Neurotrophin is recognized as an important regulatory substance in nervous system. However, it cannot cross brain-blood barrier because of the properties of its high molucular weight. To address this issue, considerable efforts have been made to find small molecules that mimic neurotrophic properties. As past of our continuing studies on neurotrophic-like active compounds in Illicium species, we investigated the chemical constituents of the pericarps of I. jiadifengpi, resulting in the isolation of two seco-prezizaane-type sesquiterpenoids 1 and 2 named jiadifenolide and 3,10-epoxymajucin. In this symposium, we present the structure elucidation and neurotrophic activit of new compounds. The structures of 1 and 2 were elucidated by analysis of spectroscopic data and comparison of their NMR data with those of majucin (4). It is surprised that the Dess-Martin oxidation of known sesquiterpene, neomajucin (3), gave rise to 1 in a straightforward fashin. This means that the absolute configuration of 1 can be assigned as the same of 3. To the best of our knowledge, jiadifenolide is the first example of a unique seco-prizizaane-type sesquiterpenoid with a γ-lactone formed between C-11 keto and C-4 hydroxyl groups. Compounds 1 and 2 significantly enhance neurite outgrowth in the primary cell cultures of fetal rat cortical neurons at 0.01μmolL^<-1> and 10μmolL^<-1>, respectively. It is worthy of note that compound 1 has a potential to significantly promote differentiation of multipotent neural stem cell line MEB5 cells into neurons at 1μmolL^<-1> and 0.1μmolL^<-1>.
