Abstract

Chemical compositions of the essential oils from aerial, seed and root parts of nigerian Asystasia gangetica (L)

Author(s): D.Olufunke Moronkola

Volatile oils from aerial, seed and root parts of Asystasia gangetica (L) were analyzed for their constituents by means of gas chromatography and gas chromatography coupled with mass spectrometry. Fifty-four compounds were identified in aerial, twenty-one in seed, fifteen in root, respectively which are responsible for 96.80%, 65.11% and78.50% of oil in each. Aerial is dominated by phthalates (39.00%), cycloalkanes (28.23%) and aromatics (17.14%); the most abundant compounds are toluene (9.12%), methylcyclohexane (9.02%) and bisisodecyloctylphthalate (6.05%). Others in aerial are branched (6.13%) and straight chain alkanes (3.24%), esters (1.71%), alcohol (0.72%), acid (0.36%), heterocompound (0.27%), ketone (0.18%) and terpenoid (0.09%). Phthalates (24.67%), alcohols (16.28%) and straight chain alkanes (8.56%) are the largest groups in seed oil, with dinonylphthalate (9.40%), 1-octenol (8.05%) and methylcyclohexane (6.04%) as most important. Also it contain cycloalkanes (6.04%), aromatics (5.03%), terpenoid (4.03%), ester (3.02%), acid (1.01%), amide (1.01%) and branched alkane (0.50%). Root oil have alcohols (27.32%), straight chain alkanes (23.61%) and aldehydes (15.91%) as the most noticeable, while its dominant compounds are abietal (11.67%), n-tetracosane (10.08%) and palustrol (9.02%). It also have phthalate (5.83%), aromatics (5.83%) and cycloalkane (4.24%). Derivatives of phthalate are obvious in the three oils. There are no aldehyde in aerial; no ketone and aldehyde in seed; no terpenoid, ester, ketone, acid and hetero compounds in root. Notable is the low amount of ubiquitous terpenoids in aerial and seed essential oils, which is absent in root. Unsaturated compound and ether are not in the oils. Chemical composition of Asystasia gangetica (L) is reported for the first time in literature.