Pharmacokinetics of oxymatrine and its metabolite in beagle dogs by LC-MS / 中国中药杂志

<p><b>OBJECTIVE</b>To establish LC-MS method in the determination of oxymatrine and its metabolite in plasma and investigate their pharmacokinetics in beagle dogs.</p><p><b>METHOD</b>Lichrospher C18 column (4.6 mm x 250 mm, 5 microm) was used as the analytical column maintained at 25 degrees C. The mobile phase consisted of 10 mmol x L(-1) CH3COONH4 and CH3OH (25:75). Flow rate was 1 mL x min(-1). Electrospray ionization (ESI) was carried out. The ESI ion source was set in positive ion polasity mode. The selective ion monitoring (SIM) was set at m/z 265.1 and 249.2.</p><p><b>RESULT</b>The linearity ranged from 2 to 5000 ng x mL(-1) (r = 0.9991). The detection of oxymatrine and its metabolite were 0.6 and 0.3 ng x mL(-1). The RSD(%) within day and between day was less than 4.7%. The recovery of this method was more than 96.5%. The disposition was conformed to a two-compartment model. The T(1/2), Tmax, Cmax, MRT, AUC(0-->24 h) of oxymatrine were (5.5+/-1.58) h, (1.0+/-0.30) h, (2418.3 +/-970.78) ng x mL(-1), (3.2+/-0.64) h, (5797.4+/-908.16) ng x mL(-1) x h accordingly. The corresponding T(1/2), Tmax, Cmax, MRT, AUC(0-->24 h) of matrine were (9.8+/-2.77) h, (1.9+/-1.09) h, (1532.4+/-494.86) ng x mL(-1), (4.4+/-1.97) h, (5530.5+/-1042.65) ng x mL(-1) x h.</p><p><b>CONCLUSION</b>This assay was highly sensitive, rapid, simple and specific enough for determining concentrations of oxymatrine and its metabolite matrine in plasma of beagle dog.</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>

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>

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>