Norditerpenoids from Agathis macrophylla

Three new norditerpenoids, (4S,5R,9S,10R)-methyl 19-hydroxy-15,16-dinorlabda-8(17),11E-dien-13-oxo-18-oate (1), (4R,5R,9R,10R,13S/R)-13-hydroxypodocarp-8(14)-en-19-oic acid (2/3) were isolated from Agathis macrophylla, together with 11 known diterpenoids. The structures of these compounds, 1–14, were established, mainly by spectroscopic analysis. The inactivation of protein tyrosine phosphatase 1B (PTP1B) by compounds 5–9 and 11–13 was tested and the cytotoxicity of compounds 1–14 against HL60 cell and SMMC-7721 cell were evaluated. Biological screening studies indicated that compounds 5, 7/8 and 9 were mild inactivators of PTP1B, whilst compounds 1, 4, 6, 7/8, and 10–12 exhibited moderate activity against both of the tested cell lines.

► Three new norditerpenoids were isolated from Agathis macrophylla.
► Four compounds displayed inhibitory activities against PTP1B.
► Eight compounds exhibited moderate activity against the tested cell lines.