Laeviganoids A–T, <i>ent</i>-Clerodane-Type Diterpenoids from <i>Croton laevigatus</i>
Cheng-Lei Wang, Yang Dai, Qiong Zhu, Peng Xia, Qun‐Fang Liu, Jing Ai, Bin Zhou, Jian‐Min Yue
Abstract
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.