Hiroyuki Ageta

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

Abstract 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.

Fern constituents: Polypodatetraenes, novel bicyclic triterpenoids, isolated from polypodiaceous and aspidiaceous plants

Abstract Two new oily triterpenoid hydrocarbons having a novel bicyclic carbon skeleton, named α- and γ-polypodatetraenes ( 1 and 2 , respectively), were isolated from the fresh leaves of Polypodium fauriei and Lemmaphyllum microphyllum ( 1 ), and Polystichum ovatopaleaceum and P. polyblephalum ( 2 ). Their structures were established to be polypoda-8(26), 13,17,21-tetraene ( 1 ) and polypoda-7,13,17,21-tetraene ( 2 ) by physico-chemical methods.

Taraxastane glycosides from Eclipta alba

Abstract From the dried whole plants of Eclipta alba (Ecliptae Herba, Chinese name Mo Han Lian) purchased in China, four new taraxastane triterpene glycosides, named eclalbasaponins VII–X were isolated, along with eclalbasaponins I–VI. The structures of eclalbasaponins VII–X were characterized as 3β,20β,16β- and 3β,20β,28-trihydroxytaraxastane glycosides, and their sulphated saponins on the basis of spectral data.

Fern constituents: Cycloartane triterpenoids and allied compounds from Polypodium formosanum and P. niponicum

Abstract From the rhizomes of Polypodium formosanum, new triterpenoids of the cycloartane group, (24R)-cyclolaudenol and (24R)-cyclomargenol, were isolated as the corresponding acetates, alcohols and ketones, and their structures were established. Also, from the rhizomes of P. niponicum eight acetates of cycloartane derivatives and two acetates of new methyl sterols were isolated and characterized.

Fern constituents: Three new skeletal triterpenoid hydrocarbons isolated from Polypodiodes niponica

Abstract Three new triterpenoid hydrocarbons, named aonena-3,21-diene ( 1 ), podioda-7,17,21-triene ( 2 ) and podioda-8,17,21-triene ( 3 ), were isolated from fresh rhizomes of Polypodiodes niponica and their structures were established by spectral and chemical studies. Compound 1 is the first example of a final migrated product of dammarane series. Compounds 2 and 3 constitute a new migrated malabaricane series.

Fern constituents : two new triterpenoid alcohols with mono- and bi-cyclic skeletons, isolated from Polypodiodes formosana

Two new triterpenoid alcohols, 1 and 2, were isolated from the fresh rhizomes of Polypodiodes formosana. Using spectral and chemical evidences structures of 1 and 2 were established as 6α-hydroxyachilla-9,13,17,21-tetraene-tetraene and 8α-hydroxypolypoda-13,17,21-triene with their absolute configuration.

Chemical constituents of aquatic fern Azolla nilotica

Two new components, (24R)-6β-hydroxy-24-ethyl-cholest-4-en-3-one and phytyl-3,7,11,15-tetramethyl-2-hexadecanenate were isolated from the whole plants of aquatic fern Azolla nilotica. Their structures were established by spectroscopic techniques and chemical correlation. Some typical triterpenoids of ferns were also detected.

Dammarane triterpenoids from rhizomes of Pyrrosia lingua

Hexane extract of fresh rhizomes of Pyrrosia lingua (Thunb.) Farwell. yielded five new dammarane triterpenoids, designated as octanordammarane (1), (18S)-18-hydroxydammar-21-ene (3), (18S)-pyrrosialactone (5), (18S)-pyrrosialactol (7) and 3-deoxyocotillol (8), along with known dammara-18(28),21-diene (2). Structures of 1, 3, 5, 7 and 8 were elucidated by mainly 2D NMR and other spectroscopic analyses and chemical correlations.

Fern constituents: Triterpenoids isolated from Polypodium vulgare, P. fauriei and P. virginianum

Abstract The fresh rhizomes of Polypodium vulgare , P. fauriei and P. virginianum collected in Japan gave, in addition to 30 known compounds, three new triterpenoids; dammara-17,21-diene, cyclopodmenyl acetate and 21αH-hopan-22-ol. The structures were elucidated by their physical data and chemical correlations.

Composite constituents: Three gammacer-16-ene derivatives, novel triterpenoids isolated from roots of Picris hieracioides subsp. japonica

Abstract New triterpenoids, gammacer-16-en-3β-yl acetate (3), gammacer-16-en-3β-ol (4) and gammacer-16-en-3α-ol (5) were isolated from the fresh roots of Picris hieracioides subsp. japonica, Compositae. Their structures were established by chemical and spectral methods. X-ray crystallographic study of the corresponding ketone (6) confirmed the structures of 3, 4 and 5.