Detection of hepatotoxic pyrrolizidine alkaloids in Ligularia Cass. with LC/MSn / 药学学报

<p><b>AIM</b>To detect the hepatotoxic pyrrolizidine alkaloids (HPA) in the genus Ligularia Cass..</p><p><b>METHODS</b>The alkaloid extracts of Ligularia plant materials were detected and analyzed by the method of combination of TLC, and LC/MSn.</p><p><b>RESULTS</b>Among 22 species of Ligularia Cass., HPA were detected in 18 species with LC/MSn, and no HPA was detected in the remaining 4 species.</p><p><b>CONCLUSION</b>HPA was first detected with LC/MSn in L. tongelensis and other 15 species of Ligularia Cass.; HPA from these plants should be isolated, separated and identified and it is necessary to study the activities and toxicities of the HPA. The types and kinds of HPA from different species and sources are different, they should be detected separately.</p>

Analysis of impurity in caderofloxacin / 药学学报

<p><b>AIM</b>To analyse the main impurity of caderofloxacin.</p><p><b>METHODS</b>The impurity of caderofloxacin was analysed and determinated by RP-HPLC/ESI/MS with a Zorbax SB-C18 (150 mm x 4.6 mm ID, 5 microns) column. The mobile phase was acetonitrile-0.5% acetic acid solution (17:83). A compound was synthesized: 1-cyclopropyl-8-(difluoromethoxy)-6-fluoro-1, 4-dihydro-7-(1-piperazinyl)-4-oxo-3-quinoline carboxylic acid (DMCA). Its HPLC chromatogram, UV and MS spectrum were compared with those of the impurity in caderofloxacin.</p><p><b>RESULTS</b>The molecular weight of the impurity was 14 less than that of caderofloxacin. It means the impurity was a CH2-group less than caderoflixacin. The tR, UV and MS of DMCA were the same as those of the impurity in caderofloxacin.</p><p><b>CONCLUSION</b>Based on the tR (HPLC), UV and MS, the impurity of caderofloxacin is confirmed as DMCA.</p>

Study on the fingerprints of the alkaloids in Sophora flavescens / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a method for HPLC fingerprint determination of the alkaloids in S. flavescens.</p><p><b>METHOD</b>RP-HPLC, linear gradient elution, LC/MS, etc. were used to determine the fingerprint and identify the main peaks in the HPLC fingerprint.</p><p><b>RESULT</b>A satisfactory method for HPLC fingerprint determination of the alkaloids in S. flavescens. was established, and 5 peaks in the HPLC fingerprint were identified.</p><p><b>CONCLUSION</b>The perfect fingerprint can be obtained and the method can be used for quality control of S. flavescens.</p>

Determination of first-order structure of somatostatin by electrospray ionization mass spectrometry / 药学学报

<p><b>AIM</b>To determine the molecular weight and first-order structure of somatostatin.</p><p><b>METHODS</b>The molecular weight of somatostatin was determined by electrospray ionization mass spectrometry. Somatostatin was deoxidized by 2-mercaptoethanol. A series of typical fragment ions of deoxidized product were obtained by insource collision-induced dissociation (CID).</p><p><b>RESULTS</b>The m/z of quasi-molecular ion [M + H]+ of somatostatin was 1,637.8 and [M + Na]+ was 1,659.5. The m/z of double-charge ion [M + 2H]2+ was 819.5 and [M + H + Na]2+ was 830.3. It showed that the molecular weight of somatostatin was 1,636.7. The y and b series of fragment ions of deoxidized product were obtained by adjusting the fragmentor voltage. It was determined that the first-order structure of deoxidized product of somatostatin was A-G-C-K-N-F-F-W-K-T-F-T-S-C.</p><p><b>CONCLUSION</b>The molecular weight and first-order structure of somatostatin were confirmed.</p>

Impurity analysis and their structure determination of gatifloxacin / 药学学报

<p><b>AIM</b>To analyse the impurities of gatifloxacin.</p><p><b>METHODS</b>The impurity of gatifloxacin were analysized and determinated by RP-HPLC/electrospray ionization mass spectrometry with a Zorbax SB-C18(4.6 mm x 150 mm ID, 5 microns). The mobile phase was 3% acetic acid/acetonitrile-3% acetic acid/water (15:85). The two compounds were synthesized: 1-cyclopropyl-6-fluoro-1, 4-dihydro-8-methoxy-7-(1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid (DMP) and 1-cyclopropyl-6-fluoro-1, 4-dihydro-8-hydro-7-(3-methy-1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid (DMO). Their liquid chromatogram, UV, MS were compared with those of the impurity of gatifloxacin.</p><p><b>RESULTS</b>The mass of the impurity was 14 less than that of gatifloxacin. It means the impurity was CH2 less than gatifloxacin. The tR (HPLC), UV and MS of DMP were the same as those of the impurity of gatifloxacin.</p><p><b>CONCLUSION</b>Based on the tR (HPLC), UV and MS, the impurity of gatifloxacin is confirmed as DMP.</p>