Phytochemical composition and biological activities of bark extracts from seven industrially relevant tree species

Abstract

This study presents a comprehensive analysis of the phytochemical profiles and biological activities of bark extracts from seven industrially significant tree species: Pinus sylvestris, Pinus nigra, Pinus brutia, Picea orientalis, Abies nordmanniana subsp. equi-trojani, Fagus orientalis, and Quercus robur. Bioactive compounds, including phenolics, flavonoids, and alkyl esters, were identified and quantified using GC-MS and HPLC techniques. A methanol: water mixture (65:35, v/v) was found to be the most effective solvent, yielding the highest total phenolic content in Abies nordmanniana and the highest flavonoid concentration in Pinus brutia. GC-MS analysis revealed species-specific distributions of key compounds such as 2-ethylhexanol, methyl stearate, and mono(2-ethylhexyl) adipate, reflecting the chemical diversity among the species. The extracts were further evaluated for their antioxidant, antimicrobial, and enzyme-inhibitory activities. Notably, inhibition of PPO and PON1 enzymes was observed, and DNA protection assays confirmed the ability of extracts to mitigate oxidative damage. These findings highlight the potential of industrial tree bark, typically a waste product of the wood industry, as a valuable source of bioactive compounds. The study advocates for its integration into the circular economy by developing high-value products for pharmaceutical, industrial, and environmental use.