Congrats to David, on his successful PhD defense
05/28/2021External link: https://twitter.com/ciqususc/status/1398252322191458306
Please find below all relevant news regarding our Group.
Click on a headline in order to read the full article.
External link: https://twitter.com/ciqususc/status/1398252322191458306
External link: https://www.usc.es/ciqus/es/noticias/las-tesis-del-ciqus-soraya-learte
Abstract: Transcription factors (TFs) have a remarkable role in the homeostasis of the organisms and there is a growing interest in how they recognize and interact with specific DNA sequences. TFs recognize DNA using a variety of structural motifs. Among those, the ribbon-helix-helix (RHH) proteins, exemplified by the MetJ and ARC repressors, form dimers that insert antiparallel β-sheets into the major groove of DNA. A great chemical challenge consists of using the principles of DNA recognition by TFs to design minimized peptides that maintain the DNA affinity and specificity characteristics of the natural counterparts. In this context, a peptide mimic of an antiparallel β-sheet is very attractive since it can be obtained by a single peptide chain folding in a β-hairpin structure and can be as short as 14 amino acids or less. Herein, we designed eight linear and two cyclic dodeca-peptides endowed with β-hairpins. Their DNA binding properties have been investigated using fluorescence spectroscopy together with the conformational analysis through circular dichroism and solution NMR. We found that one of our peptides, peptide 6, is able to bind DNA, albeit without sequence selectivity. Notably, it shows a topological selectivity for the major groove of the DNA which is the interaction site of ARC and many other DNA-binding proteins. Moreover, we found that a type I’ β-hairpin folding pattern is a favorite peptide structure for interaction with the B-DNA major groove. Peptide 6 is a valuable lead compound for the development of novel analogs with sequence selectivity.
External link: https://www.sciencedirect.com/science/article/abs/pii/S0045206821002133
We are very happy to share here that our research article at J. Am. Chem. Soc., entitled "Kinetic Resolution of Allyltriflamides through a Pd-Catalyzed C–H Functionalization with Allenes: Asymmetric Assembly of Tetrahydropyridines" and authored by J. M. González, B. Cendón, J. L. Mascarenas and M. Gulías, has been accepted and it's already available through the journal website.
Abstract: Enantioenriched, six-membered azacycles are essential structural motifs in many products of pharmaceutical or agrochemical interest. Here we report a simple and practical method for enantioselective assembly of tetrahydropyridines, which is paired to a kinetic resolution of α-branched allyltriflamides. The reaction consists of a formal (4+2) cycloaddition between the allylamine derivatives and allenes and is initiated by a palladium(II)-catalyzed C–H activation process. Both the chiral allylamide precursors and the tetrahydropyridine adducts were successfully obtained in high yields, with excellent enantioselectivity (up to 99% ee) and selectivity values of up to 127.
External link: https://pubs.acs.org/doi/10.1021/jacs.1c01929
Abstract: Low‐valent cobalt complexes equipped with chiral ligands can efficiently promote highly enantioselective (3+2) cycloadditions of alkyne‐tethered alkylidenecyclopropanes. The annulation allows to assemble bicyclic systems containing five‐membered rings in good yields and with excellent enantiomeric ratios. We also present a mechanistic discussion based on experimental and computational data, which support the involvement of Co(I)/Co(III) catalytic cycles
External link: https://onlinelibrary.wiley.com/doi/10.1002/anie.202015202
External link: https://onlinelibrary.wiley.com/toc/15213773/2020/59/40
External link: https://twitter.com/MetBioCat/status/1305921149973327872
Abstract: Transition metal-catalyzed hydrocarbonations of unsaturated substrates have emerged as powerful synthetic tools for increasing molecular complexity in an atom-economical manner. Although this field was traditionally dominated by low valent rhodium and ruthenium catalysts, in recent years, there have been many reports based on the use of iridium complexes. In many cases, these reactions have a different course from those of their rhodium homologs, and even allow performing otherwise inviable transformations. In this review we aim to provide an informative journey, from the early pioneering examples in the field, most of them based on other metals than iridium, to the most recent transformations catalyzed by designed Ir(I) complexes. The review is organized by the type of C–H bond that is activated (with C sp2, sp or sp3), as well as by the C–C unsaturated partner that is used as a hydrocarbonation partner (alkyne, allene or alkene). Importantly, we discuss the mechanistic foundations of the methods highlighting the differences from those previously proposed for processes catalyzed by related metals, particularly those of the same group (Co and Rh).
External link: https://pubs.rsc.org/en/content/articlelanding/2020/CS/D0CS00359J#!divAbstract
Abstract: Here, we report the application of surface-enhanced Raman scattering (SERS) spectroscopy as a rapid and practical tool for assessing the formation of coordinative adducts between nucleic acid guanines and ruthenium polypyridyl reagents. The technology provides a practical approach for the wash-free and quick identification of nucleic acid structures exhibiting sterically accessible guanines. This is demonstrated for the detection of a quadruplex-forming sequence present in the promoter region of the c-myc oncogene, which exhibits a non-paired, reactive guanine at a flanking position of the G-quartets.
External link: https://pubs.acs.org/doi/abs/10.1021/acs.jpclett.0c02148
In this manuscript, we present a nickel(II)‐mediated self‐assembly of a multimeric DNA binder composed of two metal‐chelating peptides derived from a bZIP transcription factor and one short AT‐hook domain equipped with two bipyridine ligands.
External link: https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202001277