Abstract
X-ray diffraction was used to obtain information on the orientation and location of vitamin E in phospholipid model membranes. It was found that addition of α-tocopherol and to α lesser extent α-tocopheryl acetate to dielaidoylphosphatidylethanolamine (DEPE) stabilizes the hexagonal II (HII) phase at the expense of the lamellar liquid-crystalline phase and reduces the lattice constant of the HII phase. This result can be interpreted as suggesting that the vitamin E molecules are located with their long axes parallel to the hydrocarbon chains of DEPE in the HII phase.
