ABSTRACT
Objective: There are some anthraquinones, anthraquinones and flavonones in Sennae Folium which exhibited significant acidity, such as sennoside A/B and sennoside C/D. The current strategies used in separating these components are mainly based on conventional column chromatography which is time consuming, laborious and costly. This study is aimed at exploring a method of precipitation extraction of acid components in Sennae Folium. Using alkaloid as a “hook”, it is reasonable to use the principle of “acid-alkali complexation” to "fish" the acidic components in Sennae Folium. Methods: Isothermal titration calorimeter (ITC) was used to measure the extraction efficiency of different alkaloids. Then, alkaloid determined by ITC was mixed with extracting solution of Sennae Folium to form complex. High performance liquid chromatography coupled with mass spectrometry (HPLC-MS2) was used to investigate the ingredients “fished” by berberine (Ber). The mechanism of “fishing” process was explained by ITC, optical activity, fluorescence spectrometry and scanning electron microscope. Results: The ITC results proved that the choice of “hook” was particularly important in the process of “fishing”. Among the hooks, the fishing efficiency of the isoquinoline alkaloids (Ber) was the highest, reaching 10.3%. Nine ingredients were detected and determined by HPLC-MS2, and the main components were sennoside A/B and sennoside C/D. Based on ITC test of Ber and sennoside A, the combination mechanism of the two ingredients was a chemical reaction with a nearly binding ratio (2:1). Fluorescence and optical properties of the active ingredients were changed after complexation. By scanning electron microscope, we found that two types of components had obviously self-assembled behavior during the formation process. Conclusion: Ber successfully “fished” the main acidic components, sennoside A/B and sennoside C/D, from Sennae Folium. Combined with different characterizations, the “fishing” process was determined as a chemical association reaction induced by electrostatic interaction or π-π stacking. Therefore, with special identification ability, the “fishing” process had the potential of practical application.
ABSTRACT
It has been focused on that there will be precipitates when decoction of Scutellariat Radix mixed with Coptidis Rhizoma. Precipitation was derived from interaction between acidic and basic compounds. This study was based on the interaction between active ingredients after compatibility, strived to explore whether it was feasible to judge the qualities of different Scutellariat Radix by isothermal titration calorimetry (ITC), build a new method established to characterize the qualities of traditional Chinese medicine by taking a series of active ingredients as index. We selected Scutellariat Radix (including three batches of different Scutellariat Radix bought from market and immature Scutellariat Radix which usually was used as adulterant) in different batches as the samples. First, we used ITC to determine the binding heat of the reactions between berberine and the decoctions of different Scutellariat Radix. The test showed that the binding heat of berberine titrated Scutellariat Radix was Scutellariat Radix A (－317.20 μJ), Scutellariat Radix B (－292.83 μJ), Scutellariat Radix C (－208.95 μJ) and immature Scutellariat Radix (－21.53 μJ), respectively. We chose deionized water titrated by berberine (2.51 μJ) as control. The heat change of berberine titrated immature Scutellariat Radix was much less than berberine titrated Scutellariat Radix. Then we determined the absorbance of different decoctions of Scutellariat Radix by UV Spectrophotometry on the maximum absorption wavelength, and the result is： Scutellariat Radix A (0.372), Scutellariat Radix B (0.333), Scutellariat Radix C (0.272), immature Scutellariat Radix (0.124). The absorbance of immature Scutellariat Radix was also less than Scutellariat Radix. The result of ITC assay was corresponded to UV spectrophotometry test. In conclusion, ITC could be used to characterize the quality of Scutellariat Radix. The new method to characterize the qualities of traditional Chinese medicine by taking a kind of active ingredients as index building by ITC was simple, scientific and feasible.
ABSTRACT
Recently, the Chinese materia medica (CMM) compatibility theory research was focused on aspect of chemical composition, which is an important strategy to explain the principle of prescriptions. There are various chemical compositions in a compound prescription of CMM, including alkaloids, glycosides, organic acids, tannins, protein, micro elements and so on. Complex interactions always inevitably occur during the water decoction process of CMM prescription after the dissolution of active ingredients, most significantly, it also generates the precipitation. Clinically, traditional Chinese medicines (TCM) treat diseases with both precipitation and decoction. Precipitation generated process might contain the scientific connotation of CMM compatibility. Thus, the scientists had been studying the precipitation from this process. Through summarizing the results of related researches in recent years, this review introduces different interactions of various active ingredients in compound prescriptions and research progress of precipitation in decoction, aiming to lay a foundation for further study on the precipitation from CMM decoction and provide a new idea to explain the theory of CMM compatibility.