Phenolic esters from the rhizomes of Cimicifuga racemosa do not cause proliferation effects in MCF-7 cells.

Five phenylpropanoid esters, caffeoylglycolic acid, 2-caffeoylpiscidic acid (cimicifugic acid D), 3,4-dihydroxyphenacyl caffeate (petasiphenone), 3,4-dihydroxyphenyl-2-oxopropyl isoferulate (cimiciphenol) and 3,4-dihydroxyphenacyl isoferulate (cimiciphenone) were isolated from a commercially available extract of the rhizomes of Cimicifuga racemosa (L.) Nutt. (syn. Actaea racemosa L.) for the first time; the known cimicifugic acids A, B, E, F, fukinolic acid, fukiic acid and caffeic acid were also obtained. Cimiciphenone and caffeoylglycolic acid are new natural products. The structures were elucidated by means of spectroscopic data (ESI-MS, 1H-, 13C-NMR, COSY, HMQC, HMBC and NOE experiments). Ferulic acid and isoferulic acid were detected by HPLC analysis in comparison to standards. The estrogenic activity of the isolated compounds was tested in an estrogen-dependent MCF-7 mamma carcinoma cell line; 17beta-estradiol (10(-11) M) and the phytoestrogen coumestrol (10(-7) - 10(-5) M) were used as references. The results suggest that, in contrast to an earlier report, the phenolic esters do not exert a proliferative (estrogenic) effect in this test system.