4-dimethylammino-cinnamaldehyde (DMAC) assays quantify total proanthocyanidins (PACs) but do not provide qualitative PAC molecular weight distribution information and cannot discriminate between A- and B-type PACs. We developed an efficient method for assessing PAC molecular weight distributions. The PACs from three commercial cranberry extracts (A1–A3) were fractionated by molecular sieves with cut-offs of 3, 10, 30, 50, and 100 kDa, and each fraction was analyzed by DMAC assays. A1, A2, and A3 contained 27%, 33%, and 15% PACs, respectively. Approximately 28 PACs, 20 flavonols, and 15 phenolic acids were identified by UHPLC-DAD-Orbitrap MS in A1 and A3, while A2 contained only flavan-3-ols. Epicatechin was the main monomer in A1 and A3, and catechin was the main in A2. Procyanidin A2 was the main dimer in A1 and A3, representing more than 85% of the total dimers, while it constituted approximately only 24% of A2. A1 and A3 contained quercetin, isorhamnetin, myricetin, and their glycosides, which were totally absent in A2. In A1 and A3 the PACs were mainly distributed in the fractions 30–3 and <3 kDa, while in A2 more than 70% were present in the fraction less than 3 kDa. Overall, obtained data strongly suggests that A2 is not cranberry-derived, or is adulterated with another source of PACs.
Evaluation of the degree of polymerization of the proanthocyanidins in cranberry by molecular sieving and characterization of the low molecular weight fractions by UHPLC-Orbitrap mass spectrometry / C. Gardana, P. Simonetti. - In: MOLECULES. - ISSN 1420-3049. - 24:8(2019), pp. 1504.1-1504.12.
|Titolo:||Evaluation of the degree of polymerization of the proanthocyanidins in cranberry by molecular sieving and characterization of the low molecular weight fractions by UHPLC-Orbitrap mass spectrometry|
GARDANA, CLAUDIO SEBASTIANO (Corresponding)
|Parole Chiave:||Vaccinium macrocarpon; proanthocyanidins; DMAC assay; UHPLC-DAD-Orbitrap MS; molecular sieve|
|Settore Scientifico Disciplinare:||Settore BIO/09 - Fisiologia|
|Data di pubblicazione:||2019|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.3390/molecules24081504|
|Appare nelle tipologie:||01 - Articolo su periodico|
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