Asperorydines A-M: Prenylated Tryptophan-Derived Alkaloids with Neurotrophic Effects from Aspergillus oryzae.

As part of our program to discover new bioactive agents from fungi, 13 new alkaloids accompanying 13 known related alkaloids were isolated from a wild strain of Aspergillus oryzae L1020. Compounds 1 and 2 have unprecedented 6/6/5/7/5 and 6/6/6/5/5 chemical skeletons, representing new members of quinoline alkaloids. Compound 3 is a new macrolactam with an unusual 6/5/6/8 ring system. Compounds 4-13 are new α-cyclopiazonic acid-related alkaloids. The absolute configurations of 1-4, 8, and 9 were assigned by electronic circular dichroism calculations. Compounds 2, 5, 6, 11, 14, 22, and 26 exhibit pronounced neurite outgrowth-promoting effects on PC12 cells in the range of 25-100 μM.