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Chemical studies of three representatives of the genus Pseudophegopteris (Thelypteridaceae) revealed that the genus is characterized by the occurrence of unusual flavonoids with a modified B-ring related to protogenkwanin (VII). From P. hirtirachis HOLTT., three novel compounds, protogenkwanone (I), tetrahydroprotogenkwanone (II) and tetrahydroprotogenkwanin (III), were isolated, along with protogenkwanin 4'-O-β-D-glucoside (VI). From P. subaurita CHING, two new acylated glucosides of protogenkwanin, protogenkwanin 4'-O- (2-O-acetyl) -β-D-glucoside (IV) and 4'-O- (6-O-acetyl) -β-D-glucoside (V), were obtained, together with I, II and VI. From P. bukoensis HOLTT., IV, V and VI were isolated, in addition to apigenin 7-O-α-L-rhamnoside and kaempferol. The structures of the new compounds were determined by means of spectroscopic methods and chemical transformations.

Aus den Rhizomen von Woodwardia orientalis Sw. wurden eine Reihe von Phytosterin-Derivaten (freie Sterine, Sterin-Ester, Sterin-Glucoside, veresterte Sterin-Glucoside) und eine neue Triterpen-Verbindung, die wir Woodwardinsaure nannten, isoliert. Die Struktur der Woodwardinsaure wurde als 3β-Hydroxy-21β-H-Δ22(29)-hopen-23-carbonsaure aufgeklart.