Abstract

We report composition of Ruellia tuberosa L. (Acanthaceae) leaf, stem, root, fruit, and flower volatile oils from Nigeria. The five volatile oils were obtained by hydro-distillation using all-glass Clevenger apparatus designed to British Pharmacoepia specifications and were procured in 0.09 to 0.36% yields. Each was separately examined using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis. Our results revealed leaf oil contain 24 compounds, which make-up 86.95% of it; stem oil has 15 compounds (accounting for 93.96%); root oil with 42 compounds being 91.49%; fruit oil contain 60 compounds which amount to 89.68% and flower oil has 6 compounds representing 95.06% of the oil. Dominant compound sin each essential oil are (%): leaf (E-phytol 21.06, tributylacetyl citrate 19.44, heptacosane 7.55); stem (m-xylene 33.83, heptacosane 16.57, p-xylene 9.67); root (heptane 22.25, heptacosane 12.89, borneol 12.48); fruit (hexacosane 15.43, sextone 13.12, heneicosane 11.14) and flower (tributylacetyl citrate 67.78, 2-methyl-2-pentanol 10.15, 1-methyl-1-cyclopentanol 6.90). Important classes of compounds in Nigerian R. tuberosa volatiles are monoterpenes, monoterpenoids, sesquiterpenes, sesquiterpenoids, hydrocarbons, aromatics, esters, alcohols, sulphur compounds, ketones and aldehydes.109 compounds were identified in the five essential oils of R. tuberosa. These compounds have high therapeutic effects and are characteristic of R. tuberosa. The oils are good sources of sextone (methylcyclohexane), β-linalool and alcohols. We present the volatile constituents in the leaf, stem, root, fruit, and flower of R. tuberosa which have not been earlier reported in literature.

Key words: Ruellia tuberosa, Acanthaceae, essential oil, gas chromatography-mass spectrometry (GC-MS), sextone, monoterpenoids, sesquiterpenoids, linalool, alcohol.