Abstract
1. When submitted to some thermal and photochemical treatments, luteochrome, C40H56O2, suffers partial trans-cis isomerization and rearrangement into aurochrome. By means of chromatography a quantitative study of the resulting complex mixture was possible. 2. All-trans luteochrome was more stable to thermal and photochemical treatments than all-trans-β-carotene mono- and di-epoxides. However, considerable amount of stereoisomerization occurred when subjected to some treatments such as illumination in the presence of iodine or melting of crystals. 3. Luteochrome yielded four kinds of cis forms whose spectral characteristics were studied and their tentative configurational assignments were made. Some of these isomers were adsorbed on a chromatographic column, above or below the corresponding all-trans form. None of the cis forms crystallized.
