Polymorphism of ceramide 6: a vibrational spectroscopic and X-ray powder diffraction investigation of the diastereomers of N-(α-hydroxyoctadecanoyl)-phytosphingosine
摘要:
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 La 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. (C) 2004 Elsevier Ireland Ltd. All rights reserved.
Polymorphism of ceramide 6: a vibrational spectroscopic and X-ray powder diffraction investigation of the diastereomers of N-(α-hydroxyoctadecanoyl)-phytosphingosine
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 La 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. (C) 2004 Elsevier Ireland Ltd. All rights reserved.