The Synthesis and Antimicrobial Activity of Heterocyclic Derivatives of Totarol.

The synthesis and antimicrobial activity heterocyclic analogs of the diterpenoid totarol are described. An advanced synthetic intermediate with a ketone on the A-ring is used to attach fused heterocycles and a carbon-to-nitrogen atom replacement is made on the B-ring by de novo synthesis. A-ring analogs with an indole attached exhibit, for the first time, enhanced antimicrobial activity relative to the parent natural product. Preliminary experiments demonstrate that the indole analogs do not target the bacterial cell division protein FtsZ as had been hypothesized for totarol.