From the dried rhizomes of Oleandra wallichii, six hydrocarbons [hop-22 (29)-ene, neohop-13 (18)-ene, fern-7-ene, fern-8-ene, fern-9 (11)-ene and adian-5-ene], an ozonide (adian-5-ene ozonide, a new compound), three acetates (dryocrassyl acetate, neriifolyl acetate and tetrahymanyl acetate), a lactone (hopan-28, 22-olide), three mono-ols (hydroxyhopane, tetrahymanol and neriifoliol) and a diol (hopan-22, 28-diol, the first example from nature) with cycloartanoid alcohol mixture, sterol mixture and a mixture of fatty acid esters of cycloartanoid alcohols, neriifoliol, dryocrassol and sterols were detected as pentacyclic triterpenoids. The occurrence of various kinds of hopane and migrated hopane group hydrocarbons and their oxygenated compounds suggests that this fern is related to Adiantum (Pteridaceae) from a chemotaxonomical point of view. Especially, adian-5-ene ozonide, has been found only in O. wallichii and Adiantum monochlamys.
