Integration of the (RO)B3LYP/6-311++G(2df,2p) with the PM6 method into a two-layer ONIOM is found to produce reasonably accurate BDE(O-H)s of phenolic compounds. The chosen ONIOM model contains only two atoms of the breaking bond as the core zone and is able to provide reliable evaluation for BDE(O-H) for phenols and tocopherol. Deviation of calculated values from experiment is +/-(1-2) kcal/mol. BDE(O-H) of several curcuminoids and flavanoids extracted from ginger and tea are computed using the proposed model. The BDE( O-H) values of enol curcumin and epigallocatechin gallate are predicted to be 83.3 +/- 2.0 and 76.0 +/- 2.0 kcal/mol, respectively. (C) 2012 Elsevier B.V. All rights reserved.