biostudies-literatureUnknown12(18)Wu ZLEleven undescribed <i>ent</i>-kaurane-type diterpenoid acids, namely noueinsiancins A-K (1-11), together with sixteen related known analogs (12-27) were isolated from <i>Nouelia insignis</i> Franch. The chemical structures and absolute configurations of the new compounds were confirmed by the extensive spectroscopic data, electronic circular dichroism (ECD) data analysis and single crystal X-ray diffraction. Additionally, the anti-inflammatory assay was applied to estimate the nitric oxide (NO) inhibitory activities of all compounds by using lipopolysaccharide (LPS)-induced RAW 264.7 cells <i>in vitro</i>. The results revealed that 4-7 and 13-17 significantly inhibited NO production at the concentrations of 2.5 μM, 5.0 μM and 10.0 μM. Meanwhile, compounds 6 and 7 were found to down-regulatRSC advances11155-11163https://www.ebi.ac.uk/biostudies/studies/S-EPMC8995843biostudies-literatureNew <i>ent</i>-kaurane diterpenoid acids from <i>Nouelia insignis</i> Franch and their anti-inflammatory activity.PMC8995843Zhang WDSun ZSLi HLWu ZLLi JYHuang PLfalseNew <i>ent</i>-kaurane diterpenoid acids from <i>Nouelia insignis</i> Franch and their anti-inflammatory activity.Eleven undescribed <i>ent</i>-kaurane-type diterpenoid acids, namely noueinsiancins A-K (1-11), together with sixteen related known analogs (12-27) were isolated from <i>Nouelia insignis</i> Franch. The chemical structures and absolute configurations of the new compounds were confirmed by the extensive spectroscopic data, electronic circular dichroism (ECD) data analysis and single crystal X-ray diffraction. Additionally, the anti-inflammatory assay was applied to estimate the nitric oxide (NO) inhibitory activities of all compounds by using lipopolysaccharide (LPS)-induced RAW 264.7 cells <i>in vitro</i>. The results revealed that 4-7 and 13-17 significantly inhibited NO production at the concentrations of 2.5 μM, 5.0 μM and 10.0 μM. Meanwhile, compounds 6 and 7 were found to down-regulat2022-01-01T00:00:00Z2022 Apr2025-04-04T23:16:38.246Z2025-04-04T23:16:38.246ZS-EPMC89958433542504710.1039/d2ra01684b