Toshimasa Ochi

Publications (3)9.38 Total impact

• Article: Anti-Helicobacter pylori compounds from Santalum album.

  Toshimasa Ochi, Hirofumi Shibata, Tomihiko Higuti, Ko-hei Kodama, Takenori Kusumi, Yoshihisa Takaishi
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  ABSTRACT: Six new sesquiterpenes, (Z)-2beta-hydroxy-14-hydro-beta-santalol (1), (Z)-2alpha-hydroxy-albumol (2), 2R-(Z)-campherene-2,13-diol (3), (Z)-campherene-2beta,13-diol (4), (Z)-7-hydroxynuciferol (5), and (Z)-1beta-hydroxy-2-hydrolanceol (6), together with five known compounds, (Z)-alpha-santalol (7), (Z)-beta-santalol (8), (Z)-lanceol (9), alpha-santaldiol (10), and beta-santaldiol (11), were isolated from Santalum album, by using bioassay-guided fractionation for Helicobacter pylori. The structures were determined by extensive NMR studies. The absolute configuration of compound 3 was determined by a modified Mosher method. The crude extracts as well as the isolated compounds showed antibacterial activity against H. pylori. Especially, compounds 7 and 8 have strong anti-H. pylori activities against a clarithromycin-resistant strain (TS281) as well as other strains.
  Journal of Natural Products 07/2005; 68(6):819-24. · 3.13 Impact Factor
• Article: New sesquiterpenes from Capsicum annuum.

  Yousuke Kawaguchi, Toshimasa Ochi, Yoshihisa Takaishi, Kazuyoshi Kawazoe, Kuo-Hsiung Lee
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  ABSTRACT: The ethyl acetate soluble fraction of a MeOH extract of the dried stems and roots of Capsicum annum gave 10 new sesquiterpenoids (1-10) and nine known compounds. The structures of the new compounds were elucidated on the basis of spectroscopic evidence. The isolated new compounds were evaluated for their cytotoxic activities.
  Journal of Natural Products 12/2004; 67(11):1893-6. · 3.13 Impact Factor
• Article: Antioxidant activity of a new capsaicin derivative from Capsicum annuum.

  Toshimasa Ochi, Yoshihisa Takaishi, Kentarou Kogure, Izumi Yamauti
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  ABSTRACT: A new capsaicin derivative, 6' ',7' '-dihydro-5',5' "-dicapsaicin (1), and a known capsaicin metabolite, omega-hydroxycapsaicin (2),(1) were isolated from the fruit of Capsicum annuum. Their structures were established on the basis of spectroscopic evidence. Compound 1 showed almost the same antioxidant activity as capsaicin, but did not have a pungent taste.
  Journal of Natural Products 09/2003; 66(8):1094-6. · 3.13 Impact Factor