Diverse ent-kaurane diterpenoids from Isodon henryi

Phytochemical investigation of Isodon henryi led to the isolation of two new diterpenoids, isohenolides AB (1-2), one new natural diterpenoid (3) and thirteen known ones (4-16). These diterpenoids showed various ent-kaurane skeletons, in which isohenolide A (1) was a rare 6,8 cyclo ent-kaurane containing an unprecedented 11,15-lactone group, and possessed a 6/5/6/6/6/6 ring system. Their structures were confirmed by comprehensive UV, IR, HRESIMS, NMR analyses and ECD calculations. Most compounds were also screened for anti-inflammatory actions on LPS-induced RAW 264.7 cells, and compounds 8 and 16 exhibited stronger NO inhibition. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

Phytochemical investigation of Isodon henryi led to the discovery of two new diterpenoids, isohenolides AB (1-2), one new natural diterpenoid (3), and thirteen known ones (4-16). These compounds exhibited diverse structures and showed anti-inflammatory activities.