title: Polymorphism of ceramide 6: a vibrational spectroscopic and X-ray powder diffraction investigation of the diastereomers of N-(alpha-hydroxyoctadecanoyl)-phytosphingosine.
abstract: A preparative chromatographic method was developed for the quantitative isolation of the diastereomers of synthetic N-(alpha-hydroxyoctadecanoyl)-phytosphingosine (DL-CER6). The L- and the D-compound were studied each by means X-ray powder diffraction, FT-Raman and FT-IR spectroscopy. The diastereomers exhibit different thermotropic polymorphism. Three lamellar crystalline and a lamellar liquid crystalline phase were found for L-CER6. The natural occurring D-CER6 forms an Lalpha phase with a larger repeating distance than the L-CER6. The two lamellar crystalline phases of the D-compound have a significant larger dimension than those of the L-compound. The addition of water lowers the phase transition temperatures but does not induce structural changes such as incorporation into the lamellar sheets.
authors.affiliation: Department of Pharmacy, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, D-06120 Halle/Saale, Germany.
authors.forename: Steve
authors.initials: S
authors.lastname: Raudenkolb
authors.forename: Siegfried
authors.initials: S
authors.lastname: Wartewig
authors.forename: R H H
authors.initials: RH
authors.lastname: Neubert
mesh_terms: D002151:Calorimetry; D002518:Ceramides / Q000737:chemistry*; D002855:Chromatography, Thin Layer; D015394:Molecular Structure; D033362:Powder Diffraction; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000737:chemistry; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014732:Vibration; D014961:X-Ray Diffraction
chemical_list: D002518:Ceramides; C504327:N-(alpha-hydroxyoctadecanoyl)phytosphingosine; C012491:phytosphingosine; D013110:Sphingosine