Isolation and evaluation of kaempferol glycosides from the fern Neocheiropteris palmatopedata

Six kaempferol glycosides including three hitherto unknown compounds (1-3) were isolated from the roots of the fern Neocheiropteris palmatopedata. Compounds 1 and 2 were determined to possess an unusual sugar moiety containing a 4,4-dimethyl-3-oxo-butoxy substituent group, respectively. The isolates were evaluated for their cancer chemopreventive potential based on their ability to inhibit tumor necrosis factor-α-induced induced NF-κB, nitric oxide (NO) production, aromatase, quinone reductase 2 (QR2) and COX-1/-2 activities.