Résumé:
The Algerian flora contains a wide variety of plant species with potential to be used in medicinal applications. This study was carried out in order to quantify and to compare the fatty acids compositions, the phenolics and the flavonoïds contents of Thymelaea hirsuta
leaves, flowers and twigs, and to determine the relationship that may exist between beneficial fatty acids and phenolics. Phenolic compounds and flavonoïds were extracted with methanol:water (80:20; v/v), and quantified photometrically. Methylated fatty acids were determined qualitatively and quantitatively by GC/MS. The results showed that leaves contain the higher concentration of total phenolics (19.83±0.42mgGAE/g DW) than flowers (16.78±0.67mgGAE/g DW) and twigs (6.17±0.82mgGAE/g DW). The flavonoïds contents were estimated at 5.00±0.17 and 5.17±0.06mgQE/g DW in leaves and flowers, respectively, and just 1.30±0.10mgQE/g DW in twigs. In addition, GC/MS analysis revealed 25 different fatty acids. The most dominant components were Oleic acid (Leaves: 15.56±0.12; flowers: 12.53±0.09; twigs: 12.29±0.05%), Adrenic acid (Leaves: 16.35±0.17; flowers: 5.03±0.08; twigs: 7.87±0.05%) and Palmitic acid (Leaves: 33.02±0.06; flowers: 33.02±0.06; twigs: 30.94±0.04%). The sum of unsaturated fatty acids (MUFAs+PUFAs) are most accumulated in leaves (38.14±0.04%), compared to flowers (29.98±0.03%), and twigs (28.23±0.04%). contents of UFAs, among plant parts, are positively correlated with phenolics (r = 0.79) and flavonoïds contents (r = 0.61), as well as omega3 (phenolics: r = 96.42%, Flavonoids: r = 86.7%). Findings of the study suggested that leaves are a better source of phenolic compounds which can play an effective role against unsaturated
fatty acids peroxidization. They could be applied in pharmaceutical and medicinal applications, as well as natural food preservatives.
