Three diprenylated indole alkaloids, mangrovamides A-C (1-3), featured a bicyclo [2.2.2] diazaoctane core and possessed a novel gamma-methyl proline and isoprene derived dimethyl gamma-pyrone functionalities hitherto unknown among the family of paraherquamides, were isolated from the fungus Penicillium sp., which was separated from a mangrove soil sample. The structures were elucidated based on NMR, X-ray, and CD methods. The possible biosynthetic pathway of these compounds is proposed. (C) 2014 Elsevier Ltd. All rights reserved.