Shuzo Takagi

Antimicrobial agents from Bletilla striata

Abstract Three new bibenzyls and two new dihydrophenanthrenes, which exhibit antimicrobial activity, were isolated from tubers of Bletilla striata. They were identified by various spectroscopic methods.

Biphenanthrenes from Bletilla striata

Abstract From tubers of Bletilla striata , three new biphenanthrenes were isolated, together with batatasin Ill and 3′-O-methylbatatasin III. The structures were elucidated from their spectroscopic data.

Blestrianol A, B and C, biphenanthrenes from Bletilla striata

Abstract Three biphenanthrenes, blestrianol A, B and C and one dibenzylphenanthrene were isolated from tubers of Bletilla striata . The structures were elucidated as 4,4′-dimethoxy-9,9′,10,10′-tetrahydro-[1′,3-biphenanthrene]-2,2′,7,7′-tetraol, 4′,5-dimethoxy-8-(4-hydroxybenzyl)-9,9′,10,10′-tetrahydro-[1′,3-biphenanthrene]-2,2′,7,7′-tetraol,4′,5-dimethoxy-8-(4-hydroxybenzyl)-9,10-dihydro-[1′,3-biphenanthrene]-2,2′,7,7′-tetraol and 1,8-bi(4-hydroxybenzyl)-4-methoxy-phenanthrene-2,7-diol by their spectroscopic data.

Stilbenoids from Bletilla striata

Abstract Five new stilbenoids, three bibenzyls, one dibenzyldihydrophenanthrene and one benzoyldihydrophenanthrene, were isolated from tubers of Bletilla striata . The new structures were elucidated as 3,3′-dihydroxy-4-( p -hydroxybenzyl)-5-methoxybibenzyl, 3,3′-dihydroxy-2-( p -hydroxybenzyl)-5-methoxybibenzyl, 3′,5-dihydroxy-2-( p -hydroxybenzyl)-3-methoxybibenzyl, 2,7-dihydroxy-1,3-bi( p -hydroxybenzyl)-4-methoxy-9,10-dihydrophenanthrene and 2,7-dihydroxy-1-( p -hydroxybenzoyl)-4-methoxy-9,10-dihydrophenanthrene, by their spectroscopic data.

Four stilbenoids from Pleione bulbocodioides

Abstract Two dihydrophenanthropyrans, shanciol E and F, and two bibenzyls, bulbocodin C and D, were isolated from tubers of Pleione bulbocodioides . The new structures were elucidated to be 3-hydroxy-11-methoxy-2-(4′-hydroxy-3′,5′-dimethoxyphenyl)-2,3,5,6-tetrahydro-4H-phenanthro[2,1-b] pyran-8-ol; 4-hydroxy-11-methoxy-3-(4′-hydroxy-3′-methoxyphenyl)-3,4,5,6-tetrahydro-2H-pehnanthro[2,1-b] pyran-8-ol; 3′,5-dihydroxy-3-methoxy-2,4-di( p -hydroxybenzyl)bibenzyl; 3,3′-dihydroxy-5-methoxy-2,4-di( p -hydroxybenzyl)bibenzyl; respectively, on the basis of spectroscopic data and chemical correlations.

A polyphenol and two bibenzyls from Pleione bulbocodioides

Abstract From tubers of Pleione bulbocodioides , one new polyphenol, pleionol, and two new bibenzyls, bulbocodin and bulbocol were isolated together with three known compounds, 3,3′-dihydroxy-4-( p -hydroxybenzyl)-5-methoxybibenzyl, 3,3′-dihydroxy-2-( p -hydroxybenzyl)-5-methoxybibenzyl, 3′,5-dihydroxy-2-( p -hydroxybenzyl)-3-methoxybibenzyl. The new structures were elucidated as 2,8-dihydroxy-5-(4′-hydroxy-3′-methoxyphenyl)-4-methoxy-10,11-dihydrodibenzo[a,d]cycloheptene, 2′,3-dihydroxy-5-methoxy-2,5′,6-tri( p -hydroxybenzyl)bibenzyl and 3,3′-dimethoxy-5-hydroxy-2-( p -hydroxybenzyl)bibenzyl from their spectroscopic data.

A flavanonol rhamnoside from Hypericum japonicum

Abstract A new flavanonol (2R,3R)-taxifolin-7-rhamnoside, from whole plant of Hypericum japonicum has been isolated together with the known quercitrin and vincetoxicoside B. Their structures were elucidated using spectral techniques.

Benzylphenanthrenes from Bletilla striata

Abstract Three benzylphenanthrenes were isolated from tubers of Bletilla striata and their structures elucidated by spectroscopic methods. The structures of previously isolated dihydrophenanthrene were revised by NOE experiments.

Methylated stilbenoids from Bletilla striata

Abstract From tubers of Bletilla striata , four permethylated stilbenoids were isolated together with 3,5-dimethoxybibenzyl and the anthraquinone, physcion. The new structures were elucidated as 2,4,7-trimethoxy-phenanthrene, 2,4, 7-trimethoxy-9,10-dihydrophenanthrene, 2,3,4,7-tetramethoxyphenanthrene and 3.3′,5-trimethoxybibenzyl on the basis of spectroscopic data.

A chromene from Hypericum japonicum

Abstract A new 2,2-dimethyl-3′,7-dihydroxy-6-phenyl-2′,5-chromenecarbolactone was isolated from the whole plant of Hypericum japonicum . Its structure was elucidated by spectral methods and it was named sarolactone.