Seiko Hirotani

Blazeispirol A, an unprecedented skeleton from the cultured mycelia of the fungus Agaricus blazei

Abstract Blazeispirol A, an unprecedented skeleton has been isolated from the cultured mycelia of Agaricus blazei(Agaricaceae). Its structure was elucidated to be the previously unknown spiro [4,10b-ethanonaphtho[1,2-b]pyran-2,2′-furan] skeleton which was established by extensive 1D and 2D NMR spectral data and X-ray analysis.

Blazeispirols B, C, E and F, des-A-ergostane-type compounds, from the cultured mycelia of the fungus Agaricus blazei

Four new des-A-ergostane derivatives including blazeispirols B, C, E and F were isolated from the cultured mycelia of fungus Agaricus blazei Murill and were established to be (20S, 22R, 23R, 24S)-14beta,22: 22,25-diepoxy-5-methoxy-des-A-ergosta-5,7,9,11-tetraen-23-ol; (20S, 22S, 23R, 24S)-14beta,22: 22,25-diepoxy-5-methoxy-des-A-ergosta-5,7,9-trien-23-ol; (20S, 22S, 23R, 24S)-14beta, 22: 22, 25-diepoxy-5-methoxy-des-A-ergosta-5,7,9,11-tetraene-19,23-diol and (20S, 22S, 23R, 24S)-14beta,22: 22,25-diepoxy-des-A-ergosta-5,7,9-triene-5,23-diol by comparison of extensive 1D and 2D NMR spectral data with that of blazeispirol A.

Blazeispirane and protoblazeispirane derivatives from the cultured mycelia of the fungus Agaricus blazei

Two blazeispirane derivatives including blazeispirols G and I were isolated from the cultured mycelia of the fungus Agaricus blazei Murill and were established to be (20S, 22S, 23R, 24S)-14 beta,22: 22,25-diepoxy-5-methoxy-des-A-ergosta-5,7,9-triene-11 alpha,23-diol and (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-5-methoxy-des-A-ergosta-5,7,9,11-tetraene-23,28-diol by comparison of extensive 1D and 2D NMR spectral data with that of blazeispirol A. Furthermore, four blazeispirol derivatives blazeispirols, U, V, V(1) and Z(1) were isolated form the same source described above. Their structures were determined to be (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-23-hydroxyergosta-4,6,8,11-tetraen-3-one, (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-6 alpha,7 alpha,23-trihydroxyergosta-4,8,11-trien-3-one, (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-6 beta,7 alpha,23-trihydroxyergosta-4,8,11-trien-3-one and (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-23-hydroxy-4,5-seco-ergosta-6,8-diene-3,5-dione by extensive 1 D and 2D NMR spectral data.

Blazeispirol D and Z, as the actual intermediates of blazeispirol A biosynthesis from the cultured mycelia of the fungus Agaricus blazei

Abstract Two novel blazeispirol derivatives, blazeispirol D and Z, as the actual intermediates of blazeispirol A biosynthesis have been isolated from the cultured mycelia of Agaricus blazei (Agaricaceae). The structures were elucidated to be (20 S ,22 S ,23 R ,24 S )-14β, 22: 22, 25-diepoxy-des- A -ergosta-5,7,9,11-tetraene-5,23-diol and (20 S ,22 S ,23 R ,24 S )-14β,22:22,25-diepoxy-23-hydroxy-4,5-seco-ergosta-6,8,11-triene-3,5-dione by comparison of extensive 1D and 2D NMR spectral data with that of blazeispirol A. It is discussed that the compounds are the actual intermediates of blazeispirol A biosynthesis.

Blazeispirol X and Y, two novel carbon skeletal sterols from the cultured mycelia of the fungus Agaricus blazei

Two novel blazeispirol derivatives, blazeispirol X and Y, have been isolated from the cultured mycelia of Agaricus blazei (Agaricaceae). The structures were elucidated to be (20S,22S,23R,24S)-1 (10→6) abeo-14β,22:22,25-diepoxyergosta-5,7,9,11-tetraene-3α,23-diol and (20S,22S,23R,24S)-14β,22:22,25-diepoxy-9,23-dihydroxyergosta-4,7,11-triene-3,6-dione by comparison of extensive 1D and 2D NMR spectral data with that of blazeispirol A.

A FACILE SYNTHESIS OF SPIROISOXAZOLINES : INTRAMOLECULAR CYCLIZATION OF 3-ARYL-2-NITROACRYLATES PROMOTED BY TITANIUM TETRACHLORIDE

Abstract Titanium tetrachloride-induced cyclization of 3-(o- or m-substituted p-methoxyphenyl)-2-nitro acrylates (1) provided stereoselectively (4α,5β)-1-oxa-2-azaspiro[4,5]deca-2,6,9-trien-8-ones (2). Ortho-substituted p-methoxyphenyl nitroacrylates gave 2 in good yield. 3-(4′-methoxy-1′-naphthyl)-2-nitroacrylate also reacted with titanium tetrachloride to give quantitatively (4α,5β)-4′-oxospiro[isoxazole-(4H)5,1′(4′H)-naphthalene]. 3-(10′-methoxy-9′-anthryl)-2-nitroacrylate was converted to 10-oxospiro-[anthracene-(10H)9,5′(4′H)-isoxazole].

Formation of Novel Isoxazoline Spiro Compounds by a Reaction of Aryl Substituted a-Nitroacrylates with Titanium Tetrachloride and Toluene

New spiroisoxazoline derivatives were synthesized via novel cyclization of arylsubstituted α-nitroacrylates (naphthyl and phenanthryl analogues) with TiCl 4 and toluene. The structural determination by single crystal X-ray analysis is reported