Alessandro Altieri

Aromatic Core Extension in the Series of N‐Cyclic Bay‐Substituted Perylene G‐Quadruplex Ligands: Increased Telomere Damage, Antitumor Activity, and Strong Selectivity for Neoplastic over Healthy Cells

Based on previous work on both perylene and coronene derivatives as G‐quadruplex binders, a novel chimeric compound was designed: N,N′‐bis[2‐(1‐piperidino)‐ethyl]‐1‐(1‐piperidinyl)‐6‐[2‐(1‐piperidino)‐ethyl]‐benzo[ghi]perylene‐3,4:9,10‐tetracarboxylic diimide (EMICORON), having one piperidinyl group bound to the perylene bay area (positions 1, 12 and 6, 7 of the aromatic core), sufficient to guarantee good selectivity, and an extended aromatic core able to increase the stacking interactions with the terminal tetrad of the G‐quadruplex. The obtained “chimera” molecule, EMICORON, rapidly triggers extensive DNA damage of telomeres, associated with the delocalization of telomeric protein protection of telomeres 1 (POT1), and efficiently limits the growth of both telomerase‐positive and ‐negative tumor cells. Notably, the biological effects of EMICORON are more potent than those of the previously described perylene derivative (PPL3C), and more interestingly, EMICORON appears to be detrimental to transformed and tumor cells, while normal fibroblasts expressing telomerase remain unaffected. These results identify a new promising G‐quadruplex ligand, structurally and biologically similar on one side to coronene and on the other side to a bay‐monosubstituted perylene, that warrants further studies.

Xanthene and Xanthone Derivatives as G-Quadruplex Stabilizing Ligands

Following previous studies on anthraquinone and acridine-based G-quadruplex ligands, here we present a study of similar aromatic cores, with the specific aim of increasing G-quadruplex binding and selectivity with respect to duplex DNA. Synthesized compounds include two and three-side chain xanthone and xanthene derivatives, as well as a dimeric “bridged” form. ESI and FRET measurements suggest that all the studied molecules are good G-quadruplex ligands, both at telomeres and on G-quadruplex forming sequences of oncogene promoters. The dimeric compound and the three-side chain xanthone derivative have been shown to represent the best compounds emerging from the different series of ligands presented here, having also high selectivity for G-quadruplex structures with respect to duplex DNA. Molecular modeling simulations are in broad agreement with the experimental data.

Monoterpenoids glycosides content from two Mediterranean populations of Crucianella maritima L.

In this study, the iridoidic content of two accessions of Crucianella maritima L., one from Sardinia and the second from Latium, was examined and compared. From a qualitative point of view, the iridoidic pattern of the two samples was similar, since the same compounds (asperuloside, asperulosidic acid and deacetyl asperulosidic acid) were isolated. Asperuloside was the main compound in both accessions. Asperulosidic acid was the second compound in the accession from Sardinia, while the accession from Latium exhibited a similar amount of asperulosidic acid and deacetyl asperulosidic acid. These iridoids can be considered as chemotaxonomic markers for parts of the Rubiaceae family, in particular for the Rubioideae subfamily to which C. maritima belongs.

Phytochemical pattern of Gentiana species of Appennino in Central Italy

The molecular pattern of two Gentiana species, G. dinarica and G. lutea, present in a protected area of Appennino Centrale in Italy, was examined. Results were compared with literature data, examining the differences between the two species.