Antifungal Activity of Alkaloids from the Seeds of Chimonanthus praecox

Two alkaloids, D-Calycanthine (1) and L-folicanthine (2), were isolated from the active MeOH extract of the seeds of Chimonanthus praecox LINK. The structures of the two compounds were established by H-1- and C-13-NMR, and MS (FAB, ESI) analyses. In the in vitro tests, compounds 1 and 2 showed significant inhibitory activities against five plant pathogenic fungi Exserohilum turcicum, Bipolaris maydis, Alternaria solani, Sclerotinia sderotiorum, and Fusarium oxysportium, among which B. maydis was found to be the most susceptible to 1 with an EC50 value of 29.3 mu g/ml, followed by S. sderotiorum to 2 with an EC50, value of 61.2 mu g/ml. To our knowledge, this is the first report of isolation and LC/MS/MS identification as well as of antifungal properties of these alkaloids from the seeds of this plant.