Chemical composition, antioxidant activity and inhibitory effects of essential oil of Eucalyptus teretecornis grown in north-western Himalaya against Alternaria alternata

Abstract

The essential oil obtained from fresh leaves of Eucalyptus teretecornis (family Myrtaceae) was analysed by gas chromatography/mass spectrometry (GC/MS). Twenty eight compounds were identified and β-pinene (22.55%), α-pinene (22.50%), 1,8-cineole (19.84%), limonene (5.62%), β-fenchol (3.10%), α-phellandrene (2.90%), α-eudesmol (2.66%) and 4-(2-methylcyclohex-1-enyl)-but-2-enal (2.34%) were the main components. The antifungal activity of the essential oil was assayed against Alternaria alternata using bioautography. Two main bioactive components namely a 1 (R f =0.27) and a 2 (R f =0.33) were observed that produced inhibition zone of 4 mm and 8 mm in diameter respectively. The minimum inhibitory amount (MIA) of a 1 and a 2 against A. alternata was determined as 28 μg and 10 μg, respectively using bioautography assay. Components corresponding to a 1 and a 2 were determined as β-fenchol (oxygenated monoterpene) and α-eudesmol (oxygenated sesquiterpene) respectively using GC/MS analysis. The antioxidant activity of the essential oil and its bioactive fraction was evaluated by DPPH radical scavenging assay, β-carotene/linoleic acid bleaching assay, reducing power assay and metal chelating assay. In addition fraction of the essential oil that showed antioxidant activity was analyzed using GC/MS and α-fenchol, 4-terpineol and carvacrol were the main components.

Phytochemistry, Antioxidant, and Lipid Peroxidation Inhibition of the Essential Oils ofLavandula OfficinalisL. in Iran

“…[19] The regions showing DPPH scavenging activity were scrapped off then, they were eluted with chloroform. All resulting constituents were analyzed by GC/MS and also tested for their antioxidant activities.…”

Efficacy Of Chemically Characterized Carum Copticum Essential Oil As An Antioxidant And Lipid Peroxidation Inhibition

“…copticum essential oil, the TLC-bioautography method was carried out (11,12). The diluted oil (1:20 in methanol) was spotted on silica gel sheets (silica gel 60 F254 TLC plates) and developed in n-hexane-ethyl acetate (9:1).…”

“…For the isolation and identification of the active compounds in the essential oil, TLC was performed using the conditions previously described (12). The regions showing DPPH• scavenging activity were scrapped off then, they were eluted with chloroform.…”

Analyses of the Essential Oil from Bunium persicum Fruit and its Antioxidant Constituents

“…I bleaching Absorbance of sample after 2 h of assay / Initial absorbance of sample 100 2.5.3 Rapid screening for antioxidants For screening of antioxidant compounds in B. persicum essential oil, the TLC-bioautography method was carried out 9,22 . The diluted oil 1:10 in methanol was spotted on silica gel sheets silica gel 60 F 254 TLC plates and developed in n-hexane-ethyl acetate 9:1 .…”

“…2.6 Activity guided fractionation of the essential oil for antioxidants For the isolation and identification of the active compounds in the essential oil, PTLC was performed using the conditions previously described 9 . The regions showing DPPH scavenging activity were scrapped off then, they were eluted with chloroform.…”