Academic literature on the topic 'Phenolic acids – Physiological effect'

Salinity is a major abiotic stress negatively affecting plant growth and consequently crop production. The effects of short-term salt stress were evaluated on seedlings of three globally important Brassica crops—Chinese cabbage (Brassica rapa ssp. pekinensis), white cabbage (Brassica oleracea var. capitata), and kale (Brassica oleracea var. acephala)—with particular focus on phenolic acids. The physiological and biochemical stress parameters in the seedlings and the levels of three main groups of metabolites (total glucosinolates, carotenoids, and phenolics) and individual phenolic acids were determined. The salt treatments caused a dose-dependent reduction in root growth and biomass and an increase in stress parameters (Na+/K+ ratio, reactive oxygen species (ROS) and glutathione (GSH)) in all seedlings but most prominently in Chinese cabbage. Based on PCA, specific metabolites grouped close to the more tolerant species, white cabbage and kale. The highest levels of phenolic acids, particularly hydroxycinnamic acids, were determined in the more tolerant kale and white cabbage. A reduction in caffeic, salicylic, and 4-coumaric acid was found in Chinese cabbage and kale, and an increase in ferulic acid levels was found in kale upon salinity treatments. Phenolic acids are species-specific among Brassicaceae, and some may participate in stress tolerance. Salt-tolerant varieties have higher levels of some phenolic acids and suffer less from metabolic stress disorders under salinity stress.

NaCl stress causes oxidative stress in plants; γ-aminobutyric acid (GABA) could alleviate such abiotic stress by enhancing the synthesis of phenolics, but the underlying mechanism is not clear. We investigated the effects of GABA on phenolics accumulation in soybean sprouts under NaCl stress by measuring changes in the content of physiological biochemicals and phenolic substances, in the activity and gene expression of key enzymes, and in antioxidant capacity. GABA reduced the oxidative damage in soybean sprouts caused by NaCl stress and enhanced the content of total phenolics, phenolic acids, and isoflavones by 16.58%, 22.47%, and 3.75%, respectively. It also increased the activities and expression of phenylalanine ammonia lyase, cinnamic acid 4-hydroxylase, and 4-coumarate coenzyme A ligase. Furthermore, GABA increased the activity of antioxidant enzymes and the antioxidant capacity. These events were inhibited by 3-mercaptopropionate (an inhibitor for GABA synthesis), indicating that GABA mediated phenolics accumulation and antioxidant system enhancement in soybean sprouts under NaCl stress.

In México, around 82% of the total production of maize is grown under rainfed conditions leading to a water stress environment which affects physiologic and biochemical process of the plant. Maize bran is a composited plant material consisting mainly in aleurone layer, testa and pericarp; the cell walls of these tissues are composed of proteins, non-starch polysaccharides, phenolic acids and lignin which are potential bioactive substances for human nutrition. In this research it was investigated the effect of water stress on cell wall components in the bran of three genotypes of maize by applying irrigation and water stress treatments. The content of protein, lignin, arabinoxylans, total phenols and phenolic acids was performed in the bran of ʽCebúʼ, ʽDK2027ʼ and ʽDK2034ʼ genotypes. Water stress applied through grain development stage increased protein levels of ʽCebúʼ, ʽDK2027ʼ and ʽDK2034ʼ in 4.05, 16.13 and 0.40% respectively. Respecting to lignin content, water stress increased levels at 1.28, 2.26 and 4.24% for ʽCebúʼ, ʽDK2027ʼ and ʽDK2034ʼ, respectively. Arabinoxylans content also increased in water stress treatment at levels of 1.28, 2.26 and 3.66% in ʽCebúʼ, ʽDK2027ʼ and ʽDK2034ʼ. On the other hand, water stress treatment decreased the levels of total phenols and hydroxycinnamic acids in the three maize hybrids analysed. Reduction of total phenols was 35.34, 5.59 and 31.57% for ʽCebúʼ, ʽDK2027ʼ and ʽDK2034ʼ, respectively. In addition, the levels of t-ferulic, c-ferulic and p-coumaric acids decreased 17.74, 23.93, 29.83% in ʽCebúʼ, 8.92, 8.62, 24.03% in ʽDK2027ʼ and 13.66, 11.03, 10.38% in ʽDK2034ʼ respectively.

AbstractThe aim of the present study was the evaluation of the antioxidant content in phenolic and non-phenolic extracts of ten wine samples, trying to elucidate the potential role of unusual antioxidant compounds. Samples of wines processed from red and white grapes (Vitis vinifera L.), deprived of the volatile fraction at low temperature and buffered at physiological pH, were fractionated by C18 into two fractions: FR1 and FR2. Non-phenolics, such as tartaric, malic, lactic, and succinic acids; glucose; fructose; and glycerin were mainly found in FR1, while polyphenols were present exclusively in FR2. Peroxyl radical quenching was assayed by the ORAC method, while superoxide and hydroxyl radical scavenging activity were assayed by electron paramagnetic resonance. In the ORAC and superoxide assays, most of the activity was found in FR2, while in hydroxyl radical assay, the activity was found in FR1. Model solutions were used to attribute a role to the single compounds in the evaluation of wine’s ROS scavenging capacity: the ORAC and superoxide anion scavenging effects were mainly attributed to the polyphenols, averaging 94.8%, with some contribution from glycerin, particularly in white wines. Unexpectedly, the main chemical responsible for hydroxyl radical scavenging activity was glycerin (56.1%), with the polyphenols scavenging at 18.1%.

Phaeocystis globosa is regarded as a notoriously harmful algal bloom species. Suppressing harmful algae using algicidal substances extracted from plants is considered an effective method. The physiological and biochemical processes of P. globosa were explored by exposure to different concentrations of aqueous extracts of Cyperus rotundus. All treatments indicated various inhibitory effects on the algal growth compared to the control samples without adding extracts. At 48 h, the 4, 8, and 16 mg/mL treatment groups showed a significant inhibitory effect, consistent with a decrease in the chlorophyll-a content and photosynthetic efficiency. The images of the transmission electron microscope (TEM) further confirmed that a subset of the cells in the treatment groups exhibited morphological anomalies. The algicidal active substances were mainly identified as phenolic acids containing maximal content of quinic acid in aqueous extracts according to the results of ultra-high-performance liquid chromatography-tandem time-of-flight mass spectrometer (UPLC-HRMS). The 50% anti-algal effect concentration of quinic acid was 22 mg/L at 96 h (EC50–96h). Thus, the phenolic acids might be considered as major inhibitors of the growth of P. globosa. These results demonstrated that the aqueous extracts of C. rotundus could potentially control the growth of P. globosa.

In the present study, an in vitro digestion method has been used to assay the influence of the physiological conditions in the mouth, stomach, and intestine on the stability and activity in different cell models of the main phenolic compounds from Viburnum opulus fresh juice (FJ), phenolic-rich juice (PJ), and the bioavailable fractions (DFJ and DPJ). The data obtained indicate that the V. opulus samples achieved after in vitro digestion had an influence on cellular glucose and lipid metabolism. The bioavailable fraction of both digested juices stimulated glucose uptake and decreased lipid accumulation by L6 myoblasts and HepG2 hepatocytes. Both DFJ and DPJ reduced the secretion of inflammatory cytokines by 3T3-L1 adipocytes: interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Simultaneously, DFJ and DPJ enhanced oxidative stress in MIN6 cells and decreased glucose-stimulated insulin secretion (GSIS). UPLC–MS analysis revealed qualitative and quantitative changes in hydroxycinnamic acids. In particular, the content of chlorogenic acid decreased drastically; its content in the bioavailable fraction was almost 7 times and 30 times lower than in the FJ and PJ, respectively. Our results suggested that although the phenolic compounds of V. opulus juices undergo transformation during digestion, they are still potent antioxidant agents with biological activity.

Functional drinks are intended for systematic consumption as part of food rations; they preserve and improve health, as well as reduce the risk of developing certain diseases. Functional drinks contain ingredients that have the ability to have a positive effect on physiological functions and metabolic processes in the human body. The functional ingredients of alcohol-free beverages are: vitamins, macro- and microelements, dietary fiber, organic acids, phenolic and other compounds. Functional drinks include non-alcoholic energy drinks, fortified juices and sports drinks, therapeutic and therapeutic-table mineral waters.

Plants reconfigure their metabolic pathways to cope with water deficit. The aim of this study was to determine the status of the physiological parameters and the content of phenolic acids in the upper most ear leaf of maize inbred lines contrasting in drought tolerance in terms of improved plant productivity e.g., increased grain yield. The experiment was conducted under irrigation and rain-fed conditions. In drought-tolerant lines, the effect of water deficit was reflected through a chlorophyll and nitrogen balance index increase followed by a flavonols index decrease. The opposite trend was noticed in drought susceptible inbreds, with the exception of the anthocyanins index. Moreover, in comparison to irrigation treatment, opposite trends in the correlations between grain yield and physiological parameters found under water deficit conditions indicated the activation of different metabolic pathways in defense against water deficit stress. Concerning phenolic acid content, water deficit caused the reduction of protocatechuic, caffeic, and sinapic acid in all inbreds evaluated. However, the highly pronounced increase of ferulic and especially cinnamic acid content under water deficit conditions indicated possible crucial role of these secondary metabolites in preventing the harmful effects of water deficit stress, which, in turn, might be useful in maize breeding selection for drought tolerance.

Research Highlights: Warming alters the chemical composition of Cunninghamia lanceolata (Lamb.) Hook, resulting in increased production of macromolecular compounds that protect against heat stress. Background and Objectives: Low latitude forests are experiencing obvious climatic warming; however, the plant physiological responses to warming are not well understood. As warming induces moisture stress, we hypothesized that warming activates metabolites (i.e., lipids, phenolic compounds, amino acids) and causes damage to the leaves, exemplified by the increased concentrations of reactive oxygen species. Materials and Methods: We conducted a warming experiment in a C. lanceolata plantation. Plant physiological traits associated with nutrient status, reactive oxygen species, antioxidant enzymes species, and metabolites were measured. Results: Warming altered the chemical composition of C. lanceolata as it increased C:N ratios of leaves and roots. In particular, the concentrations of N and P in leaves and roots were significantly decreased under the warming condition, which might be related to the biomass production, namely, a dilution effect. Under the warming condition, most of the phospholipid compounds and proteins significantly increased. Leaf C, carbohydrates, amino acids, organic acids, flavonoids, and phenolic compounds were identified to have significantly lower concentrations under the warming treatment than those under the control treatment. These results suggested that moisture stress under the warming treatment may drive C deficiency and metabolic restriction in plants. Conclusions: Under the warming condition, C. lanceolata changed its energy utilization strategy and invested more resources to produce macromolecular compounds for protecting against heat stress. Warming in sub-tropical forests alters plant chemical properties, and thus may have an important consequence for nutrient cycling and soil C sequestration.

Phenolic acids and natural extracts, as ecofriendly environmental agents, can be used as bio bactericides against the growth of plant pathogenic bacteria. In this study, isolation trails from infected potato tubers and stems that showed soft rot symptoms in fields revealed two soft rot bacterial isolates and were initially identified through morphological, physiological, and pathogenicity tests. The molecular characterization of these isolates via PCR, based on the 16S rRNA region, was carried out by an analysis of the DNA sequence via BLAST and Genbank, and showed that the soft rot bacterial isolates belong to Pectobacterium carotovorum subsp. carotovorum (PCC1) and Dickeya solani (Ds1). The in vitro results of the tested phenolic acids against the cultured bacterial isolates proved that concentrations of 800, 1600, and 3200 μg/mL were the most effective. Ferulic acid was the potent suppressive phenolic acid tested against the Ds1 isolate, with an inhibition zone ranging from 6.00 to 25.75 mm at different concentrations (25–3200 μg/mL), but had no effect until reaching a concentration of 100 μg/mL in the PCC1 isolate, followed by tannic acid, which ranged from 7.00 to 25.50 mm. On the other hand, tannic acid resulted in a significant decrease in the growth rate of the PCC1 isolate with a mean of 9.11 mm. Chlorogenic acid was not as effective as the rest of the phenolic acids compared with the control. The n-hexane oily extract (HeOE) from Bougainvillea spectabilis bark showed the highest activity against PCC1 and Ds1, with inhibition zone values of 12 and 12.33 mm, respectively, at a concentration of 4000 μg/mL; while the HeOE from Citharexylum spinosum wood showed less activity. In the GC/MS analysis, nonanal, an oily liquid compound, was found ata percentage of 38.28%, followed by cis-2-nonenal (9.75%), which are the main compounds in B. spectabilis bark HeOE, and 2-undecenal (22.39%), trans-2-decenal (18.74%), and oleic acid (10.85%) were found, which are the main compounds in C. spinosum wood HeOE. In conclusion, the phenolic acids and plant HeOEs seem to raise the resistance of potato plants, improving their defense mechanisms against soft rot bacterial pathogens.

[Truncated abstract. Please see the pdf format for the complete text.] Interest in the role of peroxynitrite in the pathogenesis of atherosclerosis has increased due to many in vitro studies which have demonstrated its potent oxidising and nitrating capability and immunohistochemical staining studies which demonstrate nitration of tyrosine in vivo. It is frequently suggested that the production of nitric oxide and superoxide at sites of inflammation implicates peroxynitrite as the major damaging reactive nitrogen species in vivo. Evidence for a role for peroxynitrite is often demonstrated by measurement of 3-nitrotyrosine yet even this cannot distinguish peroxynitrite from other nitrating species. Clearly, however, if peroxynitrite is important in atherogenesis, then identification of mechanisms for its detoxification could provide a means of preventing such effects. Therefore, this Thesis has sought to determine whether phenolic compounds of dietary origin can be preferentially nitrated by reactive nitrogen species thereby protecting endogenous structures, such as low density lipoproteins, from atherogenic modifications. This Thesis focuses upon phenolic acids as they have received relatively less attention than other classes of phenolic compounds, such as flavonoids, yet they are quite abundant in socially important beverages such as red wine. In order to complete the required analyses, the development of methods to detect phenolic acids and their nitration products together with 3-nitrotyrosine, dityrosine and 5-nitro-γ-tocopherol was necessary. The initial in vitro experiments described herein sought to determine the products of reaction of peroxynitrite with phenolic acids of the 4-hydroxy and 3,4-dihydroxy type and then to examine whether these products could account for a protective effect upon tyrosine, lipids and endogenous anti-oxidants, if any was observed, when isolated LDL was treated with SIN-1, which releases peroxynitrite through the simultaneous generation of nitric oxide and superoxide. A concurrent minor focus was to examine the relationship between structure and activity of these phenolic acids under various regimes of oxidative insult. These experiments indicate that, at least in this in vitro model, oxidation is a dominant mechanism over nitration. Peroxynitrite was shown to nitrate coumaric acid in moderate yields but exclusive oxidation of caffeic acid appeared to occur. Although a potential role for γ-tocopherol as an anti-nitration agent was inferred, all types of chemical treatment of LDL in the presence of phenolic acids yielded oxidation as the primary end point. In fact, nitration of tyrosine was not detected and nitration of coumaric acid was at the limit of detection. Since nitration of tyrosine is generally regarded as important in many disease states, a more physiological nitrating mechanism involving artificially stimulated neutrophils was used. This system demonstrated that although physiologically relevant reactive nitrogen species can result in nitration of phenolic compounds, in a complex system including biological structures (LDL) and phenolic compounds, oxidation but not nitration of all species appears to occur. As a consequence of the results above, an examination of carotid plaque was undertaken to determine to what extent nitration occurred relative to oxidation in atherosclerotic tissue. These studies applied methods developed herein to detect 3-nitrotyrosine and dityrosine in complex biological matrices as markers of nitration and oxidation respectively. The data obtained demonstrated that nitration was a minor modification of protein (0.01%) compared to oxidation (0.3%) even in a highly diseased tissue such as carotid artery plaque. A secondary study examining plasma revealed that dityrosine, which has been implicated in irreversible albumin aggregation in chronic renal failure and more recently in heart disease, is elevated in chronic renal failure subjects compared to well matched controls. A separate examination of plasma from healthy subjects revealed that in both the fasting and post prandial state 3-nitrotyrosine could not be detected and, in fact, interfering species could be problematic in the GC-MS analysis of 3-nitrotyrosine. The lack of nitration of any substrate observed in vitro using reactive nitrogen species generated in the aqueous phase, the relative lack of nitration of tyrosine in plaque proteins and the lipophilicity of nitric oxide, the precursor of all reactive nitrogen species, suggested that nitration could be more closely associated with lipid structures. The known ability of γ-tocopherol to form 5-nitro-γ-tocopherol was used to probe this concept. The 5-nitro-γ-tocopherol content of lipid extracts obtained from carotid artery plaques was very high (30%). This indicated that nitration is predominantly a lipid phase phenomenon and that nitrating species are present in much greater abundance than oxidising species in vivo.

Our objective was to investigate the mode of interaction between selected food proteins and phenolic compounds. Bovine serum albumin (BSA), bovine beta-lactoglobulin, and soybean glycinin were used with the following phenolic compounds; 3,4,5-trihydroxybenzoic acid (gallic acid), 3,4-dihydroxy cinnamic acid (caffeic acid), p -hydroxycinnamic acid (courmaric acid), and 5,7-dihydroxy 4-methoxy isoflavone (biochanin A). The interaction was investigated using incubation temperatures of 35°, 45° and 55°C at pH 5, 7 and 9. Native and SDS-polyacrylamide gel electrophoresis (PAGE), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy were used to identify protein-phenol interactions. Certain phenolic compounds combined with BSA and prevented protein aggregation. In general, the thermal stability of the proteins increased as a result of interaction with phenolic compounds; the most pronounced effect was observed with beta-lactoglobulin in the presence of gallic acid at pH 7. The interaction of the phenols with the proteins resulted in changes in protein secondary structure. (Abstract shortened by UMI.)

[ES] La citricultura se enfrenta a escenarios ambientales cambiantes que provocan diferentes estreses bióticos y abióticos que pueden dificultar la producción o afectar a la calidad de la fruta. El patrón sobre el cual se injerta una variedad específica es una importante herramienta para mejorar su adaptabilidad a cada área de cultivo. En la presente Tesis se realiza el estudio del efecto del patrón sobre la calidad físico-química y nutricional de la fruta en variedades de gran interés comercial en la actualidad, mandarinas 'Clemenules' y 'Tango' y naranjas sanguinas 'Tarocco Rosso' y 'Moro'. En 'Clemenules' se llevó a cabo la evaluación de la calidad de la fruta de árboles injertados sobre ocho patrones en tres momentos de cosecha durante dos campañas. Los patrones Forner-Alcaide 13 y C-35 destacaron por adelantar el cambio de color, lo que es de gran interés comercial. Por otra parte, Forner-Alcaide V17 destacó por mantener niveles óptimos de acidez hasta el final de la campaña y presentar el mayor contenido en vitamina C, flavonoides, glucosa y fructosa. Carrizo Citrange también indujo altas concentraciones de sacarosa y vitamina C. 'Tango' es una mandarina de reciente introducción en el área mediterránea de gran interés por su periodo de recolección tardío. En esta Tesis se abordó el estudio de los cambios en la calidad fisicoquímica, nutricional y sensorial de la mandarina 'Tango' injertada sobre dos patrones (Carrizo Citrange y Forner-Alcaide 5) en las dos áreas principales de producción de Andalucía. Los resultados revelaron que la calidad de la fruta se vio influenciada por la localización de las parcelas, lo que se relacionó con la composición de la textura del suelo. En ambas localizaciones, Forner-Alcaide 5 indujo mayor contenido en acidez, sólidos solubles totales, sacarosa, vitamina C y ácido cítrico en la fruta. Las determinaciones físico-químicas, junto con la evaluación sensorial permitieron establecer el momento óptimo de recolección dependiendo de las diferentes condiciones estudiadas. También se ha incluido un estudio del comportamiento postcosecha de esta variedad, ya que no existían datos en nuestras condiciones de cultivo. La mandarina 'Tango' presentó síntomas externos de daños por frío a partir de los 20 días almacenada a 1°C y 5°C. Se realizó un estudio micro-estructural para caracterizar la alteración. Los frutos del patrón Forner-Alcaide 5 presentaron una menor incidencia de los daños por frío. El almacenamiento a 9°C no comprometió la calidad externa o interna. Dentro del grupo de naranjas, en los últimos años existe una creciente demanda por las naranjas sanguinas para su consumo en fresco. Para evaluar el efecto del patrón se tomaron las variedades 'Moro' y 'Tarocco Rosso' injertadas sobre ocho patrones. La calidad interna se vio afectada por el momento de cosecha, siendo más evidente en 'Moro'. En ambas variedades el patrón afectó a los parámetros de calidad durante la maduración. En 'Moro', se observó una reducción en el color del zumo debido a la degradación de los antocianos, siendo los patrones C-35, Macrophylla y Volkameriana los que mostraron un mayor descenso. Esta degradación se relacionó con los cambio de la temperatura durante el periodo de recolección. En 'Tarocco Rosso' no se evidenció ninguna degradación, lo que sugiere que esta variedad es menos sensible a los cambios de temperatura. En esta variedad Forner-Alcaide 5 y Forner-Alcaide 13 produjeron fruta con mayor contenido en antocianos y azúcares. Además se llevó a cabo el estudio de la aptitud a la frigoconservación de las variedades de sanguinas 'Tarocco Rosso' y 'Sanguinelli'. Mientras que la calidad interna no se vio afectada por el almacenamiento (1°C, 5°C y 9°C) durante 45 días, la fruta presentó síntomas de daños por frío a 1°C. 'Sanguinelli' presentó mayor incidencia que 'Tarocco Rosso'. Estas sanguinas se pueden almacenar entre 5 y 9°C<br>[CA] La citricultura s'enfronta constantment a escenaris ambientals canviants que provoquen diferents estressos biòtics i abiòtics. El patró sobre el qual s'empelta una varietat específica és una important eina per a millorar la seua adaptabilitat agronòmica en cada àrea de cultiu. En la present Tesi s'ha dut a terme l'estudi de l'efecte del patró sobre la qualitat físic-química i nutricional de la fruita en varietats de gran interés comercial, mandarines 'Clemenules' i 'Tango' i, taronges sanguines 'Tarocco Rosso' i 'Moro'. En 'Clemenules' es va dur a terme l'avaluació de la qualitat de la fruita d'arbres empeltats sobre huit patrons en tres moments de collita, en dues campanyes. Entre els patrons avaluats, Forner-Alcaide 13 i C-35 van destacar per avançar el canvi de color. D'altra banda Forner-Alcaide V17 va destacar per mantindre nivells òptims d'acidesa fins al final de la campanya i va presentar el major contingut en vitamina C, flavonoides, glucosa i fructosa. Carrizo Citrange també va induir altes concentracions de sacarosa i vitamina C en la fruita. 'Tango' és una mandarina de recent introducció en l'àrea mediterrània amb gran interés pel seu període de recol·lecció que comença quan finalitza el de les clementines. En la present Tesi es van estudiar els canvis en la qualitat físic-química, nutricional i sensorial de la mandarina Tango empeltada sobre dos patrons (Carrizo Citrange i Forner-Alcaide 5) durant el període de collita en les dues àrees principals de producció d'Andalusia. La qualitat de la fruita es va veure influenciada per la localització, la qual cosa es va relacionar amb la composició de la textura del sòl. En totes dues localitzacions, Forner-Alcaide 5 va ser el patró que va induir major contingut en acidesa, sòlids solubles totals, sacarosa, vitamina C i àcid cítric en la fruita. Les determinacions físic-químiques i l'avaluació sensorial van permetre establir el moment òptim de recol·lecció depenent de les diferents condicions estudiades. També s'ha inclòs un estudi del comportament postcollita d'aquesta varietat, ja que no existien dades en les nostres condicions de cultiu. La mandarina 'Tango' va presentar símptomes externs de danys per fred a partir dels 20 dies emmagatzemada a 1°C i 5°C. Es va realitzar un estudi micro-estructural per a caracteritzar l'alteració provocada per les baixes temperatures. Els fruits del patró Forner-Alcaide 5 van presentar una menor incidència dels danys per fred. L'emmagatzematge a 9°C no va comprometre la qualitat externa o interna d'aquesta varietat. Dins del grup de taronges, en els últims anys existeix una creixent demanda per les taronges sanguines pel seu consum en fresc. Per a avaluar l'efecte del patró sobre sanguines es van prendre dues varietats, 'Moro' i 'Tarocco Rosso' empeltades sobre huit patrons. La qualitat interna es va veure influenciada pel moment de collita, la qual cosa va ser més evident en la varietat 'Moro'. En totes dues varietats el patró va afectar els canvis en els paràmetres de qualitat estudiats. En 'Moro', es va observar una reducció en el color del suc degut a la degradació del antocians. Aquesta degradació es va relacionar amb el canvi de la temperatura experimentada durant el període de recol·lecció. 'Tarocco Rosso' és menys sensible als canvis de temperatura. En aquesta varietat els patrons Forner-Alcaide 5 i Forner-Alcaide 13 van produir la fruita amb major contingut en antocianos i sucres. A mes s'aporta l'estudi de l'aptitud a la frigoconservació en les sanguines 'Tarocco Rosso' i 'Sanguinelli'. Mentre que la qualitat interna no es va veure afectada per l'emmagatzematge a cap de les temperatures assajades (1°C, 5°C i 9°C) durant 45 dies, la fruita va presentar símptomes de danys per fred a 1°C. `Sanguinelli' va presentar major incidència que 'Tarocco Rosso'. La fruita es pot emmagatzemar entre 5°C i 9°C durant 30 dies en el cas de 'Sanguinelli' i fins a 45 en e<br>[EN] Citriculture faces changing environmental scenarios that cause biotic and abiotic stress. The rootstock onto which a specific variety is grafted is an important tool to help to improve its agronomic adaptability to each crop area. The present Thesis was carried out to study the effect of rootstock on physico-chemical and nutritional fruit quality in some varieties of commercial interest today: 'Clemenules' and 'Tango' mandarins, and 'Tarocco Rosso' and 'Moro' blood oranges. In 'Clemenules', the fruit of the trees grafted into eight rootstocks at three harvest times was evaluated by performing studies during two seasons. Forner-Alcaide 13 and C-35 Citrange stood out for their earlier color change, which is very interesting for this variety, in which early harvesting is a relevant aspect from the commercial point of view. Forner-Alcaide V17 stood out for maintaining optimum acidity levels until the season ended and presented the highest contents in vitamin C, flavonoids, glucose and fructose. Carrizo Citrange brought about high concentrations of sucrose and vitamin C in fruit. 'Tango' is a mandarin variety that has been recently introduced into the Mediterranean Region. Its harvest time is very interesting because it starts when that of clementines ends. The present Thesis studies changes in the physico-chemical, nutritional and sensorial quality of 'Tango' fruit grafted onto two rootstocks (Carrizo Citrange and Forner-Alcaide 5) during the harvest period in the two main production areas in Andalusia. The results revealed that fruit quality during harvest was influenced by the location, which was particularly related to soil texture composition. In both areas, Forner-Alcaide 5 was the rootstock that induced higher acidity content, and more total soluble solids, sucrose, vitamin C and citric acid in fruit. The physico-chemical determinations, along with the sensorial evaluation, allowed the optimum harvest time to be established depending on the different studied conditions. This Thesis also includes a study about this variety's postharvest behavior as no data are available for our crop conditions. The 'Tango' mandarin presented outer chilling injury symptoms after being stored for 20 days at 1°C and 5°C. A microstructural study was done to characterize the alteration caused by low temperatures. The Forner-Alcaide 5 rootstock fruit showed a lower chilling injury incidence. Storage at 9°C did not compromise quality fruit. Among oranges, demand for blood oranges to be eaten fresh has grown in recent years, basically due to their high content in anthocyanins and their positive effect for human health. To assess the effect that rootstock had on blood oranges, two varieties were taken, 'Moro' and 'Tarocco Rosso', grafted onto eight rootstocks. Internal quality was strongly influenced by harvest time, which was more evident for 'Moro'. In both varieties, rootstock affected changes in the quality parameter studied. In 'Moro', juice color faded as anthocyanins degraded, and rootstocks C-35 Citrange, Macrophylla and Volkameriana showed the most marked reduction. Such anthocyanin degradation was related to the change in temperature that took place during the harvest period. In 'Tarocco Rosso', anthocyanins did not undergo degradation, which suggests that this variety is less sensitive to changes in temperature. In this variety, rootstocks Forner-Alcaide 5 and Forner-Alcaide 13 gave fruit with a higher content of anthocyanins and sugars. This Thesis also includes a study of the suitability of cold storage of two blood orange varieties: 'Tarocco Rosso' and 'Sanguinelli'. Although storage at any tested temperature (1°C, 5°C and 9°C) did not affect internal quality for 45 days, fruit displayed chilling injury symptoms at 1°C, with a higher incidence for 'Sanguinelli' than for 'Tarocco Rosso'. Fruit can be stored between 5°C and 9°C for 30 days for 'Sanguinelli' and for up to 45 days with 'Tarocco Rosso'.<br>This study has been supported by Instituto Valenciano de Investigaciones Agrarias and co-financed by FEDER and European Social Fund. The authors thank Anecoop S. Coop. and Frutaria Agricultura, S.L for supplying the fruit herein used and its technical support.<br>Morales Alfaro, J. (2021). Effect of Rootstock on the Fruit Quality of Mandarins "Clemenules" and "Tango", and Blood Oranges "Tarocco Rosso" and "Moro" [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/165858<br>TESIS

Methylglyoxal (MGO) is a reactive carbonyl species found in Manuka honey reported to cause advanced glycation end products (AGE) formation. AGE’s increase the risk for hyperglycaemia resulting in neuropathy, arteriosclerosis, retinopathy and Alzheimer’s disease. Phenolic acids such as pyrogallol (PY) are known to trap MGO, lessening the harmful effects of MGO as an AGE precursor. However, MGO is also a very effective antibacterial agent therefore; its trapping could have negative side effects. Manuka honey contains both phenolic acids such as gallic acid (GA), caffeic acid (CA) as well as MGO and it is unknown whether trapping of MGO by phenolic acids reduces the antioxidant activity of phenolic acids or the antibacterial activity of MGO. Phenolic acids PY, GA and CA were combined with MGO in a 1:1 and 1:2 ratio. The trapping of MGO with polyphenolic acids was determined with Liquid chromatography-mass spectrometry (LCMS). Total polyphenolic acids (TPC) was determined with the TPC assay. Antioxidant activity was determined with 2,2-diphenyl-2-picrylhydrazyl (DPPH), Trolox equivalent antioxidant capacity (TEAC) and Oxygen Radical Absorbance Capacity (ORAC) assays. The effect on cell number and viability was determined with crystal violet and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays on Caco-2 and SC-1 cells. Cellular antioxidant activity was determined with Dichlorodihydrofluorescein diacetate assay. Lastly, antibacterial activity was determined with the turbidity assay on Gram positive B. subtilis and Gram negative E. coli and the ultrastructural morphology of B. subtilis was further investigated with scanning electron microscopy. PY was the only phenolic acid used with trapping ability, forming mono- and di- adducts with MGO reported with the LCMS results, resulting in a decrease in TPC and antioxidant activity measured with the DPPH assay. GA did not show any alteration when combined with MGO at 1:1 and 1:2 ratio in all antioxidant content and activity assays. The antioxidant content of CA in combination with MGO was decreased, although its antioxidant activity (DPPH) was increased at 1:2 ratio. The antioxidant activity measured with the ORAC assay was increased with PY and CA combined with MGO. TEAC assay did not show any changes when phenolic acids were combined with MGO a 1:1 and 1:2 ratio. The cytotoxicity of phenolic acids combined with MGO did not cause a change in cell number or viability of SC-1 and Caco-2 cells. MGO and phenolic acids alone and in combination did no cause oxidative damage (without 2,2'-Azobis(2- amidinopropane) dihydrochloride (AAPH). All phenolic acids in combination with MGO retained the ability to reduce AAPH induced oxidative damage. The polyphenolic acids showed minor inhibition of the growth of B. subtilis and E. coli. PY only reduced the antibacterial activity of MGO at a 1:1 combination of B. subtilis. GA and CA did not alter the antibacterial activity of MGO when combined at 1:1 or 1:2 ratio. This study showed that phenolic acids with the ability to trap MGO can be altered by the mono- and di-MGO adduct formation, altering its antioxidant activity and can further alter the antibacterial activity of MGO.<br>Dissertation (MSc)--University of Pretoria, 2017.<br>Anatomy<br>MSc<br>Unrestricted

Thirteen Ball State University, male basketball players participated in this study to examine the effects of an amino acid supplement, Rebuild IITM and glutamine, on strength and vertical jump performance. Rebuild IITM contains high levels of BCAA and glutamine.The thirteen subjects were divided into two groups, Rebuild IIT"'' (n=7) and placebo (n=6). Both groups participated in a ten week strength and conditioning training program. Subjects were pre and post-tested on the hang clean, bench press, squat, and the vertical jump. Changes in percent body fat were also compared. Pre and post measures were analyzed using a 2x2 ANOVA variance with a significant level set at p<0.05. Both groups showed significant increases between pre and post-test measurements in all of the variables measured, but could not be significantly proven to be due to treatment effect. It was concluded that with a controlled strength and conditioning program, basketball players would increase strength and vertical jump performance and decrease percent body fat. Yet in order to determine whether an amino acid supplement may further increase these measurements, a dietary recall must be obtained.<br>School of Physical Education

Computer-mediated communication [CMC] is beginning to be used more frequently in traditional classrooms. A group of physical chemistry professors have developed Physical Chemistry On-Line [PCOL] modules designed to augment in-class instruction and engage students at geographically dispersed institutions in activities to help them learn physical chemistry concepts. These modules use context-rich scenarios with a guided-inquiry approach, and the WWW and e-mail for information distribution and communication. This allows for intra- and inter-institutional collaboration between module participants. Three modules implemented during the Fall 2000 term are evaluated in this study. In order to assess the effectiveness of PCOL, each student completed a pre-module and post-module survey, pre-module and post-module content questions, and participated in an online discussion group. The primary focus of this analysis was to determine the student's: 1) perception of on-line activities, 2) perception of on-line interactions, and 3) use of computers.<br>School of Physical Education

Fourteen Ball State University softball players participated in this study to examine the effects of an amino acid supplement, Rebuild II TM, on strength and performance. Rebuild II TM contains high levels of BCAAs and glutamine. Two groups strength trained for ten weeks with the treatment group consuming Rebuild II TM, and the control group consuming a placebo. Subjects were pre and post-tested on the bench press, squat and machine shoulder press for strength, and performed a 90-foot sprint and a vertical jump for performance measures. LBW was calculated from the subjects body weight and percent fat. Pre and post measures were analyzed using a two way Anova variance with repeated measures test with a significant level set at p< 0.05. Both groups showed significant increases in strength and vertical jump performance, but only the Rebuild II TM group had a significant increase in LBW and decrease in percent fat. It was concluded that with a controlled weight training program, softball players will increase strength and vertical jump performance, and by adding an amino acid supplement to an athletes diet, there may be larger increases in LBW and decreases in percent fat while strength training.<br>School of Physical Education

Cyclopropene fatty acids (CPFA) found in cottonseed oil (CT) have been shown to reduce production of progesterone, a precursor of estrogen. Estrogenic hormones have been implicated in enhancing growth of mammary tumors. In this study, the effect of dietary cottonseed oil on estrogen production by mature female mice was determined by measuring urinary estrogen using High Performance Liquid Chromatography.At four months of age, five groups of three Strain A/ST female mice were placed on 20% fat diets containing 0, 2.5, 5.0, 10, and 20% cottonseed oil. The remainder of the fat in the experimental diets was corn oil sufficient to provide the balance of the 20% fat content in conjunction with other nutrients of equal percentages in all diets. At five day intervals mice were housed in metabolic cages and twenty-four hour urine samples were collected. Urine was purified on C18 columns and eluted with 1% phosphoric acid: acetonitrile: methanol: (54:35:11). Estrogen was quantified by High Performance Liquid Chromatography using a 250 X 5mm C18 column, hydrocortisone as an internal standard, and variable wavelength recorder set at 242 nm. The level of urinary estrogens after day 35 of the study was lower in all diets containing cottonseed oil. This is in agreement with several authors who have reported instances of physiological abnormalities in mammals which were fed increasing but low levels of dietary cyclopropenes. Since elevated estrogen levels have been identified as a risk for breast cancer, this study examines the relationship between dietary cyclopropenes and estrogen hormone production in strain A/St mice.<br>Department of Biology

Prostaglandin E2 (PGE2), a byproduct of arachidonic acid metabolism, has been suspected to be involved in tumor promotion. It has been suggested that diet may modulate PGE2 level in organisms thus affecting the implantation and growth of the tumor tissue. PGE2 content was investigated in mice fed ad libitum four types of fatty acid diets: saturated fatty acid diets: a stearic acid and a palmitic acid, and polyunsaturated fatty acid diets: a low fat (safflower 1%) and a high fat diet (safflower 15%). Tumor cells were implanted subcutaneously in mice and harvested when tumors reached .05- 4g. The extracted PGE2 were derivatized and quantified by High Performance Liquid Chromatography (HPLC). The results showed that there is a negative correlation between the level of PGE2 and the size of the tumors. PGE2 level declined as the tumor grew. This suggests that during the early stage of growth the tumor requires higher level of PGE2 to boost its growth. As the tumor becomes more adapted to its environment, it no longer depends on PGE2 to survive. Diet was also seen to be important in tumor suppression. Saturated fatty acid diet (SA-1) showed a suppressive effect on tumor growth. A visual comparison showed that polyunsaturated high fat diet produced more PGE2 than saturated fatty acid. This high level of PGE2 correlate with the highest tumor weights obtained in the Polyunsaturated high fat diet group.<br>Department of Biology

Whole grain wheat has a diverse supply of hydrophilic and lipophilic antioxidants which include phenolic compounds (phenolic acids, flavonoids, anthocyanins which are present only in pigmented wheat, alkylresorcinols, and to a lesser extent proanthocyanidins), carotenoids (mainly lutein and zeaxanthin) and tocochromanols (α, β, γ and δ - tocopherols and tocotrienols). This diversity of antioxidants function to protect consumers from radical-induced oxidative damage caused by various free radicals produced endogenously from metabolic processes and exogenously from sunlight and other chemicals and environmental pollutants. They also chelate metal ions which could catalyze oxidation reactions in the physiological system, thereby providing antioxidant protection. However, phenolic compounds might exert pro-oxidant effect when bound to heavy metal ions. This effect could be prevented by the diverse antioxidant system in wheat.

Maize is one of the mostly consumed grains in the world. It possesses a greater potentiality of being an alternative to rice and wheat in the near future. In field condition, maize encounters abiotic stresses like salinity, drought, water logging, cold, heat, etc. Physiology and production of maize are largely affected by drought. Drought has become a prime cause of agricultural disaster because of the major occurrence records of the last few decades. It leads to immense losses in plant growth (plant height and stem), water relations (relative water content), gas exchange (photosynthesis, stomatal conductance, and transpiration rate), and nutrient levels in maize. To mitigate the effect of stress, plant retreats by using multiple morphological, molecular, and physiological mechanisms. Maize alters its physiological processes like photosynthesis, oxidoreductase activities, carbohydrate metabolism, nutrient metabolism, and other drought-responsive pathways in response to drought. Synthesis of some chemicals like proline, abscisic acid (ABA), different phenolic compounds, etc. helps to fight against stress. Inoculation of plant growth-promoting rhizobacteria (PGPR) can result to the gene expression involved in the biosynthesis of abscisic acid which also helps to resist drought. Moreover, adaptation to drought and heat stress is positively influenced by the activity of chaperone proteins and proteases, protein that responds to ethylene and ripening. Some modifications generated by clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 are able to improve maize yield in drought. Forward and reverse genetics and functional and comparative genomics are being implemented now to overcome stress conditions like drought. Maize response to drought is a multifarious physiological and biochemical process. Applying data synthesis approach, this study aims toward better demonstration of its consequences to provide critical information on maize tolerance along with minimizing yield loss.

Gut health is fundamental for human well-being and prevents chronic degenerative diseases and is influenced by the interaction between gut microbiota and food components. In recent years, interest in phenolic compounds has increased due to their health benefits such as antioxidant, antidiabetic, antimicrobial, anti-atherosclerotic, anti-inflammatory, anticarcinogenic, cardio- and neuro-protective properties. Legumes are an essential source of phytochemicals, particularly flavonoids and phenolic acids, distributed mainly in the seed coat, and have been reported to exhibit multiple biological effects. Flavonoids present in legumes have been shown to regulate metabolic stability and membrane transport in the intestine, thus improving bioavailability. Seed processing such as cooking allows the release of phenolic compounds, improving polyphenols digestion and absorption at the intestinal level, maintaining their protective capacity in the oxidative process at the cellular level, and modulating the gut microbiota. All these actions improve gut health, avoiding diseases like irritable bowel syndrome, inflammatory bowel disease, obesity, diabetes, colitis, and colorectal cancer. The effect of the consumption of legumes such as chickpea, pea, and bean, as well as the contribution of phenolic compounds to gut health, will be reviewed in this study.

Nuts are a combination of prebiotic fiber and phytonutrients and have antioxidant, anti-inflammatory effects. According to 2005 “My Pyramid” it has been grouped with the meat and bean group. Bioactive compounds of nuts such as resveratrol, phytosterols, phenolic acids, flavonoids, and carotenoids display synergistic effects on preventing many age related pathologies. Resveratrol has been reported to extend the lifespan in model organisms such as yeast, Drosophila and mouse. Reports propose nuts as the best substitute for red meat to reduce mortality risk. Macadamia nuts with a rich source of monounsaturated fats (oleic and palmitoleic acids) imparts cholesterol lowering effects thereby preventing coronary artery disease. Anacardic acid, a phenolic lipid found in cashew nut shells, is specifically enriched in metastatic melanoma patients in response to immunotherapy. The non-bio-accessible materials of nuts serve as a substrate for human gut microbiota. Regular Walnut enriched diet improves lipid content and enhances probiotic and butyrate producing bacteria composition in healthy individuals. This also reduces cardiovascular risk factors by promoting beneficial bacteria. Gut microbiota diversity studies report an enrichment with genera capable of producing short chain fatty acids (SCFA) following consumption of nuts. The prebiotic effect of nuts can be partly from refining butyrate producing bacteria composition. Hence an optimized diet rich with nuts can be an intervention for promoting a healthy microbiota population and thereby improving overall physiology.

In conditions of severe gut dysbiosis, there is a risk of developing diseases of the host organism in general and of the brain in particular, as evidenced by a growing number of studies. This chapter focuses on several groups of low-molecular-weight compounds that originate primarily from the gut microbiota. It discusses the results of experimental and clinical studies on the effect of microbial metabolites (such as short-chain fatty acids, phenolic metabolites of tyrosine, indolic metabolites of tryptophan, trimethylamines) on the brain. Several studies have proven that the microbial metabolite profiles in the gut and serum are interlinked and reflect a disruption of the gut microbial community. Using 16S ribosomal RNA gene sequencing, it was found that the gut microbiota of patients with positive or negative dynamics of neurological status differ taxonomically. The chapter also presents data obtained from animal germ-free (GF) models. Many researchers would like to consider the gut microbiota as a new therapeutic target, including for the treatment of brain diseases, stroke prevention, reduction of neuroinflammation, and more successful neurorehabilitation of patients.

Soil organic matter (SOM) is probably the most important constituent of soils. The effect of SOM on soil properties far exceeds the relative percentage of this material in soils. The small amount of organic matter in soils, usually from 1 to 5%, is very important in providing a reserve food source for microorganisms and higher plants. Almost all properties of SOM are beneficial for plant growth. Soil organic matter can be defined as a complex, heterogeneous mixture of plant and animal remains in various stages of decay, microbial cells—both living and dead—microbially synthesized compounds, and derivatives of all of the above through microbial activity. Soil organic matter is probably the most complex of all naturally occurring substances. Some compounds in SOM are distinctive to soil and are not present in plants or animals. By examining the composition of SOM, one can see why it is such a complex material. The following compounds have been isolated from chemical SOM extracts: . . . 1. Carbohydrates (sugars, polysaccharides)—about 75% of dry weight 2. Lignin (a plant polymer of phenyl propane units) 3. Proteins (combinations of amino acids) 4. Hydrocarbons—fats, waxes, resins, and oils 5. Tannins (phenolic substances) 6. Pigments (chlorophyll) 7. Organic acids (many in the biochemical Krebs cycle) 8. Miscellaneous compounds—includes organic P, organic S, polynuclear hydrocarbons, nucleic acid derivatives, alcohols, aldehydes, esters, etc. . . . Whenever organic materials are added to a soil the physical properties of soil structure, water-holding capacity, and soil color are changed. The extent of change in these properties depends on the amount and type of organic material added, the soil microorganisms present in the soil, and the speed at which decomposition occurs. Aggregation and granulation (crumb formation) is increased by polysaccharides produced by microorganisms during decomposition. This improves soil tilth (ability to work the soil) and helps stabilize the soil crumbs. The ability of a soil to hold water is greatly increased by addition of SOM. This results in greater infiltration (water moving into the soil) and adsorption of water by the SOM, with consequently less erosion and loss of soil particles and fertility.

The aim of this work was to evaluate the influence of vacuum application on the phenolic acid content of osmodehydrated eggplant, carrot and beetroot samples. The contents of catechins and chlorogenic acid were determined by HPLC analysis. Changes in the contents of phenolic acids after the osmotic processes were observed. It was found a reduction in catechins and chlorogenic acids, probable due to the migration and degradation losses. In a general way, the vacuum reduced the catechin and chlorogenic acid contents, compared to the osmotic dehydration at atmospheric pressure. Keywords: Pulsed vacuum osmotic dehydration; chlorogenic acid; catechins.

Due to instability in the first in vitro period, platelet-aggregometry is usually deliberately postponed until ca. 1 hour after venepuncture (VP) . At that time aggregability is fairly constant for 1 hour or more. Investigation of the period immediately followed VP, hcwever, revealed a high aggregation resistance - measured as the threshold ADP-concentration which the platelets just could resist before they aggregate maximally and irreversibly - which subsequently decreased exponentially with time. This “Transient Aggregation Resistance” (TAR) appeared to be superimposed on a stable, so called Baseline Aggregation Resistance (BAR) .The latter, measurable 60 min or more after VP, yields the “classical” threshold ADP-concentration.Parallel aggregation-studies started 6 min after VP, subsequent studies were performed every 4 min. pH was controlled during storage of PRP at rocmtenperature. Extrapolation of the TAR-curve to t=0 (i.e. time of VP) yields the maximal value:TARmax Coefficients of variation for TARmax-method: 9.4% (n=6) ; intraindividial 15% (n=15, over 3 yrs); interindividual: 51% (n=16,wide range).This TAR-phencmenon which is proven to be caused by a plasma-factor, can be influenced by dietary n-3 fattty acids and can be also inhibited by ASA,suggesting a prostanoid nature. The physiological significance of TAIfoax can be illustrated by the following findings:1. Patients with myocardial infarction, hyperlipoproteinemia, sickle cell anemia (i.e. diseases with a high risk for thrombotic complications) have low TARmax-values. 2.Individuals with “spontaneous platelet aggregation” in vitro,but asymptomatic, have positive TARmax-values. 3.There is a clear,reciproke age-dependency of TARmax It is concluded that a technique is available measuring the effect of circulating,labile platelet-aggregation influencing plasma factor(s). Furthermore, using this technique,it was found that normal fresh plasma contains a labile aggregation-inhibiting factor which is several orders of magnitude more potent than other stabile factors either present in plasma or associated with platelets. This factor is probably of prostanoid nature and might have significance as a reflection of the antithrcmbotic potential of the endothelium.

Plasminogen activation provides an important source of localized proteolytic activity not only during fibrinolysis, but also during ovulation, cell migration, epithelial cell differentiation, tumor invasion and a variety of other physiological processes. Precise regulation of plasminogen activator (PA) activity thus constitutes a critical feature of many biological processes. This control is achieved in large part through the action of specific PA inhibitors (PAIs). Although 4 distinct PAIs have been detected,1the endothelial cellTderived inhibitor (PAI-1) is the only one that efficiently inhibits both urokinase (Kd=2.3×10−13M; Kassoc =1.6×108 M−1s−1) and single-chaintissue-type PA (tPA; Kd=1.3×lO−15 M Kd=3.9×lO7M−1s−1). It also inhibits trypsin (Kassoc=6.8×106M−1 s−1 ) ancl Plasmin (Kassoc=7.6×l05 M−1 s5 Analysis of the effect of PAI-1 on the rate of plasminogen activation revealed a competitive type of inhibition when urokinase was employed but a linear mixed type of inhibition when single chain tPA was employed. These results suggest that the interaction of PAI-1 with tPA, in contrast to its interaction with urokinase, may involve 2 sites on the tPA molecule.PAI-1 has been purified from medium conditioned by cultured bovine aortic endothelial cells and partially characterized. It is a major biosynthetic product of these cells, accounting for as much as 12% of the total protein released by the cells in 24 h. It has an M of 50,000, an isoelectric point of 4.5-5.0, and is immunologically and biochemically related to the rapidly acting inhibitor present in human platelets and in the plasma of some patients at risk to develop thrombotic problems. Although it is relatively stable to conditions which inactivate most protease inhibitors (acid pH, SDS), it is extremely sensitive to oxidants. The molecular cloning of the PAI-1 gene revealed that the mature human protein is 379 amino acids long, contains an NH2-terminal valine, lacks cysteines and has a methionine at the Pi position of it's reactive center. The conversion of this methionine to methionine sulfoxide may be responsible for the rapid inactivation of PAI-1 by oxidants. Human PAI-1 has extensive (30%) homology with α1-antitrypsin and antithrombin III and is thus a member of the serine proteinase inhibitor (serpin) family; a group of related molecules that control the major protease cascades of the blood. The PAI-1 gene is approximately 12.2 kilobase pairs in length and is organized into nine exons and eight introns.The production of PAI-1 by endothelial cells is stimulated by endotoxin, interleukin-1, tumor necrosis factor, and transforming growth factor β(TGFβ). The cells are extremely sensitive to TGFβwith maximal effects (100-fold stimulation) observed with 1-2 ng/ml. These changes were relatively specific for PAI-1, and could be detected at both the protein and the RNA level. Interestingly, TGFgalso stimulated the amount of PAI-1 present in the extracellular matrix (ECM) of BAEs. PAI-1 was one of the primary ECM components of these cells, constituting 10-20% of the ECM proteins detected after SDS-PAGE.One of the most unusual properties of PAI-1 is that it exists in blood and in various cellular samples in both an active and an inactive (latent) form, the ratio depending on the source. The latent form can be converted into the active one by treatment with denaturants like SDS or guanidine-HCl. Although the majority of the cell-associated PAI-1 is active, it rapidly decays (t1/2=3 h) into the latent form once it is released from the cells. In contrast, the half-life of ECM associated PAI-1 was greater than 24 h. These data suggest that PAI-1 is produced by BAEs in an active form, and is then either released into the medium where it is rapidly inactivated, or released into the subendothelium where it binds to ECM. The specific binding of PAI-1 to ECM protects it from this inactivation.