• Title/Summary/Keyword: Monocyclosqualene

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Structure of Three New Terpenoids, Spiciformisins a and b, and Monocyclosqualene, Isolated from the Herbs of Ligularia fischeri var. spiciformis and Cytotoxicity

  • Lee, Kyung-Tae;Koo, Sung-Ja;Jung, Seung-Hee;Choi, Jong-Won;Jung, Hyun-Ju;Park, Hee-Juhn
    • Archives of Pharmacal Research
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    • v.25 no.6
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    • pp.820-823
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    • 2002
  • The diethylet er fraction from the leaves extract of Ligularia fischeri var. spiciformis (Compositae) was subjected to silica gel column chromatography and yielded three new terpenoids named spiciformisin a (1), spiciformisin b (3), and monocyclosqualene (2). Acyclic diterpenes, spiciformisin a and -b, were established as 3,7,11,15-tetramethyl-1,3(20)-hexadecadiene and 3,7,11,15-tetramethyl-1,3,6,10,14-hexadecapentaene (IUPAC), respectively. A monocyclic triterpene, monocyclosqualene, were determined as [3,8,12,16,16-pentamethyl-(3,7,11,15-hexadecatetraenyl)]-3,3,5-trimethyl-1-cyclohexene. The structures were determined on the basis of NMR and MS analysis. Spiciformicin b showed potent cytotoxicity ($IC_{50},{\;}<9.7{;\}{\mu\textrm{g}}/ml$ against HL-60) in contrast to no cytotoxicity ($IC_{50},{\;}>200{\;}}{\mu\textrm{g}}/ml against HL-60 cells) of spiciformicin a with a cis-conjugated dienyl diexomethylene.