Flavan-3-ols in trichomes, pistils and phelloderm of some tree species

Tissues from nine tree species were examined histochemically for the presence of flavan-3-ols including the catechins. It was possible to stain these phenolics selectively with p-dimethylaminocinnamaldehyde (DMACA) and to show that they were located in trichomes, pistils and shoot phelloderm. The staining intensity of the tissues was categorized into four groups. The flavan-3-ols were extracted from three tree species and the diverse components were distinguished using a combination of HPLC and chemical reaction detection (CRD). Twelve flavan-3-ols were isolated from pistils of Tilia grandifolia and 32 from leaves of Acer platanoides. The hairs of the leaves of dormant buds from Aesculus hippocastanum yielded 13 components. Epicatechin and ( + )-catechin were present in all three species.