In the present work, we studied the chemical composition of the essential oil of Cistus ladanifer and 

Cistus libanotis  growing in Eastern Morocco. The essential oils were obtained by hydrodistillation and 

their chemical composition was analysed using gas chromatography- mass spectrometry (GC–MS). 

Camphene, borneol, cyclohexanol-2, 2, 6 tremethyl, terpineol-4 and α-pinene were the main constituents 

of the essential oil of C. ladanifer, while in the essential oil of C. libanotis we obtained terpineol-4, γ-

terpinene, camphene, sabinene, α-terpinene and α-pinene. The antioxidant potential of various extracts 

(water, ethanol, ethanol: water (50:50), methanol, methanol: water (50:50), acetonitrile)  and essential 

oils of C. ladanifer and C. libanotis  were carried out by the method of 1,1-diphenyl-1-picrylhydrazylhydrate (DPPH) free radical scavenging. Total phenolic and flavonoid contents were determined. The result show that C. ladanifer of the leaves of methanol: water (50:50) extract had the highest value of total phenolic content and the lowest was present in ethanol: water (50:50) extract of the stem and acetonitrile extract of the flowers of C. libanotis. From our experimental results, the extract of flowers, fruit, stem and leaves of those plants showed highest potential as free radical scavengers. 

 

Key words: Antioxidant, phenolics, flavonoids, essential oil, extracts, gas chromatography- mass spectrometry (GC–MS).