Analysis of lipid composition and characterization of acyl steryl glycosides in rose petals by using nontargeted LC/MS

Edible roses are rich in bioactive metabolites including lipids and they are widely used in food and traditional medicine. The phytochemicals present in roses are known for their potential antioxidant, anticancer, and anti-inflammatory properties. Although roses have health benefits, comprehensive lipid composition data on roses are limited. To explore the lipid metabolites in rose samples, high-performance liquid chromatography with linear ion-trap Orbitrap mass spectrometry was applied in a non-targeted manner. The technique was used to comprehensively profile and correlate lipids in two cultivars of edible roses Sahime and Apple roses, which were harvested in Shimane Prefecture, Japan. A simple single-phase extraction of total lipids and their analysis in positive/negative ionization modes led to the identification of 166 molecular lipid species from five major lipid categories. The multivariate statistical analysis of each lipid molecule revealed species-specific differences between the two rose samples. In both the rose petal samples, saturated fatty acids were more dominant than monounsaturated and polyunsaturated fatty acids. Phospholipids, including phosphatidylcholine and phosphatidylglycerol, were significantly higher in Sahime roses than in Apple. Lysophosphatidylinositol and cardiolipin levels were significantly higher in Apple roses. Sphingolipids such as ceramides, were lower and hexosylceramides were higher in Sahime roses than in Apple roses. Furthermore, sterol lipids including acyl steryl glycosides (ASGs), steryl glycosides, and sulfoquinovosyldiacylglycerol were significantly higher in Sahime roses. In conclusion, a comprehensive lipid analysis was performed and several lipids such as ASGs, were characterized for the first time. This study revealed a detailed characterization of lipids and their comparative fingerprints in Sahime and Apple rose petals. Thus, edible roses have considerable potential for applications in the production of functional foods.