14246-53-8Relevant articles and documents
NMR-based assignment of isoleucine: Vs. allo -isoleucine stereochemistry
Anderson, Zoe J.,Hobson, Christian,Needley, Rebecca,Song, Lijiang,Perryman, Michael S.,Kerby, Paul,Fox, David J.
, p. 9372 - 9378 (2017)
A simple 1H and 13C NMR spectrometric analysis is demonstrated that permits differentiation of isoleucine and allo-isoleucine residues by inspection of the chemical shift and coupling constants of the signals associated with the proton and carbon at the α-stereocentre. This is applied to the estimation of epimerisation during metal-free N-arylation and peptide coupling reactions.
A modular approach towards drug delivery vehicles using oxanorbornane-based non-ionic amphiphiles
Janni, D. Sirisha,Reddy, U. Chandrasekhar,Saroj, Soumya,Muraleedharan
supporting information, p. 8025 - 8032 (2016/12/18)
The self-assembly of non-ionic amphiphiles with a hydroxylated oxanorbornane head-group was controlled using amino acid units as spacers between hydrophilic and lipophilic domains to get spherical supramolecular aggregates. The ability of these systems to harbour therapeutic agents like ibuprofen, and their drug-release profiles were evaluated. Apart from directing the assembly, the intervening amino acid unit was found to help in drug entrapment as well. The presence of cholesterol improved their drug-loading ability, and an encapsulation efficiency of up to 66% was shown by the formulation containing the phenylalanine residue as the spacer (NC1c). There was no burst release, and 45% drug release was observed at the end of 24 h in this case (cf. soyaphosphatidylcholine based formulation = 49%). The results from SEM, Cryo-TEM, PXRD and confocal microscopic studies with some insights into molecular packing in this class of aggregates are also included.
Structure and thermotropic phase behavior of a homologous series of n -Acylglycines: Neuroactive and antinociceptive constituents of biomembranes
Reddy, S. Thirupathi,Krovi, Krishna Prasad,Swamy, Musti J.
, p. 4944 - 4954 (2014/12/10)
N-Acylglycines (NAGs) with different acyl chains have been found in the mammalian brain and other tissues. They exhibit significant biological and pharmacological properties and appear to play important roles in communication and signaling pathways within and between cells. In view of this, a homologous series of NAGs have been synthesized and characterized in the present study. Differential scanning calorimetric (DSC) studies show that the transition enthalpies and entropies of dry as well as hydrated NAGs exhibit a linear dependence on the acyl chain length. Most of the NAGs show a minor transition below the chain-melting phase transition, suggesting the presence of polymorphism in the solid state. Structures of N-myristoylglycine (NMG) and N-palmitoylglycine (NPG) were solved in monoclinic system with C2/c and P21 space groups, respectively. Analysis of the crystal structures show that NAGs are organized in a bilayer fashion, with head-to-head (and tail-to-tail) arrangement of molecules. The acyl chains in both structures are essentially perpendicular to the bilayer plane, which is consistent with a lack of odd-even alternation in the thermodynamic properties. The bilayer is stabilized by strong hydrogen bonding interactions between COOH groups of the molecules from opposite leaflets as well as N-H···O hydrogen bonds between the amide groups of adjacent molecules in the same leaflet and dispersion interactions among the acyl chains. Powder X-ray diffraction data show that the d-spacings for the NAGs with different acyl chains (n = 8-20) exhibit a linear dependence on the chain length, suggesting that all the NAGs investigated here adopt a similar packing arrangement in the crystal lattice. These observations are relevant for understanding the role of N-acylglycines in biological membranes.
