Abstract:

The chemical composition of essential oils isolated by hydrodistillation from the aerial parts of Ziziphora clinopodioides Lam. and Ziziphora pamiroalaica Juz. were analyzed by gas chromatography/mass spectrometry (GC-MS). Ten constituents representing 99.7% of the Z. clinopodioides oils were identified, which contained (+)-(R)-Pulegone (80.7%), Menthone (8.3%), Piperitenone (4.9%) and (+)-Isomenthone (2.6%) as the major components; On the other hand, twenty-nine constituents representing 99.8% of the oils from Z. pamiroalaica. were identified, the major compounds consisted of (+)-(R)- Pulegone (45.9%), (+)-Isomenthone (24.1%), (+)-Neomenthol(10.1%), Thymol (9.4%). The antioxidant activity of the oils was assessed by measurement of the free radical scavenging (DPPH) activity, the reductive potential, Superoxide anion scavenging activity, NaNO2 scavenging ability and by the TBARS assay, compared with that of synthetic antioxidants: Thymol, Vitamin C (VC) and butylated hydroxytoluene (BHT). Results showed that the oil from Z. pamiroalaica. was better than that from Z. clinopodioides in antioxidant abilities.

Key words: Ziziphora clinopodioide Lam., Ziziphora pamiroalaica Juz, essential oils, GC-MS analysis, antioxidant activity