Effect of Constituent Units, Type of Interflavan Bond, and Conformation on the Antioxidant Properties of Procyanidin Dimers: A Computational Outlook

Table 3

Bond dissociation enthalpy (BDE) of the procyanidin dimers calculated in aqueous medium (SMD model) using the M05-2X/6- DFT method.

Procyanidin dimer	BDE (kcal/mol)
	Extension unit (EU)				Terminal unit (TU)
	3′-OH	4′-OH	5-OH	7-OH	3′-OH	4′-OH	5-OH	7-OH
PB3 Com	85.51	82.36	88.57	88.77	84.04	83.03	87.27	87.21
PB3 Ext	84.60	81.87	88.53	89.92	86.11	82.42	86.51	85.78
PB4 Com	86.27	83.03	88.28	88.79	85.70	82.42	86.96	87.10
PB4 Ext	83.85	81.91	88.27	89.11	85.32	82.28	86.89	86.98
PB5	86.45	83.57	90.64	92.79	86.53	83.30	84.98	89.07
PB6	86.16	82.87	88.46	90.86	85.83	82.50	85.53	87.42
PB7	86.83	82.96	90.60	92.79	85.82	82.50	84.72	88.70
PB8	85.78	82.50	88.71	90.98	86.37	83.33	85.26	86.84

PB3 (C4α–C8, catechin); PB4 (C4α–C8, catechin-epicatechin); PB5 (C4β–C6, epicatechin); PB6 (C4α–C6, catechin); PB7 (C4β–C6, epicatechin-catechin); PB8 (C4α–C6, catechin-epicatechin).