[The impurity profiling of paclitaxel and its injection by UPLC-MS/MS].

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method was developed to elucidate the impurity profiles of paclitaxel and paclitaxel injections from different Chinese pharmaceutical companies. The fragmentation patterns for paclitaxel and the related impurities were analyzed and summarized. To remove the interference from auxiliary materials, such as hydrogenated castor oil, paclitaxel was dissolved in ethanol for acid, base, peroxide, and light induced forced degradation analysis, which could produce all the impurities exist in the paclitaxel injection. A total of 10 impurities were characterized, such as cephalomannine (1), 7-epi-10-deacetylpaclitaxel (2), 7-epipaclitaxel (3), baccatin Ⅲ (4), ethyl ester side chain (5), 7-epi-baccatin Ⅲ (6), 10-deacetylpaclitaxel (7), paclitaxel isomer(C3-C11 bridge) (8), paclitaxel isomer (9), and N-benzoyl-(2R,3S)-3-phenylisoserine (10), respectively. Among them, compounds 1-3 could be introduced during manufacture processing. In the forced degradation studies, while acid induced degradation products included 3-7, base induced degradation could produce 2-7 and 10; while 7 is the main compound produced by hydrogen peroxide treatment, 4 compounds (3-5 and 7) were produced by high temperature environment and 5 compounds (2-5 and 9 which is the first reported) from intensity light exposure. Furthermore, 8 was the main impurity came from intensity light exposed paclitaxel powder. The results from this study provide an important reference in processing, optimization, quality control and evaluation of paclitaxel.

[Quantitative determination of bosentan by proton nuclear magnetic resonance with internal standard method].

The study aims to establish a quantitative nuclear magnetic resonance (QNMR) method for the determination of the absolute content of bosentan. Proton nuclear magnetic resonance spectroscopy [1H NMR] spectra were obtained in CDCl3 with the internal standard dimethyl terephthalate and zg30 pulse sequence by using a Bruker AVANCE II 400 spectrometer. The content of bosentan is determined with QNMR in comparison with the result obtained by mass balance method. The result is 96.25% by QNMR and 96.54% by mass balance method. A rapid and accurate QNMR method has been established for the quantitative determination of the absolute content of bosentan. The study provides a new way for the quality control and calibration of a new reference standard material, it could be the complementary with the mass balance method for the assay of standard reference.

A case of Klinefelter syndrome with aplastic anemia.

In this manuscript, we report the first patient who suffered from Klinefelter syndrome with aplastic anemia and hyperprolactinemia.

Novel coumarin and furan from the roots of Angelica pubescens f. biserrata.

A new natural coumarin, angepubebisin (1), and a new furan, angepubefurin (2), together with the five known compounds, umbelliferone, angelol B (3), ulopterol (4), peucedanol (5), and scopoletin, were isolated from the roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan. The structures of angepubebisin (1) and known compounds were determined by spectroscopic methods, including IR, UV, EI-MS, HR-FTICR-MS, 1D-, and 2D-NMR spectral analyses, and angepubefurin (2) was determined by HR-FTICR-MS and X-ray diffraction analyses.