Claudia Gargiulli

Flavonoid Composition of Citrus Juices

In the early nineties the presence of flavonoids in Citrus juices began to attract the attention of a number of researchers, as a result of their biological and physiological importance. This short review will explore two different aspects. The first part will focus on analytical techniques for the characterization of juices from different Citrus fruits regarding their flavonoid content (even if present in only trace amounts), concentrating on the most widely used methods (LC-MS and LC-MS-MS). The second part analyzes data reported in the literature regarding the composition of Citrus juices. The main components that have been detected so far are flavanone-O-glycosides and flavone-O- or -C-glycosides. The presence of such derivatives in various hand-squeezed and industrial juices is discussed, with special emphasis on their correlation to different species.

Calix[5]arene-based heteroditopic receptor for 2-phenylethylamine hydrochloride.

Novel (1,2-3,5)-calix[5]arene-bis-crown-3 and (1,3)-calix[5]arene-crown-3 derivatives, bearing one or three ureido moieties at the lower rim, respectively, have been synthesized and investigated as heteroditopic receptors for inorganic and organic salts. Tris-ureido-calix[5]arene-crown-3 10, in particular, efficiently binds 2-phenylethylamine hydrochloride (PEA.HCl) as a spatially separated ion pair.

Recognition and binding of paraquat dichloride by cyclodextrin/calix[6]pyrrole binary host systems

The synergic effect of paired anion and cation receptors in the recognition of organic salts is demonstrated by the combined action of acylated cyclodextrins and calix[6]pyrrole in the solubilisation and complexation of paraquat dichloride in organic solvents, and its extraction from water solution into dichloromethane.

A DFT study on a calix[5]crown-based heteroditopic receptor

The structures and binding energies of complexes formed between tris-ureido-calix[5]crown 1 and n- and 2-phenylethylammonium chloride have been determined by density functional calculations. Density functional theory analysis shows that the heteroditopic receptor 1 binds organic salt species with positive cooperativity.

31-Benz-yloxy-5,11,17,23,29-penta-tert-butyl-calix[5]arene-32,33,34,35-tetra-ol.

The title compound, C62H76O5, known to be one of the most versatile synthetic precursors/intermediates of calix[5]arene derivatives, adopts an approximate C s-symmetric cone-in conformation. The aryloxybenzyl ring is tilted in such a way that the p-tert-butyl group fills the macrocycle cavity, while the benzyl group moves away from the cavity axis. In the crystal, this conformational arrangement is secured by intra- and intermolecular O—H⋯O hydrogen bonds forming inversion dimers. Four tert-butyl groups are disordered over two orientations, with occupancy ratios of 0.745 (6):0.255 (6), 0.837 (5):0.163 (5), 0.850 (5):0.150 (5) and 0.845 (8):0.155 (8).