Covering: 1996 to 2010 Cancer is one of the major causes of death worldwide. As a consequence, many different therapeutic approaches, including the use of glycosides as anticancer agents, have been developed. Various glycosylated natural products exhibit high activity against a variety of microbes and human tumors. In this review we classify glycosides according to the nature of their aglycone (non-saccharidic) part. Among them, we describe anthracyclines, aureolic acids, enediyne antibiotics, macrolide and glycopeptides presenting different strengths and mechanisms of action against human cancers. In some cases, the glycosidic residue is crucial for their activity, such as in anthracycline, aureolic acid and enediyne antibiotics; in other cases, Nature has exploited glycosylation to improve solubility or pharmacokinetic properties, as in the glycopeptides. In this review we focus our attention on natural glycoconjugates with anticancer properties. The structure of several of the carbohydrate moieties found in these conjugates and their role are described. The structure–activity relationship of some of these compounds, together with the structural features of their interaction with the biological targets, are also reported. Taken together, all this information is useful for the design of new potential anti-tumor drugs.
This feature article describes chemoselective techniques for the assembly of neoglycopeptides and oligosaccharide mimics. Chemoselective ligation, allowing the use of aqueous environments and non-protected substrates, provides rapid access to complex glycoconjugates. The role of these molecules in recognition, signal transduction pathways and other events of fundamental biomedical significance is an object of study in the emerging field of chemical glycomics.
10 November 2010 in Organic & Biomolecular Chemistry
The antibiotic tetracycline was reported to possess an anti-amyloidogenic activity on a variety of amyloidogenic proteins both in in vitro and in vivo models. To unveil the mechanism of action of tetracycline on Aβ1–40 and Aβ1–42 at both molecular and supramolecular levels, we carried out a series of experiments using NMR spectroscopy, FTIR spectroscopy, dynamic laser light-scattering (DLS) and atomic force microscopy (AFM). Firstly we showed that the co-incubation of Aβ1–42 oligomers with tetracycline hinders the toxicity towards N2a cell lines in a dose-dependent manner. Therefore, the nature of the interaction between the drug and Aβ oligomers was investigated. To carry out NMR and FTIR studies we have prepared Aβ peptide solutions containing assemblies ranging from monomers to large oligomers. Saturation transfer difference (STD) NMR experiments have shown that tetracycline did not interact with monomers at variance with oligomers. Noteworthy, in this latter case we observed that this interaction was very peculiar since the transfer of magnetization from Aβ oligomers to tetracycline involved all drug protons. In addition, intermolecular cross-peaks between tetracycline and Aβ were not observed in NOESY spectra, indicating the absence of a specific binding site and suggesting the occurrence of a supramolecular interaction. DLS and AFM studies supported this hypothesis since the co-dissolution of Aβ peptides and tetracycline triggered the immediate formation of new aggregates that improved the solubility of Aβ peptides, preventing in this way the progression of the amyloid cascade. Moreover, competitive NMR binding experiments showed for the first time that tetracycline competes with thioflavin T (ThT) in the binding to Aβ peptides. Our data shed light on a novel mechanism of anti-amyloidogenic activity displayed by tetracycline, governed by hydrophobic and charge multiparticle interactions.
The use of modified carbohydrates, such as sugar amino acids (SAA), iminosugars and policyclic derivatives, as scaffolds for the generation of bioactive compounds, and the use of carbohydrates as building blocks or ligands for the production of polymers for biomedical applications, is reviewed.
25 September 2020 in European Journal of Organic Chemistry