title: Stereochemical study of tolperisone, a muscle relaxant agent, by circular dichroism and ultraviolet spectroscopy.
abstract: The stereochemistry of tolperisone, a chiral aryl-alkyl basic ketone was investigated by means of circular dichroism (CD) and ultraviolet (UV) spectroscopy. The unusually high optical activity of tolperisone hydrochloride in the n-->pi* region is interpreted by the presence of a chiral conformer in solution. For stereochemical reasons, the C = O group and the aromatic moiety lack coplanarity by forming an inherently dissymetric chromophore, of M helicity. Similar helicity prevails in the crystal phase, according to the solid-state CD spectrum of (-)-tolperisone HCl salt. The chirality rule proposed by Snatzke for nonplanar benzoyl chromophores predicts the absolute configuration of (-)-tolperisone hydrochloride to be R, in agreement with other alpha-methyl-beta-amino-ketones.
authors.affiliation: Department of Molecular Pharmacology, Institute of Chemistry, Budapest, Hungary. ZSFERI@CRIC.CHEMRES.HU
authors.forename: F
authors.initials: F
authors.lastname: Zsila
authors.forename: M
authors.initials: M
authors.lastname: Hollósi
authors.forename: A
authors.initials: A
authors.lastname: Gergely
mesh_terms: D002942:Circular Dichroism; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D009125:Muscle Relaxants, Central / Q000737:chemistry* / Q000302:isolation & purification; D011427:Propiophenones / Q000737:chemistry; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D014049:Tolperisone / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D009125:Muscle Relaxants, Central; D011427:Propiophenones; D012997:Solvents; C030848:eperisone; D014049:Tolperisone