Phenanthrene derivatives from Appendicula reflexa as new CDK1/cyclin B inhibitors

► The epiphytic orchid Appendicula reflexa yielded six phenanthrene derivatives. ► Of these, one monomeric and one dimeric phenanthrenes were new. ► Two monomeric phenanthrenes showed potent inhibiting activity on CDK1/cyclin B. ► This is the first report on the chemical study of a species of the genus Appendicula.