Biotransformation of clerodane diterpenoids by Rhizopus stolonifer and antibacterial activity of resulting metabolites

► Transformation of clerodane 1 and 2, by Rhizopus stolonifer, yielded metabolites 3-8. ► Metabolites 4, 7 and 8 were found to be new compound. ► Metabolite 8 showed a good activity against Gram-negative and positive bacteria.