Folahan O. Ayorinde

Synthesis of azelaic acid and suberic acid fromVernonia galamensis oil

We have demonstrated the potential ofVernonia galamensis seed oil as a source of dibasic acids. Reaction of nitric acid withV. galamensis oil afforded a homologous series of dibasic acids that include butanedioic acid, pentanedioic acid, hexanedioic acid (adipic), heptanedioic acid (pimelic), octanedioic acid (suberic), nonanedioic acid (azelaic), decanedioic acid (sebacic), and undecanedioic acid. Using a combination of chloroform extraction and subsequent water crystallizations, we have isolated suberic acid (∼95% purity by GC) and azelaic acid (∼95% purity by GC). The isolated yield of suberic acid is 15% and of azelaic acid is 11%. Reported reaction of nitric acid with ricinoleic acid (from castor oil) gave 8.8% suberic acid and 7.2% of a mixture of suberic and azelaic acids.

Synthesis of Toughened Elastomer from Vernonia galamensis Seed Oil

AbstractsThis paper examines the synthesis of a toughened elastomer fromVernonia galamensis seed oil by reacting vernonia oil with vernonia oil-derived suberic acid (octanedioic acid), and cross-linking the pre-polymer in the immediate presence of cross-linked polystyrene preparedin situ. The paper also demonstrates that the progress of reaction can be followed by monitoring the generation of hydroxyl groups using infrared spectroscopy. Analysis of some crystalline material on the cooler parts of the reaction vessels revealed the presence of component fatty acids of vernonia oil. Transmission electron microscopy characterization of the synthesized toughened elastomer suggests that vernonia oil-suberic acid polyester and polystyrene polymer are interpenetrating.

Enzymatic synthesis and spectroscopic characterization of 1,3-divernoloyl glycerol fromVernonia galamensis seed oil

Abstractcis-12,13-Epoxy-cis-octadecenoic (vernolic) acid occurs in triglycerides of the seed oil ofVernonia galamensis. The seeds also contain a lipase capable of hydrolyzing the triglycerides. Previous investigators incubated the seed ofVernonia anthelmintica and isolated 5.6% yield of 1,3-divernoloyl glycerol. We used crude lipase extract fromV. galamensis seed to synthesize 1,3-divernoloyl glycerol from vernonia oil in pentane at 40% yield. A 94% conversion of the 1,3-divernoloyl glycerol to pure vernolic acid (5.34% oxirane = 98.9% purity) was achieved by a low-energy saponification process. The carbon-13 nuclear magnetic resonance (NMR) spectrum of the 1,3-divernoloyl glyceride indicates a potential for using carbon-13 NMR spectroscopy in the identification of isomeric diglycerides. Thus the paper describes the synthesis, spectroscopic and chemical characterization of 1,3-divernoloyl glycerol, in addition to providing quantitative carbon-13 NMR studies ofV. galamensis oil.

Chemical evaluation of defattedvernonia galamensis meal

The defatted meal ofVernonia galamensis is rich in crude protein (43.76±0.17%) with methionine as the first limiting amino acid and lysine the second when calculated based on the FAO Provisional Scoring Pattern. The carbohydrate fraction (6.575) is rich in sucrose (2.36%), fructose (1.90%) and glucose (0.77%). Levels of the macrominerals, calcium (11.08 mg/g), potassium (14.18 mg/g) and magnesium (6.90 mg/g) not only meet nutritional requirements but are also higher than in contemporary oilseeds. The level of phosphorus is high (644 mg/g), perhaps accounting for the fairly high phytate (25.42±0.06 mg/g) content, although this value is slightly less than for American Association of Cereal Chemists (AACC) standard wheat bran (31.42±0.03 mg/g).Residual oil content of defatted meal was found to be approximately 0.5%, but could be higher depending on the method of extraction. Lipid analysis of the residual oils shows vernolic acid (76.06±1.80%) as the major component of the saponifiables (97.74±0.20%). C18∶2 (11.64±0.69%), C16∶0 (2.22±0.12%), C18∶0 (2.63±0.11%), C18∶1 (6.58±0.19%), and C20∶0 (trace) were all identified.Sterols constitute the major (94.65±0.08%) component of the unsaponifiables (2.06±0.16%) with β-sitosterol (32%) and Δ5-avenasterol (30%) being the major constituents. Cholesterol was fairly low (4.6%). Phytochemical screening for other possible toxicants did not reveal significant levels of antinutritional components.

Pilot plant extraction of oil fromVernonia galamensis seed

Vernonia galamensis seed containing 40–42% oil and 30–34% epoxy acid, (cis-12,13-epoxy-cis-9-octadecenoic) was processed to oil and meal. Seed conditioning, pressing and solvent extraction research were conducted in pilot facilities at the French Oil Mill Machinery Co. (Piqua, OH). The robust lipase system was successfully inactivated by treating 200 lb. batches ofV. galamensis seed in a cooker/conditioner at 195–200°F and >10% moisture. Conditioned seed was mechanically pressed and the press discharge cone setting was varied during operation from 1/32″ to 3/32″ to demonstrate the feasibility of both full pressing and prepressing. Prepressing successfully reduced oil level in the press cake to ca. 20%. Press cake was extracted with hexane in a 1.5-ft3 batch-type, four-stage percolation unit with a 6″ square extraction cross section. Solvent extraction reduced oil level in the defatted meal to 1–2%. The defatted meal was desolventized and toasted. Excessive foaming of the vernonia oil extract made complete solvent stripping in the oil stripping unit difficult.

PhSeCl as a chlorinating agent for activated benzene derivatives

Abstract Regiospecific chlorination of some aromtic compounds using benzeneselenyl chloride are reported.

Citronellyl citronellate and citronellyl geranate in the European hornet, vespa crabro (hymenoptera: vespidae)

Abstract Citronelly citronellate and citronellyl geranate, new insect natural products, have been identified in the van der Vechts gland of the European hornet.

Mass spectrometric characterization ofVernonia galamensis oil

Vernonia galamensis seed oil is a natural source of epoxidized triacylglycerols, which consist of 52% trivernolin and a mixture of other triacylglycerols. Epoxidized oils are used for industrial applications, such as coatings and plastic formulations. To determine the major molecular species present in Vernonia oil, desorption chemical ionization/mass spectrometry and mass spectrometry/mass spectrometry were used to determine its glyceride composition. Seven triacylglycerols predominated: divernoloylarachidonate, trivernolin, divernoloylstearate, divernoloyloleate, divernoloyllinoleate, dilinolenoyl vernolate and divernoloylpalmitate.

Acid-catalyzed alcoholysis ofVernonia galamensis oil

We have demonstrated the potential ofVernonia galamensis seed oil as a source of hydroxy alkoxy fatty esters. Reaction of the oil with various alcohols (methanol, ethanol, 1-propanol and 2-propanol), under acidic conditions, resulted in transesterification as well as epoxy ring opening in all cases. The major products, the hydroxy alkoxy fatty esters, constituted approximately 80% of the product mixtures, of which the 12-hydroxy-13-alkoxy isomers were the major constituents. These derivatives were isolated by solvent extraction and/or column chromatography to afford 78–80% of pure isomers. Alcoholysis with butanol resulted in a poor yield of the hydroxy butoxy esters. A discussion of the isolation and mass-spectrometric characterization of these new esters is provided.

Synthesis and isolation of epoxy secondary amidesvia direct amidation ofVernonia galamensis seed oil

Vernonia galamensis oil, containing naturally epoxidized triglycerides, was reacted withn-butylamine,n-pentylamine andn-hexylamine to afford high yields of epoxidized secondary amides. Three reaction conditions were investigated: (i) reflux with amines as solvents, (ii) reflux with hexane as the solvent and (iii) room temperature with the amines as solvents. Reactions with amines as refluxing solvents were completed in 1–5 h, while those with hexane went to completion within 2 to 5 d. Room temperature reactions were onlyca. 80% complete after several days. Reactivity was increased with higher amine homologs at both reflux and room temperature reaction conditions. Isolated yields of epoxy-containing amides were about 80% with purity exceeding 96% in all cases. Spectroscopic characterization of the previously unreported alkyl-vernolamides is provided.