title: An unusual conformation of gabapentin (Gpn) in Pyr-Gpn-NH-NH-Pyr stabilized by weak interactions.
abstract: The crystal structure of N-[(1-{2-oxo-2-[2-(pyrazin-2-ylcarbonyl)hydrazin-1-yl]ethyl}cyclohexyl)methyl]pyrazine-2-carboxamide monohydrate (Pyr-Gpn-NN-NH-Pyr·H2O), C19H23N7O3·H2O, reveals an unusual trans-gauche (tg(-)) conformation for the gabapentin (Gpn) residue around the C(γ)-C(β) (θ1) and C(β)-C(α) (θ2) bonds. The molecular conformation is stabilized by intramolecular N-H...N hydrogen bonds and weak C-H...O interactions. The packing of the molecules in the crystal lattice shows a network of strong N-H...O and O-H...O hydrogen bonds together with weak C-H...O and π-π inteactions.
authors.affiliation: Medicinal Chemistry Division, Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi 180 001, India.
authors.forename: Naiem Ahmad
authors.initials: NA
authors.lastname: Wani
authors.affiliation: X-ray Crystallography Laboratory, Post-Graduate Department of Physics & Electronics, University of Jammu, Jammu Tawi 180 006, India.
authors.forename: Vivek Kumar
authors.initials: VK
authors.lastname: Gupta
authors.affiliation: X-ray Crystallography Laboratory, Post-Graduate Department of Physics & Electronics, University of Jammu, Jammu Tawi 180 006, India.
authors.forename: Rajni
authors.initials: R
authors.lastname: Kant
authors.affiliation: Medicinal Chemistry Division, Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi 180 001, India.
authors.forename: Subrayashastry
authors.initials: S
authors.lastname: Aravinda
authors.affiliation: Medicinal Chemistry Division, Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi 180 001, India.
authors.forename: Rajkishor
authors.initials: R
authors.lastname: Rai
mesh_terms: D000588:Amines / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003509:Cyclohexanecarboxylic Acids / Q000737:chemistry*; D000077206:Gabapentin; D006834:Hydrazines / Q000737:chemistry*; D006860:Hydrogen Bonding; D008968:Molecular Conformation; D015394:Molecular Structure; D011719:Pyrazines / Q000737:chemistry*; D013237:Stereoisomerism; D005680:gamma-Aminobutyric Acid / Q000737:chemistry*
chemical_list: D000588:Amines; D003509:Cyclohexanecarboxylic Acids; D006834:Hydrazines; C000592708:N-((1-(2-oxo-2-(2-(pyrazin-2-ylcarbonyl)hydrazin-1-yl)ethyl)cyclohexyl)methyl)pyrazine-2-carboxamide monohydrate; D011719:Pyrazines; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin
keywords: conformation; crystal structure; gabapentin; hydrogen bonding; medicinal compounds; weak interaction; ω-amino acid