Non-targeted lipidomics analysis of lipid distribution and variation of Eucommia ulmoides oliver by ultra-high performance liquid chromatography

Eucommia ulmoides Oliver (EU) is an important natural polymer source to relieve the serious shortage of natural rubber (NR), and the lipids of EU as potential non-rubber component have inherently a strong intramolecular connection to rubber biosynthesis. In this paper, Non-target lipidomics analysis platform based on ultra-high performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS) system was used to determine the lipids in EU. The orthogonal partial least square discriminant analysis (OPLS-DA) and a statistical analysis approach were used to compare the differences of lipids in EU. Total 6 categories, 26 classes and 785 species of lipids were identified in leaves, seed kernels, seed cases and barks of EU. The contents of EU lipids with time in female and male leaves were compared. The lipids contents in female EU leaves were more abundant than that in male EU leaves, and the content of most phospholipids in the female and male leaves both increased obviously after September. The content of lipids between seed cases and leaves were compared, and further screened for different glycerophospholipids between them. There were 53 phospholipids in the seed cases and fresh leaves samples of EU that had significantly different contents. Therefore, this study provides a theoretical basis for the identification of lipids in different EU organs and also helps further explore the relationship between lipids with rubber in EU.