The Structural Transformation Of The Three Natural Compounds And Activity

This dissertation is composed of three parts. Part A described the synthesis ofmonoterpene alkaloid-like compounds from geniposide and bioactivity. Part Belaborated the methods of content determination of hedychiol A from Hedychiumyunnanense and photosensitized oxidation of coronarin E. Part C reported the studyon preparation of two derivatives of Bergenin and their analgesic activity.Part A The synthesis monoterpene alkaloid-like compoundsfrom genipin and bioactivityThis paper reported two methods of using genipin to prepare monoterpenealkaloid-like. Iridoids and their glycosides constitute an important class of naturalproducts;more over, they are biosynthetic precursors to a broad range of indolalkaloids, with joint biosynthetic key intermediates like secologanin. Given the insome cases well-investigated incorporation of nitrogen atoms into iridoids or its glycosides to give iridoid alkaloids, the presumably biomimetic synthesis ofmonotepene alkaloid-like compounds from its nitrogen-free starting material,genipin, may be rewarding. Genipin was obtained from the enzymatic hydrolysis ofgeniposide, which was isolated from Gardenia jasminoides. Genipin could beconsidered to be the analogue of glutaraldehyde, therefore it coule easily react withamines, ethanolamine, or other nitrogen-containing compounds under variousconditions to get monoterpene alkaloid-like compounds.The methods introduced to prepare the monoterpene alkaloid-like compoundswere listed below:(1) Reductive amination of genipin and amines in ethanol-H₂O solution,with NaBH₄ as reductant.(2) Reductive amination of genipin and amines in methanol solution,with NaBH₃CN as reductant.(3) Reaction of dihydrogenipin and amines.18 monoterpene alkaloid-like compounds prepared from genipin and amines wereobtained. Preliminary bioactivity tests of some products were performed. Someproducts showed weak inhibition effect against diabetes PTP1B target enzyme.Part B The content determination of hedychiol A andphotosensitized oxidation of coronarin E from HedychiumThis paper reported the methods of content determination of hedychiol A fromHedychium yunnanense and photosensitized oxidation of coronarin E. Highperformance liquid chromatography was employed to determinate the content of hedychiol A.: coloum C₁₈, methanol-H₂O(8: 2) as mobile phase, with 1.0mL/min, andλ_max=233nm. Coronarin E was oxidized under sunlight with methylene blue asphotosensitizer in methanol. The relation of absorbance and concentration of the samplewas good within 4.0～20.0ug/mL(r=0.999). Average rate of recovery and precision was98.7%, 2.88% respectively. After photosensitized oxidation, two labdane-typediterpenoid derivatives were obtained. Biological screening indicated that compound1 did not show inhibition activity against A-549 cell.Part C Study on the preparation of two derivatives ofbergenin and their analgesic activity.This paper showed the preparation of two derivatives of bergenin and theiranalgesic activity. Selective sulfonylation and Mannich reaction of bergenin werecarried out respectively and two derivatives were obtained. Two products analgesiceffects were observed by employing the writhing test in mice. Two products obviouslyinhibited the writhing responses of mice with dose 60mg/Kg, 100mg/Kg respectively.Comparison of the structures of the two derivatives indicates that the analgesicactivity may caused by their basic framework.