Permalink : http://hdl.handle.net/2115/52360

Raman spectroscopic analysis was applied to observe the phase transition of dielaidoylphosphatidylcholine (DEPC) liposome under 0.5 MPa Xe pressurization conditions. After the band assignments on DEPC molecule, detailed measurements of the methylene C-H stretching mode spectra were performed. The data revealed that all three peaks associated with DEPC, including the C-H stretching mode,shifted to lower wavenumbers at lower temperatures and that the relative intensities of Raman spectra changed simultaneously. These changes on Raman spectra occurred at approximately 280 K, suggesting a gel to liquid crystalline phase transition. This temperature is lower than that under atmospheric pressure, and it is consistent with DEPC liposomes exposed to Xe measured with differential scanning calorimetric under similar conditions.