How to Increase the Reactivity of Hydroxylmethylation of Tea Catechins?–A Theoretical Study of the Introduction of a Galloyl Moiety at C-3 Position–

Abstract

Tea catechins and related compounds, (-)-Epicatechin gallate and (-)-Epigallocatechin ga llate, which have a galloyl moiety at the C-3 position (see Figure 1), show higher reactivity of hyd roxylmethylation than others. We performed theoretical calculations on 5 tea catechins by the semi-e mpirical molecular orbital method.
It is found that introduction of a galloyl moiety makes HOMO localize at the C-6 and C-8 positions. These variations of orbital energies lead to a high reactivi ty. It is suggested that the introduction of functional groups that have a large -electron system in to tea catechins raises the reactivity of hydroxylmethylation.