Property (R) for Bounded Linear Operators

We introduce the spectral property (R), for bounded linear operators defined on a Banach space, which is related to Weyl type theorems. This property is also studied in the framework of polaroid, or left polaroid, operators.     

On the rank of certain matrices

This note is an appendix to the paper “Osculating spaces and diophantine equations (with an Appendix by Pietro Corvaja and Umberto Zannier)” by M. Bolognesi and G. Pirola.     

The relationship between the electrospray ionization behaviour and biological activity of some phosphino Cu(I) complexes

Electrospray ionization mass spectrometry was usefully employed for the characterization of three phosphino copper(I) complexes of medicinal interest. This technique revealed that the original [CuL₄]⁺ pro‐drugs (L = hydrophilic tertiary phosphine) underwent dissociation with production of coordinative unsaturated [CuL₃]⁺ and [CuL₂]⁺ species, which represented key intermediates for the activation of potential biological properties. The more favoured was the displacement of the ligands from the [CuL₄]⁺ parent complex, the more favoured was in turn the possibility for the metal ion to directly interact with biological substrates, including pharmacological targets related to cancer proliferation. An inverse correlation between the stability and the cytotoxic activity of the three copper(I) complexes investigated has been clearly established. Copyright © 2010 John Wiley & Sons, Ltd.     

Structure determination of chamaedryosides A—C,three novel nor‐neo‐clerodane glucosides from Teucrium chamaedrys,by NMR spectroscopy

Three new nor‐neo‐clerodane diterpenes, named chamaedryoside A (1), B (2) and C (3), have been isolated from the organic extracts of Teucrium chamaedrys (L.) and their structural characterization has been accomplished by ¹H and ¹³C‐NMR spectra, and DEPT, by COSY, TOCSY, HSQC, HSQC‐TOSCY and HMBC experiments, as well as by ESI‐MS/MS techniques. The stereostructures have been elucidated by NOESY and computational calculations. Copyright © 2009 John Wiley & Sons, Ltd.     

Ipso nitration. Nitrodeformylation reactions in nitrothiophenealdehydes

Nitration of 4-nitro-2-thiophenealdehyde afforded 2,4-dinitrothiophene and small quantities of 4,5-dinitro-2-thiophenealdehyde; 5-nitro-2-thiophenealdehyde gave instead 3,5-dinitro-2-thiophenealdehyde as the main product and some 2,5-dinitrothiophene. The two dinitrothiophenes form through a nitrodeformylation reaction which represents an interesting example of the nitration at an ipso position in a strongly deactivated substrate.     

Oxidative decarboxylation of cyclohexane monocarboxylic acid III. Initiated oxidation

A mechanism is suggested for the oxidative decarboxylation of cyclohexane monocarboxylic acid initiated by decomposition of H₂O₂. The process is a non-branching chain reaction. Cyclohexanone and cyclohexanol form in termination reactions.