Microtropins A–I 6′-O-(2″S,3″R)-2″-Ethyl-2″,3″-dihydroxybutyrates of aliphatic alcohol β-d-glucopyranosides from the branches of Microtropis japonica》.pdfVIP

Phytochemistry 87 (2013) 140–147 Contents lists available at SciVerse ScienceDirect Phytochemistry journal homepage: www.elsevier .com/locate/phytochem 0 00 00 00 00 00 Microtropins A–I: 6 -O-(2 S,3 R)-2 -Ethyl-2 ,3 -dihydroxybutyrates of aliphatic alcohol b-D-glucopyranosides from the branches of Microtropis japonica Yuka Uemura a, Sachiko Sugimoto a, Katsuyoshi Matsunami a, Hideaki Otsuka a,b,⇑, Yoshio Takeda b, Masatoshi Kawahata c, Kentaro Yamaguchi c a Department of Pharmacognosy, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan b Department of Natural Products Chemistry, Faculty of Pharmacy, Yasuda Women’s University, 6-13-1 Yasuhigashi, Asaminami-ku, Hiroshima 731-0153, Japan c Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Kagawa Campus, 1314-1 Shido, Sanuki-shi, Kagawa 769-2139, Japan a r t i c l e i n f o a b s t r a c t Article history: From the branches of Microtropis japonica (Celastraceae), nine aliphatic glucosides, named microtropins Received 6 August 2012 A–I, were isolated. The 6-position of glucose was esterified with (2S,3R)-2-ethyl-2,3-dihydroxybutyric Received in revised form 1 October 2012 acid. Microtropins A–D contained a rare natured product nitrile functional group in their aglycones. Available online 5 December 2012 The absolute structures of the (2S,3R)-2-ethyl-2,3-dihydroxybutyric acid moiety and aglycone of micro-