The rhizome of Dryopteris crassirhizoma NAKAI exhibited significant antioxidant activity, as assessed by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in vitro. Two phloroglucinol derivatives, flavaspidic acids PB (1) and AB (2), were isolated from the rhizome of D. crassirhizoma by a bioassay-guided fractionation. 1H-, 13C-NMR, and UV analysis were used to determine the ...

American Journal of Botany 99(4): 730–750, 2012; http://www.amjbot.org/ © 2012 Botanical Society of America The last decade has seen a nearly exponential increase in the number of molecular phylogenies published at various taxonomic levels across the plant tree of life. Vast uncharted territory still remains, however, particularly for ferns. Ferns are sister to seed plants ( Pryer et al., 2001 ...