Platensimycin and platencin are novel natural product antibiotics that inhibit bacterial growth by inhibiting fatty acid biosynthesis enzymes FabF and FabF/FabH, respectively. Continued search for the natural congeners for structure activity relationship studies led to the isolation of a congener which possesses all of the twenty carbons of diterpenoid unit, a potential biosynthetic intermediate of platensic acid unit of platensimycin. Isolation, structure, and activity of homoplatensimide A and biosynthetic relationship to platensimycin have been described.