Structural Feature and Molecular Interaction of Basic Amino Acid-Picric Acid Complexes by X-Ray Crystal Analyses.

l-Methioninium picrate

“…The main motifs of hydrogen bonding present in the title compound (i.e. hydrogen bonds formed by carboxylic group…phenolic oxygen and amino-group…nitro group oxygen) are also present in other well-known amino acid picrates, excluding L-argininium picrate [13] and L-ornithinium [13,21]. In the former, the carboxylic group is deprotonated and the arginine side chain is bound to the phenolic oxygen of picric acid, whereas in the latter, the carboxylic H-atom of the picrate molecule as switched to the nitro-group.…”

“…Previously, picrates of L-valine [11], L-asparagine [12] and L-arginine, [13] as well as picrates of L-proline [14][15][16][17][18], L-threonine [19,20], Lornithine [13,21] and L-histidine [22][23][24] were discovered. The authors of [10] obtained the previously known L-valinium picrate and a new crystal, L-isoleucinium picrate.…”

Imidazole-4-acetic Acid–Picric Acid (1/1) Complex

“…Picrates have therefore been used frequently in the identification or quantitative analysis of organic compounds through complex formation and their structural features have also been evaluated at the atomic level. As part of a series examining the interaction features of biomolecule--PA complexes, we have already analyzed the crystal structures of the picrates of tryptophan metabolites and basic amino acids (Ishida, Nagata, In, Doi, Inoue, Extine & Wakahara, 1993;Nagata, In, Tomoo, Doi, Ishida & Wakahara, 1995) as typical aromatic and polar nonaromatic biomolecules, respectively. This paper presents the X-ray crystal structure of the 1:1 imidazole-4-acetic acid (ImAA)-PA complex.…”

Molecular and crystal structure of Nα-(9-fluorenyl)-methoxycarbonyl-L-ornithine hydrochloride diethyl ether solvate

“…The search for ornithine and its derivatives [7] indicated the crystal structural data for six salts only: L-Orn 9 HC1 [8,9], DL-Orn 9 HBr [10], L-Orn 9 HNO3 [11], L-Orn dipicrate [12], L-Orn 9 D-Asp 9 H20 [13] and L-Orn 9 L-Asp 9 0.5H20 [14]. So far, no crystal structures for N-or C-protected omithine derivatives have been analysed.…”