1.Compaction properties of L-lysine salts.
Sun C1, Grant DJ. Pharm Res. 2001 Mar;18(3):281-6.
PURPOSE: To examine the effects of salt form, i.e., different anions with a common cation (L-lysinium), on compaction properties and to identify the factors that determine the tensile strength of tablets.
2.X-ray studies of crystalline complexes involving amino acids and peptides. XLIV. Invariant features of supramolecular association and chiral effects in the complexes of arginine and lysine with tartaric acid.
Selvaraj M1, Thamotharan S, Roy S, Vijayan M. Acta Crystallogr B. 2007 Jun;63(Pt 3):459-68. Epub 2007 May 16.
The tartaric acid complexes with arginine and lysine exhibit two stoichiometries depending upon the ionization state of the anion. The structures reported here are DL-argininium DL-hydrogen tartrate, bis(L-argininium) L-tartrate, bis(DL-lysinium) DL-tartrate monohydrate, L-lysinium D-hydrogen tartrate and L-lysinium L-hydrogen tartrate. During crystallization, L-lysine preferentially interacts with D-tartaric acid to form a complex when DL-tartaric acid is used in the experiment. The anions and the cations aggregate into separate alternating layers in four of the five complexes. In bis(L-argininium) L-tartrate, the amino acid layers are interconnected by individual tartrate ions which do not interact among themselves. The aggregation of argininium ions in the DL- and the L-arginine complexes is remarkably similar, which is in turn similar to those observed in other dicarboxylic acid complexes of arginine. Thus, argininium ions have a tendency to assume similar patterns of aggregation, which are largely unaffected by a change in the chemistry of partner molecules such as the introduction of hydroxyl groups or a change in chirality or stoichiometry.
3.Synthesis, growth, crystal structure and characterization of a new organic NLO crystal: L-lysine 4-nitrophenolate monohydrate (LLPNP).
Mahadevan M1, Magesh M2, Ramachandran K3, Anandan P4, Arivanandhan M5, Hayakawa Y5. Spectrochim Acta A Mol Biomol Spectrosc. 2014 Sep 15;130:416-22. doi: 10.1016/j.saa.2014.04.033. Epub 2014 Apr 18.
L-lysine 4-nitrophenolate monohydrate (LLPNP) has been synthesized and grown by solution growth method at room temperature using deionised water as a solvent. The crystal structure of the materials was solved by single crystal X-ray diffraction analysis and it was found that the material has orthorhombic system. The crystallinity of the grown crystals was studied by the powder X-ray diffraction analysis. Molecular structure of the grown crystal was investigated by 1H NMR spectroscopy. The various functional groups of the sample were identified by Fourier transform infrared and Fourier transform-Raman spectroscopic analyses. Thermal stability of the grown crystal has been studied by Thermogravimetric and Differential thermal (TG&DTA) analysis. The optical absorption of the grown crystals has been ascertained by UV-Vis-NIR absorption studies. Second harmonic generation (SHG) efficiency of the material has been determined by Kurtz and Perry technique and the efficiency was found to be 4.
4.X-ray studies on crystalline complexes involving amino acids and peptides. XLI. Commonalities in aggregation and conformation revealed by the crystal structures of the pimelic acid complexes of L-arginine and DL-lysine.
Saraswathi NT1, Roy S, Vijayan M. Acta Crystallogr B. 2003 Oct;59(Pt 5):641-6. Epub 2003 Sep 25.
The complexes of L-arginine and DL-lysine with pimelic acid are made up of singly positively charged zwitterionic amino acid cations and doubly negatively charged pimelate ions in a 2:1 ratio. In both structures, the amino acid molecules form twofold symmetric or centrosymmetric pairs that are stabilized by hydrogen bonds involving alpha-amino and alpha-carboxylate groups. In the L-arginine complex, these pairs form columns along the shortest cell dimension, stabilized by intermolecular hydrogen bonds involving alpha-amino and alpha-carboxylate groups. The columns are connected by hydrogen bonds and water bridges to give rise to an amino acid layer. Adjacent layers are then connected by pimelate ions. Unlike molecular ions aggregate into alternating distinct layers in the DL-lysine complex. In the amino acid layer, hydrogen-bonded lysinium dimers related by a glide plane are connected by hydrogen bonds involving alpha-amino and alpha-carboxylate groups into head-to-tail sequences.