| Summary: | 碩士 === 國立臺灣大學 === 藥學研究所 === 102 === In this thesis, the phytochemical investigation of Bretschneidera sinensis Hemsley was initiated. The leaves and twigs were extracted with ethanol and the crude extract was separated by using extensive column chromatography. As a result, six new sulfur-containing alkaloids were isolated and their structures determined.
Compounds 1-4 were identified as new heterocyclic compounds, which belong to the skeleton of 3-methyl-1,3-benzothiazine-2,4-dione, while compounds 5 and 6 were characterized as new sulfur-containing alkaloids, which belong to the skeleton of N-benzyl-S-methyl-thiocarbamate.
All of these structures were elucidated and established on the basis of spectroscopic analysis such as 1D NMR (1H and 13C NMR) and 2D NMR (HSQC, HMBC) techniques. We also applied the physical methods including melting point, ultraviolet spectroscopy (UV) and high resolution electrospray ionization mass spectroscopy (HRESIMS) to confirm the structures. In addition, all of the isolated compounds were further determined by comparing with the chemical databases, Reaxys.
Finally, all the isolated compounds were tested for the biological activities including anti-inflammatory and cytotoxic activities.
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