Optimization of chromatographic buffer conditions for the simultaneous analysis of phosphatidylinositol and phosphatidylinositol phosphate species in canola

The phosphatidylinositols and phosphatidylinositol phosphates are a set of closely related lipids known to influence various cellular functions. Irregular distributions of these molecules have been correlated with the development and progression of multiple diseases, including Alzheimer's, bipolar disorder, and various cancers. As a result, there is continued interest regarding the speciation of these compounds, with specific consideration on how their distribution may differ between healthy and diseased tissue. The comprehensive analysis of these compounds is challenging due to their varied and unique chemical characteristics, and current generalized lipidomics methods have proven unsuitable for phosphatidylinositol analysis and remain incapable of phosphatidylinositol phosphate analysis. Here we improved upon current methods by enabling the sensitive and simultaneous analysis of phosphatidylinositol and phosphatidylinositol phosphate species, whilst enhancing their characterization through chromatographic resolution between isomeric species. A 1 mM ammonium bicarbonate and ammonia buffer was determined optimal for this goal, enabling the identification of 148 phosphatidylinositide species, including 23 lyso-phosphatidylinositols, 51 phosphatidylinositols, 59 oxidized-phosphatidylinositols, and 15 phosphatidylinositol phosphates. As a result of this analysis, four distinct canola cultivars were differentiated based exclusively on their unique phosphatidylinositide-lipidome, indicating analyses of this type may be of use when considering the development and progression of the disease through lipidomic profiles.

Automated summary

Phosphatidylinositols and phosphatidylinositol phosphates are closely related lipids that have been found to impact various cellular functions and are correlated with the development and progression of diseases. The analysis of these compounds is challenging due to their unique chemical characteristics, and current lipidomics methods are unsuitable. In this study, a new method was developed to enable the sensitive and simultaneous analysis of phosphatidylinositols and phosphatidylinositol phosphates, allowing for the identification of 148 species. This analysis was able to differentiate four distinct canola cultivars based on their phosphatidylinositide-lipidome, suggesting the potential use of lipidomic profiles in studying disease development and progression.