Research Article Tarik Chelouati, Soufyane Lafraxo, Mohammed Bouslamti, Azeddin El Barnossi, Mohamed Chebaibi, Mohamed Akhazzane, Ahmad Mohammad Salamatullah, Hiba-Allah Nafidi, Mohammed Bourhia*, Badiaa Lyoussi, Ahmed Samir Benjelloun Study on antioxidant and antimicrobial potential of chemically profiled essential oils extracted from Juniperus phoenicea (L.) by use of in vitro and in silico approaches https://doi.org/10.1515/chem-2022-0333 received March 8, 2023; accepted April 29, 2023 Abstract: Juniperus phoenicea (L.) is a medicinal plant that has been used in phytotherapy as a treatment of certain pathological infections. In this context, the present work aimed to valorize the essential oil of J. phoenicea seeds (EOGP) by studying its chemical composition, and antiox- idant and antimicrobial activities. The EOGP was extracted by use of hydrodistillation and characterized by gas chromatography (GC–MS). The antioxidant power was evaluated by three methods (TAC, DPPH, and FRAP). The antimicrobial power was evaluated against Staphylococcus aureus (ATCC6633), Escherichia coli (K12), Bacillus subtilis (DSM6333), Proteus mirabilis (ATCC29906), Candida albi- cans (ATCC10231), Aspergillus niger (MTCC282), Aspergillus flavus (MTCC9606), and Fusarium oxysporum (MTCC9913). The GC/MS results revealed a total identification of 99.98% with a dominance of carvacrol (39.81%) followed by p-cymen-3-ol (34.44%) and o-cymene (13.60%). Findings showed that EOGP exhibited important antioxidant power as IC50 was determined to be 26 μg/mL for 2,2-diphenyl-1- picrylhydrazyl, while EC50 was 216.34 μg/mL for ferric reducing antioxidant power and total antioxidant capa- city was 720 mg AAE/g. The antimicrobial power on solid medium revealed that the inhibition diameters ranged from 11.30 ± 0.58 to 20 mm for the bacterial strains and from 9.33 ± 0.57 to 54.43 ± 0.29 mm for fungi. Notably, minimum inhibitory concentrations ranged from 18 to 19 μg/mL for bacterial strains and from 5.04 to 10.09 μg/mL for fungal strains. Overall, our results demonstrated the importance of EOGP as a source of natural antioxidant and antibacterial medicines against clinically relevant pathogenic strains. Keywords: Juniperus, GC/MS, essential oils, monoter- penes, bacteria, fungal 1 Introduction The floristic diversity of the Mediterranean region is esti- mated at 25,000 species or 30,000 species and subspe- cies, which is equivalent to around 10% of the world’s higher plants [1]. The Iberian Peninsula and Morocco are located at one of two major poles of plant diversity, while Tarik Chelouati, Mohammed Bouslamti, Badiaa Lyoussi, Ahmed Samir Benjelloun: Laboratory of Natural Substances, Pharmacology Environment, Modeling, Health and Quality of Life, Faculty of Sciences Dhar El Mahraz, University Sidi Mohamed Ben Abdellah, Fez, Morocco Soufyane Lafraxo, Azeddin El Barnossi: Laboratory of Biotechnology and Environment, Agri-Food and Health, Faculty of Sciences Dhar El Mahraz, Sidi Mohammed Ben Abdellah University, P.O. Box 1796 (Atlas), 30000 Fez, Morocco Mohamed Chebaibi: Laboratory of Biomedical and Translational Research, Faculty of Medicine and Pharmacy of Fez, University of Sidi Mohamed Ben Abdellah, BP 1893, Km 22, Road of Sidi Harazem, Fez, Morocco Mohamed Akhazzane: Engineering Laboratory of Organometallic and Molecular Materials and Environment, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, P.O. Box 1796 (Atlas), 30000 Fez, Morocco  * Corresponding author: Mohammed Bourhia, Department of Chemistry and Biochemistry, Faculty of Medicine and Pharmacy, Ibn Zohr University, Laayoune 70000, Morocco e-mail: bourhiamohammed@gmail.com Ahmad Mohammad Salamatullah: Department of Food Science & Nutrition, College of Food and Agricultural Sciences, King Saud University, 11 P.O. Box 2460, Riyadh 11451, Saudi Arabia Hiba-Allah Nafidi: Department of Food Science, Faculty of Agricultural and Food Sciences, Laval University, 2325 Quebec City, QC G1V 0A6, Canada Open Chemistry 2023; 21: 20220333 Open Access. © 2023 the author(s), published by De Gruyter. This work is licensed under the Creative Commons Attribution 4.0 International License.