New diterpenoids and phenolic amides from Icacina mannii Oliv

Fourteen undescribed compounds including five neoclerodanes (1–5), three labdanes (12–14), three pimarane (15–17) derivatives, one carbamate (24) and two clovamide-type amides (25 and 26), along with twenty-two known compounds (6–11, 18–23 and 27–36) were isolated from the tuber and stem of Icacina mannii. Their structures were elucidated by 1D and 2D NMR and HR-ESI-MS data analysis, and by comparing their NMR data with those of the literature. [Display omitted] •Thirty-six compounds were isolated from Icacina mannii Oliv.•Eleven diterpenoids including five neoclerodanes, three labdanes, three pimarane are newly described.•Two phenolic amides and a rare carbamate are newly described.•This is the first report of labdane and neo-clerodane diterpenes and lignans in the genus Icacina.