A new L-alanine derivative, N-fumaryl-L-alanine dimethyl ester (1), and a new natural product N,N-bis[(S)-1-methoxycarbonylethyl]fumaric diamide (2), along with three known compounds sohirnone A (3), chaetoglobosin C (4), and chaetoglobosin F (5), were isolated from the mangrove endophytic fungus Penicillium chrysogenum V11. Their structures were elucidated by comprehensive spectroscopic analyses. Primary bioassays showed that compounds 3, 4, and 5 had moderate or weak in vitro antifungal activities on Fusarium oxysporum and/or Rhizoctonia solani.