| Summary: | 博士 === 高雄醫學大學 === 藥學研究所博士班 === 94 === From the root bark of Artocarpus rigida, a novel phenolic compound containing an oxepine ring, artocarpol I (1) and a new biphenylpropanoid, artocarpol J (2) were isolated. The structures including relative configurations were elucidated by spectroscopic data. Artocarpol I (1) and artocarpol J peracetate (3) strongly inhibited in a concentration-dependent manner the formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB)–stimulated superoxide anion formation in neutrophils with IC50 values of 17.1 + 0.40 and 20.5 + 2.60 ????, respectively. Biogenetically all the novel phenolic compounds isolated from this plant seem to be derived from stilbene.
From the root bark of Artocarpus elasticus, five new prenylated flavonoids, artelastoheterol (4), artelasticinol (5), cycloartelastoxathone (6), artelastoxanthoe (7), and cycloartelastoxanthendiol (8), along with five known compounds, were isolated. The structures of 4-8 were elucidated by spectroscopic methods and through comparison with data reported in the literature. The preciously known compound, artonol A (9), exhibited cytotoxic activity against the A549 human cancer cell line, with an ED50 value of 1.1 ?慊/mL.
From the heartwood of Garcinia subelliptica, Garcinielliptones HA (15), HC (17), and HF (20), possessing unprecedented terpenoid skeleton, along with three new terpenoids, garcinielliptones HB (16), HD (18), and HE (19) were established by extensive analysis of spectroscopic data. The ability of 15-20 to induce DNA-cleavage activity was examined using pBR322, a supercoiled, covalently closed circular DNA, and analyzed by agarose gel electrophoresis. In the present of Cu (II), compounds 17 and 18 caused significant breakage of supercoiled plasmid pBR322. The products were relaxed circles with no detectable linear forms. In the Cu (II)-mediated DNA damage of 17, Cu (I) was shown to be an essential intermediate by using the Cu (I)-specific sequestering reagent neocuproine. In the Cu (II)-mediated DNA damage of 18, Cu (I) was not shown to be an essential intermediate by using the same Cu (I)-specific sequestering reagent.
The involvement of active oxygen species, H2O2 and O2·- in the 17-Cu (II)-mediated breakage reaction, was established by the inhibition of DNA damage by catalase and revealed DNA breakage by KI and superoxide dismutase.
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