ABSTRACT
The chemical composition of the essential oil obtained from aerial parts of Nepeta graciliflora was analysed, for the first time, by GC-FID and GC-MS. A total of 27 compounds were identified, constituting over 91.44% of oil composition. The oil was strongly characterised by sesquiterpenes (86.72%), with ß-sesquiphellandrene (28.75%), caryophyllene oxide (12.15%), α-bisabolol (8.97%), α-bergamotene (8.51%), ß-bisabolene (6.33%) and ß-Caryophyllene (5.34%) as the main constituents. The in vitro activity of the essential oil was determined against four micro-organisms in comparison with chloramphenicol by the agar well diffusion and broth dilution method. The oil exhibited good activity against all tested organisms.
Subject(s)
Anti-Bacterial Agents/pharmacology , Nepeta/chemistry , Oils, Volatile/chemistry , Sesquiterpenes/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Bridged Bicyclo Compounds/isolation & purification , Bridged Bicyclo Compounds/pharmacology , Gas Chromatography-Mass Spectrometry , Microbial Sensitivity Tests , Monocyclic Sesquiterpenes , Oils, Volatile/pharmacology , Polycyclic Sesquiterpenes , Sesquiterpenes/chemistry , Sesquiterpenes/isolation & purificationABSTRACT
The composition of essential oil isolated from Senecio nudicaulis Wall. ex DC. growing wild in Himachal Pradesh, India, was analysed, for the first time, by capillary gas chromatography (GC) and GC-mass spectrometry. A total of 30 components representing 95.3% of the total oil were identified. The essential oil was characterised by a high content of oxygenated sesquiterpenes (54.97%) with caryophyllene oxide (24.99%) as the major component. Other significant constituents were humulene epoxide-II (21.25%), α-humulene (18.75%), ß-caryophyllene (9.67%), epi-α-cadinol (2.90%), epi-α-muurolol (2.03%), ß-cedrene (1.76%), longiborneol (1.76%), 1-tridecene (1.16%) and citronellol (1.13%). The oil was screened for antioxidant activity using DPPH, ABTS and nitric oxide-scavenging assay. The oil was found to exhibit significant antioxidant activity by scavenging DPPH, ABTS and nitric oxide radicals with IC50 values of 10.61 ± 0.14 µg mL(- 1), 11.85 ± 0.28 µg mL(- 1) and 11.29 ± 0.42 µg mL(- 1), respectively.
