Bioactive constituents from Gerbera piloselloides with anti-inflammatory and antiproliferative activities

A phytochemical investigation of the 95% ethanol extract from Gerbera piloselloides obtained fourteen com-pounds, including three undescribed phenone-monoterpenes (1a/1b and 2), seven undescribed chromone-monoterpenes (3a/3b-5a/5b and 6), and one undescribed coumarin-monoterpene (8). Among them, four pairs of enantiomers (1a/1b and 3a/3b-5a/5b) were successfully isolated by the chiral-phase HPLC resolution. The structures and absolute configurations were unambiguously determined based on comprehensive spectroscopic data, electronic circular dichroism (ECD) data, and X-ray diffraction analysis. Structurally, compound 1 is the first 5-methylphenone monoterpene formed through a circular 6-membered carbocycle. And their anti-inflammatory and antiproliferative activities were evaluated via LPS stimulated RAW 264.7 cells and five human cancer lines (HepG2, MDA-MB-231, SCG-7901, A549 and MCF-7), respectively. Compounds 4b, 5a and 5b showed moderate inhibitory effect against nitric oxide (NO) production with IC(50 )values ranging from 12.52 to 15.75 mu M. Compound 8 significantly inhibited the proliferation of MDA-MB-231 human cancer line in a dose -dependent manner. Furthermore, the connection between phenone-monoterpenes, chromone-monoterpenes, and coumarin-monoterpenes in biosynthesis were also discussed.

Automated summary

This study identified several previously undescribed compounds from the extract of Gerbera piloselloides, including some that showed inhibitory effects on nitric oxide production and cancer cell proliferation.