Vernolic Acid Research Articles

Genetic study for seed germination and shattering in Euphorbia lagascae in response to different seed treatments

Euphorbia lagascae Spreng is a promising emerging oilseed crop, with its seed oil accounting for approximately 50% of the seed weight. Euphorbia oil contains a significant amount of vernolic acid, comprising two-thirds of its composition, which boasts various industrial applications, including acting as a stabilizer-plasticizer and natural dye. However, this species was known to have a high degree of seed-shattering and a low germination rate, which act as two important barriers to large-scale production and exploitation. Therefore, the objective of this study is to determine the genetic control of seed germination and seed-shattering traits in order to develop a reliable pipeline that would be applicable for industries and breeders to select superior E. lagascae lines and design a robust breeding scheme in a short time at reduced labor costs. For this objective, five different wild-type genotypes of E. lagascae that demonstrated high germination potential were crossed with an ethyl methanesulfonate (EMS) mutant genotype that produces non-shattering capsules. The F2 populations from two successful crosses (A and B) were separated into three different treated groups for seed germination evaluation and to study the segregation of 200 individuals per F2 population. The three treatments were: light, gibberellic acid (GA3), and control treatment. Consequently, plants treated with approximately 250 μmol/m2/s of light showed significant improvement in germination up to 75% in cross A and 82.4 % in cross B compared with the control plants and the group treated with 0.05% GA3. According to the chi-square test results, the inheritance pattern of seed germination in response to light treatment follows a 3:1 segregation ratio between germinated and non-germinated seeds, indicating a dominant gene action in the F2 generation. The same conclusion was followed for the shattering trait in the group treated with light, which was also simply inherited as a 3:1 ratio for shattering vs. non-shattering capsules. Our results emphasize the importance and significance of light treatment in producing uniform populations through acceptable germination and shattering resistance of the mutant genotypes of E. lagascae. This is the first report of light treatment that significantly improved seed germination of E. lagascae, which may enhance efforts in the development of this new industrial crop as a feedstock for vernolic acid production.

In silico Prediction of Malvaviscus arboreus Metabolites and Green Synthesis of Silver Nanoparticles - Opportunities for Safer Anti-Bacterial and Anti-Cancer Precision Medicine.

Biogenic silver nanoparticles (AgNPs) may be a feasible therapeutic option in the research and development towards selectively targeting specific cancers and microbial infections, lending a role in precision medicine. In-silico methods are a viable strategy to aid in drug discovery by identifying lead plant bioactive molecules for further wet lab and animal experiments. Green synthesis of M-AgNPs was performed using the aqueous extract from the Malvaviscus arboreus leaves, characterized using UV spectroscopy, FTIR, TEM, DLS, and EDS. In addition, Ampicillin conjugated M-AgNPs were also synthesized. The cytotoxic potential of the M-AgNPs was evaluated using the MTT assay on MDA-MB 231, MCF10A, and HCT116 cancer cell lines. The antimicrobial effects were determined using the agar well diffusion assay on methicillin-resistant S. aureus (MRSA) and S. mutans, E. coli, and Klebsiella pneumoniae. Additionally, LC-MS was used to identify the phytometabolites, and in silico techniques were applied to determine the pharmacodynamic and pharmacokinetic profiles of the identified metabolites. Spherical M-AgNPs were successfully biosynthesized with a mean diameter of 21.8 nm and were active on all tested bacteria. Conjugation with ampicillin increased the susceptibility of the bacteria. These antibacterial effects were most predominant in Staphylococcus aureus (p < 0.0001). M-AgNPs had potent cytotoxic activity against the colon cancer cell line (IC50=29.5 μg/mL). In addition, four secondary metabolites were identified, Astragalin, 4-hydroxyphenyl acetic acid, Caffeic acid, and Vernolic acid. In silico studies identified Astragalin as the most active antibacterial and anti-cancer metabolite, binding strongly to the carbonic anhydrase IX enzyme with a comparatively higher number of residual interactions. Synthesis of green AgNPs presents a new opportunity in the field of precision medicine, the concept centered on the biochemical properties and biological effects of the functional groups present in the plant metabolites used for reduction and capping. M-AgNPs may be useful in treating colon carcinoma and MRSA infections. Astragalin appears to be the optimal and safe lead for further anti-cancer and anti-microbial drug development.

Preparation and characterization of vernolic acid methyl ester functionalized ordered mesoporous materials

ABSTRACT. Vernonia oil is a naturally epoxidized triglyceride oil extracted from the seed of Vernonia galamensis, a native plant in East Africa. After hydrolysis to vernolic acid (VA) and derivatization, vernolic acid methyl ester (VAME) is synthesized and used to functionalize ordered mesoporous materials (OMM). Al-MCM-41 with Si/Al ratio of 15, pure silica SBA-15 and periodic mesoporous organosilica (PMO) are employed as supports exploring the different surface properties. Following optimization of the VAME/OMM ratios, selected samples, i.e. those with 13% VAME, were impregnated with AgNO3 in NaBH4 to obtain Ag-nanoparticles. The final AgVAME-OMM potential catalysts were characterized by transmission electron microscopy, observing an efficient loading of Ag nanoparticles in pure silica SBA-15 with VAME with 500 m2 specific surface area and 6 nm pore size.&#x0D; &#x0D; KEY WORDS: Vernolic acid methyl ester, Vernonia oil, Functionalization, Ordered mesoporous materials, Catalysis&#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2023, 37(3), 689-702. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v37i3.12

Antioxidant, cholesterol lowering activity, and analysis of Caesalpinia bonducella seeds extract

Tombili plant (Caesalpinia bonducella) belongs to the family of Fabaceae. The seed extract of tombili has been empirically used as a traditional medicine. The purpose of this research was to fractionate tombili seed extract and test their antioxidant and cholesterol lowering activities. Extraction was made into fractions using n-hexane, ethyl acetate, and methanol as a solvent. The chemical compound of the ethyl acetate fraction was analyzed using liquid chromatography-mass spectrometry (LC-MS/MS). Antioxidant activity was tested using the DPPH method. The highest antioxidant activity was shown in ethyl acetate fraction with an IC50 value of 86.153 μg/mL. The second was the methanol fraction with an IC50 value of 94.053 μg/mL, and the third was the n-hexane fraction with an IC50 value of 100.933 μg/mL. The cholesterol lowering activity analysis showed that all fractions could inhibit cholesterol. The highest anti-cholesterol activity shown in ethyl acetate fraction with the concentration of 600 μg/mL can inhibit 81.5% of the cholesterol activity. The LC-MS/MS analysis showed that the ethyl acetate fraction contained glucoside, homoplantaginin, and vernolic acid compounds.

Greener extraction‐chemical modification‐polymerization pipeline of vernolic acid from Ethiopian ironweed plant

AbstractEpoxidized oils are commonly used in the plastics industry as additives in the formulation of polyvinyl chloride (PVC) and as monomers in the coating industry. They are produced from petrochemical feedstocks or by chemical epoxidation of natural oils. Currently, the synthesis processes of these materials are expensive, utilize volatile organic solvents and hazardous oxidants, which are unfavorable for the environment. There is a need to find natural epoxidized oils. Vernonia galamensis (ironweed) is a plant found in abundance in Ethiopia with no commercial value, but its seeds contain 40 wt% epoxide rich triglycerides. V. galamensis oil contains up to 80 wt% of vernolic acid (VA), a mono‐unsaturated fatty acid with an additional epoxide functionality. The presence of alkene and epoxide(oxirane) groups offers excellent opportunities to synthesize new building blocks for polymerisations. Here, we report a green and efficient extraction methodology (up to 80% of extraction‐efficiency) of the triglyceride vernonia oil from V. galamensis using supercritical carbon dioxide (scCO2). We then report the synthesis of a series of polymerisable monomers (conversion in monomers 64%–99%) based on the VA obtained from the saponification process. Finally, the novel monomers are polymerized into different polymers through polycondensation using a mixture of metal‐based and enzyme catalysts.

Euphorbia lagascae seed oil obtained by pre-pressing and solvent extraction

This study evaluated the oil extraction from the Euphorbia lagascae seeds by pre-pressing followed by solvent extraction. The objective was to assess the effect of starting seed moisture content (MC) and heating temperature on oil extractability and quality of pressed and solvent-extracted oils. The expelling conditions evaluated seed moisture (5% and 10% MC) that were subjected to three temperature levels (ambient, 60 °C and 104 °C for 20 min) then screw-pressed. The press cakes were extracted with hexane using a Soxhlet extractor. Among the starting seed MC and heat treatment combinations evaluated, seeds with 5% MC and heated at 104 °C produced press cake with 16.4% oil content suitable for solvent extraction. Pre-pressing E. lagascae seeds without flaking adequately prepared the pressed cake for solvent extraction recovering 99.8% of the total oil. The combined press- and hexane-extracted oils had the lowest free fatty acid (FFA, 1.15%), diacylglycerides (DAG, 1.55%), and phospholipids (39 ppm P) contents. The vernolic acid content and the fatty acid composition of the extracted oils practically remained the same. Oil refining is necessary to reduce the FFA content and oil color to meet the specifications of the intended application.

Critical metabolic pathways and genes cooperate for epoxy fatty acid-enriched oil production in developing seeds of Vernonia galamensis, an industrial oleaginous plant

BackgroundVernonia galamensis native to Africa is an annual oleaginous plant of Asteraceae family. As a newly established industrial oil crop, this plant produces high level (> 70%) of vernolic acid (cis-12-epoxyoctadeca-cis-9-enoic acid), which is an unusual epoxy fatty acid (EFA) with multiple industrial applications. Here, transcriptome analysis and fatty acid profiling from developing V. galamensis seeds were integrated to uncover the critical metabolic pathways responsible for high EFA accumulation, aiming to identify the target genes that could be used in the biotechnological production of high-value oils.ResultsBased on oil accumulation dynamics of V. galamensis seeds, we harvested seed samples from three stages (17, 38, and 45 days after pollination, DAP) representing the initial, fast and final EFA accumulation phases, and one mixed sample from different tissues for RNA-sequencing, with three biological replicates for each sample. Using Illumina platform, we have generated a total of 265 million raw cDNA reads. After filtering process, de novo assembly of clean reads yielded 67,114 unigenes with an N50 length of 1316 nt. Functional annotation resulted in the identification of almost all genes involved in diverse lipid-metabolic pathways, including the novel fatty acid desaturase/epoxygenase, diacylglycerol acyltransferases, and phospholipid:diacylglycerol acyltransferases. Expression profiling revealed that various genes associated with acyl editing, fatty acid β-oxidation, triacylglycerol assembly and oil-body formation had greater expression levels at middle developmental stage (38 DAP), which were consistent with the fast accumulation of EFA in V. galamensis developing seed, these genes were detected to play fundamental roles in EFA production. In addition, we isolated some transcription factors (such as WRI1, FUS3 and ABI4), which putatively regulated the production of V. galamensis seed oils. The transient expression of the selected genes resulted in a synergistic increase of EFA-enriched TAG accumulation in tobacco leaves. Transcriptome data were further confirmed by quantitative real-time PCR for twelve key genes in EFA biosynthesis. Finally, a comprehensive network for high EFA accumulation in V. galamensis seed was established.ConclusionsOur findings provide new insights into molecular mechanisms underlying the natural epoxy oil production in V. galamensis. A set of genes identified here could be used as the targets to develop other oilseeds highly accumulating valued epoxy oils for commercial production.

Optimization of Partial Epoxidation on Jatropha curcas Oil Based Methyl Linoleate Using Urea-hydrogen Peroxide and Methyltrioxorhenium Catalyst

Natural epoxy fatty acids such as Coronaric acid (9,10-epoxy-12Z-octadecenoic acid) and vernolic acid (12,13-epoxy-9Z-octadecenoic acid) are rich in of Vernolia galamensis, Vernolia anthelmintica and Chrysanthemums coronanium. The two fatty acids each contains an oxirana ring and a double bond C = C. The oil or its derivatives are suitable for industrial usage as reactive diffluent of alkyd resins, plasticizers and stabilizers, surface coatings, surfactants and lubricants, as intermediates in chemical reactions for making linear epoxides of composite materials and polymers. However, the use of such oils on an industrial scale is impossible due to limited resources. Therefore, epoxidation reactions need to be carried out to overcome the demand for partial epoxide fatty acids. Partially epoxidation of methyl linoleate at room temperature (30°C) in the presence of pyridine, methyltrioxorhenium (MTO) as catalyst and urea-hydrogen peroxide (UHP) as oxidant was studied by using response surface methodology (RSM). A five-level-four-factors central composite rotatable design (CCRD) was used to optimize the partially epoxidation conditions and study the effect of MTO, UHP, pyridine and reaction time on relative conversion to oxirane (RCO). Quadratic polynomial model was employed to generate response surface plots for RCO. At optimal condition, 79.05% monoepoxide was formed at the RCO of 58.15% under condition of 0.75 mol% mole ratio of MTO, 300 mol% mole ratio of UHP and 9 mol% of pyridine at 120 min reaction time. It can be concluded that the effect of UHP mole ratios was the dominant factor to control the degree of partial epoxidation of methyl linoleate followed by mole ratio of MTO, reaction time and mole ratio of pyridine to formed methyl 12,13-epoxy-9Z-octadecenoate or/and methyl 9,10-epoxy-12Z-octadecenoate.

Seed oil content and fatty acid composition response to ethyl methanesulphonate mutagenesis in vernonia

Vernonia [Centrapalus pauciflorus (Willd.) H.Rob.] is a novel industrial oilseed crop that can be used to produce vernolic acid, a naturally epoxidised fatty acid. The study objective was to determine whether ethyl methylsulphonate (EMS) mutagenesis significantly altered seed oil content and fatty acid compositions in selected vernonia accessions. Seeds were harvested from mutant plants with and without visual chlorophyll mutations from the Vge-1 and Vge-4 vernonia accessions, subjected to seed oil content and fatty acid composition analyses and compared with untreated controls. Visual chlorophyll mutations confirmed EMS mutation in harvested plants. Ethyl methylsulphonate mutagenesis significantly reduced vernolic acid composition, and significantly increased linoleic, oleic, palmitic, stearic and arachidic acid composition in the Vge-1 accession. In Vge-4, palmitic acid composition was significantly increased. Results obtained suggested that the effect of EMS mutagenesis on fatty acid composition in vernonia could be accession-specific and influenced by mutation level. The significant but negative association between vernolic acid and other fatty acids indicates that there is potential to increase vernolic acid while at the same time reducing the contents of other fatty acids through EMS mutagenesis in vernonia. There is a need to assess EMS mutagenesis impact on seed oil over successive generations to confirm results from this study.

Undiagnosed hypertension in potential kidney donors and case for comprehensive medical and psychosocial assessment

Euphorbia lagascae Spreng., naturally produces vernolic acid, which could replace the synthetic vernolic acid currently used as a plasticizer. Field trials conducted at Simcoe, Ontario from 2014 to 2016 show three breeding lines of E. lagascae performed well under field conditions when grown from transplants. Low field germination rates made agronomic studies using direct seeded plants difficult. Treatment with gibberellic acid and/or fungicide, or priming with water prior to seeding did not significantly improve germination. In general, seed yield, oil content and vernolic acid levels were not affected by nitrogen, or the application of chemical dehiscent. Higher stand densities did significantly increase seed yield and hence overall oil yield per hectare. Over the three growing seasons, oil and vernolic acid content ranged from 42%–53% and 56%–61%, respectively. Additional research to improve field germination of seed would greatly facilitate the continued development of E. lagascae as a commercial crop for the production of vernolic acid.

Agronomic performance of the novel oilseed crop Centrapalus pauciflorus in southwestern Ontario

Centrapalus pauciflorus naturally produces vernolic acid, which could replace the synthetic vernolic acid currently used as a plasticizer. Field trials conducted at Simcoe, Ontario from 2014 to 2016 show two breeding lines of C. pauciflorus (PI 642418, PI 642419), performed well under field conditions when grown from transplants. Low field germination rates made agronomic studies using direct seeded plants difficult. Variations in seeding depth, supplemental irrigation, treatment with gibberellic acid and/or fungicide, or priming with water prior to seeding did not significantly improve germination of field sown seed. In general, seed yield, oil content and vernolic acid levels were not affected by nitrogen, or early season removal of the apical meristem. Higher planting densities did significantly increase seed yield and hence overall oil yield per hectare. Over the three growing seasons, oil content ranged from 31.6 to 42.2% (ave. 37.5%) and vernolic acid content of 70.2–76.0% (ave. 73.5%). Additional research to improve field germination of seed would greatly facilitate the continued development of C. pauciflorus as a commercial crop for the production of vernolic acid.

Agronomic performance of the novel oilseed crop Euphorbia lagascae Spreng., (Euphorbiaceae) in southwestern Ontario

Euphorbia lagascae Spreng., naturally produces vernolic acid, which could replace the synthetic vernolic acid currently used as a plasticizer. Field trials conducted at Simcoe, Ontario from 2014 to 2016 show three breeding lines of E. lagascae performed well under field conditions when grown from transplants. Low field germination rates made agronomic studies using direct seeded plants difficult. Treatment with gibberellic acid and/or fungicide, or priming with water prior to seeding did not significantly improve germination. In general, seed yield, oil content and vernolic acid levels were not affected by nitrogen, or the application of chemical dehiscent. Higher stand densities did significantly increase seed yield and hence overall oil yield per hectare. Over the three growing seasons, oil and vernolic acid content ranged from 42%–53% and 56%–61%, respectively. Additional research to improve field germination of seed would greatly facilitate the continued development of E. lagascae as a commercial crop for the production of vernolic acid.

Vernonia galamensis and vernolic acid inhibit fatty acid biohydrogenation in vitro

Substituted long-chain fatty acids may be useful dietary supplements to suppress ruminal biohydrogenation of unsaturated fatty acids (UFA) and thereby increase the flow of UFA to meat and milk. The aim of this study was to determine if Vernonia galamensis (ironweed, a member of the sunflower family) and vernolic acid (cis-12,13-epoxy-cis-9-octadecenoic acid), the main constituent of the seed oil, affected the biohydrogenation of linoleic acid (LA; cis-9,cis-12-18:2) to rumenic acid (CLA; cis-9, trans-11-18:2), vaccenic acid (VA; trans-11-18:1) and stearic acid (SA; 18:0) by ruminal microorganisms. Ruminal digesta from four sheep receiving a mixed hay-concentrate diet were incubated in vitro with LA (0.2g/L) ± 0.2g/L vernolic acid or 5g/L of dried flowers or leaves of V. galamensis, either alone or combined. Vernolic acid had a substantial effect on LA metabolism, causing decreases in cis-9, trans-11 CLA and VA accumulation as well as SA production (P<0.05). Vernolic acid inhibited growth of the rumen fatty acid-biohydrogenating bacterium, Butyrivibrio fibrisolvens but not B. proteoclasticus at 0.025g/L; neither species grew at 0.05g/L. An inhibition of the metabolism of LA as well as a decrease in the accumulation of cis-9, trans-11 CLA and a slowdown in its metabolism were observed in the presence of flowers, leaves and a combination of both (P<0.05). However, only incubations with flowers, either alone or with leaves, resulted in higher accumulation of VA (P≤0.05). Vernolic acid, constituted 2% of the total fatty acid content of flowers whereas it was not detected in leaves of V. galamensis. Thus, the greater accumulation of VA observed with flowers of V. galamensis was probably due to other components rather than vernolic acid. It was concluded that vernolic acid and V. galamensis inhibit the biohydrogenation of LA in vitro. V. galamensis could potentially be used as an additive to alter ruminal biohydrogenation, leading to greater concentrations of cis-9, trans-11 CLA in meat and milk. Evaluation of V. galamensis in vivo is required to confirm the present in vitro observations.

Exploring the weed biology of two potentially novel oilseed crops:Euphorbia lagascaeandCentrapalus pauciflorus

Euphorbia lagascae and Centrapalus pauciflorus are natural sources of the plasticizer vernolic acid, and are therefore being considered as potentially new industrial oilseed crops in Canada. Both s...

Direct Polymerization of Vernonia Oil through Cationic Means

AbstractVernonia oil is obtained by extraction from Vernonia galamensis seeds. It is a triglyceride containing 70–80 % vernolic acid (12,13‐epoxy‐9‐decenoic acid). With approximately three epoxy groups per molecule, vernonia oil is a good raw material for new product development and many derivatives have been reported. In this work we report for the first time direct polymerization of vernonia oil through cationic means. The reaction entails the use of fluorosulfonic acid as a catalyst and 25–35 °C. Depending on the level of acid catalyst used, the products can range from a viscous oil to a completely insoluble resin. These products have been characterized by NMR and FT‐IR. The polymer may perhaps find applications as a thickener in lubricants and oil‐based commercial formulations.

Steric environment around acetylcholine head groups of bolaamphiphilic nanovesicles influences the release rate of encapsulated compounds

Two bolaamphiphilic compounds with identical acetylcholine (ACh) head groups, but with different lengths of an alkyl chain pendant adjacent to the head group, as well as differences between their hydrophobic skeleton, were investigated for their ability to self-assemble into vesicles that release their encapsulated content upon hydrolysis of their head groups by acetylcholinesterase (AChE). One of these bolaamphiphiles, synthesized from vernolic acid, has an alkyl chain pendant of five methylene groups, while the other, synthesized from oleic acid, has an alkyl chain pendant of eight methylene groups. Both bolaamphiphiles formed stable spherical vesicles with a diameter of about 130 nm. The ACh head groups of both bolaamphiphiles were hydrolyzed by AChE, but the hydrolysis rate was significantly faster for the bolaamphiphile with the shorter aliphatic chain pendant. Likewise, upon exposure to AChE, vesicles made from the bolaamphiphile with the shorter alkyl chain pendant released their encapsulated content faster than vesicles made from the bolaamphiphile with the longer alkyl chain pendant. Our results suggest that the steric environment around the ACh head group of bolaamphiphiles is a major factor affecting the hydrolysis rate of the head groups by AChE. Attaching an alkyl chain to the bolaamphiphile near the ACh head group allows self-assembled vesicles to form with a controlled release rate of the encapsulated materials, whereas shorter alkyl chains enable a faster head group hydrolysis, and consequently faster release, than longer alkyl chains. This principle may be implemented in the design of bolaamphiphiles for the formation of vesicles for drug delivery with desired controlled release rates.

Assessment of Oil Content and Fatty Acid Composition Variability in Two Economically Important Hibiscus Species

The Hibiscus genus encompasses more than 300 species, but kenaf (Hibiscus cannabinus L.) and roselle (Hibiscus sabdariffa L.) are the two most economically important species within the genus. Seeds from these two Hibiscus species contain a relatively high amount of oil with two unusual fatty acids: dihydrosterculic and vernolic acids. The fatty acid composition in the oil can directly affect oil quality and its utilization. However, the variability in oil content and fatty acid composition for these two species is unclear. For these two species, 329 available accessions were acquired from the USDA germplasm collection. Their oil content and fatty acid composition were determined by nuclear magnetic resonance (NMR) and gas chromatography (GC), respectively. Using NMR and GC analyses, we found that Hibiscus seeds on average contained 18% oil and seed oil was composed of six major fatty acids (each >1%) and seven minor fatty acids (each <1%). Hibiscus cannabinus seeds contained significantly higher amounts of oil (18.14%), palmitic (20.75%), oleic (28.91%), vernolic acids (VA, 4.16%), and significantly lower amounts of stearic (3.96%), linoleic (39.49%), and dihydrosterculic acids (DHSA, 1.08%) than H. sabdariffa seeds (17.35%, 18.52%, 25.16%, 3.52%, 4.31%, 44.72%, and 1.57%, respectively). For edible oils, a higher oleic/linoleic (O/L) ratio and lower level of DHSA are preferred, and for industrial oils a high level of VA is preferred. Our results indicate that seeds from H. cannabinus may be of higher quality than H. sabdariffa seeds for these reasons. Significant variability in oil content and major fatty acids was also detected within both species. The variability in oil content and fatty acid composition revealed from this study will be useful for exploring seed utilization and developing new cultivars in these Hibiscus species.

Phytochemical investigations of Vernonia galamensis seeds

Vernonia galamensis is a new potential industrial oil seed crop for semiarid areas with very high content of naturally epoxidized vernolic acid (80% of the oil). Chemical investigation of the seeds of Vernonia galamensis afforded two compounds, which are vernolic acid derivatives. Their structures were established by various spectroscopic techniques: IR, UV, NMR, and 2D NMR spectra (COSY, HSQC, and HMBC), and by comparison with literature data for the known compound methylvernolate. The cis-(12S,13R)-(3-methylpentyl) vernolate (1) and the cis-(12S,13R)-(2,3-propanediol) vernolate (2) were isolated and characterized.

Treatment of wastewater from rubber industry in Malaysia

Vernonia (Vernonia galamensis) is a new potential industrial oilseed crop. The seeds of this crop contain unusual naturally epoxidised fatty acids which are used in the production of various industrial products. The objective of this study was to evaluate and select vernonia lines in Limpopo province through seed oil content, fatty acid content and RAPD DNA markers. Significant differences were observed for the content of seed oil (22.4 - 29.05%), vernolic acid (73.09 - 76.83%), linoleic acid (13.02 14.05%), oleic acid (3.77 - 5.28%), palmitic acid (2.48 - 2.98%) and stearic acid (2.26 - 2.75%). Among the 13 RAPD DNA primers screened, primer OPA10 amplified DNA samples and resulted in 4 distinct groupings among tested lines. Four promising lines were selected; Vge-16, Vge-20, Vge-27 and Vge-32 using seed oil content, fatty acids and RAPD markers. The lines will be used for strategic breeding of vernonia as an alternative industrial oil crop in Limpopo province of South Africa or other similar environments.

Leaf lipids from Euphorbia lagascae Spreng. and Euphorbia lathyris L.

The Euphorbiaceae family is comprised of plant species that synthesise unusual fatty acids in their seed oils, e.g., Ricinus communis (ricinoleic or hydroxyoleic acid), Aleurites fordii (eleostearic acid) or Euphorbia lagascae (vernolic or epoxyoleic acid). Accumulation of triacylglycerols (TAGs) in plant leaves of many species can occur, although in smaller quantities than in seeds. This is the first report on leaf lipids in Euphorbia. Total lipid (TL) content ranged from 2274 to 5757 μg/g of fresh weight in Euphorbia lathyris and from 1562 to 9813 μg/g of fresh weight in E. lagascae. The first, fifth, tenth or fifteenth true leaves (each case from 2- to 40-day-old leaves) were sampled from plants grown in the open field and in the glasshouse at Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (Murcia, Spain). TAGs were separated by thin-layer chromatography (TLC) and represented up to 44.3% of TL in E. lagascae. The amount of TAG peaked in the first leaf and subsequently decreased with aging in all leaves. Microscope preparations revealed the presence of oil bodies (3–10 μm), possibly acting as intermediate storage products, in Euphorbia leaf mesophyll cells. Vernolic acid was identified in E. lagascae leaf lipids (0–25.7% of total fatty acids), but it was not incorporated into TAGs. These results imply that the active enzyme, diacylglycerol acyltransferase (DGAT), in the leaf of E. lagascae does not exhibit any selectivity towards the native unusual fatty acid.