Study of Croatian non-aromatic naphthalane constituents with skeletons analogous to bioactive compounds.

Non-aromatic Croatian naphthalane (NAN), shown to be efficace in the treatment of psoriasis vulgaris, was studied in order to improve our understanding of its constituents, which may be potentially responsible for its bioactivity. The components steranes and hopanes were analysed. Since NAN is a complex mixture of hydrocarbons, high-resolution GC and GC-MS were applied as the methods of choice in the study. The GC chromatogram of NAN showed a remarkable cluster in which sterane peaks prevail and composed 33+/- 1% of the sample. Identified steranes (by GC-MS) represented almost half of the cluster (48%). They were in the range from norcholestanes up to propyl cholestanes. The amount of alpha-steranes (8.9%) was higher than of beta-steranes (6.4%) and regular steranes (15.3%) dominated in the ratio 17:1 over the rearranged ones (0.9%). Steranes conserved the skeleton of bio-precursors and remained analogues of bioactive compounds, such as of vitamins D and some hormones and corticosteroids. Pentacyclic hydrocarbons hopanes, as derivatives of bacteriohopantetraol which is the physiological equivalent of cholesterol, made 4.7+/-0.2% of NAN.