Proanthocyanidin Structural Details Revealed by Ultrahigh Resolution FT-ICR MALDI-Mass Spectrometry, H-C HSQC NMR, and Thiolysis-HPLC-DAD.

Proanthocyanidins (condensed tannins) are important in food chemistry, agriculture, and health, driving demand for improvements in structure determination. We used ultrahigh resolution Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) methods to determine the exact composition of individual species in heterogeneous mixtures of proanthocyanidin polymers from grain and leaves. Fragmentation patterns obtained with FT-ICR ESI MS-MS (electrospray ionization) confirmed structural details from thiolysis-high-performance liquid chromatography (HPLC)-diode array detection (DAD) and H-C heteronuclear single quantum coherence (HSQC) NMR.