Number Of Phenolic Compounds Research Articles

Effect of <i>Meloidogyne incognita</i> infection on the accumulation of phenolic compounds in plants of the genus Mint (Mentha L.)

The purpose of the research is to compare the accumulation of phenolic compounds of different species and varieties of mint, zoned in Central Russia against the background of plant infection by Meloidogyne incognita.Materials and methods. Plants were grown from cuttings in a growing experiment in open ground. Mentha × piperita L. (varieties: Tik-Tak, Orange, Minneola, Mojito, Mitchum, Chocolate), M. spicata L. (varieties Morocco, Crispa) and M. longifolia L. (Longifolia) were taken for the study. A month later, the rooted plants were infected at the rate of 1000 sp. infective larvae of M. incognita per plant. After 8 weeks leaves were fixed in ethanol. The total content of phenolic compounds (PC), phenylpropanoids, flavonoids and catechins was studied using a spectrophotometer. The determination of the total content of PС was carried out using the Folin-Cecolte reagent with measurement at 725 nm, phenylpropanoids – by direct measurement of optical density at 330 nm, flavonoids – by reaction with aluminum chloride at 415 nm, the total content of flavans (catechins - flavan-3-ols), their oligomeric forms – proanthocyanidins, as well as leukoanthocyanidins were assessed by reaction with vanillin at 500 nm.Results and discussion. It has been shown that the accumulation of phenols is related to the species of plants. The varieties Mentha × piperita L. in most cases contained more phenols than M. spicata L. and M. longifolia L. A significant number of PC was noted in the violet-colored varieties Mitchum, Chocolate and Orange. The total content of PC almost completely correlates with the content of their precursors – phenylpropanoids. In terms of the content of flavonoids, the Mitchum variety stands out noticeably, and in terms of the content of catechins, the Orange variety stands out. Nematode infection in most varieties causes a noticeable increase in the total accumulation of soluble PC, phenylpropanoids and flavans, but leads to a decrease in the content of flavonoids.

Assessing nutritional and genetic variations within foxtail millet (Setaria italica) landraces collected from indigenous communities across the Philippines

Unknown to many, the Philippines is host to a few remaining accessions of the underutilised and understudied cereal foxtail millet (Setaria italica (L.) P. Beauv.). We collected together accessions of this crop from different eco-geographical locations within the Philippines, along with a few accessions from Lanyu, Taiwan, to undertake a study of their nutritional value and genetic diversity. All accessions were field-grown in 2022, dry season (DS) at the Institute of Plant Breeding (IPB) Experiment Station, Los Baños, Laguna, Philippines. The accessions were tested for micronutrients, including Zn and Fe, nitrogen as a proxy for protein, β-carotene, phytic acid, and a number of phenolic compounds with known nutritional potential. Of the 20 accessions tested, the accessions Bayaras and GB61438 had the highest level of Zn (107.1 mg/kg) and Fe (70.52 mg/kg), respectively, higher than levels found in traditional rice varieties. For β-carotene the highest concentration was found in the accession Balles (∼10 μg/g). Twelve phenolic compounds were detected, with catechin, syringic acid, ferulic acid and kaempferol having the highest concentrations. To assess the genetic diversity, we sequenced a set of eight samples selected from among the accessions to a depth of at least 25-fold using whole-genome re-sequencing. Analysis of the population structure, using genome-wide, high-quality SNPs, showed modest diversity among the accessions, with two unadmixed groups. The accessions are monophyletic relative to their earliest common ancestor, with the very light brown accessions emerging earlier than the light brown and reddish-brown varieties. Analysis of zinc-regulated, iron-regulated transporter-like protein (ZIP) transporters within the foxtail millet reference sequence, var. Yugu1 identified 17 putative ZIP transporters. Variant calling identified SNPs primarily within 3′ and 5’ regions, and introns, indicating variation between foxtail millet accessions within regulatory gene regions rather than in structural proteins. The local foxtail millet accessions, therefore, represent a potential alternative source of nutrients which may help in addressing malnutrition in the Philippines.

POTENTIAL USE OF FOOD PRODUCTION WASTE TO OBTAIN MEDICAL AND COSMETIC PRODUCTS

One of the problems of modern technology for processing food technology products of plant origin is the use of their waste - peel, seeds, shells  oilcake, leaves and other components, containing a significant amount of bioactive compounds (phenols, peptides, carotenoids, anthocyanins, fatty acids, enzyme, fibers etc.), which in most cases are not  utilized  and are burned, or go to dumps, worsening the environmental situation.  The production of potential drugs  for the cosmetic and medical industries from them is of great interest. A similar problem  takes place also in Georgia. A large amount of waste remains after processing the corn crop - stems, leaves, corn stigmas. In this review,that is mainly based on literature data, the problem of using corn stigmas (silk), which is available in abundance, is considered. Judging by the chemical composition, corn stigma powder contains a number of phenolic compounds, pectin, glucan, glucomannan, cellulose, hemicellulose, lignin and others. It also contains Na, Mg, K, Ca, copper, iron, manganese, zinc. Many scientists have studied   antioxidant, anti-cancer, anti-inflammatory, acute and chronic activities.  Their studies and a number of other tests have shown the pharmacological activity of extracts from the powder and their safety for use ,when they are taken in certain doses. According to available data, products, obtained from corn production waste, have found wide application in cosmetology. They are used as  absorbents, fillers, proteins, emulsifiers, surfactants. All this confirms the need of using waste products from the production of corn grain - corn stigmas (silk), for further purposes.

Molecular changes in phenolic compounds in Euglena gracilis cells grown under metal stress.

Metal presence in the aquatic ecosystem has increased and diversified over the last decades due to anthropogenic sources. These contaminants cause abiotic stress on living organisms that lead to the production of oxidizing molecules. Phenolic compounds are part of the defense mechanisms countering metal toxicity. In this study, the production of phenolic compounds by Euglena gracilis under three different metal stressors (i.e. cadmium, copper, or cobalt) at sub-lethal concentration was assessed using an untargeted metabolomic approach by mass spectrometry combined with neuronal network analysis (i.e. Cytoscape). The metal stress had a greater impact on molecular diversity than on the number of phenolic compounds. The prevalence of sulfur- and nitrogen-rich phenolic compounds were found in Cd- and Cu-amended cultures. Together these results confirm the impact of metallic stress on phenolic compounds production, which could be utilized to assess the metal contamination in natural waters.

Study of total antioxidant capacity of red raspberry (Rubus idaeous L.) shoots

BACKGROUND: Today, cardiovascular, oncological, and neurodegenerative diseases are the main causes of death in the world, according to official World Health Organization (WHO) statistics. Antioxidants are used to treat and prevent these diseases. In order to develop optimal technology for obtaining drugs based on plant extracts with antioxidant action, it is necessary to determine the total antioxidant capacity of raspberry shoots.OBJECTIVES: The study aimed to determine the total antioxidant capacity of red raspberry shoots, study the content of biologically active substances (BAS), and the antioxidant activity of red raspberry shoot extracts obtained during subsequent exhaustive extraction.METHODS: The number of phenolic compounds, catechins, flavonoids, and hydroxycinnamic acids was determined by a spectrophotometric analysis method, whereas organic acids were determined by the alkalimetric method in red raspberry shoot extracts; the antioxidant activity of obtained extracts was evaluated by potentiometric method. RESULTS: The total antioxidant capacity of red raspberry shoots was 164.12 mmol-equiv./m dry weight, the sum of the total content of phenolic compounds was 24.40 mg gallic acid (GA)/mL, catechins – 21.36 mg epigallocatechin-3-O-gallate (EGCG)/mL, flavonoids – 0.77 mg rutin (R)/mL, hydroxycinnamic acids derivatives – 2.56 mg chlorogenic acid (ChA)/mL and organic acids – 1.88 mg citric acid (CA)/mL in red raspberry shoot extracts obtained during subsequent exhaustive extraction. The analysis showed that there is a very high positive correlation between antioxidant activity and total phenolic compounds, catechin, flavonoid, hydroxycinnamic acids derivatives, and organic acids content in red raspberry shoot extracts. CONCLUSIONS: Total red raspberry shoots' antioxidant capacity has been determined. The study results can be used to develop optimal technology for obtaining drugs based on the extract of red raspberry shoots, which has an antioxidant effect.

Phenolic Compound Production Increased In Vitro Regenerated Cichorium intybus L.

Chicory (Cichorium intybus L.) is a low-height perennial or biennial herb from the family of Asteraceae. Investigation of different in vitro regeneration strategies of Cichorium intybus and increasing the number of secondary metabolites in vitro regenerated plant samples were the aims of the research. Callus and plant regenerations were achieved in basal plant growth media supplemented with plant growth regulators (PGRs). Whole plant regeneration was carried out by direct organogenesis from leaf explant in Murashige and Skoog (MS) and B5 media supplemented with naphthalene acetic (NAA) acid and indole-3-butyric acid (IBA). The highest callus quantity was produced in MS medium supplemented with indole-3-acetic acid (IAA) and benzyl amino purine (BAP). The combination and concentrations of PGRs used in MS and B5 media not only provided root and shoot formation with callus, but also caused a change in the amounts of phenolic components. In addition, some PGRs used caused an increase in the number of phenolic compounds in callus and shoots developed from the leaf explant. When plants that grow in vitro and in vivo are compared with each other, it has been determined that plants grown in vivo contain higher amounts of some phenolic compounds. In vivo and in vitro samples were extracted in ethanol/water (80:20 v/v). The analysis of phenolic compounds (caftaric, chicoric, and chlorogenic acids and esculin) were performed in high-performance liquid chromatography (HPLC) and inulin was in UV spectrophotometry. The caftaric and chlorogenic acids and inulin concentrations were higher in vivo samples than that in vitro. Contrarily, esculin, and chicoric acid concentrations were higher in the in vitro regenerated samples. The higher concentration of valuable compounds in the in vitro regenerated samples, especially in callus tissue, gives hope for large-scale production of secondary metabolites under laboratory conditions.

Production and evaluation of novel functional extruded corn snacks fortified with ginger, bay leaves and turmeric powder

Extruded corn snacks are accepted by all human ages especially children, but they have low functional value. Therefore, corn extruded snacks contain rich nutraceuticals dried herbs including Laurus nobilis (T1), Curcuma longa (T2), Zingiber officinale Roscoe (T3), and the mixture of these herbs (T4) were manufactured and analyzed. The results declared that all the herbal extruded corn snacks had significantly higher ash, fibers, minerals, and vitamins A and B6. For minerals, the highest percent of increase compared to control was achieved by Fe, K, Ca, Zn content in order, being the highest in T4. The contents of Vitamin A and B6 were ranged from 283 to 445 IU/100 g and from 0.01 to 0.08 mg/100 g for the herbal extrudates, respectively. The increased percent in herbal corn snacks relative to control ranged from 743 to 452%, 188 to 17.6%, and from 313 to 99% for total phenolics, flavonoids, and antioxidant activity. Besides, the highest number of phenolic compounds was recorded in T4. Despite the fact that approximately all herbal extruded products had good texture and color characteristics, the best formulation was T2 and T4 corn snacks. Furthermore, the extruded products were microbiologically safe for up to 9 months. The formulation of herbal-corn snacks could fulfill consumers’ requirement for ready-to-eat-healthy foods with acceptable sensory attributes and also economically suitable for the food industry.Graphical abstract

Characterization of pseudo-fruits of Hovenia dulcis T. at different maturation stages and drying methods

The vast majority of fruits and unprocessed vegetables, have a very short shelf life, mainly due to its high-water activity. Drying technology is an effective process, used to increase the shelf life of these products. It also can provide an effective method of consumption of fruits in food products. In this study, the influence of the maturation stage and drying method on the phenolic compounds and antioxidant activities of Japanese grape pseudo-fruits (Hovenia dulcis T.) were studied. The centesimal composition, reducing sugars and nonreducing sugars, ratio, color, phenolic compounds and antioxidant activity by oxygen radical absorbance capacity (ORAC) of the unprocessed pseudo-fruits, at different maturation stages (immature, in maturation and mature), were analyzed. Two drying methods were employed in the pseudo-fruits (oven with air circulation and freeze drying) obtaining flour from which moisture content, instrumental color, phenolic compounds and antioxidant activity were determined. The unprocessed pseudo-fruits of Japanese grape showed significant content of phenolic compounds at the early stages of maturation and high antioxidant capacity when mature (at the final stages of maturation). In addition, they showed a high content of fibers and sugars, and can be used as raw material in the food industry. After dehydration, the freeze-drying process provided a more stable color, because this process minimizes the enzymatic browning reactions, and preserved a greater number of phenolic compounds. The antioxidant activity, however, showed to be associated with the drying method, being higher in the flour obtained from lyophilized immature pseudo-fruits.

Magnetite Nanoparticles Different Sizes Effectiveness On Growth And Secondary Metabolites In Ginkgo Biloba L. Callus

This study investigated the effects of magnetite nanoparticles (MNPs) various sizes (10.77, 20.5, and 29.3 nm), and different concentrations (0.5, 1, and 2 ppm) on the growth and production of active constituents in Ginkgo biloba L callus. The best medium for callus growth and proliferation of Ginkgo biloba L was MS medium supplemented with 1 ppm naphthalene acetic acid (NAA), 1 ppm Kinetin, and 0.5 ppm MNPs with a size of 10 nm, which gave the maximum fresh weight of callus and percentage increase in fresh weight after two subcultures. The maximum accumulation of ginkgolide A and bilobalide were achieved when callus was elicited by MNPs 10 nm at 2 ppm. This study also focused on estimating phenolic compounds and scavenging free radicals (antioxidant activity) for their indirect effect on active constituents production. Also, MNPs different sizes had a clear effect on the number of phenolic compounds, where the maximum values were recorded with (2 ppm + size 10.77 nm). The major components were quercetin, kaempferol, p-coumaric acid, rutin, and caffeic acid. Moreover, the highest percentage of antioxidant activity (DPPH) was recorded when callus treated with (2 ppm + size 10.77 nm) which reached 77.29 %. This study highlights the importance of MNPs for the production of ginkgolide A and bilobalide from Ginkgo biloba L. and focusing on the relationship between their size and concentration. Besides, to provide a good and permanent source of active substances of medical and industrial importance on a large scale and at the lowest cost.

Are biosynthesized nanomaterials toxic for the environment? Effects of perlite and CuO/perlite nanoparticles on unicellular algae Haematococcus pluvialis.

The properties of nanomaterials such as perlite nanoparticles and their increased application have raised concerns about their probable toxic impacts on the aquatic ecosystems and algae. Here, a novel biochemical synthesis and immobilization of CuO is reported on perlite nanoparticles (CuO/Per-NPs) and its toxic effect on alga has been compared with nanoperlites. This biosynthesis of CuO/Per-NPs performed using phytochemicals of Haematococcus pluvialis, Sargassum angustifolium, and walnut leaves in the aqueous extract. The structural, morphological, and colloidal properties of the as-synthesized nanoparticles have been confirmed by various methods. According to the obtained results, the morphology of the synthesized CuO/Per-NPs was spherical with sizes ranging from about 13 to 24 nm. Besides, the effects of Per-NPs and CuO/Per-NPs on unicellular algae H. pluvialis were studied. The changes in the amount of chlorophyll a, chlorophyll b, and Carotenoids in the presence of different concentrations of Per-NPs (25, 50, 100 mg/L) were more than CuO/Per-NPs. Also, decreased growth rate and efficiency of photosystem II confirmed the toxic effects of Per-NPs. However, the toxicity of CuO/Per-NPs appears to be lower than that of Per-NPs, which can be due to the changes in the surface and cationic charge of modified nanoperlit. These changes lead to a decrease in the interaction of nanoparticles with H. pluvilalis and a reduction in ROS production. Finally, the results of GC-MS used to evaluate volatile compounds, indicated an increase in the number of phenolic compounds in comparison to the control samples in 25, 50, and 100 mg/L treatments of nano-perlite.

Involvement of Phenolic Compounds and Their Composition in the Defense Response of Fusarium oxysporum infected Berangan Banana Plants

Fusarium wilt is one of the most common destructive banana diseases which causes great losses to the global banana production. Berangan banana, known to be very susceptible towards this disease is greatly affected. Upon infection, oxidative burst involving rapid accumulation of reactive oxygen species is one of the first responses of a plant defense against biotic and abiotic stress. Secondary metabolites play an essential role in scavenging these toxic reactive radicals. In this study, a number of phenolic compounds and flavonoids were identified and the changes were documented. Compounds such as quinic acid, ferulic acid, caffeoyl glucose, p-coumaric acid, syringic acid, sinapic acid, aconitic acid, caffeic acid, p-hydroxybenzoic acid, ascorbic acid, kaempferol-rhamnose-hexose, quercetin, catechin, rutin, and isorhamnetin 3-O rutinoside increased after fungal infection. Concomitantly, DPPH radical scavenging activity, reducing power, total antioxidant activity, total flavonoid content and total polyphenol content also increased. Polyphenols, flavonoid content and antioxidant activities increased significantly on day 1 and continued to increase until day 6 before gradually declining. The phenolic and flavonoid profiles were analysed using liquid chromatography - mass spectroscopy (LCMS). The antioxidant properties were found to be closely related to plant defense system.

Antioxidant and antimicrobial responses associated with in vitro salt stress of in vitro and in vivo grown Pistacia khinjuk stocks

P. khinjuk Stocks, known as Bıttım or Buttum in Turkey, is a member of the Anacardiaceae family. The essential oil of khinjuk pistachio has been used to treat various illnesses because of their anti-inflammatory, anticancer, antipyretic, antibacterial, anthelmintic, antiviral effects in various folk medicines. At the same time, fruits of khinjuk pistachio are used as edible wild fruits. In this study, it was aimed to determine and compare the antibacterial, antioxidant activities and total phenolic and flavonoid amounts of different parts (root, stem and leaf explants) of in vivo (grown naturally) and in vitro derived khinjuk pistachio plants under salt (NaCl) stress. Ethanol extracted explants were used for performing biological and chemical parameters. According to the results, generally, in vivo samples shows higher antioxidant and antimicrobial activity besides the higher number of phenolic compounds than their counterparts in vitro. We have also determined that the biological activity of in vitro salt elicited explants was higher than in vitro control explants. Generally, both female and male in vivo samples have higher antioxidants (DPPH, ABTS, CUPRAC) and antimicrobial activities than in vitro samples. The various plant parts (root, stem, leaf) belonging to both in vivo and in vitro samples have different biological activity level. In terms of antimicrobial activity, female plant extracts are more active than all other tested extracts. As a result, although increased salinity values significantly reduced antimicrobial activity, it is determined that 100 mM NaCl applications to in vitro leaf extracts exhibited moderate antimicrobial activity against S. aureus and C. albicans.

Optimization of Microwave and Ultrasound Extraction Methods of Açai Berries in Terms of Highest Content of Phenolic Compounds and Antioxidant Activity

Rapid technological progress focuses on lowering costs, labor and time. Thus, in order to minimize the expenses of bioactive compound production, great effort is undertaken to optimize the extraction of these compounds. Green extraction is popular and relatively inexpensive. However, the same extraction method does not always work for all types of matrixes due to the biological diversity of the tissue. Therefore, the purpose of this study was to identify the optimal green extraction method of açai berries (ultrasound or microwaves) able to isolate extracts containing the highest possible number of phenolic compounds with the highest antioxidant activity. The results show that the highest content of total phenolic compounds in the extracts was obtained after the application of a temperature of 45 °C, using ultrasound for 25 min and 45 min, microwaves for 3.16 min and a water bath for 25 min. Ultrasound turned out to be the most effective method of flavonoid extraction. In turn, the highest anthocyanin content was obtained for microwave extraction. Additionally, the application of microwaves for 4.33 min (45 °C) guaranteed the highest ferric-reducing antioxidant activity (FRAP) among the extracts. The results show that the use of microwaves shortens the açai extraction time and ensures both a high content of total phenolic compounds and strong antioxidant activity in the extract.

Bioanalytical method validation for the quantification of the chlorogenic acid in Capsicum baccatum through High Performance Liquid Chromatography (HPLC-DAD)

The fruit pulp extracts of the species Capsicum baccatum are associated with a number of phenolic compounds. The aim of this study was to validate a bioanalytical method for the quantification of the chlorogenic acid present in the UENF 1613 de C. baccatum accession. The quantification was carried out through HPLC. The results obtained for the extract of C. baccatum indicated selectivity for chlorogenic acid. The values obtained for relative standard deviation, as well as for precision, in terms of repeatability and intermediate precision, did not exceed the maximum of 15% set in the criteria for the acceptance of bioanalytical methods. In terms of recovery, the accuracy rate for the phenolic compound of interest was from 77 to 93%. The validated method through external standardization was applied for the quantification of chlorogenic acid of the UENF accession.

Assessment of oxidative stability and physicochemical, microbiological, and sensory properties of beef patties formulated with baobab seed (Adansonia digitata) extract

The present study was conducted to evaluate the oxidative stability and the physicochemical, microbiological, and sensory properties of beef patties formulated with different concentrations (1%, 2%, and 3%) of baobab seed extract (BSE) during storage at 4 °C. The BSE contained a considerable number of phenolic compounds and exhibited antioxidant and antimicrobial activities (both on gram-positive and negative bacteria). The chemical composition of the patties was not altered by BSE treatment. However, the addition of 2% and 3% BSE improved the lipid stability and enhanced the antioxidant activity of beef patties during storage. Furthermore, the shelf-life of patties formulated with 2% and 3% of BSE increased from 7 days (control group) to 21 days. Moreover, the patties formulated with BSE received overall acceptability in the sensory evaluation. In conclusion, the inclusion of 2% or 3% BSE could be recommended as a natural antioxidant additive in beef patties.

BIOLOGICAL ACTIVITY OF ENDOMETABOLITES FROM SUGAR BEET (BETA VULGARIS L.) PERICARPS

Biologically active compounds of secondary metabolism are crucial for the regulation of seed germination and sprout development. The pericarp of sugar beet (Beta vulgaris L.) contains such substances. The research was focused on the extraction of the secondary metabolites and the effect of multicomponent endometabolites from sugar beet pericarps on the germination of plant seeds. The chemical composition of the metabolites and sugar beet pericarps was determined by thin-layer chromatography; differentiated separation was carried out using column chromatography and gel filtration; the total content of phenolic compounds in seed balls and pericarps was determined by the method of spectrophotometry. Pericarps of sugar beet contain a great number of phenolic compounds that have a protective function. We selected four groups of phenolic compounds of different molecular weights, the share of which averaged 5˗10 %. When studying the effect of aqueous extracts on radish seeds it was found that the eluents of the first volumes of water (3˗5 ml) showed a clear stimulating effect, while further volumes of eluents (8-9 ml) had inhibitory action. In extracts of sugar beet pericarps, phenols, flavonoids and their glycosides were found, which are highly active inhibitors and growth promoters and can be used as natural biologically active compounds.

Evaluated bioactive component extracted from Punica granatum peel and its Ag NPs forms as mouthwash against dental plaque

Abstract The bioactive components of the hydroalcoholic (MeOH 70%) Punica granatum peel crude extract (PGPC) and its methanol fraction (PGPM) were extracted and tentatively identified by LCMS/MS as a number of phenolic compounds which are used as capping agents fasting the reduction of Ag+ to Ag (0). The prepared silver nano-particles Ag NPs PGPC and Ag NPs PGPM were characterized by the transmission electron microscopy (TEM) and UV–vis spectra. Four mouthwashes were designed using PGPC, PGPM, Ag NPs PGPC and Ag NPs PGPM. The prepared mouthwashes exhibited a significant antimicrobial activity against the Streptococcus mutans and the three dental plaque isolates called Lysinibacillus cresolivorans, Lysinibacillus cresolivorans and Lysinibacillus boronitolerans. As well as, the prepared Ag NPs mouthwashes led to reduction in the cytotoxicity against BJ-1 cell line equal 35 and 23.66% with LC50 = 185.16 and 134.8 μg/mL. Finally, phenolics promote Ag NPs PGPM mouthwash to be potent anti-calculus and anti-hemorrhagic agents.

Dormancy-defense syndromes and tradeoffs between physical and chemical defenses in seeds of pioneer species.

Seeds of tropical pioneer trees have chemical and physical characteristics that determine their capacity to persist in the soil seed bank. These traits allow seeds to survive in the soil despite diverse predators and pathogens, and to germinate and recruit even decades after dispersal. Defenses in seedlings and adult plants often are described in terms of tradeoffs between chemical and physical defense, but the interplay of defensive strategies has been evaluated only rarely for seeds. Here we evaluated whether classes of seed defenses were negatively correlated across species (consistent with tradeoffs in defense strategies), or whether groups of traits formed associations across species (consistent with seed defense syndromes). Using 16 of the most common pioneer tree species in a neotropical lowland forest in Panama we investigated relationships among four physical traits (seed fracture resistance, seed coat thickness, seed permeability, and seed mass) and two chemical traits (number of phenolic compounds and phenolic peak area), and their association with seed persistence. In addition, seed toxicity was assessed with bioassays in which we evaluated the activity of seed extracts against representative fungal pathogens and a model invertebrate. We did not find univariate tradeoffs between chemical and physical defenses. Instead, we found that seed permeability - a trait that distinguishes physical dormancy from other dormancy types - was positively associated with chemical defense traits and negatively associated with physical defense traits. Using a linear discriminant analysis and a hierarchical cluster analysis we found evidence to distinguish three distinct seed defense syndromes that correspond directly with seed dormancy classes (i.e., quiescent, physical, and physiological). Our data suggest that short and long-term persistence of seeds can be achieved via two strategies: having permeable seeds that are well defended chemically, corresponding to the physiologically dormant defense syndrome; or having impermeable seeds that are well defended physically, corresponding to the physically dormant defense syndrome. In turn, transient seeds appear to have a lower degree of chemical and physical defenses, corresponding to the quiescent defense syndrome. Overall, we find that seed defense and seed dormancy are linked, suggesting that environmental pressures on seed persistence and for delayed germination can select for trait combinations defining distinct dormancy-defense syndromes.

An Amperometric Sensor Based on Tin Dioxide and Cetylpyridinium Bromide Nanoparticles for the Determination of Vanillin

Voltammetric characteristics of vanillin are determined using electrodes modified with tin dioxide nanoparticles dispersed in surfactants of various nature in the Britton–Robinson buffer solution. The best characteristics are observed for a glassy carbon electrode modified by a dispersion of SnO2 nanoparticles in cationic cetylpyridinium bromide (SnO2–CPB/GCE). The electrode is characterized by cyclic voltammetry and electrochemical impedance spectroscopy. A fourfold increase in the effective surface area of SnO2–CPB/GCE and a significant decrease in charge transfer resistance are shown in comparison with a GCE. The electrooxidation of vanillin proceeds irreversibly with the participation of two electrons and two protons and is controlled by the diffusion of the analyte. A sensor based on a SnO2–CPB/GCE was developed to determine vanillin; it functions under conditions of differential pulse voltammetry. The analytical ranges for vanillin are 0.10–100 and 100–500 µM with the limits of detection and quantification 20 and 67 nM, respectively. The developed sensor is selective to vanillin in the presence of inorganic ions, saccharides, ascorbic acid, and a number of phenolic compounds. The sensor is used for the determination of vanillin in perfumes for household chemicals and vanilla essential oils. The results are in good agreement with the data of gas chromatography.

Antioxidant and vasorelaxant activities induced by northeastern Brazilian fermented grape skins

BackgroundIn northeastern Brazil, grape pomace has become a potential alternative byproduct because of the recover phenolic compounds from the vinification process. Comparative analyses were performed between lyophilized extract of grape skins from pomace, described as fermented (FGS), and fresh, unfermented (UGS) grape skins to show the relevant brand’s composition upon the first maceration in winemaking.MethodsThe use of in vitro testing such as Folin-Ciocalteu’s, DPPH free radical scavenger and HPLC methods were performed to evidence antioxidant effect and phenolic compounds. Additionally, vascular reactivity studies were performed in third-order branches of rat superior mesenteric arteries, which were obtained and placed in organ baths containing Krebs-Henseleit solution, maintained at 37 °C, gassed with a mixture of 95% O2 and 5% CO2, and maintained at pH 7.4. The in situ formation of reactive oxygen species (ROS) was evaluated in small mesenteric rings using oxidative fluorescent dihydroethidium dye.ResultsWe found higher phenolic content and antioxidant activity in FGS when compared to UGS. HPLC analyses identified a significant number of phenolic compounds with antioxidant potential in both samples. The vasorelaxant effect induced by FGS was more potent than that induced by UGS, and the activity was attenuated after removal of vascular endothelium or by blockade of endothelium-derived relaxing factors, such as NO and EDHF.ConclusionsThe FGS extract may be a great source of natural polyphenol products with potent antioxidant effects and endothelium-dependent vasodilatory actions involving NO and EDHF pathways.