Study on LC-MS fingerprint for quality assessment of Aristolochia manshuriensis with chemical pattern recognition / 中国中药杂志

<p><b>OBJECTIVE</b>To analyze LC-MS fingerprints of Aristolochia manshuriensis for quality assessment with two different chemical pattern recognition models.</p><p><b>METHOD</b>LC-MS fingerprints of A. manshuriensis were established from 24 batches of samples from different habitats. SIMCA and Clustering analysis were used to compare the parameters of the 29 common peaks.</p><p><b>RESULT</b>Two methods had good consistency, while they reflected the inherent sample information from different perspectives, respectively.</p><p><b>CONCLUSION</b>Modern equipment analysis technology and multivariable chemical pattern recognition would be an efficient way for quality control and variety identification of A. manshuriensis.</p>

Application of HPLC-ESI-ITMS in the quality control of carboxyterminal sequence confirmation for insulin and insulin chain B / 药学学报

Application of HPLC-ESI-ITMS in the quality control of carboxyterminal sequence confirmation for insulin and insulin chain B was studied. The solution of intact insulin or insulin chain B was added to the solution of carboxypeptidase P (CPP) and carboxypeptidase Y (CPY). Fractions of appropriate volume were removed at some appointed time points, acidified with the same amount of 1% formic acid to stop the digestion, and then briefly vortexed for HPLC-ESI-ITMS analysis. Mobile phase A consisted of 0.02% TFA in 98% ultra-pure water and 2% acetonitrile. Mobile phase B consisted of 0.02% TFA in 98% acetonitrile and 2% ultra-pure water. The solution used for post-column fix consisted of propionic acid and isopropyl alcohol (20 : 80, v/v). Chromatographic separation was carried out on a reversed-phase column (Zorbax Prosphere C18, 300A, 5 microm, 2.1 mm ID x 150 mm length). The molecular weights of the multiply charged ions representing consecutive truncated losses of carboxyterminal amino acids were determined by the use of HPLC-ESI-ITMS. The differences between the consecutive truncated peptides are the experimental weights of the carboxyterminal amino acid residues. The carboxyterminal amino acid residue Ala, which released from chain B of intact insulin, was confirmed in the nanomolar concentration range by analyzing the molecular weight of the truncated peptides. Another one carboxyterminal amino acid Ala was confirmed in the nanomolar concentration range of insulin chain B. In the quality control for recombinant DNA product or natural protein, the confirmation of 1 - 3 carboxyterminal amino acid residues is regarded to be up to standard. One amino acid residue of insulin or insulin chain B could be confirmed accurately in the nanomolar concentration range. The results showed that intact insulin could be directly sequenced in the quality control without separating chain B from chain A. There would be no need to separate chain A from chain B to identify carboxyterminal of intact insulin. Furthermore, the method saved us a lot of trouble from the preparation and purification of insulin chain A and chain B.