Lipid Extracts Research Articles

Extraction of Lipids and Functional Properties of Defatted Egg Yolk Powder Obtained Using a One-Step Organic Solvent Lipid Extraction Process.

A one-step organic solvent lipid extraction method was used to separate lipids from spray-dried egg yolk. Organic solvents tested were chloroform:methanol (CM, 2:1, v:v), methyl-tert-butyl ether (MTBE), or hexane:isopropanol (HI, 3:2, v:v). The resulting defatted egg yolk powder had between 21 and 30% more protein and between 22 and 25% less lipid than the initial spray-dried egg yolk powder (p < 0.05). The solubility of the powder decreased from 20% to 4% (p < 0.05) when CM was used as the organic solvent, likely due to protein denaturation by the chloroform. Gels made from MBTE and HI-extracted protein concentrates had similar hardness (p > 0.05) and were both harder than gels made using the initial egg yolk powder (p < 0.05). MTBE gels were springier, more cohesive, and gummier (p < 0.05) with similar resistance to the initial egg yolk powder (p > 0.05). The results of this study showed that the functionality of the protein in the defatted egg yolk powder was best retained when MTBE was used as the lipid extraction solvent.

Interlaboratory Comparison of Branched GDGT Temperature and pH Proxies Using Soils and Lipid Extracts

AbstractRatios of glycerol dialkyl glycerol tetraethers (GDGT), which are membrane lipids of bacteria and archaea, are at the base of several paleoenvironmental proxies. They are frequently applied to soils as well as lake‐ and marine sediments to generate records of past temperature and soil pH. To derive meaningful environmental information from these reconstructions, high analytical reproducibility is required. Based on submitted results by 39 laboratories from across the world, which employ a diverse range of analytical and quantification methods, we explored the reproducibility of brGDGT‐based proxies (MBT′5ME, IR, and #ringstetra) measured on four soil samples and four soil lipid extracts. Correct identification and integration of 5‐ and 6‐methyl brGDGTs is a prerequisite for the robust calculation of proxy values, but this can be challenging as indicated by the large inter‐interlaboratory variation. The exclusion of statistical outliers improves the reproducibility, where the remaining uncertainty translates into a temperature offset from median proxy values of 0.3–0.9°C and a pH offset of 0.05–0.3. There is no apparent systematic impact of the extraction method and sample preparation steps on the brGDGT ratios. Although reported GDGT concentrations are generally consistent within laboratories, they vary greatly between laboratories. This large variability in brGDGT quantification may relate to variations in ionization efficiency or specific mass spectrometer settings possibly impacting the response of brGDGTs masses relative to that of the internal standard used. While ratio values of GDGT are generally comparable, quantities can currently not be compared between laboratories.

50. Anticoccidial activity of protein and lipid extracts from the black soldier fly (Hermetia illucens)

50. Anticoccidial activity of protein and lipid extracts from the black soldier fly (Hermetia illucens)

Characterizing lipid constituents of B. moojeni snake venom: a comparative approach for chemical and biological investigations.

Snake venoms are complex mixtures majorly composed of proteins with well-studied biological effects. However, the exploration of non-protein components, especially lipids, remains limited despite their potential for discovering bioactive molecules. This study compares three liquid-liquid lipid extraction methods for both chemical and biological analyses of Bothrops moojeni snake venom. The methods evaluated include the Bligh and Dyer method (methanol, chloroform, water), considered standard; the Acunha method, a modification of the Bligh and Dyer protocol; and the Matyash method (MTBE/methanol/water), featuring an organic phase less dense than the aqueous phase. Lipidomic analysis using liquid chromatography with high-resolution mass spectrometry (LC-HRMS) system revealed comparable values of lipid constituents' peak intensity across different extraction methods. Our results show that all methods effectively extracted a similar quantity of lipid species, yielding approximately 17-18 subclasses per method. However, the Matyash and Acunha methods exhibited notably higher proportions of biologically active lipids compared to the Bligh and Dyer method, particularly in extracting lipid species crucial for cellular structure and function, such as sphingomyelins and phosphatidylinositol-phosphate. In conclusion, when selecting a lipid extraction method, it is essential to consider the study's objectives. For a biological approach, it is crucial to evaluate not only the total quantity of extracted lipids but also their quality and biological activity. The Matyash and Acunha methods show promise in this regard, potentially offering a superior option for extracting biologically active lipids compared to the Bligh and Dyer method.

Study on Microwave Freeze-Drying of Krill

Antarctic krill (Euphausua superba) need to undergo freeze-drying to facilitate lipid extraction, but freeze-drying is time-consuming and energy-intensive, resulting in high processing costs. Microwave heating technology can reduce freeze-drying time and lower energy consumption costs. The objective of this study was to establish a drying kinetic model to help the microwave freeze-drying process by predicting krill drying time and evaluating the impact of the drying process on krill quality. The results showed that changing the microwave power did not alter the total energy requirement to complete drying when the sample weight was fixed. The total energy requirement for microwave drying increases with the sample weight. Comparing the three methods of freeze-drying (FD), microwave freeze-drying (MWFD), and hot-air drying at 55 °C (HAD) showed that they took 18, 0.67, and 16 h, respectively, to reach the drying endpoint for krill. Overall, HAD resulted in browning, shrinkage, and quality degradation of krill due to its high temperature and long duration. While the appearance and active ingredient contents of FD krill are slightly better than those of MWFD krill, FD requires a longer process and more energy. MWFD can reduce drying time by 20 times and energy consumption by 95% compared to FD.

Bioactive lipid‐enriched concentrates from squid discards by one‐step and two‐step extractions with non‐halogenated solvents

SummaryThis study focused on the preparation of lipid concentrates with high contents of bioactive molecules. Different one‐step and two‐step extractions with non‐halogenated solvents (hexane, HX; isopropanol, IP) were carried out on Patagonian squid (Doryteuthis gahi) discards. As a first step, HX extractions (one, two or three times) were carried out. The resulting substrates were extracted with IP (two, three or four times). Analysis of lipid extracts included total lipid, phospholipid (PL) and tocopherol values, and fatty acid (FA) profile. HX extractions led to remarkable α‐ and γ‐tocopherol values (ca. 1400 and 23 mg kg−1 lipids, respectively); no effect (P &gt; 0.05) of the number of HX extractions was observed. IP extracts provided high PL values (383–501 mg kg−1 lipids); the highest average values were detected with four IP extractions after three HX extractions. Values obtained for tocopherols and PLs were higher (P &lt; 0.05) than those obtained by employing the conventional (chloroform/methanol, 1:1) lipid extraction (ca. 496 and 11 mg kg−1 lipids and 400 g kg−1 lipids, respectively). Range values detected for eicosapentaenoic and docosahexaenoic acid values and the ω3/ω6 FA ratio were similar to those obtained by the conventional procedure. A valuable procedure is proposed for obtaining PL‐ and tocopherol‐enriched concentrates from marine waste with non‐halogenated solvents.

Cinobufagin disrupts the stability of lipid rafts by inhibiting the expression of caveolin-1 to promote non-small cell lung cancer cell apoptosis.

The study was designed to explore how cinobufagin (CB) regulates the development of non-small cell lung cancer (NSCLC) cells through lipid rafts. The effects of CB at gradient concentrations (0, 0.5, 1 and 2 µM) on NSCLC cell viability, apoptosis, reactive oxygen species (ROS) level, phosphorylation of Akt, and apoptosis- and lipid raft-related protein expression were assessed by MTT assay, flow cytometry and Western blot. Cholesterol and sphingomyelin were labeled with BODIPY to evaluate the effect of CB (2 µM) on them. Sucrose density gradient centrifugation was used to extract lipid rafts. The effect of CB on the expression and distribution of caveolin-1 was determined by immunofluorescence, quantitative reverse transcription polymerase chain reaction and Western blot. After overexpression of caveolin-1, the above experiments were performed again to observe whether the regulatory effect of CB was reversed. CB inhibited NSCLC cell viability while promoting apoptosis and ROS level. CB redistributed the lipid content on the membrane surface and reduced the content of caveolin-1 in the cell membrane. In addition, CB repressed the activation of AKT. However, caveolin-1 overexpression reversed the effects of CB on apoptosis, AKT activation and lipid raft. CB regulates the activity of Akt in lipid rafts by inhibiting caveolin-1 expression to promote NSCLC cell apoptosis.

High-resolution ion mobility based on traveling wave structures for lossless ion manipulation resolves hidden lipid features

High-resolution ion mobility (resolving power > 200) coupled with mass spectrometry (MS) is a powerful analytical tool for resolving isobars and isomers in complex samples. High-resolution ion mobility is capable of discerning additional structurally distinct features, which are not observed with conventional resolving power ion mobility (IM, resolving power ~ 50) techniques such as traveling wave IM and drift tube ion mobility (DTIM). DTIM in particular is considered to be the “gold standard” IM technique since collision cross section (CCS) values are directly obtained through a first-principles relationship, whereas traveling wave IM techniques require an additional calibration strategy to determine accurate CCS values. In this study, we aim to evaluate the separation capabilities of a traveling wave ion mobility structures for lossless ion manipulation platform integrated with mass spectrometry analysis (SLIM IM-MS) for both lipid isomer standards and complex lipid samples. A cross-platform investigation of seven subclass-specific lipid extracts examined by both DTIM-MS and SLIM IM-MS showed additional features were observed for all lipid extracts when examined under high resolving power IM conditions, with the number of CCS-aligned features that resolve into additional peaks from DTIM-MS to SLIM IM-MS analysis varying between 5 and 50%, depending on the specific lipid sub-class investigated. Lipid CCS values are obtained from SLIM IM (TW(SLIM)CCS) through a two-step calibration procedure to align these measurements to within 2% average bias to reference values obtained via DTIM (DTCCS). A total of 225 lipid features from seven lipid extracts are subsequently identified in the high resolving power IM analysis by a combination of accurate mass-to-charge, CCS, retention time, and linear mobility-mass correlations to curate a high-resolution IM lipid structural atlas. These results emphasize the high isomeric complexity present in lipidomic samples and underscore the need for multiple analytical stages of separation operated at high resolution.Graphical abstract

POTENSI LIPID MIKROALGA AURANTIOCHYTRIUM DARI HUTAN BAKAU INDONESIA SEBAGAI BAHAN BAKU PRODUKSI BIOFUEL

Microalgae's high lipid content makes them an alternative raw material for the generation of biofuel. This research examines the potential of Aurantiochytrium microalgae sourced from mangrove forests. The capacity to create omega-3 polyunsaturated fatty acids, such DHA, which have a high economic value, is one benefit of Aurantiochytrium microalgae and makes integrated production with biofuel production feasible. The possible biofuel products from Aurantiochytrium microalgae, including biodiesel and bioviation fuel, are reviewed in this research. These microalgae go through multiple steps in the biofuel production process, including isolation, cultivation, lipid extraction, and hydroprocessing and transesterification to turn the algae into biodiesel or biojet fuel. The first steps toward producing biofuel from Aurantiochytrium microalgae obtained from Indonesian mangrove forests are expected to be laid by this research.

Effect of temperature and body size on anterior and posterior regeneration in Hermodice carunculata (Polychaeta, Amphinomidae)

In recent years, population outbreaks of the annelid Hermodice carunculata (Polychaeta, Amphinomidae) are recurrently detected along the coastal zone of the Salento peninsula (Southern Italy), with impacts on marine benthic ecosystems. Annelida are renowned for their remarkable regeneration potential, enabling them to reform lost body parts. A handful of studies have reported posterior regeneration of H. carunculata, but anterior regeneration has not been fully explored. In this study, we investigated the capacity of H. carunculata collected in shallow coastal areas (Ionian Sea, 40°08’26.9” N 17°58’44.1” E) to regenerate anterior body parts under different temperature conditions (22 and 14 °C) and considering two different body sizes (∼ 4 g and 25 g). In addition, histological analysis and lipid analyses were carried out to detect changes in the reproductive cycle and lipid storage during ongoing regeneration. The results suggest that small and large-sized specimens of H. carunculata can regenerate efficiently anterior body parts in 12–20 weeks post amputation when kept at 22 °C. Small-sized worms kept at 14 °C regenerated slower but died in 24 weeks post amputation before regenerating a mouth, while large-sized worms kept at 14 °C were affected by a 100% mortality during blastema formation. In addition, lipid extraction analyses show that H. carunculata can regenerate during extended periods of starvation by de novo synthesizing lipid reserves and regeneration in H. carunculata does not negatively impact the reproductive cycle, as gametogenesis occurs also during the regenerative processes.

Evaluation of Extraction Techniques for Recovery of Microalgal Lipids under Different Growth Conditions.

Microalgal lipids contain a wide array of liposoluble bioactive compounds, but lipid extraction remains a critical limitation for their commercial use. An accelerated solvent extraction (ASE) was used to extract lipids from Chlamydomonas reinhardtii, Arthrospira platensis (Spirulina), and Chlorella vulgaris grown under either standard or nitrogen depletion conditions. Under standard growth conditions, ASE using methanol:chloroform (2:1), methyl tert-butyl ether (MTBE):methanol:water, and ethanol at 100 °C resulted in the highest recovery of total lipids (352 ± 30, 410 ± 32, and 127 ± 15 mg/g biomass from C. reinhardtii, C. vulgaris, and A. platensis, respectively). Similarly, the highest total lipid and triacylglycerols (TAGs) recovery from biomass cultivated under nitrogen depletion conditions was found at 100 °C using methanol:chloroform, for C. reinhardtii (total, 550 ± 21; TAG, 205 ± 2 mg/g biomass) and for C. vulgaris (total, 612 ± 29 mg/g; TAG, 253 ± 7 mg/g biomass). ASE with MTBE:methanol:water at 100 °C yielded similar TAG recovery for C. reinhardtii (159 ± 6 mg/g) and C. vulgaris (200 ± 4 mg/g). Thus, MTBE:methanol:water is suggested as an alternative substitute to replace hazardous solvent mixtures for TAGs extraction with a much lower environmental impact. The extracted microalgal TAGs were rich in palmitic (C16:0), stearic (C18:0), oleic (C18:1,9), linoleic (C18:2n6), and α-linolenic (C18:3n3) acids. Under nitrogen depletion conditions, increased palmitic acid (C16:0) recovery up to 2-fold was recorded from the biomasses of C. reinhardtii and C. vulgaris. This study demonstrates a clear linkage between the extraction conditions applied and total lipid and TAG recovery.

Blue mussel (Mytilus edulis) lipid extract ameliorates insulin resistance in diabetic rats by regulating the SphK/So1P signaling pathway

Studies have shown that blue mussel lipid extract (BMLE) has strong anti-inflammatory activity in both rheumatoid arthritis patients and animal arthritis models. Present study aimed to investigate the effect of BMLE on insulin resistance and its potential mechanisms. Diabetic rats were randomly divided into three groups and received corn oil (CO), fish oil (FO) and BMLE. The results showed that BMLE could effectively reduce Homeostasis model assessment of insulin resistance (HOMA-IR) in diabetic rats. BMLE group showed a significantly lower protein levels of SphK1 and a significantly higher protein levels of SphK2, AKT and P-AKT of liver and skeletal muscle compared with the both CO and FO groups. The liver sphingosine-1 phosphate (So1P) in the BMLE group was significantly higher than in the CO group. In conclusion, the present results demonstrate that BMLE can improve insulin resistance in diabetes rats by reducing inflammatory factors, regulating SphK/So1P pathway and activating insulin signaling pathway.

Lipid extraction alters amino acid composition and bulk, but not amino acid, carbon and nitrogen isotope values.

Concerns exist over observed shifts in value and variance of nitrogen isotopes following physicochemical extraction of lipids from organic matter. The mechanisms behind these apparent changes in bulk tissue δ15N values are not fully understood yet have major implications for analytical costs and integrity of data interpretations. Changes in proximate analysis, amino acid composition, C:N ratios, bulk tissue and amino acid δ13C and δ15N values, and resulting isotope-based food web metrics were compared between lipid-intact and lipid-extracted muscle tissue of fishes spanning <1% to >20% muscle fat content to identify mechanisms of nitrogen isotope fractionation associated with physicochemical lipid extraction. Bulk δ13C and δ15N values increased and %N, C:N ratios and crude protein content decreased following lipid extraction. Resulting bulk isotope niche spacing and overlap varied significantly between lipid-intact and lipid-extracted tissues. While amino acid composition significantly changed during lipid extraction, particularly for lipid-associated amino acids (e.g., Glu, Lys, Ser), individual amino acid δ13C and δ15N values, and their associated compound-specific isotope analysis of amino acids (CSIA-AA)-based food web metrics, did not. Physicochemical lipid extraction caused significant tissue composition changes (e.g., leaching of amino acids and 15N-deplete nitrogenous waste) that affected δ13C and δ15N values and tissue %C and %N beyond simply removing lipids. However, lipid extraction did not alter individual amino acid δ13C or δ15N values or their associated CSIA-AA-based food web metrics.

In vitro digestion and culture in Caco‐2 cells to assess the bioavailability of fatty acids: A case study in meat matrix enriched with ω‐3 microcapsules

AbstractThis work aimed to evaluate the Caco‐2 cells as a model to study the epithelial transport of intestinal lipid extracts subjected to in vitro digestion, to establish a standard protocol for the determination of bioaccessibility and bioavailability of fatty acids in meat matrix, especially in those enriched with ω‐3 (eicosapentaenoic (EPA) and docosahexaenoic acids (DHA)). Samples were first subjected to in vitro digestion, and then, the intestinal extract was incubated with Caco‐2 cells. A first trial was conducted to select the most influencing variables on the fatty acid transport during Caco‐2 cell incubation: fat quantity on the intestinal extract, incubation time, and shaking. Then, a second experiment was carried out to determine the influence of these variables, being the fat quantity and the incubation time the most influencing factors on the transport and bioavailability of fatty acids. The effect of shaking was not so marked but seemed to improve the bioavailability of saturated fatty acids. This study also allows establishing the most suitable conditions: intestinal extracts with 30 mg of fat, longer incubation times (8 h), and shaking, achieving active and passive fatty acid transport without compromising the integrity of the Caco‐2 cell monolayer. The accurate results obtained for major and minor fatty acids, especially EPA and DHA are remarkable, due to the interest in these bioactive compounds. Thus, this study provides a combined protocol based on static in vitro digestion followed by Caco‐2 cell incubation to assess the bioaccessibility and bioavailability of fatty acids in meat samples.

Fractionation and characterization of Dunaliella microalgal biomass and extraction of carotenoids

This paper presents findings on the application of two fractionation protocols of Dunaliella microalgal biomass with the aim to separate and recover the lipid, pigment and protein fraction, leaving as “residue” the fraction that contains carbohydrates. The first protocol (LPC) is based on the initial extraction of lipids, followed by extraction of proteins, while in the second protocol (CLP), the pigments are first extracted followed by lipids extraction. With the LPC protocol the recovered lipid fraction was 34 and 32 wt%, while the recovered proteinic fraction was 46 and 50 wt% for the two samples under study, i.e. 1120 (D. granulata) and 1220 (D. minutissima). The CLP protocol led to the initial extraction of the pigment fraction with a percentage of 10–15 wt% while the subsequently recovered lipidic fraction was 16–24 wt%. The initial biomass was characterized for its moisture (<0.7 wt% for both samples), ash (approx. 45 wt% for both samples), organic matter, elemental composition and higher heating value (HHV) which was 23 and 30 MJ/kg (organic matter based-OMB). The composition of the lipid fraction was analyzed via esterification and gas chromatography (GC-FID) showing C16 and C18 as the predominant acids in the samples. The residue/carbohydrate fraction was analyzed via acid hydrolysis and analysis by high pressure liquid chromatography (HPLC) showing about 20 wt% (-OMB) content of carbohydrates. The high ash content of the biomass was found to be co-extracted during the fractionation protocols at a percentage of ≈49 % in the lipidic fraction and 45 % in the proteinic fraction. Furthermore, emphasis was given on pigment extraction and recovery using various solvents and quantification methods. Measurements of β-carotene, carotenoids, and chlorophyll content through UV and HPLC analyses is presented with chlorophyl and carotenoid content being ≈12 wt% and ≈9 wt% for samples 1120 and 1220 (-OMB). Additionally, a comparison between three solvents (THF, dichloromethane, acetone) was performed regarding their ability to extract the pigments from the microalgal biomass showing that acetone is capable of extracting pigments when concentration of the pigments is not high. The comparison of the HPLC with the UV method, suggested that UV spectroscopy is a reliable and rapid alternative for pigments determination, while HPLC enables identification and quantitative determination of specific pigments and chlorophyll species. The study provides insights for different fractionation protocols applied in two not yet fully studied Dunaliella species as well as the chlorophyl and carotenoid content.

Impaired Suppression of Plasma Lipid Extraction and its Partitioning Away from Muscle by Insulin in Humans with Obesity.

Humans with obesity and insulin resistance exhibit lipid accumulation in skeletal muscle, but the underlying biological mechanisms responsible for the accumulation of lipid in the muscle of these individuals remain unknown. We investigated how plasma insulin modulates the extraction of circulating triglycerides (TGs) and non-esterified fatty acids (NEFAs) from dietary and endogenous sources in the muscle of lean, insulin-sensitive humans (Lean-IS) and contrasted these responses to those in humans with obesity and insulin resistance (Obese-IR). The studies were performed in a postprandial state associated with steady-state plasma TG concentrations. The arterio-venous blood sampling technique was employed to determine the extraction of circulating lipids across the forearm muscle before and after insulin infusion. We distinguished kinetics of TGs and NEFAs from dietary sources across muscle from those from endogenous sources by incorporating stable isotope-labeled triolein in ingested fat. Plasma insulin rapidly suppressed the extraction of plasma TGs from endogenous, but not dietary, sources in the Lean-IS, but same response was absent in the Obese-IR. Furthermore, in the muscle of Lean-IS, plasma insulin decreased the extraction of circulating NEFAs from both dietary and endogenous sources, but in Obese-IR subjects this response was absent for NEFAs from dietary sources. Partitioning of circulating lipids away from the skeletal muscle when plasma insulin increases, such as during the postprandial period, is impaired in humans with obesity and insulin resistance. Trial Registration: ClinicalTrials.gov ( NCT01860911 ).

Deep profiling of plasmalogens by coupling the Paternò-Büchi derivatization with tandem mass spectrometry.

Plasmalogens are a special class of glycerophospholipids characterized by a vinyl ether bond (-C = C-O-) at the sn-1 position of the glycerol backbone. Altered plasmalogen profiles have been observed in neurodegenerative diseases and cancers. Profiling of plasmalogens requires specifying the vinyl ether bond and differentiating them from various types of isobars and isomers. Herein, by coupling C = C derivatization via offline Paternò-Büchi reaction with liquid chromatography-tandem mass spectrometry, we have developed a sensitive workflow for analysis of plasmalogens from biological samples. Using bovine heart lipid extract as a model system, we profiled more than 100 distinct structures of plasmenylethanolamines (PE-Ps) and plasmenylcholines (PC-Ps) at the C = C location level, far exceeding previous reports. Analysis of human glioma and normal brain tissue samples revealed elevated n-10 C = C isomers of PE-Ps in the glioma tissue samples. These findings suggest that the developed workflow holds potential in aiding the study of altered metabolism of plasmalogens in clinical samples.

Oxylipins in Breast Implant-Associated Systemic Symptoms.

A subset of females with breast implants have reported a myriad of nonspecific systemic symptoms collectively termed systemic symptoms associated with breast implants (SSBI). SSBI symptoms are similar to manifestations associated with autoimmune and connective tissue disorders. Breast tissue is rich in adipose cells, comprised of lipids. Insertion of an implant creates an oxidative environment leading to lipid oxidation. Oxylipins can influence immune responses and inflammatory processes. In this study we explored the abundance of a spectrum of oxylipins in the periprosthetic tissue surrounding the breast implant. Because oxylipins are immunogenic, we sought to determine if they were associated with the SSBI patients. We have also attempted to determine if the common manifestations exhibited by such patients have any association with oxylipin abundance. The study included 120 patients divided into 3 cohorts. We analyzed 46 patients with breast implants exhibiting manifestations associated with SSBI; 29 patients with breast implants not exhibiting manifestations associated with SSBI (control cohort I, non-SSBI); and 45 patients without implants (control cohort II, no-implant tissue). Lipid extraction and oxylipin quantification were performed with liquid chromatography mass spectrometry (LC-MS/MS). LC-MS/MS targeted analysis of the breast adipose tissue was performed. Of the 15 oxylipins analyzed, 5 exhibited increased abundance in the SSBI cohort when compared to the non-SSBI and no-implant cohorts. The study documents the association of the oxylipins with each manifestation reported by the patient. This study provides an objective assessment of the subjective questionnaire, highlighting which symptoms may be more relevant than the others.

Chronic endometritis. Local prooxidant, antioxidant and immunometabolic disorders. An open-label, prospective, randomized study

Aim. To determine local features of lipoperoxidation processes, antioxidant defense, state of matrix metalloproteinases in chronic endometritis. Materials and methods. Eighty women aged 29.33±6.71 (min-max [24–36]) with histologically and immunohistochemically confirmed chronic endometritis and a history of reproductive losses were examined (group 1). The control group consisted of 30 patients without chronic endometritis confirmed by the results of a histochemical study and no history of reproductive losses, suffering from infertility of tubal-peritoneal origin at the age of 30.11±6.9 years (min-max [24–37]; group 2). All 130 patients underwent transvaginal echography of the pelvic organs, and histological and immunohistochemical examination of endometrial samples was performed. The activity of lipid peroxidation factors was analyzed: primary, secondary and final products of lipid peroxidation in heptane and isopropanolol fractions of uterine cavity aspirate, enzymes of the antioxidant system: superoxide dismutase, catalase, glutathione peroxidase, deoxyribonuclease I (DNase), by spectrophotometric method, remodeling factors – matrix metalloproteinases MMP-2, -9 by flow fluorimetry. Results. In patients of group 1, according to transvaginal echography of the pelvic organs, M-echo was 6.29±1.22 mm, in group 2 – 9.10±1.15 mm. In chronic endometritis, disruption of pro-oxidant and activity of antioxidant factors in the endometrium in women with chronic endometritis and a history of reproductive losses. In the heptane fraction of the phenolic extract, the concentration of primary products of lipid peroxidation (diene conjugates) was 12.98% higher than in the control, the content of secondary products of lipid peroxidation (ketodienes) was higher by 15.45%, conjugated trienes by 18.67% higher than the values in the control group, which indicates increased lipid peroxidation of endometrial cell membranes during CE. In the isopropanol phase, the products of lipid peroxidation of phospholipid acyl residues are detected. In the isopropanol fraction of the lipid extract, the amount of diene conjugates was higher, ketodienes by 24.32% and conjugated trienes by 26.14%. An increase in the activity of the enzymes superoxide dismutase by 23.98%, catalase by 14.34%, glutathione peroxidase by 12.39%, and DNase by 2.9 times was recorded compared to the indicators of group 2. Conclusion. Chronic endometritis is accompanied by changes in the system of pro-oxidant and antioxidant factors, the content of tissue remodeling products. The pathogenetic changes underlying oxidative stress in the endometrium may be increased leukocyte infiltration, imbalance of primary, secondary and end products of lipid peroxidation, enzymes superoxide dismutase, catalase, glutathione peroxidase, deoxyribonuclease I (DNase), expression of matrix metalloproteinases-2, -9.

Lipid analyses of oil-bearing biomass using a thermally induced derivatization method

This study assessed the efficacy of a commercial fatty acid (FA) methylation kit for analyzing insect/microalgal biomass lipids by comparing it to a thermally induced derivatization method, which is known for its high conversion yield and impurity resistance and serves as a benchmark for evaluating kit performance, as a comparative standard. In insect lipid analysis, kit-based derivatization demonstrated a lower yield of FA methyl esters (FAMEs) than that of the thermally induced method, which is attributable to inherent technical limitations (vulnerability to impurities). This yield discrepancy was further highlighted in microalgal lipid analyses. The efficiency of FA derivatization using the kit-based method was contingent on the lipid structure, as evidenced by the diminished conversion yields for wax esters in Euglena gracilis. Furthermore, for Chlamydomonas reinhardtii, the lower FAME yield observed with kit-based derivatization suggested potential inadequacies in lipid extraction, particularly in the presence of rigid cellular structures such as cell walls. This reduced interaction between lipids and methanol could lead to diminished FAME conversion yields. These findings highlight the notable influence of the biomass type and lipid structure on the efficiency of kit-based derivatization, potentially yielding suboptimal results in lipid analysis.