Steffimycin F, a new steffimycin-type derivative from the lichen-derived actinomycetes steptomyces sp.

•New steffimycin-type derivative, steffimycin F(1) was isolated from actinomycetes steptomyces sp. 0630c.•The absolute configuration of steffimycin f (1) was determined by calculated electronic circular dichroism (ECD).•A new (1) and two known steffimycin-type compounds (2 − 3) showed cytotoxic activities.