X-ray diffraction study of polycrystalline dipalmitoylcephalin and dipalmitoyllecithin monohydrate. 1

Using VAND's indexing method the powder diagrams of 1,2-dipalmitoyl-DL-phosphatidyl-choline (lecithin) monohydrate were indexed in the measured angle range of 0.200 <= theta <= 24.000. Cephalin crystallizes monoclinically with a = 0.986 nm, b = 0.779 nm, c = 5.462 nm, β = 92.60; lecithin triclinically with a = 0.996 nm, b = 0.859 nm, c = 5.371 nm, α = 900, β = 93.30, γ = 91.40. The results are confronted with literature data of synthetic cephalins and lecithins with a chain length of C12, C14 and C16. (author)