Effective analysis of rotundone at below-threshold levels in red and white wines using solid-phase microextraction gas chromatography/tandem mass spectrometry.

Rotundone is an oxygenated sesquiterpene belonging to the family of guaianes, giving the 'peppery' aroma to white and black pepper and to red wines. Here we describe a novel, convenient protocol for the synthesis of rotundone, starting from a commercially available compound and requiring only two reaction steps, and an improved, faster method of GC separation (30 min) with selective quantisation of rotundone using tandem mass spectrometry in multiple reaction monitoring (MRM) mode with d(5)-rotundone as internal standard. With limits of detection (LODs) of 1.5 ng/L in white wine and 2.0 ng/L in red wine, intraday repeatability CV values of 6% and 5% at 50 ng/L and 500 ng/L and interday repeatability CV values of 13% and 6% at 50 ng/L and 500 ng/L, respectively, the improved protocol provides the desired sensitivity and selectivity for routine analysis of rotundone in both white and red wines. Initial application of this method highlighted the presence of unexpectedly high concentrations of rotundone, thus explaining the origin of the distinctive peppery aroma in Schioppettino and Vespolina red wines and in Gruener Veltliner white wines.

A simple and industrially scalable method for making a PANI-modified cellulose touch sensor.

In this work we present a simple, inexpensive, and easily scalable industrial paper process to prepare sheets of conductive cellulose fibers coated with polyanilines. First, bare fibers were coated by in situ oxidative polymerization of polyaniline then, the resulting composite fibers were used to fabricate electroactive sheets. The resistivity of the sheets is 14 ± 1 Ω sq-1, a value around 1000 times lower than those reported in literature. The superior electronic proprieties of the sheets were demonstrated by assembling a capacitive touch sensor device with optimized geometry. The touch sensor shows an increase of 3-4 % of the starting electric capacity after compression and a fast response time of 52 ms. To our knowledge this is the first time that a device is prepared in this way and therefore, the herein presented results can bring an significant improvement in the development of low-cost, green and high-tech electronic devices.

Concurrent radiotherapy does not affect adjuvant CMF delivery but is associated with increased toxicity in women with early breast cancer.

We evaluated whether concurrent radiotherapy (RT) affected delivery and toxicity of adjuvant intravenous CMF (cyclophosphamide, methotrexate and 5-fluorouracil) in women with operable breast cancer. The medical charts of 321 consecutive breast cancer patients who received CMF either alone for 6 cycles, or for 4 cycles following of an anthracycline (A-CMF) were reviewed. One hundred forty-four women underwent radiotherapy concurrently with CMF. Optimal CMF delivery (success as opposite to failure) was defined as the combined achievement of an average relative dose intensity (aRDI) > or = 85% and an average percent of the total dose (aPTD) > or = 90% for the three drugs in the CMF regimen. Multivariate logistic regression analysis showed that concurrent-RT did not affect CMF delivery (OR for success 1.391 p=0.230). The sequential A-CMF regimen (OR for success 0.208, 95% C.I. 0.120-0.360, p<0.001) and age > or = 56 (OR for success 0.351, 95% C.I. 0.200-0.161, p<0.001) were independently associated with suboptimal CMF delivery. Moreover, concurrent RT was independently associated with increased leukopenia, thrombocytopenia, upper abdominal pain, mucositis and fatigue. Our retrospective analysis suggests that concurrent-RT has no impact on optimal CMF delivery, but it increases the burden of CMF-related toxicity.

Radical addition to isonitriles: a route to polyfunctionalized alkenes through a novel three-component radical cascade reaction

The reaction of aromatic disulfides, alkynes, and isonitriles under photolytic conditions affords polyfunctionalized alkenes--beta-arylthio-substituted acrylamides or acrylonitriles--in fair yields through a novel three-component radical cascade reaction. The procedure entails addition of a sulfanyl radical to the alkyne followed by attack of the resulting vinyl radical to the isonitrile. A fast reaction, e.g., scavenging by a nitro derivative or beta-fragmentation, is necessary in order to trap the final imidoyl radical, since addition of vinyl radicals to isonitriles seems to be a reversible process. The stereochemistry of the reaction is discussed, particularly with respect to the stereochemical outcome of related hydrogen abstraction reactions by the same vinyl radicals. The lower or even inverted preference for either geometrical isomer observed in our cases with respect to that encountered in hydrogen abstraction reactions is explained in terms of transition-state interactions and/or isomerization of the final imidoyl radical. The latter possibility is supported by semiempirical calculations, which show that the spin distribution in the imidoyl radical can allow rotation of the adjacent carbon-carbon double bond prior to beta-fragmentation.

Hemorrhagic nerve sheath tumors (plexiform neurofibromas) of the scalp: CT findings.

Three cases of hemorrhagic nerve sheath tumors of the scalp are presented with emphasis on CT findings. Each mass produced a mixed pattern of CT density due to the combination of tumor and hemorrhage within it. The CT findings were remarkably similar in the three patients and included a calvarial abnormality underlying the mass in each.

Cascade radical reaction of 2-alkynyl-substituted aryl radicals with aryl isothiocyanates: a novel entry to benzothieno[2,3-b]quinolines through alpha-(Arylsulfanyl)imidoyl radicals.

The novel cascade radical reaction of 2-(phenylalkynyl)aryl radicals with 4-Y-phenyl isothiocyanates (Y = H, OMe, Me, Cl, CN) provides a useful one-pot protocol for the production of 8-Y-substituted (12) and/or 9-Y-substituted benzothieno[2,3-b]quinolines (11). The whole process entails primary formation of an alpha-(2-alkynylarylsulfanyl)imidoyl radical that undergoes smooth 5-exo-dig cyclization onto the alkynyl triple bond. The derived 1-phenylvinyl radical then exhibits six-membered cyclization onto the isothiocyanate ring, to give 11, and/or five-membered ipso-cyclization to an azaspiro intermediate, whose eventual rearrangement affords 12. The overall findings clearly showed that the relative proportion of the outcoming isomeric benzothienoquinolines 11 and 12 can be markedly affected by the nature of the original isothiocyanate substituent. Moreover, the findings also furnished the first chemical evidence that enhancing the electrophilic power of the employed radical can properly enhance the reactivity of aryl radicals toward isothiocyanates.

Diastereoselectivity in Mn(III)-promoted 4-exo-trig cyclization of enamides to beta-lactams

[reaction: see text] The effect of chiral substituents on the enamide nitrogen atom upon the diastereoselection of the Mn(III)-mediated 4-exo-trig cyclization to beta-lactams was studied. A significant level of diastereoselectivity was achieved when an amino acid ester moiety was included into the enamidic skeleton. The structure of the major diastereoisomer was suggested by semiempirical calculations.

Short intramolecular S...O interactions in S-substituted 2-mercaptoacetophenones.

The non-bonded S...O intramolecular interactions in the title compounds 2-(phenylthio)acetophenone [IUPAC: 2-[2-(phenylsulfanyl)phenyl]ethanone], C(14)H(12)OS, and 2-(benzylthio)acetophenone [IUPAC: 2-[2-(benzylsulfanyl)phenyl]ethanone], C(15)H(14)OS, are unusually short, indicating the contribution of heterocyclic oxathiole-type resonance structures to the overall bonding.