Tag Archives: chirality

Chiral secondary structure in β-peptides determined by NMR

“Secondary Structure of Short β-Peptides as the Chiral Expression of Monomeric Building Units: a Rational and Predictive Model”Esther Gorrea, Gabor Pohl, Pau Nolis, Sergio Celis, Kepa K Burusco, Vicenç Branchadell, András Perczel, and Rosa M. Ortuño. Journal Of Organic Chemistry. ACCEPTED 2012 DOI: 10.1021/jo302034b

Chirality of the monomeric residues controls and determines the prevalent folding of small oligopeptides (from di- to tetramers) composed of the 2-aminocyclobutane-1-carboxylic acid (ACBA) derivatives with the same or different absolute and relative configuration. The cis-form of the monomeric ACBA gives rise to two conformers, namely Z6 and Z8, while the trans-form manifests uniquely as an H8 structure.  Continue reading Chiral secondary structure in β-peptides determined by NMR

Doctoral thesis on new Chiral Solvating Agents based on molecular tweezers

Last July I defended the doctoral thesis entitledNous agents de solvatació quiral tipus pinça amb anells antracènics: derivats de trifluorometilamines i trifluorometilcarbinols binòlics”.

The thesis focuses on the synthesis and behaviour of new Chiral Solvating Agents (CSA) based on molecular tweezers. The newly synthesized enantiopure compounds can be classified in two big groups:

  • the ones with a trifluoromethylanthrylamine backbone and an isopthalyc acid  as a linking molecule, and
  • the trifluoromethylcarbinol derivatives linked by a BINOL molecule, which adds an additional stereogenic element due to its chiral axis.

Continue reading Doctoral thesis on new Chiral Solvating Agents based on molecular tweezers

CHIRAL METABONOMICS: Giving Metabonomics a Chiral Dimension

“Chiral Metabonomics: 1H NMR-Based Enantiospecific Differentiation of Metabolites in Human Urine via Direct Cosolvation with β-Cyclodextrin” Míriam Pérez-Trujillo, John C. Lindon, Teodor Parella, Hector C. Keun, Jeremy K. Nicholson and Toby J. Athersuch. Analytical Chemistry, February 2012 DOI:10.1021/ac203291d

Differences in molecular chirality remain an important issue in drug metabolism and pharmacokinetics for the pharmaceutical industry and regulatory authorities and chirality is an important feature of many endogenous metabolites. We present a 1H NMR-based method for the rapid, direct differentiation and identification of chiral drug enantiomers in human urine without pre-treatment of any kind. Continue reading CHIRAL METABONOMICS: Giving Metabonomics a Chiral Dimension

Structural study of γ,γ-peptides

“Synthesis and structural study of highly constrained hybrid cyclobutane-proline γ,γ-peptides” by R. Gutiérrez-Abad, D. Carbajo, P. Nolis, C. Acosta-Silva, J. A. Cobos, O. Illa, M. Royo and R. Ortuño. Aminoacids, Volume 41, pages 673-686, 2011. DOI: 10.1007/s00726-011-0912-4.

Two diastereomeric series of hybrid γ,γ-peptides derived from conveniently protected derivatives of (1R,2S)- and (1S,2R)-3-amino-2,2-dimethylcyclobutane-1-carboxylic acid and cis-4-amino-l-proline joined in alternation have efficiently been prepared through convergent synthesis. Continue reading Structural study of γ,γ-peptides

Trans-cyclobutane β-dipeptides form organogels

“Self-Assembly of trans-Cyclobutane-Containing β-Dipeptides into Ordered Aggregates”,by E. Gorrea, P. Nolis, E. Torres, E. Da Silva, D. Amabilino, V. Branchadell and R. Ortuño; Chemistry – A European Journal, Volume 17, Issue 16, pages 4588–4597, April 11, 2011. DOI: 10.1002/chem.201002193

Two chiral synthetic β-dipeptides have been constructed, one with two trans-cyclobutane residues and the other with one trans and one cis fragment, 1 and 2, respectively, and investigated to get insight into the non-covalent interactions responsible for their self-assembly to form ordered aggregates, as well into parameters such as their morphology and size. Continue reading Trans-cyclobutane β-dipeptides form organogels