Biochemical and mass spectrometry recognition of phospholipid-peptide complexes in wheat sprouts extract

Total hydroalcoholic extract of wheat sprouts was treated with 90% cold acetone as a preliminary step directed to separate antioxidant peptides from antioxidant polyphenols. Surprisingly, the addition of acetone causes the formation of a yellow buoyant gelatinous drop that prevailingly contains peptides and phospholipids. In this context, evidences have been presented that support the hypothesis that peptides (and perhaps other active molecules) are complexed with phospholipids. In fact, the MS/MS analysis of some main ions, present in RP HPLC fractions of wheat sprout extract, generates several ions that correspond to molecular weight of phospholipids or phospholipid fragments. Moreover, several ions were detected that correspond to lysophosphatidylcholine or phosphatidylcholine-peptide complexes. The possibility that phospholipids can be complexed with peptides has been discussed in the light of potential involvement in the peptide bioavailability. © 2011 European Peptide Society and John Wiley & Sons, Ltd.