Analysis on protein polypeptide in Zhenzhuye and Zhengzhu Mingmu Eye Drops / 中草药

ABSTRACT

Objective: Analysis for the differences of protein polypeptide ingredients in Zhenzhu Mingmu Eye Drops and Zhenzhuye in order to provide the reference data to ensure the stability of production process of crude material and effectively control the quality of Zhenzhu Mingmu Eye Drops. Methods: Polypeptide ingredients in Zhenzhu Mingmu Eye Drops and Zhenzhuye were identified by UPLC-Q-TOF MS in positive mode using an Acquity UPLC BEH C18 (50 mm×2.1 mm, 1.7 μm) column. Mobile phase is acetonitrile-0.1% methanol; Contents of 16 amino acids were detected by pre-column derivatization RP-HPLC method. Results: Molecular weight (MW) of polypeptide and the contents of the amino acids in Zhenzhu Mingmu Eye Drops and Zhenzhuye were significantly different. In the five manufacturers, MW of polypeptide was less than 2000 in Zhenzhuye samples from the three manufacturers, while MW of polypeptides were 500-4746 for samples of the other two manufacturers and MW of main polypeptides were higher than 2000.MW ranges of main polypeptides in Zhenzhu Mingmu Eye Drops from two manufacturers were 2000-4000 and beyond 4000. There were not the polypeptides with MW beyond 4000 in samples of the other five manufacturers. The content percentages of 16 amino acids in Zhenzhu Mingmu Eye Drops from the seven manufacturers were obviously different. The mass concentration ratios of proline and alanine in Zhenzhuye produced by acid/enzyme hydrolysis from two manufacturers are beyond 1.For the other five manufacturers with water extract technique, the mass concentration ratios of proline and alanine are below 1. Conclusion: The quality standard of Zhenzhuye should be revised and water extract should be applied in preparation process to ensure the effective ingredients polypeptides (500-5000). In quality standard of Zhenzhu Mingmu Eye Drops and Zhenzhuye, the mass concentration ratio of proline/alanine and the total contents of amino acids should be added as check and content determination items, respectively, so as to effectively control the quality of Zhenzhu Mingmu Eye Drops and ensure its validity.