Abstract

STUDY OF CHEMICAL COMPOSITION OF ROSEMARY ESSENTIAL OIL FROM WESTERN MOROCCO AND EVALUATION OF ANTIOXIDANT AND ANTIBACTERIAL ACTIVITY OF ITS EXTRACTS

Sara HAIDA*, Fatima Zahra ESSADIK, Abdelaziz KRIBII, Amar HABSAOUI, Khadija OUNINE, Abdessamad BENMOUMEN and Abderahim KRIBII

Abstract

This work is inscribed in the frame of valorization of medicinal and aromatic plants from Morocco. The plant chosen for this study is rosemary (Rosmarinus officinalis L.). it can be found in the west of Morocco. The volatile fraction obtained by hydrodistillation (0.85%) was analyzed by GC-MS process and its chemical composition was determined. α-pinene, camphor, verbenone and camphene were the main components of the essential oil. The phenolic compounds of rosemary are obtained by maceration and decoction according to suitable extraction protocols. The best extract yields are recorded by the decoction. UV-visible spectrophotometry analysis showed that the highest contents of total polyphenols and flavonoids are obtained in the methanol extract by decoction. The antioxidant activity of different extracts was evaluated by free radical scavenging method with DPPH• (2,2-diphényl-1-picrylhydrazyl), aqueous extract obtained by decoction seems to be the most active (IC50 = 0.138 mg/mL). The rosemary extracts were tested for antibacterial activity by sterile disc diffusion method, using three strains of different bacteria (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa). The results show that only apolar extracts responded positively to two of three bacterial strains tested.

Keywords: Rosmarinus officinalis L., GC-MS, phenolic compounds, flavonoids, antioxidant activity, antibacterial activity.