LAUSR

Oats are commonly consumed as whole grains and generally considered as a healthy food. However, the bioactive compounds in oats have not been fully investigated. In this study, we reported for the first time the purification, structure elucidation, and chemical profile of the major triterpenoid saponins in oat bran as well as the quantification of the major triterpenoid saponins in commercial oat products. Thirteen triterpenoid saponins (1-13) were purified from oat bran. Their structures were characterized by analyzing their High-Resolution MS, 1D, and 2D NMR spectra. All the purified triterpenoid saponins have been reported from oat bran for the first time, in which compounds (1-8) are newly discovered compounds and compound (9) is a new natural product. Using ultra-high-performance liquid chromatography with tandem mass spectrometry techniques, a complete profile of oat triterpenoid saponins was established, and the contents of the thirteen purified triterpenoid saponins were quantitated in nineteen different commercial oat products. The total levels of the thirteen triterpenoid saponins varied from 1.77 to 18.20 μg/g in these nineteen products, in which oat bran (11 samples) and oatmeal (3 samples) had higher levels than cold oat cereal (5 samples). Among the eleven commercial oat bran samples, the average total levels of the thirteen triterpenoid saponins in the five sprouted oat samples are slightly higher than those in the regular oat bran products.