Labdane-type diterpenoids with cytotoxic and anti-inflammatory activities from the aerial parts of Hypoestes purpurea (L.) R. Br.

Two new ent -labdane diterpenoids, hypoestesins A-B (1 – 2) and five new labdane diterpenoids, hypopurolides H-L (3 – 7), were isolated from the aerial parts of Hypoestes purpurea. All of the structures were fully determined based on extensive analysis of 1H, 13C, 2D NMR, and HRESIMS data. The absolute configurations of 1 – 3 was established through comparing the experimental and calculated ECD curves and the structure of 5 was confirmed by single crystal X-ray diffraction experiment. Compounds 5 – 7 were unusual C23 labdane diterpenoids having a γ- acetonyl- α , β -unsaturated γ -lactone unit and each assigned as C-15 epimeric mixture. Furthermore, cytotoxic and anti-inflammatory activities of 3 – 7 were evaluated. The results showed that 3 had remarkable cytotoxic activity against HL-60, A549, SMMC-7721, MDA-MB-231, and SW480 cancer cell lines with IC 50 values ranging from 2.35 to 17.06 μ M. Compound 4 showed moderate cytotoxic activity against HL-60 and SMMC-7721 cancer cell lines with IC 50 values of 15.12 ± 0.53 and 12.92 ± 0.60 μ M, respectively. Furthermore, compound 4 was also found to exhibit inhibitory activity against NO production in RAW 264.7 macrophages with IC 50 values of 23.56 ± 0.99 μ M, compared to the positive control L-NMMA with an IC 50 value of 41.11 ± 1.34 μ M. [Display omitted] • Seven new diterpenoids were isolated from Hypoestes purpurea. • Hypopurolides J-L were unusual labdane diterpenoids with C23 skeleton. • Hypopurolides H and I exhibited potent cytotoxic activities. • Hypopurolide I also exhibit NO inhibitory activity. [ABSTRACT FROM AUTHOR]