Wax Esters Research Articles

Validation of suitable reference genes for qRT-PCR in cabbage (Brassica oleracea L.) under different abiotic stress experimental conditions

Cabbage (Brassica oleracea) is one of the most important vegetable crops worldwide. qRT-PCR is a sensitive technique for gene expression studies and choosing the appropriate reference gene is essential to obtain reliable results. In the present work, 22 candidate reference genes were evaluated under various experimental conditions, including NaCl, drought stress treatment, temperature treatments (cold and heat) and a set of hormones stress (6-BA, NAA, and ABA) treatments, across a range of tissue types and cultivars. Gene expression data taken from 45 cabbage samples was analyzed using two algorithms, geNorm and NormFinder. Suitable combinations of reference genes for qRT-PCR normalization should be applied according to different experimental conditions. In this study, the genes EF1a, GAPC2 and SAND were verified as the suitable reference genes across all tested samples. Additionally, each experimental condition had a unique set of reference genes best suited to samples within the particular condition. To validate the suitability of the candidate reference genes, the gene expression of WSD1, a gene that may be involved in biosynthesis pathway of wax esters in cabbage, was measured across all 45 samples and normalized using the three best reference gene candidates. WSD1 displayed variation in gene expression across different tissues and cultivars, and exhibited diverse up- or down- regulated expression patterns under various treatments, which indicate that BoWSD1 may play an important role in the response to abiotic stresses in cabbage. Our results provide the foundation for gene expression analysis in Brassica oleracea and other species of Brassica vegetables.

Effect of Calanus Oil Supplementation and 16 Week Exercise Program on Selected Fitness Parameters in Older Women

We investigated changes in functional fitness after an exercise program in combination with Calanus oil supplementation, a novel source of bioactive lipids rich in wax esters with omega-3 polyunsaturated fatty acid (n-3 PUFA). Fifty-five healthy sedentary women aged 65–80 (mean age 70.9 ± 3.9 years, BMI 27.24 ± 3.9 kg m−2, VO2peak 19.46 ± 3.7 ml kg−1 min−1) were enrolled in the study. The participants were divided into two groups: exercise training plus Calanus Oil supplementation (n = 28) or exercise plus placebo (sunflower oil) supplementation (n = 27). The exercise intervention program was completed by 53 participants and contained functional circuit training (twice a week, 45 min plus 15 min of stretching and balance training) and Nordic walking (once a week, 60 min) for 16 weeks. Senior fitness test, exercise stress test on bicycle ergometer, hand-grip, and body composition were evaluated before and after the program. Our results show that functional fitness and body composition improved following the interventional exercise program, but for most of the parameters there was no synergic effect of supplementing n-3 PUFA-rich Calanus oil. In comparison to the placebo group, the group with Calanus supplementation experienced significantly higher improvement of functional strength of lower body which was evaluated by the chair stand test. Supplementation with Calanus may have a synergic effect with exercise on functional strength of the lower body in the elderly.

Ten fatty acyl-CoA reductase family genes were essential for the survival of the destructive rice pest, Nilaparvata lugens.

Fatty alcohols are the precursors of sex pheromone components, wax esters and hydrocarbons in insects. Fatty acyl-CoA reductases (FARs) are important enzymes required for the reduction of fatty alcohol and thereby contribute to the production of cuticular hydrocarbon (CHC). Based on bioinformatics analyses we identified 17 FAR genes in the brown planthopper, Nilaparvata lugens. RNA interference against these genes demonstrated that ten NlFAR genes were essential for the survival of N. lugens. For instance, knockdown of NlFAR5, 6, 11 or 15 was lethal and caused a slender body shape, while the old cuticles of the respective animals remained attached to the abdomen or failed to split open from the nota. Knockdown of NlFAR9 resulted in a phenotype, with a smooth body surface and a decrease in CHC amounts. Similarly, CHC deficiency in N. lugens resulted in increased adhesion of water droplets and secreted honeydew to the insect surface and the inability of N. lugens to survive in paddy fields with varying humidity. Knockdown of NlFAR1, 4, 5, 6, 8, 9, 11 and 13 additionally resulted in female adult infertility. The present study illustrates the structural and functional differences of FAR family genes and provides potential targets for RNA interference-based rice planthopper management. © 2020 Society of Chemical Industry.

Food stress, but not experimental exposure to mercury, affects songbird preen oil composition.

Mercury is a global pollutant and potent neurotoxic metal. Its most toxic and bioavailable form, methylmercury, can have both lethal and sublethal effects on wildlife. In birds, methylmercury exposure can disrupt behavior, hormones, the neuroendocrine system, and feather integrity. Lipid-rich tissues and secretions may be particularly susceptible to disruption by lipophilic contaminants such as methylmercury. One such substance is feather preen oil, a waxy secretion of the uropygial gland that serves multiple functions including feather maintenance, anti-parasitic defense, and chemical signaling. If methylmercury exposure alters preen oil composition, it could have cascading effects on feather quality, susceptibility to ectoparasites, and mate choice and other social behaviors. We investigated whether exposure to methylmercury, either alone or in association with other stressors, affects preen oil chemical composition. We used a two-factor design to expose adult song sparrows (Melospiza melodia) to an environmentally relevant dietary dose of methylmercury and/or to another stressor (unpredictable food supply) for eight weeks. The wax ester composition of preen oil changed significantly over the 8-week experimental period. This change was more pronounced in the unpredictable food treatment, regardless of dietary methylmercury. Contrary to our prediction, we found no main effect of methylmercury exposure on preen oil composition, nor did methylmercury interact with unpredictable food supply in predicting the magnitude of chemical shifts in preen oil. While it remains critical to study sublethal effects of methylmercury on wildlife, our findings suggest that the wax ester composition of preen oil is robust to environmentally relevant doses of this contaminant.

Lipids source and degradation as revealed by molecular biomarkers in soils after acid-pretreatment: A case of a plantain soil under long-term cultivation

The extractable lipids are important components in soil organic matter (SOM) which were used to trace the sources and degradation of SOM. The protection of lipids by soil mineral have been suggested through organic solvents. But, the extraction efficiency of some lipid compounds was low. This study applied a mild acid treatment to firstly remove most of the reactive mineral particles, and without altering SOM chemical structures in 10% HF/1M HCl (1:4 w: v). Based on the obtained lipid biomarker information, we observed that the lipid extraction efficiency significantly increased by organic solvents on after removal of active minerals. The acid treatment increased the scientific to quantitative the amount of lipids. The minerals showed significant differences in the selective protection to different components of lipids. In this study, the amount range of protected n-alkanoic acids is 73~85%, n-alkanol 41~62% and n-alkanes 26~46%. After the vegetation was replaced, the increased alkenoate and alkane in soil input by the plant tissues of plantain directly, and the alkanols probably input by the hydrolysis of wax esters. Under the interference of man-made tillage activities, the C content in 0-20 cm decreased, suggesting that cultivated activities may enhance SOM degradation and accelerate SOM turnover. Understanding SOM behaviour in this area will provide important information for soil management and to evaluate carbon cycling in human-affected ecological systems.

Concentration dependent cholesteryl-ester and wax-ester structural relationships and meibomian gland dysfunction

BackgroundWith dry eye, the ratio of cholesteryl ester (CE) to wax ester (WE) decreases substantially in meibum, but the functional and structural consequences of this change are speculative. The aim of this study is to confirm this finding and to bridge this gap in knowledge by investigating the effect of varying CE/WE ratios on lipid structure and thermodynamics. MethodsInfrared spectroscopy was use to quantify CE and WE in human meibum and to measure hydrocarbon chain conformation and thermodynamics in a cholesteryl behenate, stearyl stearate model system. ResultsThe CE/WE molar ratio was 36% lower for meibum from donors with dry eye due to meibomian gland dysfunction compared with meibum from donors without dry eye. CE (5 mol %) dramatically increased the phase transition temperature of pure WE from -0.12 °C to 63 °C in the mixture. Above 5 mol % CB, the phase transition temperature increased linearly, from 68.5 °C to 85 °C. In the ordered state, CE caused an increase in lipid order from about 72% trans rotamers to about 86% trans rotamers. Above 10% CE, the hydrocarbon chains were arranged in a monoclinic geometry. ConclusionsThe CE/WE is lower in meibum from donors with dry eye due to meibomian-gland dysfunction. Major conformational changes in the hydrocarbon chains of wax and cholesteryl ester mixtures begin to occur with just 5% CB and above. General significanceCE-WE interactions may be important for in understanding lipid layer structure and functional relationships on the surface of tears, skin and plants.

Lubrication characteristics of wax esters from oils produced by a genetically-enhanced oilseed crop

In this study, purified by a newly developed method Crambe (Crambe abyssinica) oil wax esters were mixed with conventional Crambe oil to examine the lubrication characteristics of bio-based wax esters and their blends. The Quartz Crystal Microbalance (QCM) results indicate high thermal stability of wax esters and their mixtures which is further supported by observed small viscosity change with temperature increase. Fourier transform infrared spectroscopy (FTIR) analysis suggested that chemical modifications induced by heating of the Crambe oil with 15 wt% of wax esters are dominated by the stability of wax esters. Tribology tests revealed that adding 15 wt% wax esters facilitates the noticeable friction reduction and lowers the wear produced in the sliding contact at elevated temperatures.

Drought stress modulates cuticular wax composition of the grape berry.

Drought events are a major challenge for many horticultural crops, including grapes, which are often cultivated in dry and warm climates. It is not understood how the cuticle contributes to the grape berry response to water deficit (WD); furthermore, the cuticular waxes and the related biosynthetic pathways are poorly characterized in this fruit. In this study, we identified candidate wax-related genes from the grapevine genome by phylogenetic and transcriptomic analyses. Developmental and stress response expression patterns of these candidates were characterized across pre-existing RNA sequencing data sets and confirmed a high responsiveness of the pathway to environmental stresses. We then characterized the developmental and WD-induced changes in berry cuticular wax composition, and quantified differences in berry transpiration. Cuticular aliphatic wax content was modulated during development and an increase was observed under WD, with wax esters being strongly up-regulated. These compositional changes were related to up-regulated candidate genes of the aliphatic wax biosynthetic pathway, including CER10, CER2, CER3, CER1, CER4, and WSD1. The effect of WD on berry transpiration was not significant. This study indicates that changes in cuticular wax amount and composition are part of the metabolic response of the grape berry to WD, but these changes do not reduce berry transpiration.

G_Fe3O4/Ag supporting Candida rugosa lipase for the “green” synthesis of pomegranate seed oil derived liquid wax esters

Wax esters were obtained through hydrolysis/esterification of pomegranate seed oil (PSO) with cetyl alcohol in the presence of Candida rugosa lipase (CRL) immobilized on G_Fe3O4/Ag@OA (oleic acid-coated magnetic nano-hybrid) catalyst. Lipase was immobilized successfully on the as-produced nanoparticles with an efficiency, depending on the operating conditions, up to ∼94%. The immobilized CRL shows very high activity on the respect of the free counterpart, which can be attributed to the lipase conformational structure modification related to interfacial activation. The immobilized lipase was used for the wax esters synthesis from PSO in a solvent-free system. A conversion of ∼83% was observed after 12 h alcohol/FFA molar ratio 1:1, it increases up to ∼95% with an alcohol/FFA molar ratio of 2:1. After the first three cycles of use, no significant reduction of the lipase activity was observed. Analyses of wax esters properties compared with jojoba oil evidence the feasibility of the produced wax ester for different applications. Iodine number of ∼209 (gI2/100 g oil) was obtained indicating a high degree of anti-oxidant and moisturizing properties.

The use of PAH, metabolite and lipid profiling to assess exposure and effects of produced water discharges on pelagic copepods

Several laboratory studies have demonstrated that exposure to oil components cause toxicity to copepods, however, this has never been shown in natural populations of copepods. In the present study, we sampled copepods in an area of the North Sea with high density of oil production platforms discharging produced water. Environmental modelling was used to predict produced water and copepod trajectories prior to copepod sampling in situ. To maximise output from a minimal number of field samples, a novel and combined methodology was developed to allow exploitation of the same extract for several purposes; contaminant body burden, lipidomics, and metabolomics analysis. PAH body burdens were low compared to laboratory experiments where correlations between PAH body burden and acute toxicity, reproduction and molecular endpoints had been established. Still, station-specific PAH profiles strongly indicated copepod exposure to PW. NMR metabolomics, focusing on water-soluble metabolites, suggested no correlation between metabolites and stations. Interestingly, lipidomics analyses suggested site-specific fingerprints and profiles displayed for acyl-glycerols and wax esters. Potential effects of produced water exposure on lipid metabolism in copepods cannot be ruled out and deserves more attention. Our study exemplifies the importance of incorporating novel and improved analytical methodologies in environmental monitoring.

Olive Oil Oleogel Formulation Using Wax Esters Derived from Soybean Fatty Acid Distillate.

Oleogelation is an emerging technology to structure oils, which can be widely used to substitute saturated and trans fats. Extra virgin olive oil is widely recognized for its high nutritional value, but its utilization in oleogel production is currently limited. In this study, extra virgin olive oil was utilized for the production of a novel oleogel using wax esters derived from soybean fatty acid distillate (SFAD), a byproduct of industrial soybean oil refining. Different concentrations (7%, 10%, 20%, w/w) of SFAD-wax esters were used to evaluate the minimum concentration requirement to achieve oleogelation. Analyses of the mechanical properties of oleogel showed a firmness of 3.8 N, which was then reduced to around 2.1–2.5 N during a storage period of 30 days at 4 °C. Rheological analysis demonstrated that G′ is higher than G″ at 20–27 °C, which confirms the solid properties of the oleogel at this temperature range. Results showed that SFAD was successfully utilized for the oleogelation of olive oil, resulting in a novel oleogel with desirable properties for food applications. This study showed that industrial fatty side streams could be reused for the production of value-added oleogels with novel food applications.

Steryl Ester Formation and Accumulation in Steroid-Degrading Bacteria.

Steryl esters (SEs) are important storage compounds in many eukaryotes and are often prominent components of intracellular lipid droplets. Here, we demonstrate that selected Actino- and Proteobacteria growing on sterols are also able to synthesize SEs and to sequester them in cytoplasmic lipid droplets. We found cholesteryl ester (CE) formation in members of the actinobacterial genera Rhodococcus, Mycobacterium, and Amycolatopsis, as well as several members of the proteobacterial Cellvibrionales order. CEs maximally accumulated under nitrogen-limiting conditions, suggesting that steryl ester formation plays a crucial role for storing excess energy and carbon under adverse conditions. Rhodococcus jostii RHA1 was able to synthesize phytosteryl and cholesteryl esters, the latter reaching up to 7% of its cellular dry weight and 69% of its lipid droplets. Purified lipid droplets from RHA1 contained CEs, free cholesterol, and triacylglycerols. In addition, we found formation of CEs in Mycobacterium tuberculosis when it was grown with cholesterol plus an additional fatty acid substrate. This study provides a basis for the application of bacterial whole-cell systems in the biotechnological production of SEs for use in functional foods and cosmetics.IMPORTANCE Oleaginous bacteria exhibit great potential for the production of high-value neutral lipids, such as triacylglycerols and wax esters. This study describes the formation of steryl esters (SEs) as neutral lipid storage compounds in sterol-degrading oleaginous bacteria, providing a basis for biotechnological production of SEs using bacterial systems with potential applications in the functional food, nutraceutical, and cosmetic industries. We found cholesteryl ester (CE) formation in several sterol-degrading Actino- and Proteobacteria under nitrogen-limiting conditions, suggesting an important role of this process in storing energy and carbon under adverse conditions. In addition, Mycobacterium tuberculosis grown on cholesterol accumulated CEs in the presence of an additional fatty acid substrate.

Can mesopelagic mixed layers be used as feed sources for salmon aquaculture?

Salmon aquaculture is in great need of good quality balanced protein and lipid sources, particularly marine omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), to sustain a further development of the industry. One possibility is to harvest mesopelagic marine layers. Therefore, the current project analysed mesopelagic hauls from three cruises (November 2015 to October 2016) collected from the inner fjord systems around Bergen and in open-waters off Tromsø and Ålesund, Norway. Jellyfish, krill, shrimps and small amounts of the mesopelagic fish, Maurolicus muelleri and Benthosema glaciale, dominated the mixed mesopelagic hauls. Lipid content ranged between 35-40% of dry matter with two samples from autumn being 21 and 13%, with the latter haul being almost exclusively krill. In contrast, M. muelleri and B. glaciale had lipid contents of around 54 and 47% respectively. Overall, lipid was a relatively good source of marine n-3 LC-PUFA, EPA and DHA, being in the range of 15–20% of fatty acids which increased in lean samples. However, many of the trawl hauls contained wax esters (7 out of 9 hauls), equivalent to 40% or more of the lipid, with B. glaciale containing almost 90% wax esters of lipid. This presents a challenge if used in salmon diets, as their utilisation is limited. Protein contents ranged between 45-50%, increasing in lean samples. The essential amino acid content was well above the requirements for Atlantic salmon (Salmo salar) with B. glaciale generally containing higher levels compared to M. muelleri. Leucine, lysine and valine levels were particularly high. Hauls from open-waters contained mixtures of amphipods resulting in cadmium levels exceeding the maximum allowable level in feedstuffs. Arsenic levels were high or borderline. Reducing crustacean mix in hauls appear to be the only option to reduce these levels, whereas mesopelagic fish contained low levels of all heavy metals. In summary, the mesopelagic layer contains protein and lipid sources that could supply raw materials to the salmon aquaculture industry. However, high levels of wax esters, cadmium and arsenic needs to be addressed.

Effect of experimental thermal stress on lipidomes of the soft coral Sinularia sp. and its symbiotic dinoflagellates

A complete or partial loss of symbiotic dinoflagellates (SD) by the corals in response to thermal stress has been described as coral bleaching. A stress damages the photosynthetic apparatus of SD and their thylakoid membranes, and symbiotic alga cells disappear via exocytosis and/or apoptosis resulting in a disturbance of host cell membranes. Lipids play an essential role in coral metabolism and constitute the basis of membranes. At present, studies of coral bleaching typically deal with long-term lipid indices, such as total lipids and fatty acids (FAs), while short-term dynamics of lipidome (full range of all lipid molecular species) has not been considered in the context of bleaching mechanism. To evaluate the lipidomic approach to characterizing coral bleaching, the soft coral Sinularia sp. was exposed to a short-term experimental thermal stress (33 °C). The dynamics of chlorophyll level, the composition of total FAs, the amounts of total lipids and major lipid classes (such as wax esters (WE), triacylglycerols (TAG), and monoalkyldiacylglycerols (MADAG), glycolipids, ethanolamine-, choline-, serine-, inositolglycerophospholipids (PE, PC, PS, PI), and ceramide aminoethylphosphonate (CAEP)) and the variations in the content of lipid molecular species were studied during a 36-h heat exposure. >160 molecular species were identified by tandem high-resolution mass spectrometry. Under the short-term stress, a considerable decline in the levels of chlorophylls, glycolipids, and FA markers of SD was detected, whereas the variations in the content of total lipids, total phospholipids, and major FAs were not significant. The heat exposure immediately disturbed the daily cycle of the composition of glycolipid molecular species. Among the storage lipids, the content of TAG and MADAG decreased, whereas the content of polyunsaturated WE molecular species increased under the stress. The following effects were recorded for the structural lipids: a depletion in the PE, PC, and PI amounts, a conversion of PE into their lyso and oxidized derivatives, an appearance of diacyl form of PE, and a disturbance of transfer of some polyunsaturated FAs from SD to the host. The content of PS was relatively stable. Probably, PE molecular species are a primary target of thermal stress in the Sinularia host. The most dramatical changes in the Sinularia lipidome were detected between 24 h and 36 h of the exposure. A lipidomic approach is important for studies of dynamics of the coral symbiotic association and a resistance of different coral taxa during short-term bleaching events.

Calanus oil in the treatment of obesity-related low-grade inflammation, insulin resistance, and atherosclerosis.

Calanus oil (COil) is a natural product extracted from marine zooplankton Calanus finmarchicus found in the North Atlantic Ocean. This oil is rich in wax esters of polyunsaturated fatty acids (PUFAs) and has been projected as the best alternative to fish oil because its production cannot keep pace with the demands from the growing markets. The COil is the only commercially available marine source of wax esters, whereas classic ω-3 PUFAs comes from triglycerides, ethyl esters, and phospholipids. It has, in recent decades, been seen that there is an unprecedented rise in the use of PUFA-rich oil in the aquaculture industry. A simultaneous rise in the demand of PUFAs is also observed in the health care industry, where PUFAs are suggested preventing various disorders related to lifestyles such as obesity, diabetes mellitus, chronic low-grade inflammation, atherosclerosis, and brain and cardiovascular disorders (CVDs). In this review, we will explore the metabolic aspects related to the use of COil as an antioxidant, anticholesterinemic, and anti-inflammatory dietary source and its impact on the prevention and therapy of obesity-related metabolic disorders.

Coordinated\xa0transformation of the gut microbiome and lipidome of bowhead whales provides novel insights into digestion

Whale digestion plays an integral role in many ocean ecosystems. By digesting enormous quantities of lipid-rich prey, whales support their energy intensive lifestyle, but also excrete nutrients important to ocean biogeochemical cycles. Nevertheless, whale digestion is poorly understood. Gastrointestinal microorganisms play a significant role in vertebrate digestion, but few studies have examined them in whales. To investigate digestion of lipids, and the potential contribution of microbes to lipid digestion in whales, we characterized lipid composition (lipidomes) and bacterial communities (microbiotas) in 126 digesta samples collected throughout the gastrointestinal tracts of 38 bowhead whales (Balaena mysticetus) harvested by Alaskan Eskimos. Lipidomes and microbiotas were strongly correlated throughout the gastrointestinal tract. Lipidomes and microbiotas were most variable in the small intestine and most similar in the large intestine, where microbiota richness was greatest. Our results suggest digestion of wax esters, the primary lipids in B. mysticetus prey representing more than 80% of total dietary lipids, occurred in the mid- to distal small intestine and was correlated with specific microorganisms. Because wax esters are difficult to digest by other marine vertebrates and constitute a large reservoir of carbon in the ocean, our results further elucidate the essential roles that whales and their gastrointestinal microbiotas play in the biogeochemical cycling of carbon and nutrients in high-latitude seas.

Transcription Factor CsWIN1 Regulates Pericarp Wax Biosynthesis in Cucumber Grafted on Pumpkin.

Pericarp wax of cucumber is an important economic trait, determining sales and marketing. Grafting of cucumber onto pumpkin rootstock (Cucurbita moschata) is an effective way to produce glossy cucumber fruits. However, the molecular regulation mechanism of this phenomenon remains largely unknown. In the present study, transcriptome analyses, genome-wide DNA methylation sequencing, and wax metabolite analysis were performed on the pericarp of self-rooted versus grafted cucumber. We identified the AP2/ERF-type transcription factor CsWIN1 as methylated and significantly upregulated in grafted cucumber compared to self-rooted cucumber. The increased expression of CsWIN1 was also positively correlated with several key wax biosynthesis genes, including CsCER1, CsCER1-1, CsCER4, CsKCS1, and the wax transporter gene CsABC. The transcriptome expression level of these genes was validated through qRT-PCR profiles. Furthermore, wax metabolite analysis showed that more wax ester (C20 fatty acid composition), but fewer alkanes (C29 and C31) were deposited in grafted cucumber pericarp. The higher expression of CsWIN1 and wax biosynthesis genes was reflected in the glossier appearance of grafted pericarp, possibly the result of higher wax ester content and higher integration of small trichomes in the pericarp. This study demonstrates that grafting can affect the content and composition of pericarp wax in cucumber grafted on pumpkin, and a unique regulation model of CsWIN1 for wax biosynthesis may exist in cucumber.

Epicuticular Compounds of Protopiophila litigata (Diptera: Piophilidae): Identification and Sexual Selection Across Two Years in the Wild

AbstractThe epicuticular compounds (ECs) of insects serve both to waterproof the cuticle and, in many taxa, as pheromones that are important for various social interactions, including mate choice within populations. However, ECs have not been individually identified in many species and most studies of their role in mate choice have been performed in a laboratory setting. Here we newly identify and quantify the ECs of the antler fly, Protopiophila litigata Bonduriansky, and use a cross-sectional selection analysis to quantify their association with male mating success in the wild across two years (2013 and 2017). The ECs of antler flies include straight-chain and methylated alkanes, alkenes, and a family of branched wax esters. We find all ECs to be shared between males and females but also demonstrate sexual dimorphism in the abundance of several. Male EC relative abundances were significantly associated with mating success in both years, although the multivariate direction of selection differed significantly between the years. Surprisingly, only two of the 18 compounds (or groups of compounds) we identified were similarly associated with mating success across the sampling years. In 2017, we further partitioned sexual selection into intra- and intersexual components, revealing selection on ECs to be significant via female choice but not male–male competition. Our study is one of few to investigate the potential role of ECs in mating success in the wild and adds to a growing body of evidence demonstrating significant temporal variability in selection in natural populations.

Fatty acid desaturase 2 (FADS2) but not FADS1 desaturates branched chain and odd chain saturated fatty acids

Branched chain fatty acids (BCFA) and linear chain/normal odd chain fatty acids (n-OCFA) are major fatty acids in human skin lipids, especially sebaceous gland (SG) wax esters. Skin lipids contain variable amounts of monounsaturated BCFA and n-OCFA, in some reports exceeding over 20% of total fatty acids. Fatty acid desaturase 2 (FADS2) codes for a multifunctional enzyme that catalyzes Δ4-, Δ6- and Δ8-desaturation towards ten unsaturated fatty acids but only one saturate, palmitic acid, converting it to 16:1n-10; FADS2 is not active towards 14:0 or 18:0. Here we test the hypothesis that FADS2 also operates on BCFA and n-OCFA. MCF-7 cancer cells stably expressing FADS1 or FADS2 along with empty vector control cells were incubated with anteiso-15:0, iso-16:0, iso-17:0, anteiso-17:0, iso-18:0, or n-17:0. BCFA were Δ6-desaturated by FADS2 as follows: iso-16:0 → iso-6Z-16:1, iso-17:0 → iso-6Z-17:1, anteiso-17:0 → anteiso-6Z-17:1 and iso-18:0 → iso-6Z-18:1. anteiso-15:0 was not desaturated in either FADS1 or FADS2 cells. n-17:0 was converted to both n-6Z-17:1 by FADS2 Δ6-desaturation and n-9Z-17:1 by SCD Δ9-desaturation. We thus establish novel FADS2-coded enzymatic activity towards BCFA and n-OCFA, expanding the number of known FADS2 saturated fatty acid substrates from one to six. Because of the importance of FADS2 in human skin, our results imply that dysfunction in activity of sebaceous FADS2 may play a role in skin abnormalities associated with skin lipids.

Sunflower wax recovered from oil tank settlings: Revaluation of a waste product from the oilseed industry.

The sunflower oil industry produces a large amount of waste that is not currently commercially exploited, as in the case of oil-tank settlings. The recovery of a high value-added by-product, such as sunflower wax, would increase the commercial value of this waste. In this original research paper, a method that allows the recovery and purification of this by-product was developed. The wax was characterized and its potential use as an organogelator agent was investigated. The waste sample was composed of 45.1% oily material, 16.9% of this being impure waxes. Purification was performed through two different methods, obtaining three waxes with different degrees of purity. All the waxes were composed of wax esters with a range of 40-60 carbon atoms, exhibiting traces of carotenes, free fatty acids, and free fatty alcohols. The presence of phospholipids was observed in two of them. The third wax presented a higher total wax ester content and physicochemical characteristics (color and thermal behavior) similar to those of commercial sunflower waxes, and was the most efficient organogelator agent, requiring only a small amount of wax (1.5%) to structure high oleic sunflower oil. It was verified that sunflower wax could be recovered from oil-tank settlings. A purification method that allowed sunflower wax with similar physicochemical properties to those of commercial waxes to be obtained was also developed. The purified waxes were capable of structuring high oleic sunflower oil. © 2019 Society of Chemical Industry.