| The composition and oxidation and reduction properties of crude cyclolinopeptides extracted from natural flaxseed were studied. HPLC was employed to detect the contents of cyclolinopeptide C(CLC), cyclolinopeptide E(CLE), cyclolinopeptide D(CLD) and cyclolinopeptide A(CLA) in crude flaxseed cyclolinopeptides. Reduction was used to aid the separation of monomer as it could reduce the types of cyclolinopeptide in the crude cyclolinopeptides effectively. The results indicated that the cyclolinopeptides were separated well, and the linear range and correlation coefficient were 10-150 μg/mL(10-100 μg/mL for CLA) and 0999 0-0999 7, respectively. The contents of CLC, CLE, CLD and CLA in the crude cyclolinopeptides were 8.10%, 7.66%, 0.58% and 35.18% respectively. The cyclolinopeptide type in crude cyclolinopeptides could be transformed by oxidation or reduction reaction. According to the results of qualitative HPLC analysis, 6 cyclolinopeptides were left after oxidation, while only 4 cyclolinopeptides were left after reduction and were respectively determined as CLB, CLL, CLA and CLM by comparing with the standard cyclolinopeptides. Besides, they were separated well by C18 column, based on this, singular cyclolinopeptide was separated effectively in 50 min by preparative HPLC using Microsorb 100-5 C18 column （240 mm × 21.4 mm） under the conditions of column temperature 30℃, flow rate 5 mL/min and an isocratic elution of 70% acetonitrile solution. |
