Fig. 8: In vitro non-enzymatic polymerization of (−)-epicatechin (EC) with either AsA-C or AsA-C-C.
From: A role for ascorbate conjugates of (+)-catechin in proanthocyanidin polymerization
a Detection of PA dimer formation (EIC at m/z 577.1351 ± 20 ppm). b Detection of PA trimer formation (EIC at m/z 865.1985 ± 20 ppm). c Detection of PA tetramer formation (EIC at m/z 1153.2619 ± 20 ppm). d Detection of PA pentamer formation (EIC at m/z 1441.3253 ± 20 ppm). e The ratio of the peak areas of the different PAs between the EC + AsA-C-C and EC + AsA-C reaction groups. Data are shown as the mean ± SD (for n = 3 independent replicates, paired comparisons between two reaction groups). f A model of AsA-C and AsA-C-C participating in PA polymerization as extension units. During PA oligomerization, AsA-C acts as the monomeric extension unit by sequentially adding a single building block, while AsA-C-C acts as the dimeric extension unit by sequentially adding two building blocks at once. Blue dashed lines with arrows indicate that PA by-products with even number degree of polymerization (DP) in EC + AsA-C-C are possibly sourced from the depolymerization of PAs with odd number DP. Source data of Fig. 8e are provided as a Source Data file.
