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Currently, the negative effects of unified and intensive agriculture are of growing concern. To mitigate them, the possibilities of using local but nowadays underused crop for food production should be more thoroughly investigated and promoted. The soybean is the major crop cultivated for vegetable oil production in Zambia, while the oil production from local oil-bearing plants is neglected. The chemical composition of oils and cakes of a three traditional oil plant used by descendants of the Lozi people for cooking were investigated. Parinari curatellifolia and Schinziophyton rautanenii oils were chiefly composed of α-eleostearic (28.58-55.96%), linoleic (9.78-40.18%), and oleic acid (15.26-24.07%), whereas Ochna serrulata contained mainly palmitic (35.62-37.31%), oleic (37.31-46.80%), and linoleic acid (10.61-18.66%); the oil yield was high (39-71%). S. rautanenii and O. serrulata oils were rich in γ-tocopherol (3236.18 μg/g, 361.11 μg/g, respectively). The O. serrulata oil also had a very distinctive aroma predominantly composed of p -cymene (52.26%), m -xylene (9.63%), γ-terpinene (9.07%), o -xylene (7.97), and limonene (7.23%). The cakes remaining after oil extraction are a good source of essential minerals, being rich in N, P, S, K, Ca, and Mg. These plants have the potential to be introduced for use in the food, technical, or pharmaceutical industries.

Tocopherols and tocotrienols are natural compounds of plant origin, available in the nature. They are supplied in various amounts in a diet, mainly from vegetable oils, some oilseeds, and nuts. The main forms in the diet are α- and γ-tocopherol, due to the highest content in food products. Nevertheless, α-tocopherol is the main form of vitamin E with the highest tissue concentration. The α- forms of both tocopherols and tocotrienols are considered as the most metabolically active. Currently, research results indicate also a greater antioxidant potential of tocotrienols than tocopherols. Moreover, the biological role of vitamin E metabolites have received increasing interest. The aim of this review is to update the knowledge of tocopherol and tocotrienol bioactivity, with a particular focus on their bioavailability, distribution, and metabolism determinants in humans. Almost one hundred years after the start of research on α-tocopherol, its biological properties are still under investigation. For several decades, researchers' interest in the biological importance of other forms of vitamin E has also been growing. Some of the functions, for instance the antioxidant functions of α- and γ-tocopherols, have been confirmed in humans, while others, such as the relationship with metabolic disorders, are still under investigation. Some studies, which analyzed the biological role and mechanisms of tocopherols and tocotrienols over the past few years described new and even unexpected cellular and molecular properties that will be the subject of future research.

Vitamin E, a natural antioxidant, is of interest to scientists, health care pundits and faddists; its nutritional and biomedical attributes may be validated, anecdotal or fantasy. Vitamin E is a mixture of tocopherols (TPs) and tocotrienols (T-3s), each class having four substitutional isomers (α-, β-, γ-, δ-). Vitamin E analogues attain only low concentrations in most tissues, necessitating exacting invasive techniques for analytical research. Quantitative positron emission tomography (PET) with an F-18-labeled molecular probe would expedite access to Vitamin E's biodistributions and pharmacokinetics via non-invasive temporal imaging. ( R )-6-(3-[ 18 F]Fluoropropoxy)-2,7,8-trimethyl-2-(4,8,12-trimethyltrideca-3,7,11-trien-1-yl)-chromane ([ 18 F]F-γ-T-3) was prepared for this purpose. [ 18 F]F-γ-T-3 was synthesized from γ-T-3 in two steps: (i) 1,3-di- O -tosylpropane was introduced at C6-O to form TsO-γ-T-3, and (ii) reaction of this tosylate with [ 18 F]fluoride in DMF/K 222 . Non-radioactive F-γ-T-3 was synthesized by reaction of γ-T-3 with 3-fluoropropyl methanesulfonate. [ 18 F]F-γ-T-3 biodistribution in a murine tumor model was imaged using a small-animal PET scanner. F-γ-T-3 was prepared in 61% chemical yield. [ 18 F]F-γ-T-3 was synthesized in acceptable radiochemical yield (RCY 12%) with high radiochemical purity (>99% RCP) in 45 min. Preliminary F-18 PET images in mice showed upper abdominal accumulation with evidence of renal clearance, only low concentrations in the thorax (lung/heart) and head, and rapid clearance from blood. [ 18 F]F-γ-T-3 shows promise as an F-18 PET tracer for detailed in vivo studies of Vitamin E. The labeling procedure provides acceptable RCY, high RCP and pertinence to all eight Vitamin E analogues.

2-methyl-6-phytyl-1, 4-benzoquinol methyltransferase (MPBQ-MT) is a vital enzyme catalyzing a key methylation step in both α/γ-tocopherol and plastoquinone biosynthetic pathway. In this study, the gene encoding MPBQ-MT was isolated from lettuce (Lactuca sativa) by rapid amplification of cDNA ends (RACE), named LsMT. Overexpression of LsMT in lettuce brought about a significant increase of α- and γ-tocopherol contents with a reduction of phylloquinone (vitamin K1) content, suggesting a competition for a common substrate phytyl diphosphate (PDP) between the two biosynthetic pathways. Besides, overexpression of LsMT significantly increased plastoquinone (PQ) level. The increase of tocopherol and plastoquinone levels by LsMT overexpression conduced to the improvement of plants' tolerance and photosynthesis under high light stress, by directing excessive light energy toward photosynthetic production rather than toward generation of more photooxidative damage. These findings suggest that the role and function of MPBQ-MT can be further explored for enhancing vitamin E value, strengthening photosynthesis and phototolerance under high light in plants.

Background: Studies examining vitamin E intake and the percentage of the population meeting dietary guidelines do not distinguish between natural (RRR-α-tocopherol) and synthetic (all-rac-α-tocopherol) intake, even though these different isomeric forms differ in bioactivity., Objective: This study aimed to determine the effect of RRR-α-tocopherol vs. all-rac-α-tocopherol intake on the percentage of the population meeting the vitamin E recommendation and on plasma α-tocopherol stereoisomer distribution., Methods: With the use of data from the Irish National Adult Nutrition Survey (NANS), this study examined the percentage of the Irish population meeting the European Union (EU) RDA for vitamin E of 12 mg/d, correcting for a bioactivity difference in all-rac- vs. RRR-α-tocopherol, where 1 mg of all-rac-α-tocopherol is considered to be equivalent to 1:1.36 (0.74) mg in the EU RDA. In a subcohort of supplement users and nonusers, plasma α- and γ-tocopherol concentrations and α-tocopherol stereoisomer distribution were measured. Receiver operating characteristic (ROC) curve analysis was conducted to determine ability to discriminate supplement user types., Results: Analysis of the NANS showed that 100% of participants still met the recommended intake of 12 mg/d, after all-rac-α-tocopherol intake was corrected for α-tocopherol equivalent bioactivity. In the subcohort analysis, the percentage of plasma RRR-α-tocopherol was significantly lower in high all-rac-α-tocopherol supplement (>11 mg/d) users (82%) compared with nonusers and with high RRR-α-tocopherol supplement (>35 mg/d) users (91% and 93% respectively, P < 0.01). High RRR-α-tocopherol supplement users had a significantly higher plasma α-tocopherol than low all-rac-α-tocopherol supplement (<2.5 mg/d) users (34 vs. 25 μmol/L, P = 0.01). ROC analysis demonstrated an ability to distinguish between RRR- and all-rac-α-tocopherol consumers, which may be useful in investigating the potential effect of RRR- and all-rac-α-tocopherol intake on health., Conclusions: This study demonstrated that the percentage of the population meeting the vitamin E recommendation was unaffected when all-rac-α-tocopherol intake was corrected for α-tocopherol equivalent bioactivity. all-rac-α-Tocopherol intake led to a decrease in the percentage of plasma RRR-α-tocopherol relative to RRR-α-tocopherol intake., (© 2015 American Society for Nutrition.)

The proximate composition of seeds and main physicochemical properties and thermal stability of oil extracted from Lannea microcarpa seeds were evaluated. The percentage composition of the seeds was: ash (3.11%), crude oil (64.90%), protein (21.14%), total carbohydrate (10.85%) and moisture (3.24%). Physicochemical properties of the oil were: refractive index, 1.473; melting point, 22.60°C; saponification value, 194.23 mg of KOH/g of oil; iodine value, 61.33 g of I2/100 g of oil; acid value, 1.21 mg of KOH/g of oil; peroxide value, 1.48 meq of O2/kg of oil and oxidative stability index, 43.20 h. Oleic (43.45%), palmitic (34.45%), linoleic (11.20%) and stearic (8.35%) acids were the most dominant fatty acids. Triacylglycerols with equivalent carbon number (ECN) 48 and ECN 46 were dominant (46.96% and 37.31%, respectively). The major triacylglycerol constituents were palmitoyl diolein (POO) (21.23%), followed by dipalmitoyl olein (POP) (16.47%), palmitoyl linoleyl olein (PLO) (12.03%), dipalmitoyl linolein (PLP) (10.85%) and dioleoyl linolein (LOO) (9.30%). The total polyphenol and tocopherol contents were 1.39 mg GAE g-1 DW and 578.56 ppm, respectively. γ-Tocopherol was the major tocopherol (437.23 ppm). These analytical results indicated that the L. microcarpa seed oil could be used as a frying oil and in the cosmetic industry.

Background: Tocopherols are natural antioxidants with both in vivo (vitamin E) and in vitro activity. Sunflower seeds contain predominantly alpha-tocopherol (>90% of total tocopherols), with maximum vitamin E effect but lower in vitro antioxidant action than other tocopherol forms such as gamma-tocopherol. Sunflower germplasm with stable high levels of gamma-tocopherol (>85%) has been developed. The trait is controlled by recessive alleles at a single locus Tph2 underlying a gamma-tocopherol methyltransferase (gamma-TMT). Additionally, unstable expression of increased gamma-tocopherol content in the range from 5 to 85% has been reported. The objective of this research was to determine the genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds., Results: Male sterile plants of nuclear male sterile line nmsT2100, with stable high gamma-tocopherol content, were crossed with plants of line IAST-1, with stable high gamma-tocopherol content but derived from a population that exhibited unstable expression of the trait. F2 seeds showed continuous segregation for gamma-tocopherol content from 1.0 to 99.7%. Gamma-tocopherol content in F2 plants (average of 24 individual F3 seeds) segregated from 59.4 to 99.4%. A genetic linkage map comprising 17 linkage groups (LGs) was constructed from this population using 109 SSR and 20 INDEL marker loci, including INDEL markers for tocopherol biosynthesis genes. QTL analysis revealed a major QTL on LG 8 that corresponded to the gamma-TMT Tph2 locus, which suggested that high gamma-tocopherol lines nmsT2100 and IAST-1 possess different alleles at this locus. Modifying genes were identified at LGs 1, 9, 14 and 16, corresponding in most cases with gamma-TMT duplicated loci., Conclusions: Unstable expression of high gamma-tocopherol content is produced by the effect of modifying genes on tph2a allele at the gamma-TMT Tph2 gene. This allele is present in line IAST-1 and is different to allele tph2 present in line nmsT2100, which is not affected by modifying genes. No sequence differences at the gamma-TMT gene were found associated to allelic unstability. Our results suggested that modifying genes are mostly epistatically interacting gamma-TMT duplicated loci.

Four phenolics, salviaplebeiaside (1), γ-tocopherol (2), chrysosplenol-D (4), and isovitexin (5), along with α-tocoquinone (3) and β-sitosterol (6) were isolated from the aerial parts of Vitex negundo var. cannabifolia. The isolation was performed using bio-assay tracking experiments. The structures of compounds 1-5 were established by spectroscopic means. The antibacterial activities of the compounds were assessed against Escherichia coli, Bacillus subtilis, Micrococcus tetragenus and Pseudomonas fluorescens. Chrysosplenol-D (4) exhibited activities against all the four spoilage microorganisms.

gamma-Tocopherol was reacted with (E)-4-oxo-2-nonenal (ONE) at 37 degrees C in an acidic acetonitrile solution. The reaction products were isolated by reversed-phase high-performance liquid chromatography and their structures were characterized to be 5-substituted gamma-tocopherols: 5-(1-(furan-2-yl)pentyl)-gamma-tocopherol (1), 3-(1-butyl-4,5,7-trimethyl-7-(4,8,12-trimethyltridecyl)-8,9-dihydro-7H-furo[3,2-f]chromen-2yl)propanal (2), and 1-(1-butyl-4,5,7-trimethyl-7-(4,8,12-trimethyltridecyl)-8,9-dihydro-7H-furo[3,2-f]chromen-2-yl)-4-(furan-2-yl)octan-3-one (3). Compound 1 was the predominant product under the mild acidic conditions, whereas compounds 2 and 3 were relatively stable and accumulated during the reaction. Compound 1 was detected as the product when gamma-tocopherol and ONE were incubated in methyl linoleate in the presence of dicetyl phosphate. The results indicate that gamma-tocopherol may trap ONE under acidic conditions of lipid peroxidation.

Tocopherols, essential components of the human diet, are synthesized exclusively by photosynthetic organisms. To increase tocopherol content by increasing total flux to the tocopherol biosynthetic pathway, genes encoding Arabidopsis homogentisate phytyltransferase (HPT/V-TE2) and tocopherol cyclase (TC/VTE1) were constitutively overexpressed in lettuce (Lactuca sativa L.). Total tocopherol content of the transgenic plants overexpressing either of the genes was increased by more than 2-fold mainly due to an increase in gamma-tocopherol. However, chlorophyll content in the HPT/VTE2 and TC/VTE1 transgenic lines decreased by up to 20% and increased by up to 35%, respectively (P < 0.01). These results demonstrate that manipulation of the tocopherol biosynthetic pathway can increase or decrease chlorophyll content depending on the gene introduced.

Monocyte adhesion to vascular endothelium is an initial step in atherogenesis. To quantify this, we incubated monocytes with cultured endothelial cells, and quantified the adhered live monocytes using a colorimetric assay. Endothelium activated with lipopolysaccharide attracted monocytes in a dose-dependent manner and the adhesion was attenuated with post-treatments with L-ascorbic acid (53%), alpha- (40%) and gamma-tocopherol (39%), resveratrol (39%), and Lithospermum erythrorhizon root extract (45%). This non-radioactive, colorimetric assay may be useful for screening anti-atherogenic compounds in early atherogenesis.

d-gamma-Tocopherol (gamma-Toc) and its major metabolite, 2, 7, 8-trimethyl-2S-(beta-carboxyethyl)-6-hydroxychroman (S-gamma-CEHC), are currently receiving attention concerning their unique pharmacological activities. In order to achieve the efficient delivery of gamma-Toc and S-gamma-CEHC in vivo, we synthesized d-gamma-tocopheryl N,N-dimethylglycinate hydrochloride (gamma-TDMG) as a water-soluble prodrug of gamma-Toc and a two-step prodrug of S-gamma-CEHC. gamma-TDMG is a solid (mp 161-163 degrees C) and is quite soluble in water over 50 mM. The hydrolysis of gamma-TDMG was effectively catalyzed by esterases in rat and human liver microsomes. The disposition of gamma-TDMG after iv administration in rats was compared with that of gamma-Toc solubilized with the surfactant, polyoxyethylene hydrogenated castor oil. The plasma and liver levels of gamma-Toc rapidly increased after the iv administration of the gamma-TDMG. The liver availability of gamma-Toc after the administration of gamma-TDMG was two times higher than that of the gamma-Toc administration. The relative systemic availability of S-gamma-CEHC after the gamma-TDMG administration was an equivalent value (102%), and the mean residence time of S-gamma-CEHC was eight times longer than the racemic gamma-CEHC administration. Based on these results, gamma-TDMG was identified as the most promising water-soluble prodrug of gamma-Toc and the two-step prodrug of S-gamma-CEHC.

Tocopherols, synthesized by photosynthetic organisms, are micronutrients with antioxidant properties that play important roles in animal and human nutrition. Because of these health benefits, there is considerable interest in identifying the genes involved in tocopherol biosynthesis to allow transgenic alteration of both tocopherol levels and composition in agricultural crops. Tocopherols are generated from the condensation of phytyldiphosphate and homogentisic acid (HGA), followed by cyclization and methylation reactions. Homogentisate phytyltransferase (HPT) performs the first committed step in this pathway, the phytylation of HGA. In this study, bioinformatics techniques were used to identify candidate genes, slr1736 and HPT1, that encode HPT from Synechocystis sp. PCC 6803 and Arabidopsis, respectively. These two genes encode putative membrane-bound proteins, and contain amino acid residues highly conserved with other prenyltransferases of the aromatic type. A Synechocystis sp. PCC 6803 slr1736 null mutant obtained by insertional inactivation did not accumulate tocopherols, and was rescued by the Arabidopsis HPT1 ortholog. The membrane fraction of wild-type Synechocystis sp. PCC 6803 was capable of catalyzing the phytylation of HGA, whereas the membrane fraction from the slr1736 null mutant was not. The microsomal membrane fraction of baculovirus-infected insect cells expressing the Synechocystis sp. PCC 6803 slr1736 were also able to perform the phytylation reaction, verifying HPT activity of the protein encoded by this gene. In addition, evidence that antisense expression of HPT1 in Arabidopsis resulted in reduced seed tocopherol levels, whereas seed-specific sense expression resulted in increased seed tocopherol levels, is presented.

gamma-tocopherol is the major form of vitamin E in many plant seeds and in the US diet, but has drawn little attention compared with alpha-tocopherol, the predominant form of vitamin E in tissues and the primary form in supplements. However, recent studies indicate that gamma-tocopherol may be important to human health and that it possesses unique features that distinguish it from alpha-tocopherol. gamma-Tocopherol appears to be a more effective trap for lipophilic electrophiles than is alpha-tocopherol. gamma-Tocopherol is well absorbed and accumulates to a significant degree in some human tissues; it is metabolized, however, largely to 2,7,8-trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman (gamma-CEHC), which is mainly excreted in the urine. gamma-CEHC, but not the corresponding metabolite derived from alpha-tocopherol, has natriuretic activity that may be of physiologic importance. Both gamma-tocopherol and gamma-CEHC, but not alpha-tocopherol, inhibit cyclooxygenase activity and, thus, possess antiinflammatory properties. Some human and animal studies indicate that plasma concentrations of gamma-tocopherol are inversely associated with the incidence of cardiovascular disease and prostate cancer. These distinguishing features of gamma-tocopherol and its metabolite suggest that gamma-tocopherol may contribute significantly to human health in ways not recognized previously. This possibility should be further evaluated, especially considering that high doses of alpha-tocopherol deplete plasma and tissue gamma-tocopherol, in contrast with supplementation with gamma-tocopherol, which increases both. We review current information on the bioavailability, metabolism, chemistry, and nonantioxidant activities of gamma-tocopherol and epidemiologic data concerning the relation between gamma-tocopherol and cardiovascular disease and cancer.

Premenopausal women and postmenopausal women given estrogen are protected from cardiovascular diseases compared with men. Previous studies investigated whether estrogen treatment protects low density lipoprotein (LDL) from in vitro oxidation as a potential mechanistic explanation for the beneficial effect of estrogen. Results of these studies are mixed, and very few studies considered aspects of LDL that influence LDL oxidation. This study investigated whether treating postmenopausal female cynomolgus macaques with conjugated equine estrogens (CEE), medroxyprogesterone acetate (MPA), CEE + MPA, or tamoxifen, a mixed estrogen receptor agonist/antagonist, would protect LDL from in vitro oxidation. LDL was isolated from monkeys fed an atherogenic diet for 12 weeks or the same diet with CEE, MPA, CEE + MPA, or tamoxifen added at levels equivalent (on a caloric basis) to those given to women. LDL was subjected to Cu(2+) (3 micromol/L) or 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH, 1 mmol/L) and LDL oxidation was determined by the lag time before rapid formation of conjugated dienes and by the maximal rate of conjugated diene formation (propagation rate). Lag times and propagation rates were not affected by treatment. Lag times for Cu(2+) oxidation were related to LDL tocopherol while lag times for AAPH oxidation were related to high density lipoprotein (HDL) cholesterol and to LDL molecular weight. Multivariate analysis showed that LDL alpha- and gamma-tocopherol together could explain 27% of the variation in Cu(2+) mediated lag time (P < 0.005) among animals while HDL cholesterol, LDL gamma-tocopherol, and LDL molecular weight combined could explain 40% of the variation in AAPH- mediated lag time (P = 0.0006) among animals. After adjustment for these predictors, LDL lag times were not affected by treatment. In conclusion, in monkeys treated with female hormones, multiple factors influence in vitro low density lipoprotein (LDL) oxidation; future work will be needed to determine whether estrogen alters oxidation of LDL in the artery.-Schwenke, D. C., J. D. Wagner, and M. R. Adams. In vitro lipid peroxidation of LDL from postmenopausal cynomolgus macaques treated with female hormones.