Histone deacetylase inhibitor induced the production of three novel prenylated tryptophan analogs in the entomopathogenic fungus, Torrubiella luteorostrata

Suberoyl bis-hydroxamic acid (SBHA), a histone deacetylase (HDAC) inhibitor, led to significant changes in the secondary metabolism of an entomopathogenic fungus, Torrubiella luteorostrata, and induced the production of three new prenylated tryptophan analogs, luteorides A–C (1–3). The structures are characterized by the presence of an (E)-oxime group, which is an unusual functional group in natural products, and a 3-methylbuta-1,3-dienyl unit as a common substituent. The method of culturing entomopathogenic fungi in the presence of HDAC inhibitors, such as SBHA, is convenient and attractive for obtaining novel secondary metabolites.