Structure elucidation and chemical profile of sphingolipids in wheat bran and their cytotoxic effects against human colon cancer cells

Sphingolipids are known to have diverse properties and physiological functions. These distinctive lipids have been identified in wheat bran, a food well-known for its chemopreventive activity. However, the complete profile of sphingolipids in wheat bran and their contributions to the cancer preventive effect of wheat bran have not been fully explored until this study. Twelve sphingolipids (1-12) were purified from wheat bran extract and characterized by analyzing their 1D and 2D NMR spectra, and seven sphingolipids (13-19) were characterized based on their tandem mass spectra (MSⁿ: n = 2-4). To the best of our knowledge, this is the first report of sphingolipids 1, 6-9, 11-14, and 16-19 in wheat bran. In particular, 2-N-(2′-hydroxy-15′- tricosenoyl)-4-hydroxysphinganine (peak 17) is a novel compound. Additionally, compounds 2-4 were reported with complete NMR data for the first time. Sphingolipids (1-12) showed little growth inhibition against human colon cancer cell lines (HCT-116 and HT-29) in vitro.