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.