Extraction and characterization of Vernonia oil and synthesis of N-(aminoalkyl) vernolamides and N,N' polymethylene bis (vernolamides)
Abstract
Vernonia galamensis is an annual herb found growing as a common weed in most parts
of Africa, but its center of diversity is in East Africa. The dry seed of this plant consists
of about 40% naturally epoxidized oil that contains 72-80% vernolic acid (cis-12, 13epoxyoctadec-9-enoic acid). This makes this plant an excellent source of naturally
epoxidized triglyceride oil. The present study reports on the extraction of vernonia oil
and the preparation of epoxy-containing aminoamides and diamides.
The oil was extracted from different varieties of vernonia plant (var. Nairobensis; var.
Ethiopica; var.galamensis) using both soxhlet and cold extraction methods. Soxhlet
extraction was found to yield more oil (36-40%) that contains low content of vernolic
acid, while cold extraction gave a slightly lower yield of oil (20-39%) that contains a
high content of vernolic acid. VarEthiopica gave the highest yield in both extraction
methods (39-40%), while var. galamensis gave the lowest yield (20-26%). Vernonia oil
was then reacted with 1,2-diaminoethane; 1,3-diaminopropane; 1,4-diaminobutane and
1,6-diaminohexane to give the corresponding aminoamides [N-(2aminoethyl)vernolamide,
N-(3-aminopropyl )vernolamide, N-(4-aminobutyl)vernolamide,
N-(6-aminohexyl)vernol-amide)] and diamides [N,N' -Ethylene bis(vernolamide), N,N'trimethylene
bis(vernolamide), N,N' -tetramethylene bis (vernolamide) and N,N'hexamethylene
bis(vernolamide)] ofvernolic acid.
The reaction of vernonia oil with I,4-diaminobutane was used to study the following
different parameters which influenced aminolysis of the triglyceride:
(i) Molar ratios of vernonia oil to diamine (1: I; 1:2; 1:3; 1:5; 1:7 and 1:10)
(ii) Temperatures (room temperature, 500C, 600C and 700C).
(iii) Reaction period.
(iv) Solvents (without solvent, chloroform, tetrahydrofuran, carbon tetrachloride,
acetonitrile and ethanol).
Citation
M.Sc. ThesisSponsorhip
University of NairobiPublisher
Depatment of Chemistry, University of Nairobi
Description
Master of Science Thesis