Ocimum basilicum L. (Lamiaceae) commonly known as sweet basil, has been used as a traditional medicinal plant for the treatment of headaches, coughs, diarrhea, constipation, warts, worms, and kidney malfunctions. The essential oil of the flowering aerial parts of O. basilicum growing in the Western Ghats region of North West Karnataka, India, was obtained by hydro-distillation and analyzed by gas chromatography equipped with flame ionization detector and gas chromatography coupled to mass spectrometry (GC-MS). The oil was tested against six Gram-positive, eight Gram-negative bacteria, and three fungi by the tube-dilution method at a concentration range of 5.00-0.009 mg/mL. Twenty-five constituents were identified in the essential oil of O. basilicum. The major constituents were identified as methyl eugenol (39.3%) and methyl chavicol (38.3%), accounting for 98.6% of the total oil. The oil was found to be active against Gram-positive, Gram-negative bacteria, and fungi with minimal bactericidal concentration values in the range of 0.143 ± 0.031 to 0.572 ± 0.127 mg/mL, 0.781 ± 0.382 to 1.875 ± 0.684 mg/mL, and 0.312 ± 0.171 to 0.442 ± 0.207 mg/mL, respectively. The essential oil of O. basilicum of this region contains methyl eugenol/methyl chavicol chemotype and has bactericidal properties.

The chemical composition, antioxidant, cytotoxic and antiviral activities of the essential oil obtained by hydrodistillation from the aerial parts of Teucrium pseudochamaepitys (Lamiaceae) collected from Zaghouan province of Tunisia are reported. The essential oil was analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Thirty-one compounds were identified representing 88.6% of the total essential oil. Hexadecanoic acid was found to be the most abundant component (26.1%) followed by caryophyllene oxide (6.3%), myristicin (4.9%) and α-cubebene (3.9%). The antioxidant capacity of the oil was measured on the basis of the scavenging activity to the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH). The IC₅₀ value of the oil was evaluated as 0.77 mg·mL⁻¹. In addition, the essential oil was found to possess moderate cytotoxic effects on the HEp-2 cell line (50% cytotoxic concentration (CC₅₀) = 653.6 µg·mL⁻¹). The potential antiviral effect was tested against Coxsackievirus B (CV-B), a significant human and mouse pathogen that causes pediatric central nervous system disease, commonly with acute syndromes. The reduction of viral infectivity by the essential oil was measured using a cytopathic (CPE) reduction assay.

Context: Artemisia absinthium L. (Asteraceae) is an aromatic, herbaceous, perennial plant commonly known as wormwood. Artemisia absinthium is traditionally used as an anthelmintic, antiseptic, antispasmodic and for bacillary dysentery, cancers and neurodegenerative diseases. Objective: The essential oil composition of the leaves of A. absinthium growing in the Western Ghats region of North West Karnataka, India, is investigated for the first time in this region and the oil was screened for antimicrobial properties. Materials and methods: The chemical composition of the hydro-distilled essential oil obtained from the leaves of A. absinthium was analyzed by GC-FID and GC/MS. The oil was tested against five Gram positive and, eight Gram negative bacteria and three fungi by the tube-dilution method at a concentration range of 5000–9 µg/mL. Results: Results demonstrated that the leave oil was found to be rich in oxygenated monoterpenes (39.7% and 41.1%). The major compounds were borneol (18.7% and16.7%), methyl hinokiate (11.9% and 12.9%), isobornyl acetate (4.0% and 4.7%), β-gurjunene (3.8% and 4.4%) and caryophyllene oxide (3.7% and 4.3%), among 64 identified compounds, comprising 91.7% and 90.1% of the total oil. The organism Micrococcus luteus was found more susceptible to the oil with an MIC value of 25 ± 4 µg/mL, followed by Micrococcus flavus, Bacillus subtilis, Penicillium chrysogenum and Aspergillus fumigatus with MIC values of 58 ± 8, 65 ± 8, 84 ± 15 and 91 ± 13 µg/mL, respectively. Discussion and conclusion: The oil showing antimicrobial activity against bacteria and fungi validate the traditional use of the plant as an antiseptic.

The chemical composition of the essential oils of aerial parts and flowers of Chromolaena odorata (L.) R. M. King & H. Rob., collected from Western Ghats region, were obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). Fifty two and thirty four compounds were identified from aerial parts and flowers, representing 94.9 % and 95.2 % of the total oils, respectively. The essential oil from aerial parts was dominated by pregeijerene (14.2 %), epi- cubebol (9.8 %), cubebol (8.6 %), cis-sabinene hydrate (5.7 %), 10-epi-γ-eudesmol (3.8 %), germacrene-D-4- ol (3.6 %) and δ-cadinene (3.5 %), while germacrene D (24.8 %), geijerene (12.6 %), pregeijerene (12.5 %), cyperene (7.8 %), 10-epi-γ-eudesmol (4.7 %), α-muurolol (3.6 %) and khusimone (3.4 %) were identified as the major constituents of flowers oil of C. odorata.