Search

Citronella (Cymbopogon spp.) essential oil is an important component of various fragrances, cosmetics, and household products. In this study, comparative chemical composition and antimicrobial activity of Java citronella (Cymbopogon winterianus Jowitt ex Bor) essential oil, extracted by different methods, namely hydro-distillation and steam-distillation were determined by GC, GC-MS, and disc diffusion assay and microdilution broth assay. Major constituents of the essential oil were citronellal (2.2–55.4%), geraniol (14.2–53.0%), citronellol (8.2–16.4%), isopulegol (0.3–12.6%), elemol (0.8–8.2%), and limonene (0.2–5.0%). The essential oils showed inhibition of test bacteria with minimum inhibition concentration (MIC) in the range of 250–1000 µg/mL and showed anticandidal activity with MIC in the range of 125–500 µg/mL. In general, the oils were moderately active against Gram-positive and Gram-negative bacterial strains and also showed good activity against Candidal strains. The essential oils extracted from the herbage by different techniques exhibited variations in their yield, chemical composition, and antimicrobial activities. [ABSTRACT FROM AUTHOR]

In this study, antimicrobial activity of the essential oil (EO) and extracts of Himalayan-thyme (Thymus linearis Benth.) was evaluated against nine pathogenic microbial strains using disc diffusion and microdilution broth assays. The chemical composition of the EO was determined by gas chromatography-flame ionisation detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The molecular mechanism of action of the EO was investigated against three pathogenic bacteria (Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis) and three fungal strains (Candida albicans, Candida glabrata, and Candida tropicalis) using the assays of protein leakage, and DNA and RNA leakage through the membrane. Major components of the EO were thymol (54.9%), γ-terpinene (16.6%) and p- cymene (5.2%). The EO showed broad-spectrum potent antibacterial and antifungal activity (MIC 240–990 µg/mL) against test strains. The EO damaged cell membranes and altered cell membrane permeability of test microorganisms. The EO showed a time- and dose-dependent bactericidal and fungicidal effect. It could act as a promising antimicrobial agent due to its short killing time. [ABSTRACT FROM AUTHOR]

The essential oil obtained by hydro distillation of flowers of Bauhinia variegata were analyzed by GC and GC-MS analysis. Fifty one compounds have been identified in the flowers oil, representing 87.3% of total oil. The major components were identified as α-pinene (5.1%), β-pinene (2.2%), β-elemene (2.6%), γ-elemene (19.0%), δ-cadinene (3.6%), occidentalol (2.3%), cis-murrol-5-en-4-α-ol (24.4%) and α-cadinol (4.4%). This is the first report on chemical composition of B. variegata flowers essential oil of north Indian origin. [ABSTRACT FROM AUTHOR]

Rose-scented geranium (Pelargonium graveolens L'Herit. ex Aiton), belonging to the family Geraniaceae, has gained considerable attention because of its fragrance and high economic value. The compositional complexity of rose-scented geranium essential oil (GEO) has been challenging for quality control. In this study, the chemical profiles of GEOs extracted from Indian cultivars/genotypes were developed using polarity-based fractionation, followed by characterization using a combination of gas chromatography (GC-FID), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance spectroscopy (NMR). The analysis led to the identification of 121 compounds. Major components of the GEOs were citronellol (22.4–42.2 %), geraniol (5.7–30.5 %), linalool (2.1–9.8 %), citronellyl formate (4.0–9.5 %), isomenthone (5.3–7.5 %), geranyl formate (2.0–5.1 %), 6,9-guaiadiene (0.0–4.3 %), 10- epi - γ -eudesmol (0.2–6.4 %), 2-phenyl ethyl tiglate (1.0–2.1 %), geranyl tiglate (1.4–2.7 %), germacrene D (0.8–1.7 %) and geranial (0.4–1.6 %). This study identified effective markers which could help determine the authenticity of Indian cultivars/genotypes. Physical properties and chromatographic profiles of GEOs and terpeneless GEOs (TLOs) derived from Indian cultivar/genotype were compared. The two-step chromatographic separation coupled with principal component analysis allowed the identification of possible markers. The presence or absence of the sesquiterpenes, namely 10- epi - γ -eudesmol, 6,9-guaiadiene, and some other minor constituents, physical, and organoleptic properties, could effectively distinguish and define the quality of Indian cultivars/genotypes. Besides, the GEOs and TLOs prepared from different cultivars exhibited significant antimicrobial activity against Staphylococcus aureus and Candida albicans. [Display omitted] • Rose-scented geranium essential oil is known for its chemical complexity. • Chemical characterization and quality control of Indian genotypes were done. • Fractionation followed by GC-MS analysis led to the separation of co-eluting components. • The compounds identified could be viable tools for genotypes authentication. • Indian genotypes meet international standards. [ABSTRACT FROM AUTHOR]