able to provide a series of data, which allowed the assessment of the incipient modification of the stone surfaces. The degradation appeared worsened performing the same observations on sixth month replicates, suggesting that environmental conditions modified the structure and the compactness of stones and favoured the biological colonization of surfaces especially in the South-East direction of prevailing winds. For this reason the presence of fungi on the stones' surface was investigated and a morphological and molecular characterization of sampled fungi was performed. Several genera and species of fungi, possibly, involved in degradation were found. The most frequent colonies belonged to Alternaria (A. infectoria, A. citri and Alternaria sp.), Coprinopsis sp., Penicillium piceum, Fusatrium equiseti and Scytalidium termophilus.

Mucilage from seeds of chia (Salvia hispanica L.) used as soil conditioner; effects on the sorption-desorption of four herbicides in three different soils.

The objective of this work was to determine the effect of the mucilage extracted from Chia seeds (Salvia hispanica L.) as soil amendment on soil physical properties and on the sorption-desorption behaviour of four herbicides (MCPA, Diuron, Clomazone and Terbuthylazine) used in cereal crops. Three soils of different texture (sandy-loam, loam and clay-loam) were selected, and mercury intrusion porosimetry and surface area analysis were used to examine changes in the microstructural characteristics caused by the reactions that occur between the mucilage and soil particles. Laboratory studies were conducted to characterise the selected herbicides with regard their sorption on tested soils added or not with the mucilage. Mucilage amendment resulted in a reduction in soil porosity, basically due to a reduction in larger pores (radius>10µm) and an important increase in finer pores (radius<10µm) and in partcles' surface. A higher herbicide sorption in the amended soils was ascertained when compared to unamended soils. The sorption percentage of herbicides in soils treated with mucilage increased in the order; sandy-loam

Use of solar advanced oxidation processes for wastewater treatment: Follow-up on degradation products, acute toxicity, genotoxicity and estrogenicity.

Wastewater tertiary treatment by advanced oxidation processes is thought to produce a treated effluent with lower toxicity than the initial influent. Here we performed tertiary treatment of a secondary effluent collected from a Waste Water Treatment Plant via homogeneous (solar/HSO5(-)/Fe(2+)) and heterogeneous (solar/TiO2) solar advanced oxidation aiming at the assessment of their effectiveness in terms of contaminants' and toxicity abatement in a plain solar reactor. A total of 53 organic contaminants were qualitatively identified by liquid chromatography coupled to high-resolution mass spectrometry after solid phase extraction. Solar advanced oxidation totally or partially removed the major part of contaminants detected within 4.5 h. Standard toxicity tests were performed using Vibrio fischeri, Daphnia magna, Pseudokirchneriella subcapitata and Brachionus calyciflorus organisms to evaluate acute and chronic toxicity in the secondary or tertiary effluents, and the EC50% was calculated. Estrogenic and genotoxic tests were carried out in an attempt to obtain an even sharper evaluation of potential hazardous effects due to micropollutants or their degradation by-products in wastewater. Genotoxic effects were not detected in effluent before or after treatment. However, we observed relevant estrogenic activity due to the high sensitivity of the HELN ERα cell line.

Photochemical degradation of acifluorfen in aqueous solution.

To elucidate the photochemical behavior of diphenyl ether herbicides in superficial waters, the photodegradation of acifluorfen, 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoïc acid (CAS Registry No. 50594-66-6), was studied in water and acetonitrile. All experiments were carried out under laboratory conditions using a solar simulator (xenon arc) or jacket Pyrex reaction cell equipped with a 125 W high-pressure mercury lamp. The calculated polychromatic quantum efficiencies (Phi(solvent)) of acifluorfen in different solvents are as follows (units are degraded molecules photon(-1)): Phi(water) = 10(-4), Phi(acetonitrile) = 10(-4), Phi(methanol) = 10(-4), and Phi(hexane) = 10(-2). The results obtained in this work are in good agreement with the literature value of monochromatic quantum yield. HPLC-MS analysis (APCI and ESI in positive and negative modes) was used to identify acifluorfen photoproducts. These results suggest that the photodegradation of acifluorfen proceeds via a number of reaction pathways: (1) decarboxylation, (2) dehalogenation, (3) substitution of chlorine group by hydroxyl or hydrogen groups, and (4) cleavage of ether linkage, giving phenols. Photorearrangement products were studied by other investigators. No such products were observed. In addition, it was found that the trifluoro functional group on acifluorfen was not affected by any transformation, and no products of a nitro group reduction were found.