Kenji Shiojima

Carbazole alkaloids from roots of Glycosmis arborea

Abstract A new carbazole alkaloid, designated as glycoborinine, was isolated from the roots of Glycosmis arborea , along with two other known carbazole alkaloids, viz. glycozoline and glycozolidine, and two known quinoline alkaloids, viz. skimianine and 3- (3′,3′-dimethylallyl)-4,8-dimethoxy- N -methylquinolin-2-one. Its structure was elucidated mainly on the basis of its 2D NMR spectral analyses.

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.

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.

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.

Composite constituents: four new triterpenoids, neolupenol, tarolupenol and their acetates isolated from roots of a japanese dandelion, taraxacum japonicum

Neolupenyl acetate (Ia), tarolupenyl acetate (IIa) and their corresponding alcohols (Ib and IIb) were isolated from the roots of Taraxacum japonicum, and their structures were established as the members of migrated lupane series.

Seasonal fluctuation of triterpenoid constituents from dried leaflets of dryopteris crassirhizoma

Abstract Eight triterpenoids of the hopane and migrated hopane series, and a sterol mixture were isolated from the dried leaflets of Dryopteris crassirhizoma . Seasonal fluctuations in the levels of these compounds from June to October were correlated with biogenesis.

Composite constituents: new migrated gammacerane triterpenoids from roots of Picris hieracioides subsp. japonica

Migrated gammacerane triterpenoids, named pichierenyl acetate (1) and isopichierenyl acetate (2), were isolated from the fresh roots of Picris hieracioides subsp. japonica, Compositae. By spectral and chemical methods, the structures of 1 and 2 were established as the members of migrated gammacerane series with a Δ9(11) and a Δ8 double bond respectively.

Fern constituent: Preoleanatetraene, a novel bicyclic triterpenoid hydrocarbon from Polypodiodes formosana

Abstract A novel bicyclic triterpenoid hydrocarbon, preoleanatetraene ( 1 ) was isolated from the fresh rhizomes of Polypodiodes formosana and the structure of 1 was established by spectral data. A new biogenetic pathway for the oleanane triterpenoids in this fern is proposed.

Peracid induced oxidative rearrangements of triterpenoids: Products of new skeleton from bauerenyl acetate

Abstract Treatment of bauerenyl acetate (2) with m-chloroperbenzoic acid at 4 °C yielded the migrated products, viz. 7α-hydroxy-14,27-cycloisoursan-3β-yl acetate (9) and its 15α-hydroxy derivative (12) belonging to a new skeleton, 7α-hydroxyisours-14-en-3β-yl acetate (10) and 14α,15α-epoxy-7α-hydroxyisoursan-3β-yl acetate (11), besides 7α,8α-epoxybaueran-3β-yl acetate (3), bauera-7,9(11)-dien-3β-yl acetate (4), bauera-6,8-dien-3β-yl acetate (5), 7α,8α-epoxybauer-9(11)-en-3β-yl acetate (6), 7α,8α,9α,11α-diepoxybaueran-3β-yl acetate (7) and 8α,9α-epoxy-7α-hydroxybaueran-3β-yl acetate (8). The structures of all the products were elucidated mainly on the basis of 2D NMR spectral analyses. The 1H and 13C chemical shifts of bauerenyl acetate (2) and its reaction products (3–12) were assigned unambiguously.

Triterpenoids from the fern Goniophlebium mengtzeense

Abstract Two new triterpenoids, fern-9(11)-en-20α-yl palmitate and 8βH-fern-9(11)-en-7-one were isolated from the fresh fronds of Goniophlebium mengtzeense . Their structures were established by spectroscopic techniques and chemical correlation. Thirty-seven other compounds were identified from this fern.