Ph On The Compatibility Of Chemical Medicine Rhubarb And Aconite Decoction Of Rhubarb And Aconite

Objective: The study on chemical compatability of Dahuang-Fuzi Decoction is a part of the research program aided by Chinese National Nature Foundation and presided by Professor Pei Miaorong. The aim of the study is to invetigate the interation and change patten of the acid-alkaline pair drugs in the Recipe, to deduce the structure of the double salt formed by rhein and aconitine, by systemicly studying the informations got from the fingerprints of the acid components and the alkaline components.Methods:The samples were made from water decoction, water decoction centrifugation, ethanol circumfluence extract, ethanol supersonic extract of Dahuang (Rheum palmatum L.), Fuzi (Aconitum carmicaeli Debx.), pair drugs, and whole recipe. The variance of the acidic anthraquinones and the aconite alkaloids were examined through the fingerprints of each extracts by HPLC.The double salt of standard rhein and aconitine was made by simulating water decoction. The binding energy of the resulting salt was detected by X-ray photoelectron spectrograph and the ground charge distribution was caculated by quantum chemistry density functional theroy to deduce the structure of the salt.Results:(1)The aconite alkaloids: the monoester aconite alkaloids could only be detected from water decoction samples, both monoester and biester aconite alkaloids could be detected from ethanol extracts. The total amounts of aconite-like alkaloids had a tendency to decrease with the changes of compatibility from single drug to pair drugs and drug combinations in samples of water decoction and water decoction centrifugation, and were not significantly different in ethanol circumfluence extracts. The total amounts of aconite-like alkaloids of water extracts in single drug were above 25% higher than that in pair drugs, and were lowest in drug combinations. (2) The acidic anthraquinones: the total amounts of anthraquinones had a tendency to decrease with the changes of compatibility in samples of water decoction, and water decoction centrifugation, and to increase in samples of ethanol circumfluence extracts. The amounts of anthraquinones of water extracts detected in drug combinations were above 12% higher than that's in pair drugs, and that's in pair drugs were above 12% higher than that's in single drugs. The results of ethanol supersonic extract were not considered in for insufficient extraction.The structure of the double salt of rhein and aconitine: The lone-pair electrons on the N-atom of the aconitine molecule have higher negative charge and can provide electrons. The C-atom in benzoquinone of the rhein molecule has higher positive charge and can recive electrons. Rhein and aconitine can form chargetransfer complexes in certain conditions. The binding enegy will increase when the N-atom of aconitine molecule lose electron, and decrease when the C-atom in rhein molecule recives electron.Conclusion:The acid and alkaline components contained in Dahuang and Fuzi pair drugs could form insoluble double salt in both water solution and ethanol solution, reducing the amounts of toxic aconite-like alkaloids and the amounts of anthraquinones in pair drugs and drug combinations, thus reducing the toxicity of Fuzi, and neutralizing the purgitive effects of Dahuang. The formation of double salt can be promoted by adding Xixin. The results confirm the rationality of Dahuang and Fuzi compatibility from chemistry concerns. The result provides a new idea and method to study traditional Chinese recipes from the point of view of chemical monoids.The aconite alkaloids contained in Fuzi can readily be hydrolyzed in water solution, but the ester bond will difficult to break in ethanol. The amount of anthraquinones contained in Dahuang in water extracts is 2.4 times more than that in ethanol extracts. The results will be useful in new drug development and research from Dahuang Fuzi Decotion and other recipes containing Dahuang and Fuzi.The double salt of rehin and aconitine is a chargetransfer complex formed by C-atom in benzoquinone group of rhein molecule with N-atom in aconitine deacetylate derivative (hypaconitine). The extrapolation of the structure establishes a basis for future study of the double salt, and open a new reseach field for formula chemistry.