Determination of deuterium incorporation of new drug donafenib tosilate by two methods of LC-MS with natural isotope abundance correction and 1H NMR relative quantitative method / 药学学报

An LC-MS method with natural isotope abundance correction and a 1H NMR relative quantitative method were established to determine the deuterium incorporation of donafenib tosilate, a new deuterated drug molecule. First, the peak areas of isotopic impurities (non-deuterated and incompletely deuterated impurities) and deuterated drug were recorded through the single ion monitoring (SIM) mode of the established LC-MS method and then corrected in terms of the natural isotope abundance offered by ChemDraw soft, removing the nature isotope interference from 13C, 37Cl, etc. The corrected areas were subsequently used to calculate mol% of isotopologues (D0, D1, D2, D3) and Atom% D, namely, deuterium incorporation. In addition, a 1H qNMR experiment was conducted with the aromatic proton at δ 8.63 and the residual proton of isotopic impurities at δ 2.79 as quantitative peaks. The mixture of DMSO-d6 and D2O (10∶1) was employed as the solvent to change the spin-coupling between the residual proton and active hydrogen so that the residual proton could be measured as the single peak, and the sensitivity was greatly improved. The acquisition parameters were also optimized, and Atom% 1H and the deuterium incorporation were then calculated. The two methods were applied to samples of three commercial batches, and the testing results were almost consistent. Both methods proved accurate, sensitive, fast and independent of standard substances and accurate weighing, which could be applied to the determination of the deuterium incorporation of donafenib tosilate and provide a reference for other deuterated drugs.

Determination of terpene lactones in Ginkgo biloba leaves in different ages by UPLC-TQ-MS / 中国中药杂志

<p><b>OBJECTIVE</b>To establish an ultra-high performance liquid chromatography coupled with triple quadrupole mass (UPLC-TQ-MS) for determination of four terpene lactones.</p><p><b>METHOD</b>Chromatographic separation was carried out on a ACQUITY UPLC BEH C18 column (2.1 mm x 100 mm, 1.7 microm) with isocratic elution of 70% methanol at a flow rate of 0.4 mL x min(-1), the column temperature was set at 30 degrees C; Waters Xevo TQ worked in multiple reaction monitoring mode.</p><p><b>RESULT</b>All calibration curves were linear (r > 0.990 3) over the tested ranges. The average recoveries ranged from 98.83% to 103.9% with RSD value below 3.0%. The contents of total terpene lactones in Ginkgo biloba leaves were significantly different in different ages. The contents in the leaves of young ginkgo tree were higher than that in old tree.</p><p><b>CONCLUSION</b>The method was simple and fast with high precision, sensitivity and repeatability, which can be used for qualitative and quantitative analysis of terpene lactones in G. biloba leaves.</p>

Study on optimization of drying method and its mechanism in Ginkgo biloba leaves / 中国中药杂志

To provide a scientific evidence for the initial primary processing method, an ultra-high performance liquid chromatography combined with a triple quadrupole electrospray tandem mass spectrometry (UPLC-MS/MS) was used to analyze the contents variation of catechins, flavonoids, flavonoid glycosides, biflavones, terpene lactones and phenolic acids during the process of drying in the sun, in the shade, and baked with 35, 45, 60, 80 degrees C, respectively. The results show that drying in the 80 degrees C is conducive to the accumulation of catechins, flavonoid glycosides, terpene lactones, better than the effects of other procedures. Therefore, the fast drying at 80 degrees C is beneficial for the retention of various types of active ingredient of Ginkgo biloba, and this method could be applied as a preferably dry processing.

Metabolism of naringin produced by intestinal bacteria / 药学学报

Naringin has been reported to possess a wild range of biological activities. However, the route and metabolites of naringin produced by intestinal bacteria are not well understood. In this paper, different bacteria were isolated from human feces and their abilities to convert naringin to different metabolites were studied. Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) with automated data analysis software (MetaboLynx) was applied to fast analysis of naringin metabolites. Using MSE and mass defect filter techniques, three metabolites were detected and tentatively identified. The results indicated that acetylation, hydrolyzation and hydrolyzation with hydrogenation were the major metabolic pathways of naringin in vitro. Then, we studied the gene sequence of the 16S rRNA of the bacteria by extraction of genomic DNA of the strain, PCR amplification and clone of the 16S rRNA. The consequence proved that Enterococcus sp.30, Bacillus sp.46, Escherichia sp.54 and Escherichia sp.63 have the peculiar metabolism characteristic of naringin.

The incompatibility mechanism based on the interaction of multiple-components for Flos Genkwa and Radix et Rhizoma Glycyrrhizae / 药学学报

By investigating the interaction between components from Flos Genkwa (FG) and Radix et Rhizoma Glycyrrhizae (RRG) and the dissolution profile of toxic components in co-decoction, the characteristics and possible mechanism of incompatibility were revealed. Ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and ultra-high performance liquid chromatography triple-quadrupole mass spectrometry (UPLC-TQ/MS) were used to analyze multi-components in different herb extractions prepared by different ratios of FG/FG processed by vinegar (FGV) and RRG, which reflect the interaction and characteristics of multiple components in incompatibility combinations. The results showed that the components dissolution was influenced by compatibility ratio with certain regularity. Whether FG processed by vinegar or not, with the increase of RRG in co-decoction, the dissolution of diterpenes, especially for yuanhuacine, yuanhuadine and yuanhuajine, the toxic ingredients of FG, increased significantly. From these results, the material basis and one possible mechanism of incompatibility between FG and RRG is the increasing dissolution of diterpenes, toxic components of FG in co-decoction process, which caused by interaction between multi-components in these two herbs.

Construction of a rapid identification method for chemical constituents in traditional Chinese medicine based on liquid chromatography-hybrid mass spectrometry-database / 中国中药杂志

<p><b>UNLABELLED</b>To establish a rapid component identification method for chemical constituents contained in traditional Chinese medicines and natural products by using liquid chromatography-mass spectrometry database technology.</p><p><b>METHOD</b>Ultra-high performance liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was applied to collect the retention time and mass spectrum data of chemical constituents contained in traditional Chinese medicines and natural products, and establish a mass spectrum database. The Identify function from Chromalynx XS module in Masslynx workstation was applied to identifiy each chromatographic peak in an automatic and rapid manner. The retention time correction method was used to correct the retention time of identical compounds in different chromatographic systems, in order to improve the adaptability of the method.</p><p><b>RESULT</b>Currently, the UPLC-MS library contains LC-MS information of more than 210 such chemical constituents as alkaloids, flavonoids, quinones, phenylpropanoids and terpenes, including retention times, xact molecular weights of quasi-molecular ion peaks and their fragment ions under positive and negative modes, respectively. The detection rate of identifying samples by suing the method was around 90%.</p><p><b>CONCLUSION</b>Compared with manual identification, the method is simple, rapid and highly accurate. The usage of the linear correction for retention times helps solve the disunity of mass spectrum databases caused by different retention times in different chromatographic systems to a certain extent, and expand the application range of the method.</p>

Identification of the metabolites of Sinisan extract in rat plasma, urine, feces and bile after intragastric administration / 药学学报

Sinisan is a widely used traditional Chinese medicine (TCM) in treating various diseases; however, the in vivo metabolic profile of its multiple components remains unknown. In this paper, ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was applied to identify the metabolites of Sinisan extract in rat plasma, urine, feces and bile after intragastric administration. Using MS(E) and mass defect filter techniques, 41 metabolites of 10 parent compounds (naringin, naringenin, hesperidin, neohesperidin, liquiritin, liquiritigenin, glycyrrhizic acid, glycyrrhetinic acid, saikosaponin a and saikosaponin d) were detected and tentatively identified. It was shown by our results that these compounds was metabolized to the forms of hydroxylation, glucuronidation, sulfation, glucuronidation with sulfation and glucuronidation with hydroxylation in vivo.