Comparative Chemical and Biological Analysis of Wood and Tar Essential Oils from Cedrus atlantica and Juniperus oxycedrus in Morocco

Abstract

Wood tar essential oils have garnered attention for their potential therapeutic benefits and industrial applications. However, despite their historical significance, comprehensive analyses comparing artisanal and laboratory-produced variants are notably absent in current literature. Therefore, this research aims to bridge this gap by conducting chemical analysis to identify key constituents in artisanal and laboratory-produced essential oils of wood tar, as well as their antimicrobial and antioxidant activities. The DPPH and FRAP assays were employed to assess antioxidant activity to determine EC₅₀ values. The results of the study revealed the following major phytoconstituents in the tar: β-himachalene (30.24%; 22.78%), α-himachalene (16.06%;14.23%), and y-Gurjunene (9.69%;7.88%). Similarly, for AJTEO and LJTEO, the major constituents observed were α-Cedrene (32.85%; 27.89%), Terpinen-4-ol (7.06%;10.13%), and β- Cedrene (3.51%; 4.85%). In the antimicrobial assessment, laboratory wood tar EO shows stronger inhibition against tested organisms than artisanal wood tar EO. Juniper tar EO was more effective than cedar tar EO. LCTEO displayed potent antioxidant activity, with an EC₅₀ value of 16.09 µg/mL, followed by ACTEO at 17.659 µg/mL. AJTEO and LJTEO exhibited robust antioxidant effects with EC₅₀ values <1.25 µg/mL. In the FRAP assay, LCTEO demonstrated potent antioxidant activity with a value of 395.66 ± 0.02 µg/mL, while ACTEO showed an EC₅₀ of 532.71±0.053 µg/mL. AJTEO displayed an EC₅₀ value of 293.3±0.012 µg/mL, and LJTEO exhibited an EC₅₀ of 238.12±0.014 µg/mL. This research compares artisanal and laboratory-produced wood tar essential oils and their potential for application in pharmacy and cosmetic industries as antimicrobial and antioxidant agents.