Fern constituents: pentacyclic triterpenoids isolated from Polypodium niponicum and P. formosanum

From the dried rhizomes of Polypodium niponicum and P. formosanum, 16 hydrocarbons, three alcohols, five acetates, one epoxide and two ketones of pentacyclic triterpenoids belonging to the hopane, neohopane, fernane, trisnorhopane, oleanane, taraxerane, multiflorane, friedelane and taraxastane groups were isolated and characterized.