[Determination of the Amino Acids in the Raw and Processed Products of Turtle Shell by HPLC Combining Pre-column Derivatization].

Objective: To establish the pre-column derivatization combining HPLC to determine the contents of the amino acids of the raw and processed products of Turtle shell. Methods: The samples were prepared by the acidic hydrolysis method, derivatized by OPA and FMOC, and analyzed by C18 column with gradient elution. Results: 18 kinds of amino acids were separated within 38 min, which showed a good linear relationship( r ≥0. 9991). The average recoveries of 16 amino acids in the samples were between 90. 43% ~110. 69%,and the RSD were between 0. 76% ~ 5. 89%( n = 6). Conclusion: This method can be used to determine the contents of the amino acids in the raw and processed products of Turtle shell.

[Technical optimization for extracting hypotensive active peptides from Agrocybe aegerita].

OBJECTIVE: To optimize the techniques for extracting hypotensive active peptides from Agrocybe aegerita. METHODS: The effects of the liquid/solid ratio, extraction time and temperature, pH value of the initial liquid on the extraction percentage (EP) of the hypotensive active peptides were investigated, and inhibition percentage (IP) of the extracts on angiotensin I-converting enzyme was determined. RESULTS: Optimal extraction of the hypotensive active peptides from Agrocybe aegerita was achieved with the liquid/solid ratio of 40:1, extraction time of 3 h, extraction temperature at 30 degrees Celsius;, and pH=8 of the initial liquid. The EP of the hypotensive active peptides from Agrocybe aegerita could reach 87.7% with IP of the extracts on angiotensin I-converting enzyme of 54.0%. CONCLUSION: This method is simple and efficient for extracting hypotensive active peptides from Agrocybe aegerita.