Structure of oligomeric proanthocyanidines from Hedysarum thienum roots studied by thiolysis and MALDI-TOF MS

Oligomeric proanthocyanidines from Hedysarum theinum roots that were cleaved by benzylmercaptan were shown to be heterogeneous mixtures consisting of prodelphinine and procyanidine structural units with the former dominating. Fractionation of oligomeric proanthocyanidines on polyamide and MCI gel CHP20P sorbent isolated fractions containing primarily mixtures of di- and trimeric, tri- and tetrameric, or tetra- and pentameric proanthocyanidines. Analysis by mass spectrometry (MALDI-TOF) showed that fractions of trimers and tetramers contained more proanthocyanidines with a single A-type bond than fractions of dimers and trimers.