UPLC-MS fingerprints, phytochemicals and quality evaluation of flavonoids from Abrus precatorius leaves

Abrus precatorius leaves (APL) are one herb with the function of preventing and treating diabetes and widely used in health care and tea drinking in China. The objective of this study was to investigate the fingerprints, phytochemicals and quality evaluation of flavonoids from APL. Seven flavonoids were isolated and identified by NMR, ESI-MS and UV, with compounds 1-4, 6 from APL for the first time. An UPLC-ESI-Q-TOF/MS method was first established to evaluate the fingerprints. Similarity results showed that the overall quality of APL from different sources was relatively stable, but there were also some content differences, which could be used for regional classification. Total 29 compounds were identified by UPLC-MS/MS. An HPLC method was established to simultaneously determine the contents of seven flavonoids and could be used to identify and distinguish the quality of APL. The content of flavonoids in APL from different sources was 2.31-11.0%. This is the first report on the fingerprints, HPLC method and quality profile of seven flavonoids from APL.