Abstract
The Onocleaceae family, a small group within the Pteridophytes, comprises four genera, but has been phytochemically studied mainly for Pentarhizidium orientale, Pentarhizidium intermedium, and Matteuccia struthiopteris. To date, a total of 91 compounds have been isolated from these three species, including 15 flavonoids, 48 flavonoid glycosides, 6 stilbenes, 4 isocoumarins, 2 phthalides, 3 chromones, 2 lignan glycosides, 8 isoprenoid derivatives, and 3 phenolic compounds. Notably, most flavonoids and flavonoid glycosides possess C-methyl groups at the C-6 and/or C-8 positions, with several conjugated to (S)-3-hydroxy-3-methylglutaryl (HMG) moieties. Although not all isolates have been evaluated for their pharmacological activities, several compounds have demonstrated bioactivities such as antiviral, anti-inflammatory, α-glucosidase inhibitory, aldose reductase inhibitory, and antioxidant effects.