A Strong Antifungal Activity of 7-O-Succinyl Macrolactin A vs Macrolactin A from Bacillus amyloliquefaciens ELI149.

Chemical analysis of the crude extract of bacterial strain Bacillus amyloliquefaciens ELI149, which had been previously isolated from soil, resulted in the isolation and characterization of two known macrolactin derivatives, macrolactin A (1) and 7-O-succinyl macrolactin A (2). The structures of two compounds were assigned by 1D/2D NMR techniques. The two compounds were demonstrated antifungal activity against some important phytopathogens. However, the presence of the succinyl moiety at C-7 gives to the molecule more activity being the second compound more active than the first, showing for the first time, a structure/activity relationship. The cellular damage was also studied in two important phytopathogen fungi.