Monoterpenoid Indole And Pyridine Alkaloids, Biomimetic Synthesis Of Gentian Soup Compound

Monoterpenoid indolopyridine alkaloids are a small group of alkaloids composed of trymptamine and substituted pyridine moieties, the latter being derived from a secologanin aglucone unit by insertion of nitrogen. In some cases the full C₁0 unit is present; in others it has been modified by removeal of the ester, vinyl, or other group. It is significant that most of the indolopyridines occur together with structurally related glycoalkaloids whose aglycones constitute obvious precursors for the pyridine units by condensation with ammonia, either endogenous or used in extraction procedures. Subsequent modification can then be rationalized in simple combinations of oxidation, addition of water, p-dicarbonyl or retro-aldol cleavages etc., all of which can occur spontaneously, and hence in many cases the alkaloids are artifacts. Ever since gentiopicroside become available in large quantities in this laboratory, it has been exploited as the starting material instead of secologanin in enantiospecific alkaloid synthesis. In general, the approach has been "biomimetic", following the key steps according to the similar mechanism that occur in nature or which are thought to occur. It also could contribute to elucidation of some aspects of the biosynthesis of these alkaloids, as well as providing a means of obtaining large quantities for pharmocological purposes of those only isolated in minor amounts.Compound prescriptions are the chief form of medication in the traditonal Chinese medicine. Different from the western drugs, the traditonal Chinese drugs possess very complex composition and the compound prescription, which consists of more than one drug, is of course even more complicated. During the decoction of the compound prescription, there may be some chemical change, quantitatively or qualitatively. The Long-dan decoction was used as example to compare the composition of compound prescription and individual drugs. The results showed that there were some changes during the decoction. Some components in the single drugs were disappeared during the decoction and some new components were created. The concentrations of some components were increased and some were decreased.