The tuber of Humirianthera rupestris (Icacinaceae) contains the degraded diterpenoids 3β,20-epoxy-3αhydroxy-14-oxo-9β-podocarpan-19,6β-olide (humirianthenolide A), 3β,20-epoxy-3α,14α-dihydroxy-9β-podocarpan-19,6β-olide (humirianthenolide B), 3β,20; 16,14-diepoxy-3α-hydroxy-17-nor-15-oxo-9β-abiet-l3-en-l9,6β-olide (humirianthenolide C), 3β,20-epoxy-3α,14-dihydroxy-13-oxo-9β-podocarp-8(14)-en-l9,6β-olide (humirianthenolide D), 3β,20-epoxy-3α-hydroxy-14-oxo-8α,9β-podocarpan-l9,6β-olide (humirianthenolide E) and 3β,20-epoxy-3α,14β- dihydroxy-8α,9β-podocarpan-19,6β-olide (humirianthenolide F). ¹H NMR and ¹³C NMR spectroscopy were effective for the determination of the humirianthenolide structures.