Studies on essential oil from rose-scented geranium, Pelargonium graveolens L'Hérit. (Geraniaceae)

Rose-scented geranium, Pelargonium graveolens L'Hérit. (Geraniaceae), is an economically important plant. GC-MS analysis of the essential oil, prepared by hydro-distillation from this plant species, showed the presence of iso-menthone (15.71%), epi-α-cadinol (15.49%), iso-menthol (6.46%), geranyl formate (6.22%), geraniol (6.16%) and citronellol (5.53%). The composition of the absolute prepared by solvent extraction was compared to that of the essential oil. Change in citronellol to geraniol ratio in the absolute was monitored during leaf development. Estimation of the ratio of the two compounds was carried out using 1H NMR spectroscopy. Geraniol content was highest in young leaves and citronellol content increased with increase in leaf age. Meta-analysis of the essential oil constituents reported from different countries was carried out. Menthone and isomenthone as well as citronellol and geraniol were negatively correlated. A significantly positive correlation was found between geraniol and linalool.