Phytoprostanes

Metabolites derived from radical oxidation of PUFA: NEO-PUFAs, promising molecules for health?

Oxidative stress plays a critical role in numerous pathological processes. Under these stress conditions, the free radical-catalyzed lipid peroxidation generates in vivo a large number of key products that are involved in many physiological and pathophysiological processes. Among these products are neuroprostanes, which arise from the peroxidation of docosahexaenoic acid (DHA), and isoprostanes, resulting from arachidonic acid (AA) and eicosapentaenoic acid (EPA) through the same peroxidation process. These non-enzymatic oxygenated metabolites newly appointed NEO-PUFAs have gained recognition as reliable markers of oxidative stress in neurogenerative and cardiovascular diseases. Moreover, some of them display a wide range of biological activities. The ability to detect and measure these metabolites offers precious insights into the mechanisms of oxidative damage and holds potential therapeutic implications for various health conditions, including neurodegenerative diseases. This review focuses on the role of neuroprostanes as biomarkers for oxidative stress and related diseases, highlighting their potential applications in medical research and treatment.

Stress-Induced Production of Bioactive Oxylipins in Marine Microalgae

Microalgae, stemming from a complex evolutionary lineage, possess a metabolic composition influenced by their evolutionary journey. They have the capacity to generate diverse polyunsaturated fatty acids (PUFAs), akin to those found in terrestrial plants and oily fish. Also, because of their numerous double bonds, these metabolic compounds are prone to oxidation processes, leading to the creation of valuable bioactive molecules called oxylipins. Moreover, owing to their adaptability across various environments, microalgae offer an intriguing avenue for biosynthesizing these compounds. Thus, modifying the culture conditions could potentially impact the profiles of oxylipins. Indeed, the accumulation of oxylipins in microalgae is subject to the influence of growth conditions, nutrient availability, and stressors, and adjusting these factors can enhance their production in microalgae culture. Consequently, the present study scrutinized the LC-MS/MS profiles of oxylipins from three marine microalgae species (two Haptagophytes and one Chlorophyte) cultivated in 1 L of photobioreactors under varying stress-inducing conditions, such as the introduction of H2O2, EtOAc, and NaCl, during their exponential growth phase. Approximately 50 oxylipins were identified, exhibiting different concentrations depending on the species and growth circumstances. This research suggests that microalgae metabolisms can be steered toward the production of bioactive oxylipins through modifications in the culture conditions. In this instance, the application of a low dose of hydrogen peroxide to Mi 124 appears to stimulate the production of nonenzymatic oxylipins. For Mi136, it is the application of salt stress that seems to increase the overall production of oxylipins. In the case of Mi 168, either a low concentration of H2O2 or a high concentration of AcOEt appears to have this effect.

Groundnut and tree nuts: a comprehensive review on their lipid components, phytochemicals, and nutraceutical properties

The health benefits of nut consumption have been extensively demonstrated in observational studies and intervention trials. Besides the high nutritional value, countless evidences show that incorporating nuts into the diet may contribute to health promotion and prevention of certain diseases. Such benefits have been mostly and certainly attributed not only to their richness in healthy lipids (plentiful in unsaturated fatty acids), but also to the presence of a vast array of phytochemicals, such as polar lipids, squalene, phytosterols, tocochromanols, and polyphenolic compounds. Thus, many nut chemical compounds apply well to the designation "nutraceuticals," a broad umbrella term used to describe any food component that, in addition to the basic nutritional value, can contribute extra health benefits. This contribution analyses the general chemical profile of groundnut and common tree nuts (almond, walnut, cashew, hazelnut, pistachio, macadamia, pecan), focusing on lipid components and phytochemicals, with a view on their bioactive properties. Relevant scientific literature linking consumption of nuts, and/or some of their components, with ameliorative and/or preventive effects on selected diseases - such as cancer, cardiovascular, metabolic, and neurodegenerative pathologies - was also reviewed. In addition, the bioactive properties were analyzed in the light of known mechanistic frameworks.

Wheat Oxylipins in Response to Aphids, CO2 and Nitrogen Regimes

Wheat is critical for food security, and is challenged by biotic stresses, chiefly aphids and the viruses they transmit. The objective of this study was to determine whether aphids feeding on wheat could trigger a defensive plant reaction to oxidative stress that involved plant oxylipins. Plants were grown in chambers with a factorial combination of two nitrogen rates (100% N vs. 20% N in Hoagland solution), and two concentrations of CO₂ (400 vs. 700 ppm). The seedlings were challenged with Rhopalosiphum padi or Sitobion avenae for 8 h. Wheat leaves produced phytoprostanes (PhytoPs) of the F₁ series, and three types of phytofurans (PhytoFs): ent-16(RS)-13-epi-ST-Δ¹⁴-9-PhytoF, ent-16(RS)-9-epi-ST-Δ¹⁴-10-PhytoF and ent-9(RS)-12-epi-ST-Δ¹⁰-13-PhytoF. The oxylipin levels varied with aphids, but not with other experimental sources of variation. Both Rhopalosiphum padi and Sitobion avenae reduced the concentrations of ent-16(RS)-13-epi-ST-Δ¹⁴-9-PhytoF and ent-16(RS)-9-epi-ST-Δ¹⁴-10-PhytoF in relation to controls, but had little or no effect on PhytoPs. Our results are consistent with aphids affecting the levels of PUFAs (oxylipin precursors), which decreased the levels of PhytoFs in wheat leaves. Therefore, PhytoFs could be postulated as an early indicator of aphid hosting for this plant species. This is the first report on the quantification of non-enzymatic PhytoFs and PhytoPs in wheat leaves in response to aphids.

Oxylipins and Reactive Carbonyls as Regulators of the Plant Redox and Reactive Oxygen Species Network under Stress

Reactive oxygen species (ROS), and in particular H2O2, serve as essential second messengers at low concentrations. However, excessive ROS accumulation leads to severe and irreversible cell damage. Hence, control of ROS levels is needed, especially under non-optimal growth conditions caused by abiotic or biotic stresses, which at least initially stimulate ROS synthesis. A complex network of thiol-sensitive proteins is instrumental in realizing tight ROS control; this is called the redox regulatory network. It consists of sensors, input elements, transmitters, and targets. Recent evidence revealed that the interplay of the redox network and oxylipins–molecules derived from oxygenation of polyunsaturated fatty acids, especially under high ROS levels–plays a decisive role in coupling ROS generation and subsequent stress defense signaling pathways in plants. This review aims to provide a broad overview of the current knowledge on the interaction of distinct oxylipins generated enzymatically (12-OPDA, 4-HNE, phytoprostanes) or non-enzymatically (MDA, acrolein) and components of the redox network. Further, recent findings on the contribution of oxylipins to environmental acclimatization will be discussed using flooding, herbivory, and establishment of thermotolerance as prime examples of relevant biotic and abiotic stresses.

Acute and Rapid Response of Melissa officinalis and Mentha spicata to Saline Reclaimed Water in Terms of Water Relations, Hormones, Amino Acids and Plant Oxylipins

The use of reclaimed water is considered an efficient tool for agricultural irrigation; however, the high salinity associated to this water could compromise plant quality and yields. Balm and spearmint plants were submitted for 15 days to three irrigation treatments in a controlled chamber: control with EC: 1.2 dS m^-1 (control), reclaimed water from secondary effluent (EC: 1.6 dS m^-1) (S) and water from secondary effluent with brine (EC: 4.4 dS m^-1) (SB). The plant water status, stomatal and hormonal regulation, nutritional response, concentration of amino acids and plant oxidative stress-based markers, as well as growth were evaluated. Both species irrigated with saline reclaimed water reduced leaf water potential and gas exchange in comparison with control plants, following 2 days of exposure to irrigation treatments. Nevertheless, spearmint plants recovered photosynthetic activity from the seventh day onwards, maintaining growth. This was attributed to hormonal changes and a greater accumulation of some amino acids and some plant oxylipins (phytoprostanes) in comparison to balm plants, which contributed to the improvement in the organoleptic and health-promoting properties of spearmint. A longer irrigation period with saline reclaimed water would be necessary to assess whether the quality of both species, especially spearmint, could further improve without compromising their growth.

First Total Synthesis of Phytoprostanes with Prostaglandin-Like Configuration, Evidence for Their Formation in Edible Vegetable Oils and Orienting Study of Their Biological Activity

Phytoprostanes (PhytoP) are natural products, which form in plants under oxidative stress conditions from α-linolenic acid. However, their epimers with relative prostaglandin configuration termed phytoglandins (PhytoG) have never been detected in Nature, likely because of the lack of synthetic reference material. Here, the first asymmetric total synthesis of such compounds, namely of PhytoGF_1α (9-epi-16-F_1t -PhytoP) and its diastereomer ent-16-epi-PhytoGF_1α (ent-9,16-diepi-16-F_1t -PhytoP), has been accomplished. The synthetic strategy is based on radical anion oxidative cyclization, copper(I)-mediated alkyl-alkyl coupling and enantioselective reduction reactions. A UHPLC-MS/MS study using the synthesized compounds as standards indicates PhytoG formation at significant levels during autoxidation of α-linolenic acid in edible vegetable oils. Initial testing of synthetic PhytoGs together with F₁ -PhytoP and 15-F_2t -IsoP derivatives for potential interactions with the PGF_2α (FP) receptor did not reveal significant activity. The notion that PUFA-derived oxidatively formed cyclic metabolites with prostaglandin configuration do not form to a significant extent in biological or food matrices has to be corrected. Strong evidence is provided that oxidatively formed PhytoG metabolites may be ingested with plant-derived food, which necessitates further investigation of their biological profile.

Bioavailable phytoprostanes and phytofurans from Gracilaria longissima have anti-inflammatory effects in endothelial cells

BACKGROUND

An array of bioactive compounds with health-promoting effects has been described in several species of macroalgae. Among them, phytoprostanes (PhytoPs) and phytofurans (PhytoFs), both autoxidation products of α-linolenic acid, have been seen to exert immunomodulatory and antiinflammatory activities in vitro. The purpose of this study was to explore the bioaccesibility, bioavailability, and bioactivity of PhytoPs and PhytoFs obtained from the edible red algae Gracilaria longissima, and to gain insight into the anti-inflammatory activity of their bioavailable fraction in human endothelial cells.

METHODS

The PhytoPs and PhytoFs profile and concentration of G. longissima were determined by UHPLC-QqQ-MS/MS. Algal samples were processed following a standardised digestion method including gastric, intestinal, and gastrointestinal digestion. The bioavailability of the PhytoPs and PhytoFs in the characterized fractions was assessed in a Caco-2 cell monolayer model of the intestinal barrier. The inflammation response of these prostaglandin-like compounds in human endothelial cells, after intestinal absorption, was investigated in vitro.

RESULTS

Simulated digestions significantly reduced the concentration of PhytoPs and PhytoFs up to 1.17 and 0.42 μg per 100 g, respectively, on average, although permeability through the Caco-2 cell monolayer was high (up to 88.2 and 97.7%, on average, respectively). PhytoP and PhytoF-enriched extracts of raw algae impaired the expression of ICAM-1 and IL-6 inflammation markers. The inflammation markers progressed in contrast to the relative concentrations of bioactive oxylipins, suggesting pro- or anti-inflammatory activity on their part. In this aspect, the cross-reactivity of these compounds with diverse receptors, and their relative concentration could explain the diversity of the effects found in the current study.

CONCLUSIONS

The results indicate that PhytoPs and PhytoFs display complex pharmacological profiles probably mediated through their different actions and affinities in the endothelium.

Chemical and biological properties of cocoa beans affected by processing: a review

Cocoa (Theobroma cacao L.) is widely cultivated in tropical countries. The cocoa beans are a popular ingredient of confectionery. Cocoa beans contain various chemicals that contribute to their bioactivity and nutritional properties. There has been increasing interest in developing cocoa beans for "healthy" food products. Cocoa beans have special combination of nutrients such as lipids, carbohydrates, proteins and other compounds of biological activities. The bioactive phytochemicals include methylxanthines, polyphenols, biogenic amines, melanoidins, isoprostanoids and oxalates. These phytochemicals of cocoa are related to various in vivo and in vitro biological activities such as antioxidation, anti-cancer, anti-microbial, anti-inflammation, anti-diabetes, cardiovascular protection, physical improvement, anti-photoaging, anti-depression and blood glucose regulation. The potential of bioactive compounds in cocoa remains to be maximized for food and nutritional applications. The current processing technology promotes the degradation of beneficial bioactive compounds, while maximizing the flavors and its precursors. It is not optimized for the utilization of cocoa beans for "healthy" product formulations. Modifications of the current processing line and non-conventional processing are needed to better preserve and utilize the beneficial bioactive compounds in cocoa beans.

Phytoprostanes and phytofurans modulate COX-2-linked inflammation markers in LPS-stimulated THP-1 monocytes by lipidomics workflow

Inflammation is a fundamental pathophysiological process which occurs in the course of several diseases. The present work describes the capacity of phytoprostanes (PhytoPs) and phytofurans (PhytoFs) (plant oxylipins), present in plant-based foods, to modulate inflammatory processes mediated by prostaglandins (PGs, human oxylipins) in lipopolysaccharide (LPS)-stimulated THP-1 monocytic cells, through a panel of 21 PGs and PG's metabolites, analyzed by UHPLC-QqQ-ESI-MS/MS. Also, the assessment of the cytotoxicity of PhytoPs and PhytoFs on THP-1 cells evidenced percentages of cell viability higher than 90% when treated with up to 100 μM. Accordingly, 50 μM of the individual PhytoPs and PhytoFs 9-F_1t-PhytoP, 9-epi-9-F_1t-PhytoP, ent-16-F_1t-PhytoP, ent-16-epi-16-F_1t-PhytoP, ent-9-D_1t-PhytoP, 16-B₁-PhytoP, 9-L₁-PhytoP, ent-16(RS)-9-epi-ST-Δ¹⁴-10-PhytoF, ent-9(RS)-12-epi-ST-Δ¹⁰-13-PhytoF, and ent-16(RS)-13-epi-ST-Δ¹⁴-9-PhytoF were evaluated on their capacity to modulate the expression of inflammatory markers. The results obtained demonstrated the presence of 7 metabolites (15-keto-PGF_2α, PGF_2α, 11β-PGF_2α, PGE₂, PGD₂, PGDM, and PGF_1α) in THP-1 monocytic cells, which expression was significantly modulated when exposed to LPS. The evaluation of the capacity of the individual PhytoPs and PhytoFs to revert the modification of the quantitative profile of PGs induced by LPS revealed the anti-inflammatory ability of 9-F_1t-PhytoP, ent-9-D_1t-PhytoP, 16-B₁-PhytoP, 9-L₁-PhytoP, and ent-9(RS)-12-epi-ST-Δ¹⁰-13-PhytoF, as evidenced by their capacity to prevent the up-regulation of 15-keto-PGF_2α, PGF_2α, PGE₂, PGF_1α, PGDM, and PGD₂ induced by LPS. These results indicated that specific plant oxylipins can protect against inflammatory events, encouraging further investigations using plant-based foods rich in these oxylipins or enriched extracts, to identify specific bioactivities of the diverse individual molecules, which can be useful for nutrition and health in the frame of well-defined pathophysiological processes.

Evaluation of Phoenix dactylifera Edible Parts and Byproducts as Sources of Phytoprostanes and Phytofurans

Even though traditionally date-fruit has been featured by a marginal use, mainly restricted to its dietary intake, in recent years, it has raised the range of applications for this agro-food production. These new uses have entailed an enlarged production of date fruits and, simultaneously, of date palm byproducts. Encouraged by the traditional medicinal uses of dates, according to their phytochemical composition, the present work was focused on the evaluation of a new family of secondary metabolites, the plant oxylipins phytoprostanes (PhytoPs) and phytofurans (PhytoFs), in six separate matrixes of the date palm edible parts and byproducts, applying an UHPLC-ESI-QqQ-MS/MS-based methodology. The evaluation for the first time of date palm edible parts and byproducts as a dietary source of PhytoPs and PhytoFs provides evidence on the value of six different parts (pulp, skin, pits, leaves, clusters, and pollen) regarding their content in these plant oxylipins evidenced by the presence of the PhytoPs, 9-F_1t-PhytoP (201.3-7223.1 ng/100 g dw) and 9-epi-9-F_1t-PhytoP (209.7-7297.4 ng/100 g dw), and the PhytoFs ent-16(RS)-9-epi-ST-Δ¹⁴-10-PhytoF (4.6-191.0 ng/100g dw), and ent-16(RS)-13-epi-ST-Δ¹⁴-9-PhytoF as the most abundant compounds. Regarding the diverse matrixes assessed, pollen, clusters, and leaves for PhytoPs and skins and pollen for PhytoFs were identified as the most interesting sources of these compounds. In this concern, the information obtained upon the detailed characterization performed in the present work will allow unravelling the biological interest of PhytoPs and PhytoFs and the extent to which these compounds could exert valuable biological activities upon in vitro (mechanistic) and in vivo studies, allocating the effort-focus on the chemical species of PhytoPs and PhytoFs responsible for such traits.

Effects of Deficit Irrigation, Rootstock, and Roasting on the Contents of Fatty Acids, Phytoprostanes, and Phytofurans in Pistachio Kernels

Pistachio (Pistacia vera L.) is a drought-tolerant species grown under the semiarid conditions of the Mediterranean basin. For this reason, it is essential to make an exhaustive quantification of yield and quality benefits of the kernels because the regulated deficit irrigation will allow significant water savings with a minimum impact on yield while improving kernel quality. The goal of this scientific work was to study the influence of the rootstock, water deficit during pit hardening, and kernel roasting on pistachio (P. vera, cv. Kerman) fruit yield, fruit size, and kernel content of fatty acids phytoprostanes (PhytoPs) and phytofurans (PhytoFs) for the first time. Water stress during pit hardening did not affect the pistachio yield. The kernel cultivar showed a lower oleic acid and a higher linoleic acid contents than other cultivars. Kernels from plants grafted on the studied rootstocks showed very interesting characteristics. P. integerrima led to the highest percentage of monounsaturated fatty acids. Regarding the plant oxylipins, P. terebinthus led to the highest contents of PhytoPs and PhytoFs (1260 ng/100 g and 16.2 ng/100 g, respectively). In addition, nuts from trees cultivated under intermediate water deficit during pit hardening showed increased contents of the 9-series F₁-phytoprostanes and ent-16(RS)-9-epi-ST-Δ¹⁴-10-phytofuran. However, roasting of pistachios led to PhytoP degradation. Therefore, plant cultivar, deficit irrigation, rootstock, and roasting must be considered to enhance biosynthesis of these secondary metabolites. New tools using agricultural strategies to produce hydroSOS pistachios have been opened thanks to the biological properties of these prostaglandin-like compounds linking agriculture, nutrition, and food science technology for further research initiatives.

Phytoprostanes and Phytofurans-Oxidative Stress and Bioactive Compounds-in Almonds are Affected by Deficit Irrigation in Almond Trees

Almonds have gained consumers' attention due to their health benefits (they are rich in bioactive compounds) and sensory properties. Nevertheless, information about phytoprostanes (PhytoPs) and phytofurans (PhytoFs) (new plant markers of oxidative stress and compounds with biological properties for human health) in almonds under deficit irrigation is scarce or does not exist. These compounds are plant oxylipins synthesized by the oxidation of α-linolenic acid (ALA). Besides, they are biomarkers of plant oxidative degradation and biologically active molecules involved in several plant defense mechanisms. hydroSOStainable or hydroSOS mean plant foods made from from plants under controlled water stress. Almonds are a good source of polyunsaturated fatty (PUFAs) acids, including a high content of ALA. This paper aimed to describe the influence of diverse irrigation treatments on in vitro anti-oxidant activity (AAc) and total phenolic content (TPC), as well as on the level of ALA, PhytoP, and PhytoF in "Vairo" almonds. The AAc and TPC were not affected by the irrigation strategy, while the in vivo oxidative stress makers, PhytoPs and PhytoFs, exhibited significant differences in response to water shortage. The total PhytoP and PhytoF contents ranged from 4551 to 8151 ng/100 g dry weight (dw) and from 33 to 56 ng/100 g dw, respectively. The PhytoP and PhytoF profiles identified in almonds showed significant differences among treatments. Individual PhytoPs and PhytoFs were present above the limit of detection only in almonds obtained from trees maintained under deficit irrigation (DI) conditions (regulated deficit irrigation, RDI, and sustained deficit irrigation, SDI) but not in control almonds obtained from fully irrigated trees. Therefore, these results confirm PhytoPs and PhytoFs as valuable biomarkers to detect whether an almond-based product is hydroSOStainable. As a final conclusion, it can be stated that almond quality and functionality can be improved and water irrigation consumption can be reduced if controlled DI strategies are applied in almond orchards.

Optimization of Free Phytoprostane and Phytofuran Production by Enzymatic Hydrolysis of Pea Extracts Using Esterases

Given the growing interest in phytoprostanes (PhytoPs) and phytofurans (PhytoFs) in the fields of plant physiology, biotechnology, and biological function, the present study aims to optimize a method of enzymatic hydrolysis that utilizes bacterial and yeast esterases that allow the appropriate quantification of PhytoPs and PhytoFs. To obtain the highest concentration of PhytoPs and PhytoFs, a response surface methodology/Box-Behnken design was used to optimize the hydrolysis conditions. Based on the information available in the literature on the most critical parameters that influence the activity of esterases, the three variables selected for the study were temperature (°C), time (min), and enzyme concentration (%). The optimal hydrolysis conditions retrieved differed between PhytoPs (21.5 °C, 5.7 min, and 0.61 μg of enzyme per reaction) and PhytoFs (20.0 °C, 5.0 min, and 2.17 μg of enzyme per reaction) and provided up to 25.1- and 1.7-fold higher contents relative to nonhydrolyzed extracts. The models were validated by comparing theoretical and experimental values for PhytoP and PhytoF yields (1.01 and 1.06 theoretical/experimental rates, respectively). The optimal conditions were evaluated for their relative influence on the yield of individual nonesterified PhytoPs and PhytoFs to define the limitations of the models for obtaining the highest concentration of most considered compounds. In conclusion, the models developed provided valuable alternatives to the currently applied methods using unspecific alkaline hydrolysis to obtain free nonesterified PhytoPs and PhytoFs, which give rise to more specific hydrolysis of PhytoP and PhytoF esters, reducing the degradation of free compounds by classical chemical procedures.

Potential of Physalis peruviana calyces as a low-cost valuable resource of phytoprostanes and phenolic compounds

BACKGROUND

In Colombia, agro-industrial residues represent an enormous economic and environmental problem, which could be reduced if different techniques for the addition of value to such residues were implemented by this industrial sector. One of the fruits with the highest export rates is Physalis peruviana (goldenberry); however, this fruit is generally marketed without its calyx, generating a large amount of residues. To develop a strategy to add value to these residues, it is essential to know their chemical composition.

RESULTS

In the present work, phytoprostanes (PhytoPs) - new active oxylipins - have been detected for the first time in Physalis peruviana calyces by ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS), F_1t -phytoprostanes and D_1t -phytoprostanes being the predominant and minor classes, respectively. In addition, we were able to characterize the phenolic compounds profile of this matrix using LC-IT-DAD-MS/MS, describing six phenolic derivatives for the first time therein.

CONCLUSIONS

This study increases our knowledge of the chemical composition of the calyces of this fruit and thereby supports the recycling of this class of residue. Consequently, goldenberry calyces could be used as phytotherapeutic, nutraceutic, or cosmetic ingredients for the development of diverse natural products. © 2018 Society of Chemical Industry.

Statement of Foliar Fertilization Impact on Yield, Composition, and Oxidative Biomarkers in Rice

In rice crops, fertilization is a naturalized practice, although inefficient, that could be improved by applying foliar fertilization. Phytoprostanes (PhytoPs) and phytofurans (PhytoFs) are products of α-linolenic acid peroxidation, useful as biomarkers of oxidative degradation in higher plants. The objective was to determine the effect of the foliar fertilization on the concentration of PhytoPs and PhytoFs and its relationships with modifications of yield and quality of rice productions. It was described that the concentration of biomarkers of stress decreased with the application of foliar fertilization, being the response significantly different depending the genotypes and compound monitored. Moreover, fertilization did not modify significantly the parameters of yield (961.2 g m^-2), 1000 whole-grain (21.2 g), and protein content (10.7% dry matter). Therefore, this is the first work that describes the effect of fertilization on PhytoPs and PhytoFs in rice genotypes and reinforces the capacity of these compounds as biomarkers to monitor specific abiotic stress, in this case, represented by nutritional stress.

Impact of Salicylic Acid Content and Growing Environment on Phytoprostane and Phytofuran (Stress Biomarkers) in Oryza sativa L

Phytoprostanes (PhytoPs) and phytofurans (PhytoFs) are oxylipins synthesized by nonenzymatic peroxidation of α-linolenic acid. These compounds are biomarkers of oxidative degradation in plant foods. In this research, the effect of environment and supplementation with salicylic acid (SA) on PhytoPs and PhytoFs was monitored by ultra-high-performance liquid chromatography coupled to electrospray ionization and triple quadrupole mass spectrometry (UHPLC-ESI-QqQ-MS/MS) on seven rice genotypes from Oryza sativa L. subsp. japonica. The plastic cover environment and spray application with 1 and 15 mM SA produced a reduction in the concentration of most of these newly established stress biomarkers [9-F_1t-PhytoP, ent-16-F_1t-PhytoP, ent-16- epi-16-F_1t-PhytoP, 9-D_1t-PhytoP, 9- epi-9-D_1t-PhytoP, 16-B₁-PhytoP, 9-L₁-PhytoP, ent-16( RS)-9- epi-ST-Δ¹⁴-10-PhytoF, ent-9( RS)-12- epi-ST-Δ¹⁰-13-PhytoF, and ent-16( RS)-13- epi-ST-Δ¹⁴-9-PhytoF] by 60.7% on average. The modification observed in the level of PhytoPs and PhytoFs differed according to the specific oxylipins and genotype, demonstrating a close linkage between genetic features and resistance to abiotic stress, to some extent mediated by the sensitivity of plants to the plant hormone SA that participates in the physiological response of higher plants to stress. Thus, in plants exposed to stressing factors, SA contribute to modulating the redox balance, minimizing the oxidation of fatty acids and thus the syntheis of oxylipins. These results indicated that SA could be a promising tool for managing the thermotolerance of rice crop. However, it remains necessary to study the mechanism of action of PhytoPs and PhytoFs in biochemical processes related to the defense of plants and define their role as stress biomarkers through a nonenzymatic pathway.

Structural/Functional Matches and Divergences of Phytoprostanes and Phytofurans with Bioactive Human Oxylipins

Structure-activity relationship (SAR) constitutes a crucial topic to discover new bioactive molecules. This approach initiates with the comparison of a target candidate with a molecule or a collection of molecules and their attributed biological functions to shed some light in the details of one or more SARs and subsequently using that information to outline valuable application of the newly identified compounds. Thus, while the empiric knowledge of medicinal chemistry is critical to these tasks, the results retrieved upon dedicated experimental demonstration retrieved resorting to modern high throughput analytical approaches and techniques allow to overwhelm the constraints adduced so far to the successful accomplishment of such tasks. Therefore, the present work reviews critically the evidences reported to date on the occurrence of phytoprostanes and phytofurans in plant foods, and the information available on their bioavailability and biological activity, shedding some light on the expectation waken up due to their structural similarities with prostanoids and isoprostanes.

Total syntheses of all tri-oxygenated 16-phytoprostane classes via a common precursor constructed by oxidative cyclization and alkyl-alkyl coupling reactions as the key steps

A unified strategy for the total synthesis of the methyl esters of all phytoprostane (PhytoP) classes bearing two ring-oxygen atoms based on an orthogonally protected common precursor is described. Racemic 16-F_1t-, 16-E₁-PhytoP and their C-16 epimers, which also occur as racemates in Nature, were successfully obtained. The first total synthesis of very sensitive 16-D_1t-PhytoP succeeded, however, it quickly isomerized to more stable, but so far also unknown Δ¹³-16-D_1t-PhytoP, which may serve as a more reliable biomarker for D-type PhytoP. The dioxygenated cyclopentane ring carrying the ω-chain with the oxygen functionality in the 16-position was approached by a radical oxidative cyclization mediated by ferrocenium hexafluorophosphate and TEMPO. The α-chain was introduced by a new copper-catalyzed alkyl-alkyl coupling of a 6-heptenyl Grignard reagent with a functionalized cyclopentylmethyl triflate.

Comparative Study of the Phytoprostane and Phytofuran Content of indica and japonica Rice (Oryza sativa L.) Flours

Phytoprostanes and phytofurans (PhytoPs and PhytoFs, respectively) are nonenzymatic lipid peroxidation products derived from α-linolenic acid (C18:3 n-3), considered biomarkers of oxidative degradation in plant foods. The present work profiled these compounds in white and brown grain flours and rice bran from 14 rice cultivars of the subspecies indica and japonica by ultrahigh performance liquid chromatography coupled to electrospray ionization and triple quadrupole mass spectrometry. For PhytoPs, the average concentrations were higher in rice bran (0.01-9.35 ng g^-1) than in white and brown grain flours (0.01-1.17 ng g^-1). In addition, the evaluation of rice flours for the occurrence PhytoFs evidenced average values 1.77, 4.22, and 10.30 ng g^-1 dw in rice bran, brown grain flour, and white grain flour, respectively. A significant correlation was observed between total and individual compounds. The concentrations retrieved suggest rice bran as a valuable source of PhytoPs and PhytoFs that should be considered in further studies on bioavailability and bioactivity of such compounds.

Assessment of Isoprostanes in Human Plasma: Technical Considerations and the Use of Mass Spectrometry

Oxygenated lipid mediators released from non-enzymatic peroxidation of polyunsaturated fatty acids (PUFA) are known to have functional roles in humans. Notably, among these lipid mediators, isoprostanes molecules are robust biomarkers of oxidative stress but those from n-3 PUFA are also bioactive molecules. In order to identify and assess the isoprostanes, the use of mass spectrometry (MS) for analysis is preferable and has been used for over two decades. Gas chromatography (GC) is commonly coupled to the MS to separate the derivatized isoprostanes of interest in biological samples. In order to increase the accuracy of the analytical performance, GC-MS/MS was also applied. Lately, MS or MS/MS has been coupled with high-performance liquid chromatography to assess multiple isoprostane molecules in a single biological sample without derivatization process. However, there are limitations for the use of LC-MS/MS in the measurement of plasma isoprostanes, which will be discussed in this review.

Effect of the season on the free phytoprostane content in Cornicabra extra virgin olive oil from deficit-irrigated olive trees

BACKGROUND

The effect of regulated deficit irrigation (RDI) on the phytoprostane (PhytoP) content in extra virgin olive (Olea europaea L., cv. Cornicabra) oil (EVOO) was studied. During the 2012 and 2013 seasons, T0 plants were irrigated at 100% ETc, while T1 and T2 plants were irrigated avoiding water deficit during phases I and III of fruit growth and saving water during the non-critical phenological period of pit hardening (phase II), developing a more severe water deficit in T2 plants. In 2013, a fourth treatment (T3) was also performed, which was similar to T2 except that water saving was from the beginning of phase II to 15 days after the end of phase II.

RESULTS

9-F1t -PhytoP, 9-epi-9-F1t -PhytoP, 9-epi-9-D1t -PhytoP, 9-D1t -PhytoP, 16-B1 -PhytoP and 9-L1 -PhytoP were present in Cornicabra EVOO, and their contents increased in the EVOO from RDI plants.

CONCLUSION

Deficit irrigation during pit hardening or for a further period of 2 weeks thereafter to increase irrigation water saving is clearly critical for EVOO composition because of the enhancement of free PhytoPs, which have potential beneficial effects on human health. The response of individual free PhytoPs to changes in plant water status was not as perceptible as expected, preventing their use as biomarkers of water stress.

Biologically Active Oxylipins from Enzymatic and Nonenzymatic Routes in Macroalgae

Marine algae are rich and heterogeneous sources of great chemical diversity, among which oxylipins are a well-recognized class of natural products. Algal oxylipins comprise an assortment of oxygenated, halogenated, and unsaturated functional groups and also several carbocycles, varying in ring size and position in lipid chain. Besides the discovery of structurally diverse oxylipins in macroalgae, research has recently deciphered the role of some of these metabolites in the defense and innate immunity of photosynthetic marine organisms. This review is an attempt to comprehensively cover the available literature on the chemistry, biosynthesis, ecology, and potential bioactivity of oxylipins from marine macroalgae. For a better understanding, enzymatic and nonenzymatic routes were separated; however, both processes often occur concomitantly and may influence each other, even producing structurally related molecules.

Dependency of Phytoprostane Fingerprints of Must and Wine on Viticulture and Enological Processes

Wine is one of the most consumed alcoholic beverages around the world. Red wine has demonstrated several benefits for health maintenance. One group of potential anti-inflammatory compounds is the phytoprostanes, oxidative degradation products of linolenic acid. The aim of the present study was to measure, for the first time, the phytoprostane content in wine and must by an UHPLC-QqQ-MS/MS method after solid-phase extraction. The data showed two predominant classes of phytoprostanes: F1- and D1-phytoprostane series. In wines, the total phytoprostane concentration ranged from 134.1 ± 2.3 to 216.2 ± 3.06 ng/mL. Musts showed concentrations between 21.4 ± 0.8 and 447.1 ± 15.8 ng/mL. The vinification and aging procedures for the production of wine seem to influence the final phytoprostane levels in red wine and to modify the phytoprostane profile. The high concentrations observed and previous reports on anti-inflammatory effects of phytoprostanes make further research on the benefits of phytoprostanes more important.

Phytoprostanes in almonds: identification, quantification, and impact of cultivar and type of cultivation

The phytoprostane profile in 11 almonds cvs varied greatly according to the genotype and several factors (agricultural system conventional or ecological and irrigation).