Unusually high quantity of 4-hydroxybenzoic acid accumulation in cell wall of palm mesocarps

Presence of 4-hydroxybenzoic acid in the mesocarp walls of 22 genera of Arecaceae (Palmae) was investigated using a TLC/UV spectra analysis method and confirmed by HPLC and ESI-MS. The genera collected mainly belong to the Copryphoideae and Arecoideae subfamilies. All the investigated genera possess an unusually high amount of 4-hydroxybenzoic acid, which varied from 5.6 mg/g dry wt cell wall material (CWM) (Areca catechu) to 1.0 mg/g dry wt CWM (Roystonea regia). Apart from 4-hydroxybenzoic acid, ferulic acid is also found in all the genera studied along with some traces of 4-coumarate. This work presents an overview of the major wall-bound phenolics found in the mesocarp of different palms, and on the basis of this occurrence, a possible hypothesis for considering 4-hydroxybenzoic acid as a chemotaxonomic marker of this particular family can be drawn.