ABSTRACT
The root of Anacyclus pyrethrum (L.) Lag., Asteraceae, is very widely used for treating various diseases in Traditional Uygur Medicine, particularly in the treatment of vitiligo. However, there have been few studies on the quality standards of A. pyrethrum in China. A. pyrethrum contains abundant N-alkylamides, which are considered to be the principal components. Therefore, based on the previous research in our group, six N-alkylamides were obtained by using column chromatography. We used ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry to determine the mass spectrometry cleavage mechanism of these six monomer components and established the mass spectrometry cleavage law of N-alkylamides. Then, we used the ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry method to rapidly identify and analyze the N-alkylamide components of the A. pyrethrum methanol extract. Finally, twenty N-alkylamides were identified, including eleven N-isobutylamides, two N-methyl isobutylamides, six 4-hydroxyphenylethyl-amide and one 2-phenylethylamide. Five of these compounds were identified as new compounds that have not been reported to date. Two of these compounds were identified for the first time in this herb. Therefore, this work provides an approach for the quality analysis of N-alkylamides in the root of A. pyrethrum. A search of the literature showed that the content determination in the A. pyrethrum quality standard is still a remaining problem. N-alkylamides are the main components of A. pyrethrum. Even though ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry has the advantages of lower time and higher efficiency compared to high-performance liquid chromatography, considering the ease of repeatability and universality of the quality control method, we chose to use high-performance liquid chromatography for content determination. In this experiment, high-performance liquid chromatography was used for the first time to establish a simple, rapid and accurate method for evaluating the N-alkylamide content in A. pyrethrum with five N-alkylamides used as the standards. Finally, this work provides a qualitative and quantitative method for the analysis of N-alkylamides in A. pyrethrum, improving the quality control standards for A. pyrethrum.
Keywords:
N-alkylamides; Quantitative analysis; Qualitative analysis
