Fig. 7: Recombinant SmLAC1 catalyzed the oxidation of procyanidins B1, B2, and B3 in vitro.

a–c UPLC analysis of the products from procyanidins B1, B2, and B3 under the catalysis of SmLAC1. d MS/MS spectra of the products 1, 2, and 3. e–g 1H NMR assignments of 14 protons on the six rings of products 1, 2, and 3, respectively. h–j 13C NMR assignments of 30 carbons in products 1, 2, and 3, respectively.