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OBJECTIVE To establish a method for simultaneous determination of atorvastatin （ATV） and its active metabolites 2-hydroxy atorvastatin acid （2-HAT）， 4-hydroxy atorvastatin acid （4-HAT） and toxic metabolite atorvastatin lactone （ALT） in rat plasma and apply it for pharmacokinetic study. METHODS LC-MS/MS method was adopted for analysis. The one-step precipitation method was used for processing plasma samples （plasma samples were pretreated by acidification to adjust pH value so as to prevent inversion of configuration）， gradient elution was used to analyze the samples， and the analysis time was 5 min. Electrospray positive ionization was adopted， and positive ion scanning was performed in multi-reaction monitoring. The m/z of quantified ion pairs of ATV and its metabolites such as 2-HAT， 4-HAT and ATL， and internal standard pitavastatin were 559.3→ 440.2， 575.2→440.3， 575.0→440.2， 540.9→448.2 and 422.2→290.0， respectively. After conducting a comprehensive methodological investigation of the analytical method， the concentrations of ATV and its metabolites 2-HAT， 4-HAT，and ATL were determined， and the pharmacokinetic parameters of ATV and its metabolites were calculated using the non- compartment model of WinNonlin 6.1. RESULTS The results of methodological validation showed that endogenous substances in blank plasma did not interfere with the determination of the components to be tested， and the standard curve had a good linear relationship； the lower limits of quantification for ATV， 2-HAT， 4-HAT and ATL were 0.5， 0.5， 0.25 and 0.063 nmol/L， respectively. The precision， accuracy， recovery， matrix effect and stability investigation were all in line with the requirements of biological analysis. Pharmacokinetic analysis showed that after intragastric administration in rats， ATV calcium metabolized rapidly， and was mainly exposed to blood circulation in the form of ATV and 2-HAT， with the lowest concentration of lactone-type metabolites. CONCLUSIONS The established method is precise， rapid and accurate for plasma concentration analysis of ATV and its active/toxic metabolites. The application of the method could help to fully elucidate the pharmacokinetic characteristics of atorvastatin calcium in rats.
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The function of Traditional Chinese Medicine (TCM) represents the overall effect of the formula. The effect is the expression of numerous biological effects of chemical components of TCM in certain pathological conditions of the body function adjustment, and these chemicals are the material basis of the TCM function. Limited by many conditions, few studies have been done on the material base of TCM function, and most of them have been supplemented by the substance basis of TCM efficacy. This leads to the disconnection between the theory of traditional Chinese medicine and modern research, and it is difficult to scientifically explain the functional indications of Chinese medicine. This paper discusses and summarizes the ideas and methods of modern research and evaluation of the material base of TCM function.Under the guidance of TCM theory and clinical practice, we set up an index system for evaluating the TCM function, and further explained the material basis and action mechanism of TCM formula. Through the organic combination of multidisciplinary and multi-technology, it provides a reference for the establishment of a comprehensive research model of the functional material basis of TCM formula.
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Since alkaloids are the major active constituents of Rhizoma corydalis (RC), a convenient and accurate analytical method is needed for their identification and characterization. Here we report a method to profile the alkaloids in RC based on liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS/MS). A total of 16 alkaloids belonging to four different classes were identified by comparison with authentic standards. The fragmentation pathway of each class of alkaloid was clarified and their differences were elucidated. Furthermore, based on an analysis of fragmentation pathways and alkaloid profiling, a rapid and accurate method for the identification of unknown alkaloids in RC is proposed. The method could also be useful for the quality control of RC.
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Objective To study the collision-induced dissociation fragmentation pathways of the jasminoidin and catalpol in ESI-Msn. Methods The samples were studied by using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-Msn) both in positive and negative. Results The collision-induced dissociation fragmentation pathways of both compounds were described. In the spectrum of two compounds, the loss of glucose residue and whole glucose were observed in positive mode, while only the loss of glucose residue could be observed in negative mode. Furthermore, we found that as the effect of the substituting groups, the fragment ions of jasminoidin were more in positive mode and those of catalpol were more in negative mode. Conclusion Conclusion The established method could be used for the sensitive and rapid identification of this kind of iridoid glycosides。