No abstract

No abstract

A nondestructive fluorescence-based technique for evaluating Vitis vinifera L. grape maturity using a portable sensor (Multiplex) is presented. It provides indices of anthocyanins and chlorophyll in Cabernet Sauvignon, Merlot, and Sangiovese red grapes and of flavonols and chlorophyll in Vermentino white grapes. The good exponential relationship between the anthocyanin index and the actual anthocyanin content determined by wet chemistry was used to estimate grape anthocyanins from in field sensor data during ripening. Marked differences were found in the kinetics and the amount of anthocyanins between cultivars and between seasons. A sensor-driven mapping of the anthocyanin content in the grapes, expressed as g·kg(-1) fresh weight, was performed on a 7-ha vineyard planted with Sangiovese. In the Vermentino, the flavonol index was favorably correlated to the actual content of berry skin flavonols determined by means of HPLC analysis of skin extracts. It was used to make a nondestructive estimate of the evolution in the flavonol concentration in grape berry samplings. The chlorophyll index was inversely correlated in a linear manner to the total soluble solids (°Brix): it could, therefore, be used as a new index of technological maturity. The fluorescence sensor (Multiplex) possesses a high potential for representing an important innovative tool for controlling grape maturity in precision viticulture.

A meso-p-nitroaniline-calix[4]pyrrole derivative trans-coordinated to a Pt(II) center was synthesized and its structure solved by X-ray analysis. Adenosine monophosphate (AMP) was used as a model compound to evaluate the potential for the assisted delivery of the metal to the DNA nucleobases via the phosphate anion-binding properties of the calix[4]pyrrole unit. An NMR investigation of the kinetics of AMP complexation in the absence of an H-bonding competing solvent (dry CD(3)CN) was consistent with this hypothesis, but we could not detect the interaction of the calix[4]pyrrole with phosphate in the presence of water. However, in vitro tests of the new trans-calixpyrrole-Pt(II) complex on different cancer cell lines indicate a cytotoxic activity that is unquestionably derived from the coexistence of both the trans-Pt(II) fragment and the calix[4]pyrrole unit.

The ytterbium complex [Yb((S)-THP)](3+) ((S)-THP = (1S,4S,7S,10S-tetrakis(2-hydroxypropyl)-1,4,7,10-tetraazacyclododecane) is investigated in solution through NMR, near-IR absorption, and CD spectroscopy. Quantitative analysis of the paramagnetic pseudocontact NMR shift shows Lambda helicity of the ligand cage around the metal. The NIR CD spectrum recorded at acidic pH is found to be very similar to that of [Yb((R)-DOTMA)](-) ((R)-DOTMA = (1R,4R,7R,10R)-alpha,alpha',alpha'',alpha'''-tetramethyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), which in solution assumes a twisted square antiprism (TSA) conformation. The similarity of the NIR CD spectra is discussed, and it is the first proof of the Lambda(lambda,lambda,lambda,lambda) conformation of [Yb((S)-THP)](3+). NIR CD spectra recorded in the pH range of 2-9 allow one to easily follow proton dissociation and to calculate the pK of this equilibrium in water (pK(A) = 6.4 +/- 0.1). This value agrees well with that determined for [Lu((S)-THP)](3+) using potentiometric methods. This demonstrates once again that NIR CD spectroscopy is a powerful technique for investigating the solution structure and dynamics of these complexes.

No abstract

The study of the monoterpene profile allowed us to highlight similarities and differences among the four aromatic varieties and to present a hypothesis about their biosynthetic dynamics. This information is useful for further studies on gene functional characterisation and the regulation of these important berry pathways. © 2016 Society of Chemical Industry.

This is the first report on qualitative changes in VOCs induced by light environment and/or water status. This information is valuable to better understand the role of environmental factors on the sensory quality of virgin olive oil.