High Reserve in δ-Tocopherol of Peganum harmala Seeds Oil and Antifungal Activity of Oil against Ten Plant Pathogenic Fungi

This investigation included the chemical analysis of Peganum harmala (P. harmala) seed oil and its antifungal properties against 10 fungal species. Seed oils of six populations were analyzed using high performance liquid chromatography (HPLC) and gas chromatograph/mass spectrometry (GC-MS). The HPLC analysis indicated that P. harmala seed oil exhibited a very high level of tocopherol contents, with values in the range of 2385.66-2722.68 mg/100 g. The most abundant tocopherol isomer was δ-tocopherol (90.39%), followed by γ-tocopherol (8.08%) and α-tocopherol (1.14%). We discovered for the first time the presence of tocotrenols in P. harmala seed oils of the six populations studied. The GC-MS analyses revealed that linoleic acid was the main fatty acid (65.17%), followed by oleic acid (23.12%), palmitic acid (5.36%) and stearic acid (3.08%). We also studied the antifungal activity of seed oil of the Medenine (MD) population on ten fungal pathogens. The antifungal effects differed among pathogens and depended on oil concentrations. Seed oil of the MD population caused a significant decrease in mycelial growth of all fungi tested, with values ranging 31.50-82.11%, except for Alternaria sp., which showed no inhibition. The antifungal activity against the 10 selected fungi can be explained by the richness in tocols of the extracted oil and make P. harmala a promising crop for biological control. Furthermore, the importance of fatty acids and the wide geographic spread in Tunisia of this species make this crop a potential source of renewable energy.

Rana chensinensis Ovum Oil Based on CO2 Supercritical Fluid Extraction: Response Surface Methodology Optimization and Unsaturated Fatty Acid Ingredient Analysis

Rana chensinensis ovum oil (RCOO) is an emerging source of unsaturated fatty acids (UFAs), but it is lacking in green and efficient extraction methods. In this work, using the response surface strategy, we developed a green and efficient CO2 supercritical fluid extraction (CO2-SFE) technology for RCOO. The response surface methodology (RSM), based on the Box-Behnken Design (BBD), was used to investigate the influence of four independent factors (pressure, flow, temperature, and time) on the yield of RCOO in the CO2-SFE process, and UPLC-ESI-Q-TOP-MS and HPLC were used to identify and analyze the principal UFA components of RCOO. According to the BBD response surface model, the optimal CO2-SFE condition of RCOO was pressure 29 MPa, flow 82 L/h, temperature 50 °C, and time 132 min, and the corresponding predicted optimal yield was 13.61%. The actual optimal yield obtained from the model verification was 13.29 ± 0.37%, and the average error with the predicted value was 0.38 ± 0.27%. The six principal UFAs identified in RCOO included eicosapentaenoic acid (EPA), α-linolenic acid (ALA), docosahexaenoic acid (DHA), arachidonic acid (ARA), linoleic acid (LA), and oleic acid (OA), which were important biologically active ingredients in RCOO. Pearson correlation analysis showed that the yield of these UFAs was closely related to the yield of RCOO (the correlation coefficients were greater than 0.9). Therefore, under optimal conditions, the yield of RCOO and principal UFAs always reached the optimal value at the same time. Based on the above results, this work realized the optimization of CO2-SFE green extraction process and the confirmation of principal bioactive ingredients of the extract, which laid a foundation for the green production of RCOO.

Effect of elevated temperature and UV radiation on molecular structure of linoleic acid by ATR-IR and two-dimensional correlation spectroscopy

The effect of elevated temperature (44 °C) and ultraviolet (UV) radiation on molecular structure of linoleic acid (LA) was studied by Attenuated Total Reflection Infrared (ATR-IR) spectroscopy. To obtain more detailed information on molecular mechanism of these changes we applied moving-window analysis and two-dimensional correlation spectroscopy (2DCOS). Analysis of the time-dependent ATR-IR spectra of LA before and after UV irradiation revealed the structural changes in molecules of LA. The extent of these changes was significantly higher after an application of UV radiation. During 24 h experiment temperature was constant, therefore the spectral changes result from relatively slow processes (and requiring more energy), e.g. cis/trans isomerization, disruption of the C=C double bonds and partial breaking of hydrogen bonds in the cyclic dimers. As a side effect of these structural changes one can observe variations in the orientation of the chains. It is of note that the methyl and methylene groups reveal slightly different behaviour.

Distribution of Free and Esterified Oxylipins in Cream, Cell, and Skim Fractions of Human Milk

Human milk contains oxylipins involved in infant development. Although oxylipins have been identified in whole or skim milk, their localization within human milk cream, cell, and skim fractions is not known. This study determined the distribution of free and esterified oxylipins in cream, cell, and skim fractions of human milk. Out of 72 oxylipins probed by mass-spectrometry, 42, 29, and 41 oxylipins (free or bound) were detected in cream, cell, and skim fractions, respectively. Over 90% of free and bound oxylipins were derived from linoleic acid in all milk fractions. Other oxylipins were derived from n-6 arachidonic acid and dihomo-gamma-linolenic acid, and n-3 alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid. Free oxylipins were more abundant in skim milk (59.9% of total oxylipins) compared to cream and cell pellet, whereas esterified oxylipins were most abundant in milk cream and cell pellets (74.9-76.9%). The heterogenous distribution of oxylipins in different fractions of human milk may regulate the guided release of these bioactive signaling molecules within infants.

Effects of Linoleic Acid-Rich Diet on Plasma Profiles of Eicosanoids and Development of Colitis in Il-10-/- Mice

Dietary intake of linoleic acid (LA, 18:2ω-6) has risen dramatically in recent decades. Previous studies have suggested a high intake of LA could increase tissue concentrations of proinflammatory and protumorigenic ω-6-series eicosanoid metabolites, increasing risks of inflammation and associated diseases. However, the effects of a LA-rich diet on in vivo profiles of eicosanoids and development of inflammatory diseases are understudied. Here, we treated spontaneous colitis-prone (Il-10^-/-) mice with a control diet (∼3 Cal% LA) or a LA-rich diet (∼9 Cal% LA) for 18 weeks and analyzed the effects of the LA-rich diet on profiles of eicosanoids and development of colitis. We found that treatment with the LA-rich diet increased the tissue level of LA: the liver levels of LA were 5.8 ± 0.6% in the control diet-treated mice versus 11.7 ± 0.7% in the LA-rich diet-treated mice (P < 0.01). The plasma concentrations of a series of LA-derived metabolites, including 9-hydroxyoctadecadienoic acid (HODE), 9,10-dihydroxyoctadecenoic acid (DiHOME), 12,13-DiHOME, and 13-HODE were significantly increased by treatment with the LA-rich diet (P < 0.05). However, the LA-rich diet had little effect on the severity of colitis in the treated Il-10^-/- mice. These results suggest a limited role of increased consumption of dietary LA on promoting colitis in the Il-10^-/- model.

Effect of soaking conditions on the formation of lipid derived free radicals in soymilk

Lipid derived free radical in soymilks were studied by combining 5,5-dimethyl-pyrroline-l-oxide (DMPO) spin trap, chloroform-methanol extraction and electron spin resonance (ESR) spectroscopy. Five lipid derived free radical adducts: DMPO-X, DMPO-L, DMPO-R, DMPO-LOO, and DMPO-RO were presented in soymilks. The total amounts of spins increased as the soaking temperature increased from 4 °C to 50 °C and the soaking pH increased from 3 to 9 and in paralleled with the diffusion of soybean exudates to soaking water. Prolonged soaking of soybean at 50 °C resulted in a higher signal intensity of DMPO-R than that of DMPO-LOO. Soybean lipoxygenases (LOXs) were responsible for the formation of lipid derived free radicals in soymilks. Soybean exudates affected the total amounts of lipid radicals in linoleic acid (LA) - LOX model system. The relative signal intensities of DMPO-R and DMPO-LOO were depended on the contents of soybean exudates in the system.

Effect of Blanching Pomegranate Seeds on Physicochemical Attributes, Bioactive Compounds and Antioxidant Activity of Extracted Oil

This study investigated the effect of blanching pomegranate seeds (PS) on oil yield, refractive index (RI), yellowness index (YI), conjugated dienes (K232), conjugated trienes (K270), total carotenoid content (TCC), total phenolic compounds (TPC) and DPPH radical scavenging of the extracted oil. Furthermore, phytosterol and fatty acid compositions of the oil extracted under optimum blanching conditions were compared with those from the oil extracted from unblanched PS. Three different blanching temperature levels (80, 90, and 100 °C) were studied at a constant blanching time of 3 min. The blanching time was then increased to 5 min at the established optimum blanching temperature (90 °C). Blanching PS increased oil yield, K232, K270, stigmasterol, punicic acid, TPC and DPPH radical scavenging, whereas YI, β-sitosterol, palmitic acid and linoleic acid were decreased. The RI, TCC, brassicasterol, stearic acid, oleic acid and arachidic acid of the extracted oil were not significantly (p > 0.05) affected by blanching. Blanching PS at 90 °C for 3 to 5 min was associated with oil yield, TPC and DPPH. Blanching PS at 90 °C for 3 to 5 min will not only increase oil yield but could also improve functional properties such as antioxidant activity, which are desirable in the cosmetic, pharmaceutical, nutraceutical and food industries.

Modulatory Effect of Linoleic Acid During Brucella abortus 544 Infection in Murine Macrophage RAW264.7 Cells and Murine Model BALB/c Mice

In this study, we investigated the effects of linoleic acid (LA) treatment on Brucella abortus infection in professional phagocyte RAW264.7 cells, particularly during the pathogens invasion and intracellular growth in these cells, as well as in murine model BALB/c mice focusing on bacterial splenic proliferation and immunoregulatory activities. LA inhibited the growth of Brucella in a doseand time-dependent manner. The ability of the pathogen to enter the phagocytes was inhibited as was its survival within these cells. This was accompanied by increased nitrite accumulation in these cells at 24 h post-infection. The concentration of LA used in the present study did not affect the total body weight or liver function of the mice. During Brucella infection, the total splenic weight of these animals was not changed; rather, resistance to bacterial proliferation was enhanced in the spleen. Furthermore, mice treated with LA displayed elevated levels of IL-12 and IFN-γ but reduced levels of IL-10 during infection. The findings in this study showed the regulatory role of LA against B. abortus infection suggesting its potential use in designing intervention strategy for brucellosis.

Gel Properties of Soy Protein Isolate Modified by Lipoxygenase-Catalyzed Linoleic Acid Oxidation and Their Influence on Pepsin Diffusion and In Vitro Gastric Digestion

The model of lipoxygenase-catalyzed linoleic acid (LA) oxidation was selected as representative of a lipid peroxidation system to investigate the effects of oxidative modification on soybean protein isolate (SPI) gel properties and in vitro gastric digestion. Fluorescence recovery after the photobleaching (FRAP) technique was applied to evaluate pepsin diffusion in the gel. The results showed that oxidative modification increased the gel hardness as well as brought about a compact and three-dimensional network structure, which consequently decreased the water mobility as manifest by lowering the relaxation time of T_2b and T₂₁ from 0.55 and 3.22 ms for the control to 0.32 and 2.42 ms for 7LA+LOX (addition of 7 mL of LA and LOX), respectively. It was interesting to note that pepsin diffusion was significant correlated (p < 0.05) with T_2b and DH (degree of hydrolysis), indicating that water mobility might be a factor related to FITC-pepsin diffusion, which would ultimately influence the gel gastric digestion. Compared with native SPI, moderate oxidation can improve the digestibility of SPI gel by the summed effects of pepsin diffusion limitation, microstructure variation, and hydrolysis degree.

In Vitro Investigations of Acetohexamide Binding to Glycated Serum Albumin in the Presence of Fatty Acid

The interaction of drugs with human serum albumin (HSA) is an important element of therapy. Albumin affects the distribution of the drug substance in the body, as well as its pharmacokinetic and pharmacodynamic properties. On the one hand, inflammation and protein glycation, directly associated with many pathological conditions and old age, can cause structural and functional modification of HSA, causing binding disorders. On the other hand, the widespread availability of various dietary supplements that affect the content of fatty acids in the body means that knowledge of the binding activity of transporting proteins, especially in people with chronic diseases, e.g., diabetes, will achieve satisfactory results of the selected therapy. Therefore, the aim of the present study was to evaluate the effect of a mixture of fatty acids (FA) with different saturated and unsaturated acids on the affinity of acetohexamide (AH), a drug with hypoglycaemic activity for glycated albumin, simulating the state of diabetes in the body. Based on fluorescence studies, we can conclude that the presence of both saturated and unsaturated FA disturbs the binding of AH to glycated albumin. Acetohexamide binds more strongly to defatted albumin than to albumin in the presence of fatty acids. The competitive binding of AH and FA to albumin may influence the concentration of free drug fraction and thus its therapeutic effect.

Fabrication and Characterization of a Microemulsion Stabilized by Integrated Phosvitin and Gallic Acid

The purpose of this work was to conjugate phosvitin (Pv) with gallic acid (GA) to explore a new emulsifier that had both good emulsifying properties and antioxidant activity. The Pv-GA complex was prepared at a GA concentration of 1.5 mg/mL with pH 9.0. The Pv-GA complex obtained was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and characterized with infrared, ultraviolet, and fluorescence spectra. The emulsifying activity and stability of the Pv-GA complex were slightly improved, and antioxidant activities was significantly enhanced. Furthermore, the Pv-GA complex was used to load conjugated linoleic acid (CLA) for microemulsion preparation. Results showed that the Pv-GA complex could increase the viscosity and lipid antioxidant capacity of Pv-GA/CLA microemulsion. The Pv-GA/CLA microemulsion had remarkable emulsifying activity, emulsifying stability, pH, and thermal stability and poor salt stability.

The Soybean Lipoxygenase-Substrate Complex: Correlation between the Properties of Tunneling-Ready States and ENDOR-Detected Structures of Ground States

Hydrogen tunneling in enzymatic C-H activation requires a dynamical sampling among ground-state enzyme-substrate (E-S) conformations, which transiently generates a tunneling-ready state (TRS). The TRS is characterized by a hydrogen donor-acceptor distance (DAD) of 2.7 Å, ∼0.5 Å shorter than the dominant DAD of optimized ground states. Recently, a high-resolution, 13C electron-nuclear double-resonance (ENDOR) approach was developed to characterize the ground-state structure of the complex of the linoleic acid (LA) substrate with soybean lipoxygenase (SLO). The resulting enzyme-substrate model revealed two ground-state conformers with different distances between the target C11 of LA and the catalytically active cofactor [Fe(III)-OH]: the active conformer "a", with a van der Waals DAD of 3.1 Å between C11 and metal-bound hydroxide, and an inactive conformer "b", with a distance that is almost 1 Å longer. Herein, the structure of the E-S complex is examined for a series of six variants in which subtle structural modifications of SLO have been introduced either at a hydrophobic side chain near the bound substrate or at a remote residue within a protein network whose flexibility influences hydrogen transfer. A remarkable correlation is found between the ENDOR-derived population of the active ground-state conformer a and the kinetically derived differential enthalpic barrier for D versus H transfer, ΔEa, with the latter increasing as the fraction of conformer a decreases. As proposed, ΔEa provides a "ruler" for the DAD within the TRS. ENDOR measurements further corroborate the previous identification of a dynamical network coupling the buried active site of SLO to the surface. This study shows that subtle imperfections within the initial ground-state structures of E-S complexes are accompanied by compromised geometries at the TRS.

Antioxidant Activity of Pastinaca sativa L. ssp. sylvestris [Mill.] Rouy and Camus Essential Oil

In the last decade, there has been growing interest in the food industry in replacing synthetic chemicals with natural products with bioactive properties. This study's aims were to determine the chemical composition and the antioxidant properties of the essential oil of Pastianica sylvestris. The essential oil was isolated with a yield of 0.41% (w/v) by steam distillation from the dried seeds and subsequently analysed by GC-MS. Octyl acetate (78.49%) and octyl hexanoate (6.68%) were the main components. The essential oil exhibited an excellent activity for the inhibition of primary and secondary oxidation products for cold-pressed sunflower oil comparable with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), which were evaluated using peroxide and thiobarbituric acid values. The antioxidant activity of the essential oil was additionally validated using DPPH radical scavenging (0.0016 ± 0.0885 mg/mL), and β-carotene-linoleic acid bleaching assays. Also, the amounts of total phenol components (0.0053 ± 0.0023 mg GAE/g) were determined.

Physicochemical Changes and in Vitro Gastric Digestion of Modified Soybean Protein Induced by Lipoxygenase Catalyzed Linoleic Acid Oxidation

Protein oxidation results in structural modification which affects its digestion. The objective of this work was to investigate the influence of lipoxygenases (LOX) catalyzed linoleic acid (LA) oxidation on the structure and in vitro gastric digests of soybean protein isolate (SPI). Fluorescence recovery after photobleaching (FRAP) was used to evaluate the relationship between pepsin diffusion and gastric digestion. Results indicated that oxidation induced carbonyl formation and loss of free sulfhydryl. Increased surface hydrophobicity and zeta-potential verified the protein unfolding and thus resulted in a small particle size and low fluorescence intensity. Fourier transform infrared spectroscopy (FTIR) showed that oxidation caused the increases in β-sheets mostly at the expense of α-helix and random coils. Fluorescein isothiocyanate (FITC)-pepsin in SPI solution modified with 3 mL LA showed a faster diffusion rate with 80.51 μm²/s as well as a higher DH value of 9.11%, showing that pepsin diffusivity might play an important role in protein gastric digestion.

Production of gasoline range hydrocarbons from catalytic cracking of linoleic acid over various acidic zeolite catalysts

Employment of edible oils as alternative green fuel for vehicles had raised debates on the sustainability of food supply especially in the third-world countries. The non-edible oil obtained from the abundantly available rubber seeds could mitigate this issue and at the same time reduce the environmental impact. Therefore, this paper investigates the catalytic cracking reaction of a model compound named linoleic acid that is enormously present in the rubber seed oil. Batch-scale experiments were conducted using 8.8 mL Inconel batch reactor having a cyclic horizontal swing span of 2 cm with a frequency of 60 cycles per minute at 450 °C under atmospheric condition for 90 min. The performance of HZSM-5, HBeta, HFerrierite, HMordenite and HY catalysts was tested for their efficiency in favouring gasoline range hydrocarbons. The compounds present in the organic liquid product were then analysed using GC-MS and classified based on PIONA which stands for paraffin, isoparaffin, olefin, naphthenes and aromatics respectively. The results obtained show that HZSM-5 catalyst favoured gasoline range hydrocarbons that were rich in aromatics compounds and promoted the production of desired isoparaffin. It also gave a higher cracking activity; however, large gaseous as by-products were produced at the same time.

Sorghum MSD3 Encodes an ω-3 Fatty Acid Desaturase that Increases Grain Number by Reducing Jasmonic Acid Levels

Grain number per panicle is an important component of grain yield in sorghum (Sorghum bicolor (L.)) and other cereal crops. Previously, we reported that mutations in multi-seeded 1 (MSD1) and MSD2 genes result in a two-fold increase in grain number per panicle due to the restoration of the fertility of the pedicellate spikelets, which invariably abort in natural sorghum accessions. Here, we report the identification of another gene, MSD3, which is also involved in the regulation of grain numbers in sorghum. Four bulked F₂ populations from crosses between BTx623 and each of the independent msd mutants p6, p14, p21, and p24 were sequenced to 20× coverage of the whole genome on a HiSeq 2000 system. Bioinformatic analyses of the sequence data showed that one gene, Sorbi_3001G407600, harbored homozygous mutations in all four populations. This gene encodes a plastidial ω-3 fatty acid desaturase that catalyzes the conversion of linoleic acid (18:2) to linolenic acid (18:3), a substrate for jasmonic acid (JA) biosynthesis. The msd3 mutants had reduced levels of linolenic acid in both leaves and developing panicles that in turn decreased the levels of JA. Furthermore, the msd3 panicle phenotype was reversed by treatment with methyl-JA (MeJA). Our characterization of MSD1, MSD2, and now MSD3 demonstrates that JA-regulated processes are critical to the msd phenotype. The identification of the MSD3 gene reveals a new target that could be manipulated to increase grain number per panicle in sorghum, and potentially other cereal crops, through the genomic editing of MSD3 functional orthologs.

Enzymatic synthesis of structured lipids enriched with conjugated linoleic acid and butyric acid: strategy consideration and parameter optimization

Structured lipids (SLs) rich in conjugated linoleic acid (CLA) and butyric acid with functions of low calorie and weight loss were synthesized in this study. By comparison of different synthetic routes, transesterification of CLA ethyl ester (CLAee) and tributyrin under vacuum was determined as the best method. The reaction conditions for SL synthesis were screened and the best conditions were as follows: Novozym 435 as the catalyst, enzyme load 6 wt%, temperature 60 °C, substrate molar ratio 2:1 (CLAee/tributyrin), water activity 0.68, reaction time 80 min. Under these conditions, the final product contained 97.5% of SLs, in which the contents of dibutyl-conjugated linoleoyl-glycerol and butyl-diconjugated linoleoyl-glycerol were 78.4% and 19.1%, respectively. The reusability evaluation indicated that the lipase could be reused at least 17 times. The obtained SLs with functions of both fatty acids could replace natural oil in food for inhibition of obesity and thus have great potential for commercial applications.

Redox status and fatty acid composition of Mactra corallina digestive gland following exposure to acrylamide

Acrylamide (ACR), a ubiquitous agent, has various chemical and industrial applications, and it is found in backed or fried carbohydrate-rich food. It has been related to multiple toxicological effects, and it causes high cytotoxicity through oxidative stress. The present study aimed to investigate the potential effect of ACR toxicity administered at different concentrations (5, 10, and 20 mg/L), during 5 days, in order to evaluate the fatty acid (FA) composition and redox state in the digestive gland of Mactra corallina. The results showed, in ACR-treated clams, a significant increase in malondialdehyde, hydrogen peroxide, protein carbonyl, and metallothionein levels, as well as an alteration of the enzymatic (superoxide dismutase, glutathione peroxidase, and catalase) and non-enzymatic (reduced glutathione and ascorbic acid) antioxidant status. However, acetylcholinesterase activity was inhibited in a concentration-dependent manner. In our experiment, the n-3 (Omega-3) and n-6 (Omega-6) polyunsaturated fatty acid levels were significantly changed in all ACR-treated groups. A decrease in eicosapentaenoic acid (C20:5n-3, EPA) and docosahexaenoic acid (C22:6n-3, DHA) was observed in 10-mg/L and 20-mg/L ACR-treated groups. Nevertheless, arachidonic acid (C20:4n-6, ARA) and its precursor linoleic acid (C18:2n-6, LA) were increased. Besides oxidative stress parameters, FA composition may be an additional tool for assessing ACR contamination.

Effect of saline irrigation on physiological traits, fatty acid composition and desaturase genes expression in olive fruit mesocarp

The effect of salinity on physiological traits, fatty acid composition and desaturase genes expression in fruit mesocarp of olive cultivar Leccino was investigated. Significant reduction of shoot elongation (-12%) during salt treatments (80 mM NaCl) was associated with the translocation of Na in the aerial part. After 75 days of treatment, fruits from each plant were subdivided into four maturation groups (MG₀, MG₁, MG₂, MG₃) according to ripening degrees. Na accumulation increased in each MG under salinity, reaching the highest values in MG₁ fruits (2654 mg kg^-1 DW). Salinity caused an acceleration of the ripening process, increased fruit number and decreased total fatty acids content in MG₃. An increase in oleic acid at MG₁ (53%) was detected, with consequent increase in the oleic/linoleic (41%) and decrease in the polyunsaturated/monounsaturated ratios (30%). Those variations could be explained by the synergic up-regulation of OeSAD1, together with the down-regulation of OeFAD6 transcript levels.

Self-Strengthened Oxidation-Responsive Bioactivating Prodrug Nanosystem with Sequential and Synergistically Facilitated Drug Release for Treatment of Breast Cancer

Although environment-sensitive prodrug-based nanoparticles (NPs) have developed rapidly, lots of prodrug NPs still show poor selectivity and efficiency of parent drug bioactivation because of tumor heterogeneity. Herein, self-strengthened bioactivating prodrug-based NPs are fabricated via co-encapsulation of oxidation-responsive thioether-linked linoleic acid-paclitaxel conjugates (PTX-S-LA) and β-lapachone (LPC) into polymeric micelles (PMs). Following cellular uptake, PMs first release LPC to significantly elevate the reactive oxidative species (ROS) level through NAD(P)H: quinone oxidoreductase-1 (NQO1) catalysis. Then, NQO1-generated ROS in combination with endogenous high ROS levels in tumor cells could synergistically facilitate PTX-S-LA to release the active cytotoxic agent PTX. Such a novel prodrug nanosystem exhibits self-strengthened prodrug bioactivation, ultraselective release, and cytotoxicity between cancer and normal cells, prolonged circulation time, and enhanced tumor accumulation, leading to high antitumor efficiency and superior biosafety. Our findings pave the new way for the rational design of oxidation-responsive prodrug NPs for high-efficacy cancer chemotherapy.

In vitro gastrointestinal digest of catechin-modified β-conglycinin oxidized by lipoxygenase-catalyzed linoleic acid peroxidation

The aim of the present study was to enhance oxidative stability and bioaccessibility of β-conglycinin (7S) prepared from low denatured defatted soybean flours with residual lipids and high lipoxygenase (LOX) activity. The model system consisting of linoleic acid (LA), LOX and unheated 7S (UH-7S)/heated 7S (H-7S) or UH-7S-catechin/H-7S-catechin complex, and in vitro gastrointestinal (GI) digestion model were used to investigate the effect of complexation with catechin on protein oxidation and characterisation of GI digest. The interaction of UH-7S/H-7S with catechin dramatically inhibited LOX-catalyzed LA peroxidation-induced protein oxidation. The interaction also promoted the degree of proteolysis in GI digestion and intestinal absorption for oxidized UH-7S/H-7S, increasing the antioxidant activity of oxidized UH-7S/H-7S, bioaccessibility for catechin and release of di-/tripeptides with dipeptidyl peptidase-IV/angiotensin converting enzyme inhibitory effects or antioxidant activities during GI digestion. The complexation with catechin is a potential strategy to enhance the oxidative stability, GI digestibility and bioaccessibility of 7S.

Preparation, Identification, and Activity Evaluation of Eight Antioxidant Peptides from Protein Hydrolysate of Hairtail (Trichiurus japonicas) Muscle

In this report, protein of hairtail (Trichiurus japonicas) muscle was separately hydrolyzed using five kinds of proteases (alcalase, trypsin, neutrase, pepsin, and papain), and the papain- and alcalase-hydrolysates showed higher 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH•) and hydroxyl radical (HO•) scavenging activity than other three protease hydrolysates. Therefore, the protein hydrolysate of hairtail muscle (HTP) was prepared using binary-enzymes hydrolysis process (papain + alcalase). Subsequently, eight antioxidant peptides were purified from HTP using membrane ultrafiltration and chromatography technology, and their amino acid sequences were identified as Gln-Asn-Asp-Glu-Arg (TJP1), Lys-Ser (TJP2), Lys-Ala (TJP3), Ala-Lys-Gly (TJP4), Thr-Lys-Ala (TJP5), Val-Lys (TJP6), Met-Lys (TJP7), and Ile-Tyr-Gly (TJP8) with molecular weights of 660.3, 233.0, 217.1, 274.1, 318.0, 245.1, 277.0, and 351.0 Da, respectively. TJP3, TJP4, and TJP8 exhibited strong scavenging activities on DPPH• (EC₅₀ 0.902, 0.626, and 0.663 mg/mL, respectively), HO• (EC₅₀ 1.740, 2.378, and 2.498 mg/mL, respectively), superoxide anion radical (EC₅₀ 2.082, 2.538, and 1.355 mg/mL, respectively), and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical (EC₅₀ 1.652, 0.831, and 0.586 mg/mL, respectively). Moreover, TJP3, TJP4, and TJP8 showed higher reducing power and inhibiting ability on lipid peroxidation in a linoleic acid model system. These results suggested that eight isolated peptides (TJP1 to TJP8), especially TJP3, TJP4, and TJP8 might serve as potential antioxidants applied in the pharmaceutical and health food industries.

Structure-Activity Relationship (SAR) of Phenolics for the Inhibition of 2-Phenylethylamine Formation in Model Systems Involving Phenylalanine and the 13-Hydroperoxide of Linoleic Acid

Lipid hydroperoxides have been shown to produce amino acid decarboxylations. Because thermal decomposition of lipid hydroperoxides produces free radicals and reactive carbonyls, and phenolic compounds have been shown to scavenger both of them, phenolics are expected to inhibit these reactions and this protection should depend on the structures of the involved phenolics. In this study, the effect of a wide array of phenolics and their mixtures on 2-phenylethylamine formation by phenylalanine degradation in the presence of the 13-hydroperoxide of linoleic acid (LOOH) was studied. LOOH increased considerably the formation of the amine, and phenolics mostly exhibiting an inhibitory role that depended on their structure. Thus, 1,3-diphenols decreased the formation of 2-phenylethylamine because of their carbonyl trapping abilities. In contrast, the inhibition of 1,2- and 1,4-diphenols was lower because they could not trap the reactive carbonyls produced by LOOH decomposition. In addition, their free radical scavenging was likely accompanied by the formation of quinones, which acted as reactive carbonyls. The function of all other phenolics could be calculated by adding the individual functions of the different diphenols present in their structures. In fact, experimental values obtained for both mixtures of phenolics and complex phenolics correlated well with the calculated values obtained from their constituting diphenols. All of these results suggest that, when the reaction mechanisms are known, it is possible to predict the behavior of complex phenolics on the basis of their structure.

Inhibitory effect and mechanism of linoleic acid sustained-release microspheres on Microcystis aeruginosa at different growth phases

Environment-friendly algaecides based on allelopathy have been extensively studied to control harmful algal blooms (HABs). The inhibitory effects of linoleic acid (LA) sustained-release microspheres on different cell densities of Microcystis aeruginosa (M. aeruginosa) at different growth phases were studied. The results showed that the growth of M. aeruginosa could be inhibited within 4 days and the constant inhibitory rate with initial algal density of 8 × 10⁵ cells∙mL^-1 (exponential phase) was up to 96% compared with control. The chlorophyll-a content in the treatment group had the same change trend with the algal density and declined significantly at day 20th, which suggested that the microspheres could promote the degradation of chlorophyll-a. The activities of superoxide dismutase (SOD) and catalase (CAT) increased gradually within 5 days but then declined sharply, which indicated that LA microspheres could cause oxidative damage to M. aeruginosa during the process of inhibition and reduce the activities of antioxidant enzymes. In addition, the concentration of oxygen free radical (O₂^-) increased at day 10th and rose constantly, and the content of malodialdehyde (MDA) increased to 2.7 times as much as control at day 20th. Furthermore, the content of protein, nucleic acid and the conductivity in culture solution showed a significant rise. These results showed that algal cell membrane lipid peroxidation occurred and the membrane permeability increased, accompanied by the damage of cell membrane. To sum up, the destruction of algal cell membrane is the main mechanism of LA microspheres inhibiting algal growth.

Changes in Soybean (Glycine max L.) Flour Fatty-Acid Content Based on Storage Temperature and Duration

Soybeans are low in saturated fat and a rich source of protein, dietary fiber, and isoflavone; however, their nutritional shelf life is yet to be established. This study evaluated the change in the stability and quality of fatty acids in raw and roasted soybean flour under different storage temperatures and durations. In both types of soybean flour, the fatty-acid content was the highest in the order of linoleic acid (18-carbon chain with two double bonds; C18:2), oleic acid (C18:1), palmitic acid (C16:0), linolenic acid (18:3), and stearic acid (C18:0), which represented 47%, 26%, 12%, 9%, and 4% of the total fatty-acid content, respectively. The major unsaturated fatty acids of raw soybean flour-oleic acid, linoleic acid, and linolenic acid-decreased by 30.0%, 94.4%, and 97.7%, and 38.0%, 94.8%, and 98.0% when stored in polyethylene and polypropylene film, respectively, after 48 weeks of storage under high-temperature conditions. These values were later increased due to hydrolysis. This study presents the changes in composition and content of two soybean flour types and the changes in quality and stability of fatty acids in response to storage temperature and duration. This study shows the influence of storage conditions and temperature on the nutritional quality which is least affected by packing material.