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Understanding on a molecular level the acid-catalysed decomposition of the sugar monomers from hemicellulose and cellulose (e.g. glucose, xylose), the main constituent of lignocellulosic biomass is very important to increase selectivity and reaction yields in solution, key steps for the development of a sustainable renewable industry. In this work we reported a gas-phase study performed by electrospray triple quadrupole mass spectrometry on the dehydration mechanism of d-glucose. In the gas phase, reactant ions corresponding to protonated d-glucose were obtained in the ESI source and were allowed to undergo collisionally activated decomposition (CAD) into the quadrupole collision cell. The CAD mass spectrum of protonated d-glucose is characterized by the presence of ionic dehydrated daughter ion (ionic intermediates and products), which were structurally characterized by their fragmentation patterns. In the gas phase d-glucose dehydration does not lead to the formation of protonated 5-hydroxymethyl-2-furaldehyde, but to a mixed population of m/z 127 isomeric ions. To elucidate the d-glucose dehydration mechanism, 3-O-methyl-d-glucose was also submitted to the mass spectrometric study; the results suggest that the C3 hydroxyl group plays a key role in the reaction mechanism. Furthermore, protonated levulinic acid was found to be formed from the monodehydrated d-glucose ionic intermediate, an alternative pathway other than the known route consisting of 5-hydroxymethyl-2-furaldehyde double hydration.

2-Furaldehyde (2-FA), also known as furfural or 2-furancarboxaldehyde, is an heterocyclic aldehyde that can be obtained from the thermal dehydration of pentose monosaccharides. This molecule can be considered as an important sustainable intermediate for the preparation of a great variety of chemicals, pharmaceuticals and furan-based polymers. Despite the great importance of this molecule, its gas-phase basicity (GB) has never been measured. In this work, the GB of 2-FA was determined by the extended Cooks's kinetic method from electrospray ionization triple quadrupole tandem mass spectrometric experiments along with theoretical calculations. As expected, computational results identify the aldehydic oxygen atom of 2-FA as the preferred protonation site. The geometries of O-O-cis and O-O-trans 2-FA and of their six different protomers were calculated at the B3LYP/aug-TZV(d,p) level of theory; proton affinity (PA) values were also calculated at the G3(MP2, CCSD(T)) level of theory. The experimental PA was estimated to be 847.9 ± 3.8 kJ mol-1, the protonation entropy 115.1 ± 5.03 J mol-1 K-1 and the GB 813.6 ± 4.08 kJ mol-1 at 298 K. From the PA value, a ΔH°f of 533.0 ± 12.4 kJ mol-1 for protonated 2-FA was derived. Copyright © 2012 John Wiley & Sons, Ltd.

Mass spectrometric fragmentation data of neo-clerodane diterpenes are almost inexistent but they can prove helpful for the qualitative and quantitative analysis of these compounds as well as for the identification of unknown compounds belonging to this class of plant secondary metabolites. [M-H]-ions of nine neo-clerodane diterpenes (1-9), recently isolated from Teucrium chamaedrys, were generated by electrospray ionization and were fragmented in the collision cell of a Triple Quadrupole (TQ) and of a Quadrupole Ion Trap (QIT) mass spectrometer. The deprotonated neo-clerodane glucosides, chamaedryoside A and B (1, 2), readily lost the sugar residue to give, as their main fragmentation channel, the neo-clerodane ions, I and II, which were structurally characterized by TQ and QIT MS. The collision-activated dissociation (CAD) mass spectra of I and II and of deprotonated neo-clerodanes 3-9 allowed us to reach some general conclusions on the fragmentation pathways of this class of compounds. For example, teuflin and its OH derivatives, teucrin A, teuflidin and 6-β-hydroxyteucridin, showed a characteristic fragmentation pattern involving the loss of 94 Da and 124 Da from the lactone moiety, whereas a loss of 44 Da was observed for teucrin E, and of 58 Da for teucrin F and G. In addition, several compound-specific fragmentations were observed and can be proposed for the identification of individual compounds. The systematic approach allowed us to hypothesize the mechanisms of the most important collision-activated dissociation/isomerization channels. © 2010 John Wiley & Sons, Ltd.

The management of advanced stage ovarian carcinomas is presently based on initial surgical debulking, multiple drug chemotherapy including cisplatinum, second-look laparotomy. Such an aggressive approach has improved objective response rates and expected survival time, but no dramatic change has been demonstrated as for definitive cure percentages. Many Authors have attempted to turn an optimal objective response to chemotherapy (no residual or minimal residual disease at second-look) into a definitive cure with irradiation. Some reports show satisfactory results, but a high incidence of bowel obstructive complications has been demonstrated, probably due to multiple surgical manipulations before radiotherapy. A reliable diagnostic tool, that could help to avoid the second-look laparotomy (whose inherent role in improving survival is not assessed) should be therefore useful. The possible role of serum tumor markers determinations, for this purpose, is here discussed on the ground of a series of 20 patients affected by stage III ovarian carcinoma. Following this experience, a valuable role seems attributable to CA 125 in monitoring tumor response. Patients achieving values under 35 U/ml before second-look laparotomy showed tumor residuals in the range O-microscopic- < 1cm., that is, neoplastic localizations reliable for consolidation radiation therapy.

The present work illustrates a new method: soft landed protein voltammetry (SLPV); this experimental procedure is based on the coupling of ion soft landing with a voltammetric technique and allows the electrode surface to be functionalized with biologically active molecules, thus opening up numerous new perspectives ranging from molecular electronics to protein chips.

We report an intimal sarcoma presenting as an aortic aneurysm. A 68-year-old man suffered from chest pain and speech disturbance. Computed tomography showed a sacciform aneurysm of the aorta, which was resected, revealing a polypoid tumour measuring 1.5x2x2.5 cm projecting into the lumen. This proved to be a poorly differentiated high-grade sarcoma having morphological, immunophenotypic and ultrastructural features consistent with rhabdomyosarcomatous differentiation. Primary sarcomas of the aorta are extremely rare. Many cases have been diagnosed as "intimal" on the basis of their site of origin, and they are not easy to classify from their histological pattern. Electron microscopy and the use of a more comprehensive panel of immunohistochemical markers should be applied in the histological classification of"intimal" sarcoma.

To assess the role of CT brain scans as a routine restaging procedure after primary, aggressive, drug or radiation therapy of unresectable lung cancer. If early, asymptomatic brain metastases are detected and treated, survival could be improved relative to the patients showing brain involvement in a later CT scan performed during the follow-up, at the onset of neurological symptoms.One hundred patients affected with lung cancer, unresectable on account of histology (small-cell carcinoma) or advanced stage (III, IV) were submitted to chemo- and/or radiotherapy, after a clinical staging including brain CT, which was negative in all patients. Brain CT was also repeated at the end of therapy (restaging), in the absence of any neurological symptom. Further scans were obtained during the subsequent follow-up only when clinical symptoms occurred, suggesting metastases to the brain. Survival values were analyzed in the patients whose brain involvement was detected during restaging, vs those showing symptomatic brain metastases during the follow-up.Only 4 patients had asymptomatic metastases, diagnosed with the restaging brain CT scan. Their survival rate was significantly lower than that of the 20 patients whose brain involvement was shown by a follow-up CT scan, performed after the onset of neurological symptoms. However, death was rarely a consequence of brain metastases: primary or other metastatic sites were involved in the terminal events, in the greatest majority of these cases.The sudden, asymptomatic brain involvement, detected at restaging CT scan after primary therapy for unresectable lung cancer, does not correlate with a better prognosis than symptomatic metastases, diagnosed later with a follow-up CT obtained performed for clinical suspicion. Therefore the use of restaging CT scan is not warranted, as a routine procedure, except for the clinical trials intended to define optimal treatment schedules.