Norcrohalane A, an Unusual C nor-Halimane-Type Diterpenoid from Croton crassifolius.

An unusual C nor-halimane-type diterpenoid, norcrohalane A (1), a new nor-lasserane-type sesquiterpenoid, norcrolasane A (2), along with four known compounds (3-6) were isolated from the roots of Croton crassifolius. Compound 1 represents the first example of a C nor-halimane-type diterpenoid, which features a rare 6/6/6 tricyclic ring system, and the A ring is aromatic. Compound 2 is a rare nor-lasserane-type sesquiterpenoid.

Two new clerodane diterpenoids and a new pyran-2-one derivative with anti-neuroinflammatory activities from Croton crassifolius.

Two new clerodane diterpenoids (1 and 2), a new pyran-2-one derivative (3), along with five known compounds (4‒8), were isolated from Croton crassifolius. Notably, crassifolin X (1) is a novel clerodane diterpenoid, characterized with a peculiar δ-lactone core being formed between C-1 and C-4. Their structures, including absolute configurations, were established on the basis of spectroscopic methods (UV, IR, HRESIMS and NMR), and circular dichroism experiments.

Three new sesquiterpene lactones from the whole plants of .

Three new sesquiterpene lactones, named scabertopinolides H - J (-), along with four known ones, desacylisodeoxyelephantopin 2-methylbutyrate (), iso-17,19-dihydrodeoxyelephantopin (), scabertopinolide D () and 6,7,8)-8-tigloyloxy-1(10),4(5),11(13)-germacratrien-2,15,6,12-diolide () were isolated from the whole plants of . Their structures were elucidated by extensive analysis of spectroscopic data (including IR, UV, HRESIMS, 1 D and 2 D NMR) and single-crystal X-ray. These isolated compounds showed effective anti-inflammatory effects on LPS-stimulated RAW 264.