Composition and antioxidant activity of <i>Senecio nudicaulis</i> Wall. ex DC. (Asteraceae): a medicinal plant growing wild in Himachal Pradesh, India

<div><p>The composition of essential oil isolated from <i>Senecio nudicaulis</i> 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%), β-caryophyllene (9.67%), <i>epi</i>-α-cadinol (2.90%), <i>epi</i>-α-muurolol (2.03%), β-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.</p></div

Chemical composition and antibacterial activity of essential oil of <i>Nepeta graciliflora</i> Benth. (Lamiaceae)

<p>The chemical composition of the essential oil obtained from aerial parts of <i>Nepeta graciliflora</i> 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 <i>β</i>-sesquiphellandrene (28.75%), caryophyllene oxide (12.15%), <i>α</i>-bisabolol (8.97%), <i>α</i>-bergamotene (8.51%), <i>β</i>-bisabolene (6.33%) and <i>β</i>-Caryophyllene (5.34%) as the main constituents. The <i>in vitro</i> 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.</p