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Chemical investigation of the roots of Ligularia sagitta has resulted in the characterization of six eremophilenolides 6beta,8beta-dimethoxy-10beta-hydroxyeremophil-7(11)-en-12,8alpha-olide (1), 6beta-angeloyloxy-10beta-hydroxy-8beta-methoxyeremophil-7(11)-en-12,8alpha-olide (2), 6beta-(2'-methylbutanoyloxy)-10beta-hydroxy-8beta-methoxyeremophil-7(11)-en-12,8alpha-olide (3), 6beta-angeloyloxy-10beta-hydroxy-8alpha-methoxyeremophil-7(11)-en-12,8beta-olide (4), 6beta-(2'-methylbutanoyloxy)-10beta-hydroxy-8alpha-methoxyeremophil-7(11)-en-12,8beta-olide (5) and 8beta,10beta-dihydroxy-6beta-methoxyeremophil-7(11)-en-12,8alpha-olide (6), together with one monoterpene (3 R,4 R,6 S)-3,6-dihydroxy-1-menthene (7), two triterpenes lupeol (8) and ursolic acid (9), and beta-sitosterol (10). The structures of five new constituents (1-5) were elucidated by spectroscopic methods including 2D-NMR experiments. The compounds 1, 5 and 7 showed antibacterial activity by being assayed against Staphylococcus aureus, Bacillus subtilis and Escherichia coli.

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We studied the electric conductivity and structure of polymerderived carbon-rich amorphous SiC pyrolyzed at different temperatures. The conductivity of the material increased drastically with pyrolysis temperature followed an Arrhenius relationship with the activation energy of~3.4 eV. Raman and X-ray photoelectron spectroscopy analysis revealed that the order of free carbon phase increased with pyrolysis temperature, accompanied by sp 3 ?sp 2 transition. The activation energy for such a structure change was 3.1-3.8 eV, which is close to that for the conductivity change. We thus believe that the increase in the conductivity was mainly due to the increase in conductivity of the free carbon phase.R. Riedel-contributing editor Manuscript No. 34335.

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