Laeviganoids A-T, ent -Clerodane-Type Diterpenoids from Croton laevigatus .

Laeviganoids A-T ( 1 - 20 ), 20 new ent -clerodane-type diterpenoids featuring a 2-furanone ( 1 - 3 ) or a furan ( 4 - 20 ) ring, as well as six analogues ( 21 - 26 ), were isolated from the roots of Croton laevigatus . Their structures were determined by spectroscopic data analysis, experimental electronic circular dichroism measurements, and X-ray crystallographic studies. Compounds 4 - 6 , 16 , 21 - 24 , and 26 could influence the anti-inflammatory protumoral phenotype of macrophages. Among these compounds, 21 and 26 are the most potent, as evidenced by consistently downregulating the classic anti-inflammatory cytokine IL-10 and upregulating the classic pro-inflammatory cytokine TNF-α on the secretion level in RAW 264.7 cells.