Adsorption and purification of lotus seedpod proanthocyanidins by macroporous resin

14 types of macroporous resins were studied in order to compare their characteristics in absorbing and desorbing proanthocyanidins of lotus seedpod (LSPAs). Based on static adsorption, two better macroporous resins were chosen to carry out dynamic adsorption experiments, and the content and relatively molecular weight of LSPAs were analyzed. It was showed that DM130 was the optimal macroporous resin for separating and purifying LSPAs, and the optimum separating condition was as follows: LSPAs concentration 2.5mg/mL, flow rate 3BV/h, amount of saturated adsorption toward LSPAs 4~4.5BV. When the amount of elution was 5BV, 50% ethanol used as eluant, and the flowing rate was 3BV/h, the cumulation recovery of LSPAs purified by DM130 reached 96.43%, and the purity of LSPAs was the purity was increased from 22.54% to 95.31%. It was showed that the molecular weight of the purified product of LSPAs ranged from 291.1 to 1155.3 (M+H), and the polymerization ≤4 by further EI-MS analysis.