New insights on the analysis of phytosterols in pollen and anther wall of tree peony (Paeonia ostii ‘Fengdan’) revealed by GC-MS/MS

Phytosterols exhibit a wide range of pharmacological activities and have no side-effects, which have attracted more and more attention. In this study, two pre-treatment methods (alkaline hydrolysis and acid-alkali hydrolysis) were performed in parallel for the first time to investigate the effects on phytosterol analysis. The aim is to develop an analytical method for phytosterols in pollen and anther wall of tree peony (Paeonia ostii 'Fengdan') by gas chromatography-mass spectrometry. The result indicated that the contents of phytosterols in pollen (3390.02 mg/100 g DW) and anther wall (929.70 mg/100 g DW) of P. ostii 'Fengdan' were relatively high. Meanwhile, eleven phytosterols were identified, among which five phytosterols were first identified in tree peony pollen. Moreover, the effects of wall breaking and different developmental stages on phytosterol contents of pollen and anther wall of P. ostii 'Fengdan' were also discussed. The result showed that wall breaking was beneficial to sterol detection of pollen, but not necessary for anther wall. For the best harvest time, the stage of S2 had the highest content of phytosterols. In conclusion, this study successfully establishes an analytical method for phytosterols by gas chromatography-mass spectrometry, and lays a foundation for the development and utilization of pollen and anther wall of P. ostii 'Fengdan' in functional foods and pharmaceutical industry.