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Triazatruxene derivatives find many applications as lipophilic compounds, but few examples of hydrosoluble derivatives have been reported so far. In this paper, we compare different synthetic routes for the preparation of hydrophilic triazatruxene derivatives and define the most versatile pathway. The synthesized compounds are fluorescent not only in organic solvents, as reported for other lipophilic derivatives, but also in water, making them particularly suitable for biological applications.

GQuadruplexes represent a group of unusual DNA secondary structures, based on Hoogsteen G–G paired hydrophobic planar rings consisting of four guanine units. Many studies have shown that Gquadruplex structures appear to be involved in several important biological processes, such as DNA replication, gene expression and recombination, as well as cell transformation. For these reasons, in the last few years Gquadruplexes have become the main research interest of many eminent scientists in different fields: from molecular to cellular biologists, from physicians to chemists. In this respect, organic chemists can play fundamental roles in many different areas. First of all, research into specific Gquadruplex ligands as potential drugs, in particular as telomerase inhibitors and thus potential anticancer drugs, has attracted strong attention. The rational design of and the various synthetic approaches toward these kinds of ligands represent two specific fields of interest for organic chemists. The molecules capable of stabilizing Gquadruplexes covered in this review are each characterized by an aromatic core that favours stacking interactions with the Gtetrads and, in most cases, by basic side chains that interact with DNA grooves. First generations and new classes of synthetic Gquadruplex ligands, as well as natural compounds, are presented. Moreover, because the specificities of the interactions between the studied ligands and different DNA structures both duplex and quadruplex are without doubt a main concern, determining the different biological effects of these compounds, several chemists are involved in developing approaches to explore this important subject. The last part of this review is devoted to a brief introduction of new fields of application of Gquadruplex structures with open synthetic challenges: quadruplexforming modified oligonucleotides and nanostructures based on the Gquadruplex.© WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009

In this paper, we report an extensive electrospray ionization mass spectrometry ESIMS study of the noncovalent interactions between different intermolecular and intramolecular Gquadruplex structures and several perylene and coronene ligands. The selectivity of these compounds toward quadruplex structures with respect to duplex DNA, a fundamental topic for the biological evaluation and the pharmacological application of these ligands as potential chemotherapeutic agents, has also been investigated. After exploring this topic according to the classical approach based on the very simple duplex model of an autocomplementary dodecamer, we extended our analysis reporting for the first time a competition ESIMS experiment in the presence of genomic DNA fragments. Whereas those ligands showing a high level of selectivity between quadruplex and duplex oligonucleotides, in terms of binding constants and percentage of bound DNA, confirmed their selectivity in the competition experiment, the contrary was not always true: some ligands showing poor selectivity with the autocomplementary dodecamer resulted selective in the presence of genomic DNA fragments. This result suggests that physiologically nonrelevant interactions are possible with a short duplex oligonucleotide. This means that the dodecamer can fail in representing a biologically significant structural model, or, better, that it can be used to quickly screen potentially selective molecules, but bearing in mind the high probability of false negative results. Copyright © 2008 John Wiley & Sons, Ltd.

A new synthetic approach to 3-aryl isoquinolines, based on the Pd-catalyzed Suzuki cross-coupling reaction, is reported. The described procedure represents an efficient method to prepare 3-aryl isoquinolines by reaction of a preformed 3-chloro isoquinoline with a phenylboronic acid, especially when the nitrogen atom is positively charged.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The cover picture showsthe monomeric Gquadruplex structure of the 22mer human telomeric DNA sequence AGGGTTAGGG3derived by Xray crystallography in Neidle?s group G. N. Parkinson, M. P. Lee, S. Neidle, Nature2002, 417, 876 in a potassium ion solution PDB code 1KF1. The molecular graphic was produced by using the UCSF Chimera package from the Resource for Biocomputing, Visualization, and Informatics at the University of California, San Francisco supported by NIH P41 RR01081. The DNA backbone is in cyan, covered by a semitransparent meshed surface; K+ions are represented by violet spheres, and a yellow ribbon follows the strand topology. The four arrows indicate the related main areas of interest for organic chemists: design and synthesis of Gquadruplex ligands, study of ligand interactions with quadruplex and duplex DNA, quadruplexforming modified oligonucleotides and nanostructures based on the Gquadruplex. In the background, the structures of some wellknown Gquadruplex ligands, based on perylene, coronene, berberine, porphyrin and acridine moieties, are shown in yellow, as well as the natural compound telomestatin. Details are presented in the Microreview by M. Franceschin on p. 2225 ff.

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