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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Studies on the Taxoids Related to Marine Verticillenes and Comparison of Their Chemical Structures

Luh, Lon-je 13 February 2008 (has links)
In recent years, many marine invertebrates were studied in the world, and many compounds were discovered from soft corals (for example: sesquiterpenoids, diterpenoids, steroids and so on). From the previous studies on marine nature products, we found that verticillenes of soft corals have similar structures to taxoid diterpenoids of Taxus sp. This prompted us to study Taxus sp., thus we may indirectly understand the correlation of verticillienes of Taxus with verticilliene diterpenes of the soft corals. In order to discover new taxoid derivatives, the twigs and leaves of the Formosan T. sumatrana growing in Taiwan were investigated. Chromatographic separations of acetone extract of the leaves and twigs of this species yielded taxoid-enrich extracts. Fractionation of T. sumatrana has resulted in the isolation of four new compounds 1- 4. All structures were established primarily on the basis of 1D and 2D NMR experiments and other physical methods, such as mass spectroscopy, infrared, ultraviolet and optical rotation. The compound 1 is a taxoid 6/10/6 ring skeleton. The compounds, 2~4, are the verticillene skeleton, but the functional groups are different.

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