Polar Lipid Fraction Research Articles

Metal accumulation in female green sea turtles (Chelonia mydas) from Eastern Atlantic affects their egg quality with potential implications for embryonic development

Sea turtles, with their global distribution and complex life cycle, often accumulate pollutants such as metals and metalloids due to their extended lifespan and feeding habits. However, there are limited studies exploring the impact of metal pollution on the reproductive health of female sea turtles, specifically focusing on the quality of their eggs, which has significant implications for the future generations of these charismatic animals. São Tomé Island, a crucial nesting and feeding habitat for green sea turtles, underscores the urgent need for comprehensive research in this ecologically significant area. This study aimed to investigate whether metals and metalloids in the blood of nesting female green sea turtles induce genotoxic effects in their erythrocytes and affect their egg morphometric characteristics and the composition of related compartments. Additionally, this study aimed to evaluate whether the quality of energetic reserves for embryo development (fatty acids in yolk's polar and neutral lipids) is influenced by the contamination status of their predecessors. Results revealed correlations between Cu and Hg levels and increased “lobed” erythrocytes, while As and Cu negatively influenced shell thickness. In terms of energy reserves, both polar and neutral lipid fractions contained primarily saturated and monounsaturated fatty acids, with prevalent 18:1n-9, 18:0, 16:0, 14:0, and 12:0 fatty acids in yolk samples. The yolk polar fraction was more susceptible to contaminant levels in female sea turtles, showing consistent negative correlations between pollution load index and essential n3 fatty acids, including linolenic, eicosatrienoic, eicosapentaenoic, and docosapentaenoic acids, crucial for embryonic development. These metals accumulation, coupled with the reduced availability of these key fatty acids, may disrupt the eicosanoid and other important pathways, affecting reproductive development. This study reveals a negative correlation between metal contamination in female sea turtles' blood and egg lipid reserves, raising concerns about embryonic development and the species' future generations.

Bioactive lipids derived from red wine, beers, and their dealcoholized variants inhibit platelet-activating factor (PAF) induced platelet activation in vitro

This study assesses the in vitro antiplatelet properties of polar lipid extracts of two popular beers, a red wine and their 0% equivalents against platelet aggregation. Total lipids (TL) were isolated using the Bligh and Dyer method from each beverage and the total polar lipid (TPL) and total neutral lipid (TNL) fractions were further isolated using counter-current distribution. The lipid profile of each TPL fraction was analysed using LC-MS. Platelet aggregometry was performed to evaluate the TL, TNL, and TPL extracts of each beverage against platelet-activating factor (PAF) induced platelet aggregation. TPL and TL lipid fractions significantly inhibit platelet aggregation, with TPL fractions showing the highest inhibition as evidenced by generally low IC50 values, ranging from 9 μg to 553 μg. These results indicate that antiplatelet lipid microconstituents are present in beer, wine, and their 0% alcohol counterparts, in low but bioactive amounts. These lipids are characterized by predominance of saturated fatty acids (SFA) and a relatively high ratio of n-6 to n-3 polyunsaturated fatty acids (PUFA) in the TPL composition. The extracts also contained notable levels of phenolic compounds ranging from 0.05 to 0.31 mg/mL. These data provide evidence for the presence of antiplatelet lipid microconstituents that may contribute to the observed epidemiological cardioprotective effects of moderate beer and wine consumption. Furthermore, 0% alcoholic beverages may also provide comparable antiplatelet cardioprotective microconstituents devoid of the risk of ethanol ingestion.

Optimization of Esterification in the Synthesis of Surfactants Feedstock from Polar Lipid Fraction of Crude Palm Oil

Optimization of Esterification in the Synthesis of Surfactants Feedstock from Polar Lipid Fraction of Crude Palm Oil

New Forms of Neuroactive Phospholipids for DHA Enrichment in Brain.

Low levels of docosahexaenoic acid (DHA) in the brain have been related to neurological disorders, like Alzheimer's disease (AD). After ingestion, dietary DHA must cross the blood-brain barrier, where it is absorbed as lysophosphatidylcholine (LPC), due to its role as a preferential DHA carrier in the brain. This work aimed at the production of LPC-DHA extracts to be used in supplementation/food fortification intended neural enrichment in DHA. As it is rich in DHA, especially its phospholipids (PL), Atlantic mackerel (Scomber scombrus, caught in Spring/2022) was used as a raw material. The polar lipids fraction was separated and hydrolysed with Rhizomucor miehei lipase, to enzymatically convert phosphatidylcholine (PC) into LPC. The fish (muscle and by-products) lipids fraction was used for total lipids (TL) content, lipid classes (LC) and fatty acid (FA) profile evaluation, whilst polar lipids extracts were studied for LC production and FA analysis. Muscle TL ranged between 1.45 and 4.64 g/100 g (WW), while by-products accounted for 7.56-8.96 g/100 g, with the highest contents being found in March. However, PL were more abundant in muscle (22.46-32.20% of TL). For polar lipids extracts, PL represented 50.79% of TL, among which PC corresponded to 57.76% and phosphatidylethanolamine to 42.24%. After hydrolysis, nearly half of this PC was converted into LPC. When compared to the initial PC, DHA relative content (33.6% of total FA) was significantly higher after hydrolysis: 55.6% in PC and 73.6% in LPC. Such extract, obtained from this undervalued species, may represent a promising strategy to increase DHA uptake into brain cells while allowing this species to upgrade.

Archaea membranes in response to extreme acidic environments

Bipolar tetraether lipids (BTL), such as glycerol dialkyl calditol tetraether (GDNT) and glycerol dialkyl glycerol tetraether (GDGT), are the dominating lipid species in thermoacidophiles that inhabit at pH ≤ 4 and temperatures ≥65°C. BTL containing archaea membranes respond to environmental pH changes by varying the number of cyclopentane rings in the isoprenoids, the amount of GDNT relative to GDGT, the ratio of tetraethers to diethers, and the level of glycosylation in polar headgroups. These structural and compositional adjustments can alter the hydrogen bond networks in the membrane polar headgroup regions and the packing tightness and rigidity in the membrane hydrophobic core. It is likely that these changes in non-covalent interactions among archaea lipids are made to retain low membrane volume fluctuations and their low sensitivity to temperature, as illustrated in the case of liposomes made of the polar lipid fraction E (PLFE) of Sulfolobus acidocaldarius. As such, a low passive proton permeability and a near neutral intracellular pH can be maintained, and, as a result, optimal activities of soluble and membrane-bound proteins in thermoacidophiles can be retained in acidic growth conditions at elevated growth temperatures.

Purification of Triglyceride from Used Cooking Oil for Biodiesel Feedstock Using Batchwise Solvent Extraction

Green economy and blue economy are essential to applicate. One of the mandatory programs from the Indonesian government is B30, a specification of diesel fuel that has 30 percent of biodiesel content. Based on the biodiesel feedstock specification standard, the free fatty acid content is below 1%. The aim of this research was to produce biodiesel feedstock with high purity of triglyceride from used cooking oil by using batchwise solvent extraction. Batchwise solvent extraction involves the polarity of oil and solvent to separate polar and non-polar lipid fractions. The target of this research was the lowest percentage of free fatty acid and the highest percentage of triglyceride. This method also skipped the general method of refined oil products, such as degumming, neutralization, bleaching, and deodorization. The used cooking oil was mixed with a binary solvent (n-hexane and technical grade ethanol) and a single solvent (food grade ethanol 96% only). Each mixture was stirred at 300 rpm for 15 min and then poured into a separator funnel for 15 min. Polar and non-polar lipid fractions were separated. The non-polar lipid fraction was processed in the same procedure until eight stages. It was found that the batchwise binary solvent extraction produced a non-polar lipid fraction with triglyceride and free fatty acid purities of 88.81% and 2.06%, respectively. Moreover, the batchwise single solvent extraction produced a non-polar lipid fraction with triglyceride and free fatty acid purities of 95.89% and 0.93%, respectively, which is suitable with the standard of biodiesel feedstock below 1%.

Temperature-dependent vibrational behavior of bilayer doubly curved micro-nano liposome shell: Simulation of drug delivery mechanism

This article analyzes the vibrational behavior of the double-layered micro-nanosphere to simulate the drug delivery mechanism in the biological structure under the influence of the temperature environment and the viscoelastic substrate for the polar lipid fraction E (PLFE) liposome isotropic material model. In order to obtain the micro-nano structural equations of the double-layer spherical shell, the displacement-strain relations of the shell have been expressed according to the first-order shear deformation theory and the non-local strain gradient theory. The partial differential equations of motion have been obtained by applying Hamilton’s principle. The system of linear couple equations have been solved using the Galerkin method. After validating the model with the results of the articles available in the literature to determine the accuracy of the presented model, numerical results are presented to investigate the effects of various parameters such as the radius of curvature ratio to length, damping coefficient, Kelvin-Voight damping coefficient, boundary conditions and temperature on vibration frequency response are provided and discussed. Results of the current research indicates that natural frequency decreases as the damping coefficient related to the viscous effect between the liposome bilayers increase. Results of the current research can be used as a benchmark for drug delivery applications.

Reproductive quality evaluation of male Indian white prawn Penaeus indicus broodstock fed diets supplemented with polychaete extracts (Marphysa sp.)

ABSTRACT The present study determined the effect of different polychaete extracts, namely, total soluble fraction (TSF), neutral lipid fraction (NLF) and polar lipid fraction (PLF), in the maturation and sperm quality of male Penaeus indicus. Three levels (0.25, 0.50 and 1.00%) of extracts were included using a 3 × 3 factorial design. Groups fed the basal diet (BD) and fresh-frozen diet served as controls. Extracts in varying doses and control groups did not have a significant effect on broodstock survival (67–87%; p = 0.960), maturation rate (42–68%; p = 0.615), inter-spermatophore period (8–10 days; p = 0.505) or sperm viability (97–100%; p = 0.819). However, sperm counts of broodstock fed BD (11.70 × 106 ±1.05 × 106 per spermatophore) and those fed diets supplemented with polychaete extracts were significantly higher compared to that fed with control fresh diet at 0.73 × 106± .09 × 106 (p = 0.001). Spermatophore crude lipid was highest in groups fed 0.25% TSF and 0.25% PLF of broodstock (p =1.0 x10−6 ). Inclusion of TSF (0.25–1.00%) significantly increased the spermatophore crude protein content of broodstock compared to those fed with other diets (p = 1.20 × 10−5). These results demonstrate that NLF and TSF extracts are bioactive components of polychaete which when fed to male P. indicus, can stimulate aspects of sperm production.

Physiological condition of the warty venus (Venus verrucosa L. 1758) larvae modulates response to pile driving and drilling underwater sounds

Noise is now recognized as a new form of pollution in marine coastal habitats. The development of marine renewable energies has introduced new sonorous perturbations, as the wind farm installation requires pile driving and drilling operations producing low frequency sounds at high sound pressure levels. Exponential expansion of offshore wind farms is occurring worldwide, making impact studies, particularly on benthic species highly abundant and diverse in the coastal area used for wind farming, a necessity. As larval recruitment is the basis for establishing a population, we conducted an experimental study to assess the interactive effects of pile driving or drilling sounds and larval rearing temperature on the endobenthic bivalve Venus verrucosa. In ectothermic animals, temperature modifies the organism’s physiology, resulting in performance variability. We hypothesize that temperature modulation could change larval responses to noise and explore the potential interacting effects of temperature and noise. Using two distinct rearing temperatures, physiologically different batches of larvae were produced with contrasting fatty acid content and composition in the neutral and polar lipid fractions. Without defining any absolute audition threshold for the larvae, we demonstrate that the effects of temperature and noise were ontogenic-dependent and modulated larval performance at the peri-metamorphic stage, acting on the metamorphosis dynamic. At the pediveligers stage, a strong interaction between both factors indicated that the response to noise was highly related to the physiological condition of the larvae. Finally, we suggest that underwater noise reduces the compensatory mechanisms established to balance the temperature increase.

Yarrowia lipolytica as a Platform for Punicic Acid Production.

Punicic acid (PuA) is a polyunsaturated fatty acid with significant medical, biological, and nutraceutical properties. The primary source of punicic acid is the pomegranate seed oil obtained from fruits of trees that are mainly cultivated in subtropical and tropical climates. To establish sustainable production of PuA, various recombinant microorganisms and plants have been explored as platforms with limited efficiencies. In this study, the oleaginous yeast Yarrowia lipolytica was employed as a host for PuA production. First, growth and lipid accumulation of Y. lipolytica were evaluated in medium supplemented with pomegranate seed oil, resulting in the accumulation of lipids up to 31.2%, consisting of 22% PuA esterified in the fraction of glycerolipids. In addition, lipid-engineered Y. lipolytica strains, transformed with the bifunctional fatty acid conjugase/desaturase from Punica granatum (PgFADX), showed the ability to accumulate PuA de novo. PuA was detected in both polar and neutral lipid fractions, especially in phosphatidylcholine and triacylglycerols. Promoter optimization for PgFADX expression resulted in improved accumulation of PuA from 0.9 to 1.8 mg/g of dry cell weight. The best-producing strain expressing PgFADX under the control of a strong erythritol-inducible promoter produced 36.6 mg/L PuA. These results demonstrate that the yeast Y. lipolytica is a promising host for PuA production.

Characterization of three Stenotrophomonas strains isolated from different ecosystems and proposal of Stenotrophomonas mori sp. nov. and Stenotrophomonas lacuserhaii sp. nov.

Members of the genus Stenotrophomonas, and particularly Stenotrophomonas maltophilia, are opportunistic human pathogens, but not enough research has evaluated the identification of environmental Stenotrophomonas spp. However, most Stenotrophomonas spp. serves as plant-probiotic bacteria.In this study, we obtained and characterized three Stenotrophomonas strains from different ecosystems. Based on phenotypic differences, chemotaxonomic properties, ANI and dDDH identity values, and phylogenetic analyses, two novel Stenotrophomonas species are proposed for the strains identified here. The encoding genes related to plant-growth promotion in the genomes of the newly recovered Stenotrophomonas spp. were retrieved. Follow-on experiments confirmed that these strains produced the important plant hormone IAA. Thus, these Stenotrophomonas spp. could considerably contribute to shaping and maintaining ecological stability in plant-associated environments, particularly while acting as plant-probiotic microorganisms.

Bioprospecting antibiotic properties in photodynamic therapy of lipids from Codium tomemtosum and Chlorella vulgaris

The growing resistance from pathogens against antibiotics has increased the research for new compounds and strategies with antibacterial potential. Lipids from algae are emerging as natural and potent bioactive molecules with interesting results regarding the inactivation of bacteria, viruses, and fungi. The combination of algae lipids with innovative strategies, such as antibacterial photodynamic therapy (aPDT) can enhance their antimicrobial potential. In this work, we aimed to evaluate the antibacterial potential in aPDT of total lipid extracts and polar lipid fractions from the green macroalga, Codium tomentosum, and the green microalga, Chlorella vulgaris on a Gram-positive bacteria Staphylococcus aureus. Total lipid extracts and polar lipid fractions were characterized by LC-MS. The results revealed that the total extracts of algae promote S. aureus inhibition after light irradiation, with a decrease of ca. 6 log10 (CFU/mL) after 15 min of treatment with both extracts of algae. The polar lipid fractions, composed by phospholipids, glycolipids and betaine lipids, from C. tomentosum and C. vulgaris also revealed antibacterial potential in combination with aPDT, but a decrease of ca. 6 log10 (CFU/mL) was reached at 60 min of treatment, later than with the total extracts. These results unveil algae lipids as antibacterial compounds in combination with aPDT displaying an alternative from natural origin to tackle pathogen resistance.

Evaluation of maturation promoting factor in polychaete ( Marphysa sp.) on Indian White Prawn , Penaeus indicus female broodstock

Polychaete is considered the best maturation diet for penaeids; however, fluctuating supply and quality warrant detailed studies to understand the specific maturation-promoting factors present in polychaete. Indian white prawn, Penaeus indicus, was fed diets supplemented with different fractions of Marphysa sp. extracts. Fractions, such as the total soluble fraction (TSF), neutral lipid fraction (NLF), and polar lipid fraction (PLF), were incorporated in the maturation diet at 0.25, 0.50, and 1.00% following a 3 × 3 factorial design. One group was fed with basal diet (BD), and another was fed with fresh squid, mussel, and polychaete, serving as the control. After a 30-day feeding trial, results showed that the inclusion of polychaete extracts in the diet significantly improved P. indicus maturation compared to groups fed BD and control with 40% maturation rates (MR) (p = 3.4 × 10−4). MR was optimum in groups receiving diets supplemented with ≥0.5% TSF (70.00% ± 0.00) and NLF (60.00% ± 5.77). Similar improved MR was achieved in treatments receiving ≥0.25% PLF supplementation (60% ± 0.00). Accordingly, relative expression of ovarian vitellogenin mRNA of broodstock fed under 0.25 and 0.50% PLF group was 4.44 and 3.96 folds higher than BD, respectively (p = 0.003). No significant differences were detected in the broodstock survival, latency period, hepatosomatic, and gonadosomatic indices. Biochemical content analyses showed no significant differences among the nine treatments except for broodstock's higher ovary protein content in the TSF group (p = 0.037). This study highlights PLF as the most potent component of the polychaete extract in promoting gonad maturation in P. indicus maturation supplemented at a 0.25% optimum inclusion level.

Vesicular and Planar Membranes of Archaea Lipids: Unusual Physical Properties and Biomedical Applications.

Liposomes and planar membranes made of archaea or archaea-like lipids exhibit many unusual physical properties compared to model membranes composed of conventional diester lipids. Here, we review several recent findings in this research area, which include (1) thermosensitive archaeosomes with the capability to drastically change the membrane surface charge, (2) MthK channel’s capability to insert into tightly packed tetraether black lipid membranes and exhibit channel activity with surprisingly high calcium sensitivity, and (3) the intercalation of apolar squalane into the midplane space of diether bilayers to impede proton permeation. We also review the usage of tetraether archaeosomes as nanocarriers of therapeutics and vaccine adjuvants, as well as the biomedical applications of planar archaea lipid membranes. The discussion on archaeosomal therapeutics is focused on partially purified tetraether lipid fractions such as the polar lipid fraction E (PLFE) and glyceryl caldityl tetraether (GCTE), which are the main components of PLFE with the sugar and phosphate removed.

Fermentation Enhances the Anti-Inflammatory and Anti-Platelet Properties of Both Bovine Dairy and Plant-Derived Dairy Alternatives

Within the present study, the effects of fermentation on the anti-inflammatory and anti-platelet properties of both homemade and commercially purchased bovine dairy and almond, coconut, and rice-based dairy alternatives were evaluated. The extracted total lipids (TL) from homemade and commercially purchased fermented and unfermented bovine, almond, coconut, and rice-based products were further separated into their neutral lipids (NL) and polar lipids (PL) fractions by counter current distribution. The TL, PL, and NL of each sample were assessed in human platelets against the inflammatory and thrombotic mediator, platelet-activating factor (PAF), and the well-established platelet agonist, adenosine 5′ diphosphate (ADP). In all samples, the PL fractions showed significantly stronger inhibitory effects against human platelet aggregation induced by PAF or ADP, in comparison to the TL and NL, with higher specificity against PAF. PL of all fermented products (bovine yogurt and fermented dairy alternatives from almond, rice, and coconut), exhibited the strongest anti-inflammatory and anti-platelet potency, in comparison to PL from their initial pasteurized materials (bovine milk and rice, almond, and coconut-based dairy alternative drinks). PL of the pasteurized rice-based drink and, especially PL from the novel homemade rice-based fermented product (HMFRD), showed the strongest anti-PAF and anti-ADP potency compared to all samples, with anti-PAF activity being most potent overall. The unfermented pasteurized coconut-based drink showed the lowest anti-inflammatory and anti-platelet potency, and the bovine and almond-based fermented products showed an intermediate effect. Further lipidomics with LC-MS analysis of all these PL fractions revealed that fermentation altered their fatty acid content in a way that decreased their degree of saturation and increased the content of unsaturated fatty acids, thus providing a rationale for the stronger anti-inflammatory and anti-platelet potency of the more unsaturated PL fractions of the fermented products. This study has shown that fermentation alters the fatty acid content and the bio-functionality of the PL bioactives in both fermented bovine dairy and plant-based dairy alternatives, and subsequently improved their anti-inflammatory and anti-platelet functional properties.

Supercritical fluid extraction and pressurized liquid extraction processes applied to eicosapentaenoic acid-rich polar lipid recovery from the microalga Nannochloropsis sp

This work studies the simultaneous extraction and fractionation of saponifiable lipids into neutral saponifiable lipids and polar lipids (phospholipids and glycolipids) from the microalga Nannochloropsis sp. (41.9% neutral saponifiable lipids, 58.1% polar lipids, 32.5% eicosapentaenoic acid, EPA) to obtain EPA-rich polar lipid fractions, using green techniques. Several two-step extraction processes were studied, combining CO2 supercritical fluid extraction, pressurized lipid extraction, and ethanol-gas (CO2) expanded extraction. Extraction at atmospheric pressure, including the Soxhlet extraction method, was used as the reference. Firstly, a lipidic fraction rich in neutral saponifiable lipids (80.4% of total saponifiable lipids), was obtained using hexane and the Soxhlet extraction method; this extract contained 85.8% of the biomass neutral saponifiable lipids. Subsequently, in the second extraction step using ethanol, an EPA-rich polar lipid extract with 89.2% polar lipids and up to 39.6% EPA was obtained. This SL extract contained 80.1% of the glycolipids, 96% of the phospholipids and 67.8% of the EPA from the Nannochloropsis sp. biomass. Good results were obtained combining the CO2 supercritical fluid extraction and pressurized lipid extraction techniques as alternative green processes. Firstly, a lipidic fraction rich in neutral saponifiable lipids (70.3% of the total extracted saponifiable lipids) was obtained using supercritical CO2 with 10 wt% ethanol as the co-solvent, at 35 MPa, 50 °C, 8 g CO2/min for 8 h; this extract contained 81.7% of the biomass neutral saponifiable lipids. Then, in the second extraction step with pressurized ethanol, at 10 MPa, 125 °C and three extraction cycles of 5 min, an EPA-rich polar lipid extract with 85.1% polar lipids and up to 39.2% EPA was obtained. This saponifiable lipid extract contained 76.9% of the glycolipids, 71.1% of the phospholipids and 61.9% of the EPA from the Nannochloropsis sp. biomass.

The Polar Lipid Fraction E from Sulfolobus acidocaldarius Can Be Used as Liposomal Drug Stabilizing Agents to Reduce the Leakage of the Antivascular Drug Combretastatin A4 Disodium Phosphate from Tetraether/Diester Hybrid Archaeosomes

Liposomes have many advantages as therapeutic capsules over free drugs such as small molecule drugs and nucleic acids. Cholesterol is commonly used as a membrane stabilizing agent in liposomal drugs (e.g., mRNA-lipid nanoparticle COVID-19 vaccines). However, due to the vulnerability of cholesterol to oxidation and the etiological role of cholesterol in many disorders, it is desirable to find an alternative means to stabilize liposomal membranes for drug delivery. In this study, we demonstrated that the polar lipid fraction E (PLFE), which contains exclusively bipolar tetraether macrocyclic lipids, isolated from the thermoacidophilic archaeon S. acidocaldarius can greatly stabilize the liposomal formulation of the anti-vascular drug, combretastatin A4 disodium phosphate (CA4P). Stability was assessed by determining the leakage rate constant k of entrapped CA4P fluorometrically. We found that, at 37 °C, PLFE decreases the k value monotonically from 1.54 × 10−2 s−1 for 100% 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) liposomes to 3.4 × 10−5 s−1 for 100% PLFE archaeosomes, a change of k by two orders of magnitude. The changes in k of CA4P leakage are correlated well with the changes in liposomal CA4P’s cytotoxicity against MCF-7 breast cancer cells. We further showed that the reduction in spontaneous leakage of entrapped CA4P by PLFE can be attributed to the increased membrane surface charge and the increased membrane order and packing tightness in liposomes, as reflected by the zeta potential (−6.83 to −41.1 mV from 0 to 100 mol% PLFE) and diphenylhexatriene (DPH) fluorescence polarization (0.13 to 0.4 from 0 to 100 mol% PLFE) measurements. Moreover, we showed that PLFE slows down CA4P leakage more than cholesterol in POPC liposomes. These results together suggest that PLFE lipids can serve as an effective stabilizing agent for liposomal drugs and could potentially be useful for the optimization of liposomal CA4P for cancer treatment.

Compositional Features and Nutritional Value of Pig Brain: Potential and Challenges as a Sustainable Source of Nutrients.

The goal of this study was to establish the nutritional value and compositional properties of the brains of crossbred pigs (Landrace–Large white–Duroc (LLD)), in order to realize the zero-waste concept and increase the use of by-products in the sustainable meat industry. Fat (9.25% fresh weight (fw)) and protein (7.25% fw) were the principal dry matters of pig brain, followed by carbohydrate and ash. Phospholipid and cholesterol had a 3:1 ratio. Pig brain had a red tone (L* = 63.88, a* = 5.60, and b* = 15.43) and a high iron content (66 mg/kg) due to a total heme protein concentration of 1.31 g/100 g fw. The most prevalent macro-element was phosphorus (14 g/kg), followed by potassium, sodium, calcium, and magnesium. Zinc, copper, and manganese were among the other trace elements discovered. The most prevalent nitrogenous constituents were alkali-soluble protein, followed by water-soluble protein, stromal protein, salt-soluble protein, and non-protein nitrogen. Essential amino acids were abundant in pig brain (44% of total amino acids), particularly leucine (28.57 mg/g protein), threonine, valine, and lysine. The total lipid, neutral, and polar lipid fractions of the pig brain had different fatty acid compositions. The largest amount was observed in saturated fatty acids (SFA), followed by monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Stearic acid and palmitic acid were the most common SFA. Oleic acid was the most prevalent MUFA, while docosahexaenoic acid was the most common PUFA. Thus, the pig brain can be used in food formulations as a source of nutrients.

Certain, but Not All, Tetraether Lipids from the Thermoacidophilic Archaeon Sulfolobus acidocaldarius Can Form Black Lipid Membranes with Remarkable Stability and Exhibiting Mthk Channel Activity with Unusually High Ca2+ Sensitivity.

Bipolar tetraether lipids (BTL) have been long thought to play a critical role in allowing thermoacidophiles to thrive under extreme conditions. In the present study, we demonstrated that not all BTLs from the thermoacidophilic archaeon Sulfolobus acidocaldarius exhibit the same membrane behaviors. We found that free-standing planar membranes (i.e., black lipid membranes, BLM) made of the polar lipid fraction E (PLFE) isolated from S. acidocaldarius formed over a pinhole on a cellulose acetate partition in a dual-chamber Teflon device exhibited remarkable stability showing a virtually constant capacitance (~28 pF) for at least 11 days. PLFE contains exclusively tetraethers. The dominating hydrophobic core of PLFE lipids is glycerol dialky calditol tetraether (GDNT, ~90%), whereas glycerol dialkyl glycerol tetraether (GDGT) is a minor component (~10%). In sharp contrast, BLM made of BTL extracted from microvesicles (Sa-MVs) released from the same cells exhibited a capacitance between 36 and 39 pF lasting for only 8 h before membrane dielectric breakdown. Lipids in Sa-MVs are also exclusively tetraethers; however, the dominating lipid species in Sa-MVs is GDGT (>99%), not GDNT. The remarkable stability of BLMPLFE can be attributed to strong PLFE–PLFE and PLFE–substrate interactions. In addition, we compare voltage-dependent channel activity of calcium-gated potassium channels (MthK) in BLMPLFE to values recorded in BLMSa-MV. MthK is an ion channel isolated from a methanogenic that has been extensively characterized in diester lipid membranes and has been used as a model for calcium-gated potassium channels. We found that MthK can insert into BLMPLFE and exhibit channel activity, but not in BLMSa-MV. Additionally, the opening/closing of the MthK in BLMPLFE is detectable at calcium concentrations as low as 0.1 mM; conversely, in diester lipid membranes at such a low calcium concentration, no MthK channel activity is detectable. The differential effect of membrane stability and MthK channel activity between BLMPLFE and BLMSa-MV may be attributed to their lipid structural differences and thus their abilities to interact with the substrate and membrane protein. Since Sa-MVs that bud off from the plasma membrane are exclusively tetraether lipids but do not contain the main tetraether lipid component GDNT of the plasma membrane, domain segregation must occur in S. acidocaldarius. The implication of this study is that lipid domain formation is existent and functionally essential in all kinds of cells, but domain formation may be even more prevalent and pronounced in hyperthermophiles, as strong domain formation with distinct membrane behaviors is necessary to counteract randomization due to high growth temperatures while BTL in general make archaea cell membranes stable in high temperature and low pH environments whereas different BTL domains play different functional roles.

Molecular species of glycolipid and anti‐inflammation activity of lipid fractions in the green algae Halimeda incrassata Lamx. collected from Truong Sa, Viet Nam

AbstractIn this study, 40 glycolipid molecular forms have been identified belonging to 3 groups of MGDG (12), DGDG (11), SQDG (17). The MGDG molecular forms count for a high concentration in the PUFA fatty acid component such as C18:2, 18:3, 20:4. The DGDG forms mainly contain saturated fatty acids and 1 double‐bonded while the SQDG forms have the intertwine between saturated fatty acids and super long and long‐chain HUFA fatty acids (over 20C and 4 double bonds) such as C20:4, 20:5 and 22:6. Results of biological activity test for three lipid fractions of Halimeda incrassata Lamx. seaweed have showed that they have anti‐inflammatory activities from 32.57±5.75 to 41.66±1.95 μg/mL, of which the highest is the polar lipid fraction. This showed that this is a potential source to continue screening for bioactive compositions to apply on the medicine and pharmacy.