Heterologous Expression of the Biosynthetic Gene Cluster for Verticilactam and Identification of Analogues.

Verticilactam and the new geometric isomers, verticilactams B and C, were produced by heterologous expression of the biosynthetic gene cluster for verticilactam using the SUKA17 strain. Only verticilactam, a compound with a characteristic β-ketoamide unit within a 16-membered polyketide macrolactam conjugated with an octalin skeleton, had been previously reported having been isolated from JC-8444. In this report, minor verticilactam derivatives were isolated from the transformed strain, and their structures elucidated by spectral analysis.