Thu, 21 Aug 2008 11:12:20 BST CiteULike: zsferis Gergely http://www.citeulike.org/user/zsferi/author/Gergely CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/zsferi/article/2449710 <i>Chirality, Vol. 12, No. 10. (November 2000), pp. 720-726.</i><br /><br />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. Stereochemical study of tolperisone, a muscle relaxant agent, by circular dichroism and ultraviolet spectroscopy. F Zsila M Hollósi A Gergely doi:10.1002/1520-636X(2000)12:10<720::AID-CHIR4>3.0.CO;2-2 Chirality, Vol. 12, No. 10. (November 2000), pp. 720-726. 2008-03-01T00:43:49-00:00 2000 Chirality 0899-0042 12 10 720 726 no-tag http://www.citeulike.org/user/zsferi/article/2449706 <i>Chirality, Vol. 11, No. 10. (1999), pp. 741-744.</i><br /><br />Recognizing that the stereochemical structure of NMDA receptor antagonist ketamine provides valuable data about the relationship between its conformation and absolute configuration by CD-UV analysis, a method for the identification of ketamine enantiomers is proposed which avoids the need for authentic samples of the enantiomers. The ketamine enantiomers were separated by HPLC using Chiralcel OJ stationary phase. The in situ registration of CD and UV spectra, together with the application of the octant rule for cyclohexanone derivatives, makes possible the direct assignment of the eluted ketamine enantiomers. Determination of absolute configuration of ketamine enantiomers by HPLC-CD-UV technique. A Gergely F Zsila P Horváth G Szász doi:10.1002/(SICI)1520-636X(1999)11:10<741::AID-CHIR1>3.0.CO;2-2 Chirality, Vol. 11, No. 10. (1999), pp. 741-744. 2008-03-01T00:43:07-00:00 1999 Chirality 0899-0042 11 10 741 744 no-tag http://www.citeulike.org/user/zsferi/article/2449704 <i>Acta Pharm Hung, Vol. 69, No. 3. (June 1999), pp. 128-134.</i><br /><br />Chiroptical spectroscopy, and its double and triple hyphenated combinations with UV-VIS spectroscopy and/or separation techniques constitute great progress in pharmaceutical analysis, of which five recently developed methods are surveyed here, as follows: The determination of enantiomeric purity by double, CD/UV detection without, and with the latter one provides enhanced sensitivity and selectivity. The determination of chromatographic peak homogeneity, by double detection, and peak slicing by recording. The separation, identification and four stereoisomers of doubly chiral compounds, by HPLC separation on chiral column, and optical-chiroptical detection. [Novel chiroptical methods in pharmaceutical analysis] A Gergely H Hegedús P Horváth B Noszál G Szász F Zsila Acta Pharm Hung, Vol. 69, No. 3. (June 1999), pp. 128-134. 2008-03-01T00:42:29-00:00 1999 Acta Pharm Hung 0001-6659 69 3 128 134 no-tag