Isolation and synthesis of chivotriene, a chivosazole shunt product from Sorangium cellulosum

A shunt product of chivosazole biosynthesis was isolated from the fermentation broth of Sorangium cellulosum, strain So ce 12. Its structure was elucidated by NMR spectroscopy and exhibits six chiral centers, a triene, and a labile β-hydroxy ketone. The synthesis of chivotriene confirms the structure and in particular the proposed configuration at C22, which was originally deduced for chivosazole from the combination of its genetic and spectroscopic analyses. Remarkably, chivotriene exhibits biological activity usually not observed for segments of complex natural products. However, this activity is not connected to interference with the actin cytoskeleton, the intrinsic target of the chivosazoles.