101 research outputs found
Polycyclic aromatic compounds able to induce and stabilize G-quadruplex DNA structures as new telomerase inhibitors: synthesis, physicochemical properties and biochemical studies
New developments in the synthesis of emicoron
This paper reports on the modification of two synthetic steps in the usual protocol used for obtaining EMICORON. EMICORON is a benzo[ghi]perylen-diimide, which was synthesized for the first time in our laboratory in 2012, and has shown to have in vivo antitumor activities that interferes with the tumor growth and development using a multi-target mechanism of action. The provided modifications, which involved the reaction times, the reaction conditions, and the work-up procedures, allowed the global yield of the process to be increased from 28% to about 40%. Thus, this new procedure may be more suitable for recovering higher amounts of EMICORON to be used in further preclinical studies
Natural aromatic compounds as scaffolds to develop selective G-quadruplex ligands. From previously reported berberine derivatives to new palmatine analogues
In this paper, the selective interactions of synthetic derivatives of two natural compounds, berberine and palmatine,with DNA G-quadruplex structureswere reported. In particular, the previous works on this subject concerning berberine were further presented and discussed, whereas the results concerning palmatine are presented here for the first time. In detail, these palmatine derivatives were developed by inserting seven different small peptide basic chains, giving several new compounds that have never been reported before. The preliminary studies of the interactions of these compounds with various G-quadruplex-forming sequences were carried out by means of various structural and biochemical techniques, which showed that the presence of suitable side chains is very useful for improving the interaction of the ligands with G-quadruplex structures. Thus, these new palmatine derivatives might act as potential anticancer drugs
Pedicularis L. Genus. Systematics, botany, phytochemistry, chemotaxonomy, ethnopharmacology, and other
In this review, the relevance of the plant species belonging to the Pedicularis L. genus has been considered from different points of view. Particular emphasis was given to phytochemistry and ethnopharmacology, since several classes of natural compounds have been reported within this genus and many of its species are well known to be employed in the traditional medicines of many Asian countries. Some important conclusions on the chemotaxonomic and chemosystematic aspects of the genus have also been provided for the first time. Actually, this work represents the first total comprehensive review on this genus
Nor-lignans. Occurrence in plants and biological activities. A review
In this review article, the occurrence of nor-lignans and their biological activities are explored and described. Nor-lignans have proven to be present in several different families also belonging to chemosystematically distant orders as well as to have many different beneficial pharmacological activities. This review article represents the first one on this argument and is thought to give a first overview on these compounds with the hope that their study may continue and increase, after this
Phytochemical analysis and biological activities of the ethanolic extract of Daphne sericea Vahl flowering aerial parts collected in Central Italy
In this paper, the first phytochemical analysis of the ethanolic extract of Daphne sericea Vahl flowering aerial parts collected in Italy and its biological activities were reported. Eleven compounds were identified i.e., -linolenic acid (1), tri-linoleoyl-sn-glycerol (2), pheophorbide a ethyl ester (3), pilloin (4), sinensetin (5), yuanhuanin (6), rutamontine (7), syringin (8), p-coumaric acid (9), p-anisic acid (10) and caffeic acid (11). To the best of our knowledge, compounds (1-4, 7-8 and 10) were isolated from D. sericea for the first time during this work, whereas sinensetin (5) represents a newly identified component of the entire Thymelaeaceae family. The extract was found to possess radical scavenging against both DPPH and 2,20-azino-bis(3-thylbenzothiazoline-6-sulfonic acid (ABTS.+) radicals, with at least a 40-fold higher potency against the latter. Moreover, chelating abilities against both ferrous and ferric ions have been highlighted, thus suggesting a possible indirect antioxidant power of the extract. Although the precise bioactive compounds remain to be discovered, the polyphenolic constituents, including phenolic acids, tannins and flavonoids, seem to contribute to the antioxidant power of the phytocomplex. In addition, the extract produced cytotoxic effects in MDA-MB-231 and U87-MG cancer cell lines, especially at the concentration of 625 g/mL and after 48–72 h. Further studies are required to clarify the contribution of the identified compounds in the bioactivities of the extract and to support possible future applications
G-quadruplex ligands: synthesis and biological relevance. An overview and recent updates.
G-quadruplex interactive telomerase inhibitors: an exciting field to be explored, with some open challenges on the biological evaluation
G-quadruplex ligands: A selective approach to telomeres length regulation, both directly and through telomerase inhibition
G-quadruplex represents a group of unusual DNA secondary structures, based on Hoogsteen G-G pairing hydrophobic planar rings of four guanines. Many studies have reported that G-quadruplex structures appear to be involved in many important biological processes, such as DNA replication, gene expression and recombination, as well as cell transformation. The G-quadruplex has been shown to be specifically important in the structure of G-rich single-strand DNA at the end of telomeres. The presence of these structures in vivo has been demonstrated in a number of biological systems, ranging form ciliates to humans. For these reasons, in the last few years, the research of specific G-quadruplex ligands as potential drugs has gained major attention, in particular as telomeres targeting agents and telomerase inhibitors and thus potential anticancer drugs. Many eminent scientists have been working in this exciting field, as demonstrated by the success of the First International Meeting on Quadruplex DNA, held in Louisville (KY, USA) in April 2007§. The specificity of the interactions between the studied ligands and different DNA structures (both duplex and quadruplex) is surely a main topic in this area, since it determines the different biological effects of these compounds. Several approaches have been used to explore this subject, and they will be briefly summarized in this chapter. Nevertheless, particular attention should be paid when comparing biological data from different labs on telomerase inhibition by these compounds. In fact, these data, which are very important from a pharmaceutical and medicinal chemistry point of view, are affected by many factors, such as the type of cells used to extract telomerase, the presence of proteins other than telomerase in the cell extract, the amount of cell extract and DNA substrates used, as well as other features that have not been fully standardized yet. © 2011 by Nova Science Publishers, Inc. All rights reserved
- …