Analysis of in vitro serotonergic activity of black cohosh (Cimicifuga racemosa) and identification of a potential active constituent, N-methylserotonin

Phytochemistry of cimicifugic acids and associated bases in Cimicifuga racemosa root extracts

“…The pHZR CPC step yielded 7 combined fractions that eluted from the column according to pH starting from acidic around pH 1.5 to basic around pH 9.5. Fractions were combined according to their pH, TLC, and UV profiles, and subsequently tested in the 5-HT 7 competitive binding assay (Figure 3) (Powell et al , 2008). Only fraction 7 exhibited activity.…”

“…3) as the active component of the extract with a calculated content of 31 ppm in a 75% ethanol extract. Its identity was determined by means of LC-MS versus an authentic reference standard (Powell et al , 2008). …”

“…2- O -sinapoyl fukiic acid, 2- O -sinapoyl-3-hydroxy-4-(3’,4’-dihydroxyphenyl)-3-carboxybutyric acid), for which the name cimicifugic acid KS is proposed (Figure 1B). While a detailed evaluation of the 5-HT 7 activity will be published elsewhere (Powell et al , 2008), it can be summarized that the CAs show only moderate serotonergic activity. Thereby, the cimicifugic acid KK (syn.…”

“…This led to the concentration of almost all of the 5-HT 7 activity (Powell et al , 2008) in the most basic fraction (Figure 3), and resolved of Cimicifuga phenolic acids from bases such as cimipronidines and tryptamine alkaloids. From the concentrated CA fraction, purification and identification of one new CA ( 1 ) and 5 previously identified CAs free of interference with alkaloids was accomplished.…”

“…The tested fractions and pure CAs competed with [ 3 H] LSD (lysergic acid diethylamide, 5.67 nM), and receptor binding inhibition was measured. Details will be published separately (Powell et al , 2008). …”