Principal Unsaturated Fatty Acids Research Articles

The biochemical content and antioxidant capacities of endemic Tanacetum densum (Lab.) Schultz Bip. subsp. laxum, and Tanacetum densum (Lab.) Schultz Bip. subsp. amani Heywood growing in Turkey.

Medicinal plants have a significant role in preventing and curing several diseases, and Tanacetum L. is one of these plants. The aim of the present study is to determine the fatty acid, lipid-soluble vitamin, sterol, phenolic content, and antioxidant capacity of Tanacetum densum subsp. laxum and Tanacetum densum subsp. amani, to compare the effect of altitude on the biochemical content and to compare systematically by using fatty acids and phenolics. This study showed that palmitic acid (C16:0) and stearic acid (C18:0) are major sources of saturated fatty acid and oleic acid (C18:1 n9), and linoleic acid (18:2 n6c) and a-linolenic acid (C18:3 n3) are the principal unsaturated fatty acids in the two endemic Tanacetum densum taxa. Also, this study found that the unsaturated fatty acid content (60.11±1.61%) of Tanacetum densum subsp. laxum was higher than the unsaturated fatty acid content (44.13±1.28%) of Tanacetum densum subsp. amani. And also, the ω6/ω3 ratio of Tanacetum densum subsp. laxum (1.74) and Tanacetum densum subsp. amani (1.60) was found to be similar. However, this study determined that the lipid soluble vitamin and sterol content of two endemic Tanacetum taxa are low except for stigmasterol. Present study showed that catechin is principal phenolic in the Tanacetum densum taxa. This study also found that Tanacetum densum subsp. laxum and Tanacetum densum subsp. amani had the highest levels of catechin, vanillic acid, and caffeic acid content though the phenolic amounts, particularly catechin and quercetin, were dissimilar in the T. densum taxa. This study suggested that ecological conditions such as altitude may affect the biochemical content of two endemic Tanacetum densum taxa. Furthermore, the current study determined that two endemic Tanacetum L. taxa had potent radical scavenging capacities and found a correlation between total phenolics and antioxidant activity.

Exploitation of HPLC Analytical Method for Simultaneous Determination of Six Principal Unsaturated Fatty Acids in Oviductus Ranae Based on Quantitative Analysis of Multi-Components by Single-Marker (QAMS).

As one of the featured products in northeast China, Oviductus Ranae has been widely used as a nutritious food, which contains a variety of bioactive unsaturated fatty acids (UFAs). It is necessary to establish a scientific and reliable determination method of UFA contents in Oviductus Ranae. In this work, six principal UFAs in Oviductus Ranae, namely eicosapentaenoic acid (EPA), linolenic acid (ALA), docosahexaenoic acid (DHA), arachidonic acid (ARA), linoleic acid (LA) and oleic acid (OA), were identified using UPLC-MS/MS. The UFAs identified in Oviductus Ranae were further separated based on the optimized RP-HPLC conditions. Quantitative analysis of multi-components by single-marker (QAMS) method was implemented in content determination of EPA, ALA, DHA, ARA and OA, where LA was used as the internal standard. The experiments based on Taguchi design verified the robustness of the QAMS method on different HPLC instruments and chromatographic columns. The QAMS and external standard method (ESM) were used to calculate the UFA content of 15 batches of Oviductus Ranae samples from different regions. The relative error (r < 0.73%) and cosine coefficient showed that the two methods obtained similar contents, and the method validations met the requirements. The results showed that QAMS can comprehensively and effectively control the quality of UFAs in Oviductus Ranae which provides new ideas and solutions for studying the active components in Oviductus Ranae.

Fertility variation among Paeonia lactiflora genotypes and fatty acid composition of seed oil

Herbaceous peony (Paeonia lactiflora Pall.) is a prospective oilseed crop and is widely cultivated in temperate regions. In the present study, eleven fertility characteristics of sixteen peony genotypes were systematically investigated through two consecutive years of observation, and correlation analysis between the parameter seed yield per stem and other ten parameters was performed. Then the fatty acid composition in the seed oil was further determined with six peony cultivars selected from the investigation. The results showed that the examined sixteen genotypes exhibited a wide range of significant differences in fertility traits. A significant positive correlation was observed between seed yield and other seven parameters (P < 0.01). And the parameter follicle symmetry (r = 0.570**) was further established as an indicative parameter in the early selection of high-yield peony genotypes. Further determination revealed that the average oil content of peony seeds was 32.71 %. Total ten fatty acids (FAs) were detected in peony seed oil and the unsaturated fatty acids (UFAs) accounted for 94.38–95.09 %. Oleic acid (OA), linoleic acid (LA) and linolenic acid (ALA) were three principal UFAs. The contents of these UFAs varied with genotype, but were overall more balanced than those in other seed oil. ‘Hangshao’ and ‘Fenghuang Niepan’ were eventually recommended for oilseed usage due to their considerable seed yields (30.75 g and 25.63 g per stem, respectively) and high seed oil content (33.34 % and 32.56 %, respectively). These findings would provide helpful references for the selection of oleaginous peony cultivars and accelerate the development of oil peony industry.

Oxidation kinetics of rapeseed oil pressed from microwave pre-treated seeds during long-term storage

In this study oxidation kinetics of the rapeseed oils prepared from microwave (MV) pre-treated seeds (2–10 min, 800 W) and stored for 12 months was examined. As a result of seeds MV pre-treatment, degradation of monounsaturated and polyunsaturated fatty acids up to 16–17% and 30–42% was noticed. At the same time, induction period of the oils prepared from seeds microwaved for 10 min was 1.5- and 1.7-times higher than that of the control oil. During storage, the increase of oil oxidative indices displayed first-order reaction kinetic. Oils obtained from MV pre-treated seeds showed significantly lower progress of oxidation, as the values of oxidation rate constant (k) for oxidation indices decreased with longer seeds exposure to MVs. Following 12 months of storage, the rate of the principal unsaturated fatty acids decrease ranged from 4.2 mg/100 g in the control oils to 4.1–2.3 mg/100 g in the oil samples pressed from MV pre-treated seeds. Practical applications Over the last few years, thermal oilseeds pre-treatment prior to further processing has gained a substantial interest. Oxidation is one of the major causes of edible oil quality deterioration. Although favorable effect of rapeseed MV pre-treatment on the phytochemicals content has been confirmed in several studies, the impact of this pre-processing method on the oxidative stability of the oil has not yet been fully examined. Thus, the accurate knowledge of the oxidation kinetics is essential to predict the quality changes that occur during storage.

Traditional uses and seed chemical composition of Jatropha spp. (Euphorbiaceae) in Tehuacán-Cuicatlán, México

Jatropha spp. plants are used in traditional medicine, food and for the elaboration of biofuel. The Tehuacán-Cuicatlán Biosphere Reserve in México holds genetic richness and endemism for this genus, but the specific use of the plants and the seed chemical profiles are still unknown. The objectives of this research were to record the traditional forms of use of Jatropha species, and to analyze the chemical composition of Jatropha spp. seeds. For this, a semi-structured survey was conducted in 15 towns, and 20 interviews were applied in each one between May and August 2012. Data allowed to estimate the Significant Use Level and Relative Use Value per species. Besides, seeds from J. neopauciflora, J. rufescens, and J. rzedowskii were collected between August and October 2013, and to seed flour samples we determined total lipids by the Soxhlet method, crude protein by the Kjendahl method, and ashes according to AOAC methods; fatty acid profile and phorbol esters were determined by gas chromatography and by HPLC, respectively. We recorded that the species J. neopauciflora, J. oaxacana, J. rufescens, J. ciliata, and J. rzedowskii, are used as traditional medicine, food, and ornaments, except for J. ciliata, for which none use was recorded. The Significant Use Level as food was found not significant, but for medicinal purposes, J. neopauciflora obtained the highest Relative Use Value (9.0 %). The latex is used to treat 13 disorders, including dental problems (toothache, sensitivity, caries), oral diseases (oral herpes, gingivitis, and oral candidiasis) with a Significant Use Level of 32.9 %; it is also used as a hemostatic. The protein content among species varied from 23.37 to 26.06 %, and total lipids from 34.79 to 36.60 %. The principal unsaturated fatty acids were oleic (25.08 to 30.09 %) and linoleic (44.55 to 48.46 %), and the saturated fatty acids were palmitic (10.11 to 16.50 %) and stearic (9.47 to 11.15 %). Phorbol esters, the main cause of seed’s toxicity, were absent in J. neopauciflora, J. rufescens, and J. rzedowskii. In conclusion, the Significant Use Level of Jatropha species studied was low, with little cultural acceptance and sporadic utilization. The Relative Use Value was important for medicinal purposes, especially for J. neopauciflora. The dehulled seeds of J. neopauciflora, J. rufescens, and J. rzedowskii are potentially useful as food, having high protein contents, and unsaturated oleic and linoleic fatty acids. With this study we report three non-toxic Jatropha species and recommend to scientifically validate the antimycotic use of J. neopauciflora latex.

Fatty acid profile of gamma-irradiated and cooked African oil bean seed (Pentaclethra macrophylla Benth).

The safety and shelf-life of food products can be, respectively, ensured and extended with important food-processing technologies such as irradiation. The joint effect of cooking and 10 kGy gamma irradiation on the fatty acid composition of the oil of Pentaclethra macrophylla Benth was evaluated. Oils from the raw seed, cooked seeds, irradiated seeds (10 kGy), cooked, and irradiated seeds (10 kGy) were extracted and analyzed for their fatty acid content. An omega-6-fatty acid (linoleic acid) was the principal unsaturated fatty acid in the bean seed oil (24.6%). Cooking significantly (P < 0.05) increased Erucic acid by 3.3% and Linolenic acid by 23.0%. Combined treatment significantly (P < 0.05) increased C18:2, C6:0, C20:2, C18:3, C20:3, C24:0, and C22:6 being linoleic, caproic, eicosadienoic, linolenic, eicosatrienoic, ligoceric, and docosahexaenoic acid, respectively, and this increase made the oil sample to have the highest total fatty acid content (154.9%), unsaturated to saturated fatty acid ratio (109.6), and unsaturated fatty acid content (153.9%). 10 kGy irradiation induces the formation of C20:5 (eicosapentaenoic), while cooking induced the formation of C20:4 (arachidic acid), C22:6 (Heneicosanoic acid), and C22:2 (docosadienoic acid). Combined 10 kGy cooking and irradiation increased the susceptibility of the oil of the African oil bean to rancidity.

Rho signaling participates in membrane fluidity homeostasis.

Preservation of both the integrity and fluidity of biological membranes is a critical cellular homeostatic function. Signaling pathways that govern lipid bilayer fluidity have long been known in bacteria, yet no such pathways have been identified in eukaryotes. Here we identify mutants of the yeast Saccharomyces cerevisiae whose growth is differentially influenced by its two principal unsaturated fatty acids, oleic and palmitoleic acid. Strains deficient in the core components of the cell wall integrity (CWI) pathway, a MAP kinase pathway dependent on both Pkc1 (yeast's sole protein kinase C) and Rho1 (the yeast RhoA-like small GTPase), were among those inhibited by palmitoleate yet stimulated by oleate. A single GEF (Tus1) and a single GAP (Sac7) of Rho1 were also identified, neither of which participate in the CWI pathway. In contrast, key components of the CWI pathway, such as Rom2, Bem2 and Rlm1, failed to influence fatty acid sensitivity. The differential influence of palmitoleate and oleate on growth of key mutants correlated with changes in membrane fluidity measured by fluorescence anisotropy of TMA-DPH, a plasma membrane-bound dye. This work provides the first evidence for the existence of a signaling pathway that enables eukaryotic cells to control membrane fluidity, a requirement for division, differentiation and environmental adaptation.

Royal Jelly Protects Against Ultraviolet B–Induced Photoaging in Human Skin Fibroblasts via Enhancing Collagen Production

Royal jelly (RJ) is a honeybee product containing proteins, carbohydrates, fats, free amino acids, vitamins, and minerals. As its principal unsaturated fatty acid, RJ contains 10-hydroxy-2-decenoic acid (10-HDA), which may have antitumor and antibacterial activity and a capacity to stimulate collagen production. RJ has attracted interest in various parts of the world for its pharmacological properties. However, the effects of RJ on ultraviolet (UV)-induced photoaging of the skin have not been reported. In this study we measured the 10-HDA content of RJ by high-performance liquid chromatography and tested the effects of RJ on UVB-induced skin photoaging in normal human dermal fibroblasts. The effects of RJ and 10-HDA on UVB-induced photoaging were tested by measuring procollagen type I, transforming growth factor (TGF)-β1, and matrix metalloproteinase (MMP)-1 after UVB irradiation. The RJ contained about 0.211% 10-HDA. The UVB-irradiated human skin fibroblasts treated with RJ and 10-HDA had increased procollagen type I and TGF-β1 productions, but the level of MMP-1 was not changed. Thus RJ may potentially protect the skin from UVB-induced photoaging by enhancing collagen production.

IMPORTANCE AND CHEMICAL ANALYSIS OF TRIGLYCERIDES AND FATTY ACIDS COMPOSITIONS OF THREE ENTOMOPATHOGENIC NEMATODE SPECIES

Triglycerides and fatty acids compositions in the juveniles of two species of Heterorhabditis (Heterorhabditis bacteriophora and H. indica) and one species of Steinernema (Steinernema riobrave ) were analysed and determined at two ages 0 and 20 days for S. riobrave and H. indica , less than 7 and 30 days for H. bacteriophora. Results revealed that triglycerides comprised approximately 82, 88and 85 % of the total lipids in S. riobrave, H. indica and H. bacteriophora respectively, Fatty acids recorded 8, 7 and 8% of the total lipid content, so, neutral lipids are the major content of total lipids. The major fatty acids found in nematode juveniles of three species were: palmitic C16:0, stearic C18:0, oleic C18:1 and linoleic C18:2. The most abundant saturated fatty acids were palmitic (C16:0) and stearic (C18:0) acids. Oleic (C18:1) and linoleIic (C18:2) were the principal unsaturated fatty acids. These nematodes have relative high levels of poly unsaturated fatty acids. Triglycerides and fatty acids composition were declined with storage. This decline was quantitative rather than qualitative. These results might be helpful in increasing the efficiency of entomopathogenic nematodes (EPN) as biological control agents against insect pests and improving different nematode species or strains. Fatty acids may be play role in toxicity of entomopathogenic nematodes (EPN) against hosts.

Differentiation of benthic marine primary producers using stable isotopes and fatty acids: Implications to food web studies

A two-dimensional biomarker approach, using stable isotopes (δ 13C, δ 15N) and fatty acids, was used to evaluate differences both amongst and within benthic primary producer types (seagrass, fleshy red algae, calcareous red algae, brown algae, and seagrass periphyton) that are typical of the nearshore, temperate Australian region. The primary source of variance (as examined by permutational ANOVA) for all biomarkers examined was amongst primary producer types, as opposed to amongst species within type. δ 13C showed a clear separation (Monte Carlo p < 0.05) between seagrass (range of means = −10.1 to −14.0‰) and macroalgae (−14.6 to −25.2‰), but could not differentiate amongst the algal types examined. Similarly, distinct δ 15N signatures ( p < 0.05) were found only for seagrass (range of means = 3.6–4.1‰) versus calcareous red algae (4.6–5.5‰), with all other types overlapping in their mean δ 15N values. In contrast, multivariate analysis of fatty acid data (using Canonical Analysis of Principal coordinates; CAP) distinguished not only between seagrass and macroalgae, but also between red and brown algae (and to a limited extent between the calcareous and fleshy red algal types). The principal unsaturated fatty acids in the samples were C 20 polyunsaturates (found primarily in the macroalgae and periphyton), and C 18 mono- and polyunsaturates, with high proportions of 18:2n-6 and 18:3n-3 typical of the seagrasses. The C 18 monounsaturate 18:1n-7 was one of the most diagnostic compounds for the red algae examined, being present in very low amounts in seagrass and virtually absent in the brown algae. Conversely, brown algae were high in 18:4n-3, with 20:4n-3 particularly diagnostic of the kelp Ecklonia radiata. In contrast to stable isotopes, fatty acids helped distinguish different algal groups, thereby providing support that a two-dimensional approach using stable isotopes and fatty acids is likely to provide the most useful tool to distinguish primary producers in food web structure.

Retinal Microglial Activation and Chemotaxis by Docosahexaenoic Acid Hydroperoxide

Peroxynitrite generated during the early phase of experimental autoimmune uveoretinitis (EAU) causes peroxidation of docosahexaenoic acid (22:6), a principal unsaturated fatty acid of the photoreceptor membrane, to its hydroperoxide (22:6HP). During this phase, microglia migrate to the site of photoreceptors. The effect of 22:6HP on the migration of isolated retinal microglia was investigated. Retinal microglia were isolated and cultured from newborn Lewis rats and identified immunohistochemically by OX42 antibody staining. Chemotactic activity of the microglia toward 22:6HP was assayed and compared with 22:6 and other control cultures. The effect of 22:6HP on the organization of actin fibers and on the expression of Rac and Iba1 in the microglia was studied by confocal microscopy. The gene and protein expression of Rac and Iba1 in these microglia was analyzed by real-time PCR and Western blot. Ninety-five percent of isolated microglia stained for OX42 and a chemotactic assay showed that 22:6HP was a potent chemoattractant for these cells. Exposure to hydroperoxide resulted in reorganization of F-actin with intense staining within the lamellipodia. Iba1 and Rac were upregulated in these activated cells and localized in the cell periphery and the lamellipodia. 22:6HP can activate retinal microglia and is a potent chemoattractant for microglial migration in response to the activation of Rac and reorganization of actin cytoskeleton. In EAU, microglial migration toward the photoreceptors may be mediated by 22:6HP formed in the photoreceptors, and these migrating cells could help modulate the inflammation.

Two aerobic pathways for the formation of unsaturated fatty acids in Pseudomonas aeruginosa

The double bond in anaerobic unsaturated fatty acid (UFA) biosynthesis is introduced by the FabA dehydratase/isomerase of the bacterial type II fatty acid biosynthetic pathway. A DeltafabA mutant of Pseudomonas aeruginosa grew aerobically, but required a UFA supplement for anaerobic growth. Wild-type cells produced 18:1Delta11 as the principal UFA, whereas the DeltafabA strain produced only 16:1Delta9. The double bond in the 16:1Delta9 was introduced after phospholipid formation and was localized in the sn-2 position. Two predicted membrane proteins, DesA and DesB, possessed the conserved histidine clusters characteristic of fatty acid desaturases. The DeltafabADeltadesA double mutant required exogenous fatty acids for growth but the DeltafabAdesB double mutant did not. Exogenous stearate was converted to 18:1Delta9 and supported the growth of DeltafabADeltadesA double mutant. A DeltafabADeltadesAdesB triple mutant was unable to desaturate exogenous stearate and was an UFA auxotroph. We detected a 2.5-fold increase in desA expression in DeltafabA mutants, whereas desB expression was derepressed by the deletion of the gene encoding a transcriptional repressor DesT. These data add two aerobic desaturases to the enzymes used for fatty acid metabolism in proteobacteria: DesA, a 2-position phospholipid Delta9-desaturase that supplements the anaerobic FabA pathway, and DesB, an inducible acyl-CoA Delta9-desaturase whose expression is repressed by DesT.

Discovery of Aerobic Mechanisms for the Formation of Unsaturated Fatty Acids in Pseudomonas aeruginosa

Unsaturated fatty acids (UFA) are produced anaerobically, or by oxidative desaturation in the presence of oxygen. Anaerobic synthesis introduces the double bond into the growing acyl chain by the FabA dehydratase/isomerase component of the bacterial type II fatty acid biosynthetic pathway. A ΔfabA mutant of Pseudomonas aeruginosa grew without exogenous UFA but was a UFA auxotroph under anaerobic conditions. Wild-type cells produced C18:1 as the principal UFA, while the ΔfabA strain produced mainly C16:1. Two membrane proteins in P. aeruginosa, DesA and DesB, possessed the characteristic desaturase histidine clusters which are essential for catalysis. No fatty acid compositional changes were found in either ΔdesA or ΔdesB strains. ΔfabAΔdesA double mutant required UFA for growth but ΔfabAΔdesB double mutant did not. DesA expression rescued ΔfabAΔdesA strain from UFA auxotroph and elevated C16:1 production, indicating that DesA was responsible for C16:1 formation in ΔfabA strain. Acetate pulse-chase experiments demonstrated that in the ΔfabA strain the double bond in C16:1 was introduced after fatty acid biosynthesis. The C16:1 was located in the sn-2 position of phosphatidylethanolamine and the double bond was at the Δ9 position. Stearate supported the growth of ΔfabAΔdesA double mutant, and it was converted to C18:1 9, whereas wild type cell has C18:1 11. The expression of desB was induced by stearate, and repressed by oleate. Thus, P. aeruginosa has both an oxygen-dependent phospholipid desaturase (DesA) and an acy-CoA desaturase (DesB). (supported by NIH Grant GM34496)

Fatty Acid Transduction of Nitric Oxide Signaling: MULTIPLE NITRATED UNSATURATED FATTY ACID DERIVATIVES EXIST IN HUMAN BLOOD AND URINE AND SERVE AS ENDOGENOUS PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR LIGANDS*♦

Mass spectrometric analysis of human plasma and urine revealed abundant nitrated derivatives of all principal unsaturated fatty acids. Nitrated palmitoleic, oleic, linoleic, linolenic, arachidonic and eicosapentaenoic acids were detected in concert with their nitrohydroxy derivatives. Two nitroalkene derivatives of the most prevalent fatty acid, oleic acid, were synthesized (9- and 10-nitro-9-cis-octadecenoic acid; OA-NO2), structurally characterized and determined to be identical to OA-NO2 found in plasma, red cells, and urine of healthy humans. These regioisomers of OA-NO2 were quantified in clinical samples using 13C isotope dilution. Plasma free and esterified OA-NO2 concentrations were 619 +/- 52 and 302 +/- 369 nm, respectively, and packed red blood cell free and esterified OA-NO2 was 59 +/- 11 and 155 +/- 65 nm. The OA-NO2 concentration of blood is approximately 50% greater than that of nitrated linoleic acid, with the combined free and esterified blood levels of these two fatty acid derivatives exceeding 1 microm. OA-NO2 is a potent ligand for peroxisome proliferator activated receptors at physiological concentrations. CV-1 cells co-transfected with the luciferase gene under peroxisome proliferator-activated receptor (PPAR) response element regulation, in concert with PPARgamma, PPARalpha, or PPARdelta expression plasmids, showed dose-dependent activation of all PPARs by OA-NO2. PPARgamma showed the greatest response, with significant activation at 100 nm, while PPARalpha and PPARdelta were activated at approximately 300 nm OA-NO2. OA-NO2 also induced PPAR gamma-dependent adipogenesis and deoxyglucose uptake in 3T3-L1 preadipocytes at a potency exceeding nitrolinoleic acid and rivaling synthetic thiazo-lidinediones. These data reveal that nitrated fatty acids comprise a class of nitric oxide-derived, receptor-dependent, cell signaling mediators that act within physiological concentration ranges.

Fatty-acid biosynthesis in a branched-chain α-keto acid dehydrogenase mutant ofStreptomyces avermitilis

Fatty-acid biosynthesis by a branched-chain alpha-keto acid dehydrogenase (bkd) mutant of Streptomyces avermitilis was analyzed. This mutant is unable to produce the appropriate precursors of branched-chain fatty acid (BCFA) biosynthesis, but unlike the comparable Bacillus subtilis mutant, was shown not to have an obligate growth requirement for these precursors. The bkd mutant produced only straight-chain fatty acids (SCFAs) with membrane fluidity provided entirely by unsaturated fatty acids (UFAs), the levels of which increased dramatically compared to the wild-type strain. The levels of UFAs increased in both the wild-type and bkd mutant strains as the growth temperature was lowered from 37°C to 24°C, suggesting that a regulatory mechanism exists to alter the proportion of UFAs in response either to a loss of BCFA biosynthesis, or a decreased growth temperature. No evidence of a regulatory mechanism for BCFAs was observed, as the types of these fatty acids, which contribute significantly to membrane fluidity, did not alter when the wild-type S. avermitilis was grown at different temperatures. The principal UFA produced by S. avermitilis was shown to be delta9-hexadecenoate, the same fatty acid produced by Escherichia coli. This observation, and the inability of S. avermitilis to convert exogenous labeled palmitate to the corresponding UFA, was shown to be consistent with an anaerobic pathway for UFA biosynthesis. Incorporation studies with theS. avermitilis bkd mutant demonstrated that the fatty acid synthase has a remarkably broad substrate specificity and is able to process a wide range of exogenous branched chain carboxylic acids into unusual BCFAs.Key words: Streptomyces avermitilis, fatty acid biosynthesis, avermectin.

Protein and oil composition of sesame seeds (Sesamum indicum, L.) grown in the Gizan area of Saudi Arabia

Protein content, amino acid and oil composition of two cultivars of Sesamum indicum L. were studied. The cultivars (dark and white) showed ash content in the range of 6.54–7.71%, nitrogen 3.70–4.03%, protein 23.13–25.18% and oil 47.02–49.07%, respectively. Seventeen amino acids were determined including most of the essential and limiting amino acids. Comparison of the present data was made with those reported by the FAO/WHO minimum reference protein. The dark sesame seeds had significantly higher oil and lower protein contents than the white coloured seeds. Oil content were found to be 47.02% and 49.07% in the white and dark coloured seeds, respectively. Analysis by gas liquid chromatography of the oils revealed various fatty acids. The most common recorded in the order of abundance for black and white were: oleic (45.46 and 47.03%), linoleic (33.79 and 35.01%), palmitic (12.03 and 14.02%), stearic (4.93 and 5.72%) and archidic acid (1.00%). Oleic and linoleic were the principal unsaturated fatty acids, while palmitic and stearic were the main saturated fatty acid present. The percentage of the fatty acids fall within the range given by the FAO/WHO committee on fats and oils.

Polymorphic behavior of gondoic acid and phase behavior of its binary mixtures with asclepic acid and oleic acid

AbstractMolecular properties of polymorphic forms of gondoic acid [cis‐C20:1Δ11ω9 (GOA)] have been studied by X‐ray diffraction (XRD), differential scanning calorimetry (DSC), optical microscopy, and Raman scattering, in comparison to those of six principal unsaturated fatty acids: oleic acid [cis‐C18:1Δ9ω9 (OA)], erucic acid [cis‐C22:1Δ13ω9 (ERA)], petroselinic acid [cis‐C18:1Δ6ω12 (PSA)], asclepic acid [cis‐C18:1Δ11ω7 (APA)], palmitoleic acid [cis‐C16:1Δ9ω7 (POA)], and elaidic acid [trans‐C18:1Δ9ω9 (ELA)]. In addition, phase behavior of binary mixtures of GOA and APA and OA was examined by XRD and DSC. The polymorphic structures of GOA are quite similar to those of APA, ERA, POA, and partly to OA. In particular, DSC and Raman scattering studies have shown that gondoic acid exhibits conformational disordering on heating at the ω‐chain, a chain segment between the double bond and CH3 group, as a transition from all‐trans (γ form) to gauche‐rich (α form) conformations. A miscible mixing phase was observed in the mixture of GOA and APA, yet eutectic phases were observed in the GOA and OA mixtures. This is a remarkable contrast because the binary mixture systems of varying combinations of cis‐unsaturated fatty acids examined so far exhibited either eutectic nature or molecular compound formation. It is expected that specific molecular interactions between GOA and APA that originate from the equivalence of the length of the Δ‐chain, the chain segment between the cis‐double bond and COOH group, and also from the presence of the γ‐α order‐disorder transformation would be operating to form the miscible mixing phase.

Capillary gas chromatographic analyses of headspace volatiles from vegetable oils

AbstractEight different vegetable oils obtained commercially were analyzed for volatiles by capillary gas chromatography (GC). Volatiles generated in a GC static headspace sampler at 180 C were injected automatically onto a chemically bonded capillary column. Only a small number of GC peaks of low intensity were observed in the fresh samples, which varied in peroxide values from 0.2 to 3. Several major peaks were evident in the oils aged eight and 16 days at 60 C with peroxide values ranging from 16 to 65. Thirty‐four GC peaks were identified on the basis of relative retention time of reference compounds and on the basis of gas chromatography‐mass spectrometry (GC‐MS). Volatile compounds identified were those expected from the autoxidation of principal unsaturated fatty acid components of each vegetable oil tested. The relative concentrations of volatile components increased with the level of oxidation as determined by peroxide value.

Modifications of membrane lipid composition following the nutritional shift-up of starved cells a comparison with membrane biogenesis in Tetrahymena

Detailed analyses of lipid composition have been made on various membrane fractions isolated at different intervals after 24 h-starved Tetrahymena cells were refed with nutrient-rich medium. During starvation there was a marked alteration in both phospholipid polar headgroup and acyl chain compositions: an increase in 2-aminoethylphospholipid and γ-linolenic acid (18 : 3) with a concurrent decrease in phosphatidylethanolamine and palmitoleic acid (16 : 1). However, following refeeding, such an altered lipid composition was rather rapidly restored to the initial level of the control cell membranes prior to starvation. This membrane lipid modification was found to occur in good accordance with the recovery of cell size and lipid synthesis. The considerable changes in the principal unsaturated fatty acids, 16 : 1 and 18 : 3, which are formed via the palmitate and stearate desaturation pathways, respectively, were suggested to be accounted for by the levels of desaturases activities. The results of the labeling experiments with radioactive precursors have demonstrated that in the refed cells, there was a more rapid and dynamic transfer or exchange between membranes as compared with that in the exponentially growing control cells. Thus, rapid ameliorative modifications of membrane lipid composition are thought to be required for the urgent growth of membrane systems in the refed cell which should be ready to initiate new division.

Sterol galactosides and sterol esters of the cotton bud

AbstractAbout 60% of the total sterols in the cotton bud appeared in the free state; the esterified sterol glycosides contained about 50% saturated fatty acids, largely palmitic acid; the principal unsaturated fatty acid was linolenic acid. β‐Sitosterol was the major sterol in all classes of sterol derivatives. The sugar moiety of the esterified sterol glycosides and the sterol glycoside was galactose. Efforts are continuing to evaluate the minor sterols of cotton buds, some of which appear to be hydroxylated ecdysones, and to study their relationship to the development of the Boll weevil,Anthonomus grandis Boheman.