Antioxidant capacity and antibacterial activity of phenolic compounds from argentinean herbs infusions

Exploring the Impact of Infusion Parameters and In Vitro Digestion on the Phenolic Profile and Antioxidant Capacity of Guayusa (Ilex guayusa Loes.) Tea Using Liquid Chromatography, Diode Array Detection, and Electrospray Ionization Tandem Mass Spectrometry

Guayusa tea is derived from the leaves of the Ilex guayusa Loes. plant, which is native to the Amazon rainforest. Beyond its pleasant sensory properties, Guayusa tea is rich in antioxidants, phenolics, and minerals. In this study, the effects of infusion time, temperature, and solvent conditions on the color, antioxidant capacity, total phenolic content, phenolic profile, and antimicrobial activity of Guayusa (Ilex guayusa Loes.) tea were investigated. Guayusa tea samples were prepared using two different solvents, ethanol and water, with 4, 6, and 8-h infusions at 60 and 70 °C. Liquid chromatography, diode array detection, and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) were used to determine a comprehensive profile of phenolic compounds and to detect differences due to infusion conditions. Moreover, after the Guayusa tea infusion with the highest bioactive properties was determined, the effects of in vitro gastrointestinal digestion on the total phenolic content, antioxidant capacity, and phenolic compounds of the Guayusa tea infusion were measured. Phenolic profile analysis identified 29 compounds, among which chlorogenic acid and its derivatives were predominant. The increase in infusion time was correlated with an elevation in total phenolic content. Significant differences were observed between water and ethanol infusions of Guayusa in terms of phenolics and antioxidants. The total amount of phenolic compounds in the samples prepared with both solvents was found to increase after oral intake, depending on the digestion stage; meanwhile, the amounts of flavonoid compounds and di-O-caffeoylquinic acid derivatives decreased during digestion.

Antioxidant Activity of Medicinal Herbs and Spices from Plants of the Lamiaceae, Apiaceae and Asteraceae Families: Chemometric Interpretation of the Data

Plant products, especially medicinal herbs and spices, have been used for centuries as a remedy to support human health and improve the flavor of food. Therefore, the purpose of this study was to identify plant species distinguished by their high content of phenolic compounds and high antioxidant activity using advanced multivariate statistical techniques such as Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). To realize the purpose of the study, the total phenolic (TPC) and flavonoids (FC) content, antioxidant activity (TAC) and Fe(II) ion chelating capacity (FIC) of medicinal herbs and spices from plants belonging to three botanical families, Lamiaceae, Apiaceae and Asteraceae were determined. The interpretation of the obtained data revealed that the studied samples are localized in the PCA and HCA plots according to their TPC, FC, TAC and FIC values. Chemometric analysis confirmed that medicinal herbs and spices from plants belonging to the Lamiaceae family are richer sources of phenolic compounds and exhibit stronger antioxidant activity than those raw materials from plants in the Apiaceae family. In addition, no significant differences were found in terms of TPC, FC, TAC and FIC values between medicinal herbs and spices from the same plant species, i.e., oregano (Origanum vulgare), common thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), caraway (Carum carvi) and lovage (Levisticum officinale). A close relationship between antioxidant properties and contents of phenolic compounds was also confirmed.

Sourcing New Ingredients for Organic Cosmetics: Phytochemicals of Filipendula vulgaris Flower Extracts

Plant extracts are well known for their beneficial cosmetic properties based on bioactive phytochemicals with highly demonstrated antimicrobial and antioxidant capacities as phenolic compounds. This work presents the polyphenolic characterization of different extracts from organically grown Filipendula vulgaris. An ultrasound-assisted extraction procedure is proposed for obtaining ethanolic extracts at the laboratory level, both from dried and fresh plants, to be compared with those obtained by classical flower processing techniques for cosmetic purposes. The individual quantification of target phenolic compounds was carried out using liquid chromatography-mass spectrometry (LC-MS/MS). The results revealed the presence of 24 phenolic compounds in the analyzed samples, ranging in concentrations from 0.1 to 71.64 µg g−1. The total phenolic content (TPC) ranging from 1163 to 6114 mg GAE L−1, and the antioxidant activity (AA), from 6 to 52 mmol TRE L−1, were also evaluated. The differences were established between the plant material and extraction technique.

Effect of dragon fruit peel powder on quality and acceptability of fish nuggets stored in a solar cooler (5 ± 1 °C)

Fish nuggets were prepared with dragon fruit peel powder (1.0, 1.5 and 2.0% w/w) to evaluate its quality and improvement in shelf-life during 15 days storage in a prefabricated solar cooler (5 ± 1 °C). Antioxidative and antimicrobial effects of dragon fruit peel powder in fish model system were also evaluated during storage. Results showed that dragon fruit peel is a good source of dietary fibre (59.8%) and phenolic compounds [65.7 mg Gallic Acid Equivalent (GAE)/100 g of sample] and contained 6.03% protein, 6.14% fat and 4.34% ash. Use of dragon fruit peel powder significantly (p < 0.05) improved the emulsion stability and cooking yield and nuggets with peel powder had lower pH value than control. Fish nuggets with peel powder showed gradual decrease (p < 0.05) in hardness, springiness, cohesiveness, gumminess and chewiness with advancement of storage period. Nuggets with 1.5% dragon fruit peel showed better sensory attributes compared to the others. Dragon fruit peel powder significantly inhibited (p < 0.05) the lipid oxidation and microbial load in fish nuggets during the storage period. So, it can be concluded that dragon fruit peel powder may be used as antioxidant dietary fibre for improved quality and acceptability of fish nuggets in prefabricated solar cooler. 1.5% level of incorporation showed better results in terms of antioxidant activity and better shelf-life of the fish nuggets.

Evaluation of coloration, nitrite residue and antioxidant capacity of theaflavins, tea polyphenols in cured sausage

This study evaluated the effects of theaflavins (TFs), tea polyphenols (TP) and vitamin C (VC) on the nitrite residue amount, color, antioxidant capacity and N-nitrosamines inhibition in cured sausage. The addition of TFs, TP and VC combined with NaNO₂ respectively could significantly increase the a* value, nitroso pigment content and DPPH free radical scavenging rate, and effectively reduced the content of residual nitrite, metmyoglobin (MetMb) and total N-nitrosamines in cured sausages than treated only with NaNO₂ (P < 0.05), of which TFs group was the most significant (P < 0.05). It was indicated that the addition of TFs, TP could better inhibit the oxidation of cured sausages. UV-vis spectroscopy also showed pentacoordinate nitrosyl ferrohemochrome was the main pigment component in the samples. The results demonstrated that TFs and TP could contribute to the desired color and safety of sausage.

Glochidion wallichianum Leaf Extract as a Natural Antioxidant in Sausage Model System

This study highlighted the role of an 80% ethanolic Mon-Pu (Glochidion wallichianum) leaf extract (MPE), a novel natural antioxidative ingredient, in controlling the oxidative stability and physicochemical properties of a cooked sausage model system (SMS). MPE had a total extractable phenolic content of 16 mg/100 g, with DPPH● scavenging activity, ABTS●+ scavenging activity, and ferric reducing antioxidant power of 2.3, 1.9, and 1.2 mmole Trolox equivalents (TE)/g, respectively. The effects of different concentrations of MPE (0.01−10%, w/w) formulated into SMS on lipid oxidation, protein oxidation, and discoloration were compared to synthetic butylated hydroxyl toluene (BHT; 0.003%, w/w) and a control (without antioxidant). The peroxide value (PV), thiobarbituric acid reactive substances (TBARS), and protein carbonyl contents of SMS tended to increase with increasing MPE concentration (p < 0.05), indicating that high MPE excipient has a pro-oxidative effect. The lowest lipid oxidation (PV and TBARS) and protein carbonyl contents were observed when 0.01% MPE was used to treat SMS (p < 0.05), which was comparable or even greater than BHT-treated SMS. High concentrations (1−10%) of MPE incorporation led to increases in the discoloration of SMS (p < 0.05) with a negligible change in pH of SMS. The water exudate was reduced when MPE was incorporated into SMS compared to control (p < 0.05). Furthermore, MPE at 0.01% significantly reduced lipid oxidation in cooked EMS during refrigerated storage. According to the findings, a low amount of MPE, particularly at 0.01%, in a formulation could potentially maintain the oxidative stability and physicochemical qualities of cooked SMS that are comparable to or better than synthetic BHT.

Chemometric Profiling and Bioactivity of Verbena (Aloysia&nbsp;citrodora) Methanolic Extract from Four Localities in Tunisia

This research aimed to study the chemical composition of Aloysia citrodora methanolic extract and its biological activities as an antioxidant, and its antibacterial, antifungal and anti-inflammatory activities based on four bioclimatic collection stages. The contents of total phenols, total flavonoids and total tannins were determined. Nine phenolic compounds were identified by LC-DAD-ESI-MS/MS. The major compound was acteoside, a phenylpropanoid which represented about 80% of the methanolic fraction in the various regions. The antioxidant activities of different locations were measured by different analytical assays, such as DPPH, ABTS and iron reducing power. The results showed that phenolic compounds and antioxidant activities varied with climatic and environmental factors. Moreover, there was a significant dependency between regions and biological activities. The use of a principal component analysis showed that there was a close relationship among phenylpropanoids, phenolic compounds and the studied biological activities.

Evaluation of the Potential of Marine Algae Extracts as a Source of Functional Ingredients Using Zebrafish as Animal Model for Aquaculture

Research on immunotherapeutic agents has become a focus for the treatment of fish diseases. The ability of algae to produce secondary metabolites of potential interest as immunotherapeutics has been documented. The present research intended to assess antiviral and antibacterial activities of macro- and microalgae extracts against viral and bacterial pathogens and explore their immunomodulatory potential using zebrafish (Danio rerio) larvae as a model organism. The cytotoxicity and antiviral activity of eight methanolic and ethanolic extracts from two macroalgae (Fucus vesiculosus, Ulva rigida) and two microalgae (Nannochloropsis gaditana, Chlorella sp.) were analyzed in established fish cell lines. Six extracts were selected to evaluate antibacterial activity by disk diffusion and growth inhibition assays. The three most promising extracts were characterized in terms of fatty acid composition, incorporated at 1% into a plant-based diet, and evaluated their effect on zebrafish immune response and intestinal morphology in a short-term feeding trial. All extracts exhibited in vitro antiviral activity against viral hemorrhagic septicemia and/or infectious pancreatic necrosis viruses. Methanolic extracts from F. vesiculosus and U. rigida were richer in saturated fatty acids and exhibited in vitro antibacterial action against several bacteria. Most promising results were obtained in vivo with F. vesiculosus methanol extract, which exerted an anti-inflammatory action when incorporated alone into diets and induced pro-inflammatory cytokine expression, when combined with the other extracts. Moreover, dietary inclusion of the extracts improved intestinal morphology. In summary, the results obtained in this study support the potential of algae as natural sources of bioactive compounds for the aquaculture industry.

Relationship between Total Phenolic Content, Antioxidant Capacity, Fe and Cu Content from Tea Plant Samples at Different Brewing Times

The purpose of this study was to investigate the antioxidant capacity of different tea plant: mint, linden, chamomile, St. John’s wort, green and black tea in relation to total phenolic content. The antioxidant capacity of the tea infusions at different brewing times was determined using DPPH assay while the total phenolic content (TPC) was assessed using the modified Folin-Ciocalteu method. The results showed that there were significant statistical differences in antioxidant capacity depending on infusion time, according to one-way ANOVA analysis. Leaves used as components of tea infusions were analyzed by FAAS for their content of iron and copper in the dry product and in the infusion. The correlation between TPC and DPPH capacity of tea plant infusions was evaluated by Pearson correlation matrix. Total phenolics compounds content was positively and significantly correlated with DPPH capacity for all infusions time. Significant correlation was observed between TPC and the copper concentration (p < 0.05). Consequently, the correlations between the physicochemical parameters, TPC, DPPH capacity, Fe and Cu content suggested that the TPC may be a good indicator of the DPPH capacity in the tea infusions and also, suggested the influence of antioxidant compounds on mineral bioavailability.

Maclura tinctoria Extracts: In Vitro Antibacterial Activity against Aeromonas hydrophila and Sedative Effect in Rhamdia quelen

Maclura tinctoria is a tree species native from Brazil and rich in phenolic compounds. Since plant antibacterial activity is highly associated with phenolic compound concentration, we aim to evaluate the in vitro antimicrobial activity of different extracts against fish pathogenic bacteria. In addition, some phenolic compounds have central depressant effects and can be useful in aquaculture due to possible sedative and/or anesthetic effects. Four M. tinctoria extracts were extracted separately with ethanol; leaves (LE), bark (BE), heartwood (HE), and the sapwood (SE). In vitro antimicrobial activity was tested against Aeromonas strains at concentrations of 6400 to 3.125 μg/mL. The sedative effect was evaluated for 24 h with 30 and 100 mg/L concentrations. Chemical composition was analyzed by HPLC-DAD-MS. The HE extract had the best MIC (400 µg/mL) and MBC (800 µg/mL) compared to the LE, BE, and SE extracts. LE extract induced deep sedation and the BE, SE, and HE extracts induced light sedation. Additionally, BE, SE, and HE induced a normal behavior without side effects. Polyphenolic compounds with antimicrobial activity and sedative effects were identified mainly in HE. Thus, HE extract is safe and can be used as a sedative for silver catfish.

Effect of Cocoa Bean Shell Addition on Metabolite Profile and Antioxidant Activity of Herbal Infusions

Cocoa bean shell (CBS) is a by-product with aromatic characteristics that can enhance the aroma and bioactivity of herbal infusions. This study was aimed to determine the effect of the addition of cocoa bean shell on the metabolite profile and antioxidant activity of infusions made with Ilex guayusa and Vernonanthura patens and their mixtures. Metabolite profile was analyzed by gas chromatography–mass spectrometry combined with multivariate analysis. Total polyphenol content and flavonoids were determined by the Folin-Ciocalteu method and by the flavonoid-AlCl3 complex, respectively. Antioxidant activities were measured by the decolorization assay of the 2,2-diphenyl-1-picrylhydrazyl radical and the ferric reducing antioxidant power. The results revealed that the addition of CBS increases the content of phenolic acids in the infusions (caffeic acid, 4-hydroxybenzoic acid, and pyrocatechol). Nonetheless, the antioxidant activity of the infusions decreased with the addition of CBS (16.21 to 2.74 TEAC). Carboxylic acids and derivatives, major compounds present in the infusions prepared with V. patens, were the metabolites that showed the highest correlation with the antioxidant activity. This study suggests that the infusions made with CBS present a profile of metabolites different from the infusions of I. guayusa, V. patens, and their mixtures.

Spicy Herb Extracts as a Potential Improver of the Antioxidant Properties and Inhibitor of Enzymatic Browning and Endogenous Microbiota Growth in Stored Mung Bean Sprouts

The quality and shelf life of sprouts can be improved by postharvest application of water herb extracts. The effect of water infusions of marjoram, oregano, basil, and thyme on the phenolic content, antioxidant potential, and the microbiological and consumer quality of stored mung bean sprouts was studied. Compared to the control, the treatments increased total phenolic content. The highest amounts were determined in sprouts soaked in the thyme extract (6.8 mg/g d.m.). The infusions also inhibited the activity of enzymes utilizing phenolics, and marjoram and oregano were found to be the most effective. The increase in the level of phenolics was reflected in enhanced antioxidant properties (ability to quench cation radical ABTS^•+, reducing and chelating power). Both total phenolics and flavonoids, as well as antioxidant capacities, were highly bioaccessible in vitro. All the natural extracts effectively reduced the growth of total mesophilic bacteria, coliforms, and molds (they were more effective than ascorbic and kojic acids). The treatments did not exert a negative influence on the sensory properties or nutritional value of the sprouts, and even improved starch and protein digestibility. These results are very promising and may suggest a wider used of natural extracts as preservatives of minimally processed food.

Kenaf (Hibiscus cannabinus L.) Leaves and Seed as a Potential Source of the Bioactive Compounds: Effects of Various Extraction Solvents on Biological Properties

Hibiscus cannabinus (Kenaf) is a potential source of bioactive constituents and natural antioxidant. The current study determined the impact of various solvents on extraction yield, recovery of polyphenol and flavonoid, antioxidant, anticancer, and antibacterial properties of Kenaf leaves and seed. The powder of leaves and seed was separately extracted with n-hexane, ethyl acetate, ethanol, and water solvent. Among them, the ethanol extract of leaves and seed showed the highest extraction yield, and their GC-MS analysis revealed a total of 55 and 14 bioactive compounds, respectively. The total polyphenols (TP) and flavonoids (TF) content were quantified by a spectrophotometric technique where water extracts displayed a noteworthy amount of TP and TF content compared to other extracts. A similar demonstration was noticed in antioxidant activity, evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydrogen peroxide scavenging capacity. In addition, cytotoxicity and anti-lung cancer activity were identified against mouse embryonic fibroblast (NIH3T3) and human lung cancer (A549) cells. All extracts of leaves and seed were observed as non-toxic to the NIH3T3 cells, but slight toxicity was expressed by n-hexane extracts at the optimum dose (1000 µg/mL) of treatment. In parallel, n-hexane and ethanol extracts (leaves and seed) exposed promising anti-lung cancer activity at the same concentration. Furthermore, antibacterial activity was assessed using disc diffusion assay, and seed extracts exhibited a significant inhibition zone against Gram-positive and Gram-negative microorganisms. Overall, Kenaf seed extracted with polar solvents was found very potent in terms of important bioactive compounds and pharmacological aspects, which can be an excellent biological matrix of natural antioxidants.

Antibacterial and in vitro antidementia effects of aronia (Aronia melanocarpa) leaf extracts

This study investigated the antibacterial and in vitro antidementia effects of aronia (Aronia melanocarpa) leaf extracts from 3 cultivars (Nero, Viking, and McKenzie) collected at three different stages of maturity (young, harvest, and old). Bacillus cereus was susceptible to the old leaves of cultivars McKenzie and Nero, whereas Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria innocua were not inhibited by any of the extracts. Growth of B. cereus was inhibited by cv. McKenzie, resulting in increased lag time, whereas Nero had both an inhibitory and an inactivation effect. Except for cv. Viking at harvest stage, the acetylcholinesterase and butyrylcholinesterase inhibitory activity of aronia leaf extracts were about 60-70 and 70-80%, respectively. Therefore, aronia leaf is a natural resource with a potentially potent antidementia effect, besides antibacterial activity.

Tannin fraction of pistachio green hull extract with pancreatic lipase inhibitory and antioxidant activity

Polyphenolic compounds (present in different parts of the plant) have beneficial properties such as antioxidant and inhibition of key enzymes. In this research, antioxidant and anti-lipase activity of pistachio green hull (PGH) extract was investigated. Fractionation of PGH on Sephadex LH-20 furnished a tannin enriched fraction with higher antioxidant activity respect to that of the extract and of the non-tannin fraction. UHPL/MS² analyses showed the presence of phenolic compounds including galloyl-O-hexoside, galloyl-shikimic acid, galloylquinic acid, and gallic acid in tannin fraction. PGH-extract was an un-competitive inhibitor against porcine pancreatic lipase so that its IC₅₀ value was 2.26 mg/ml. In the same phenol amount (490 µg), anti-lipase activity of the tannin fraction was also more than non-tannin fraction and crude PGH-extract. This is probably due to the presence of some active polyphenolic compounds such as gallic acid. PRACTICAL APPLICATIONS: Pistachio is native to the arid regions of Central and West Asia including Iran. The green hull is main by-product of pistachio industry that has numerous phenolic compounds. Our results showed that the pistachio green hull extract has antioxidant and anti-lipase activity and these activities in its tannin fraction were higher than non-tannin fraction. Therefore, the PGH extract and its tannin fraction can be used as potential substitutes of anti-obesity drugs. This allows the use of pistachio processing waste and reduces the amount of waste.

Phytochemicals of Minthostachys diffusa Epling and Their Health-Promoting Bioactivities

The genus Minthostachys belonging to the Lamiaceae family, and is an important South American mint genus used commonly in folk medicine as an aroma in cooking. The phytochemical-rich samples of the aerial parts of Minthostachys diffusa Epling. were tested for pharmacological and health-promoting bioactivities using in vitro chemical and enzymatic assays. A range of radical scavenging activities of the samples against biological radicals such as nitric oxide and superoxide anion and against synthetic 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals, the ferric reducing antioxidant power and the lipid peroxidation inhibition were determined and ranked using the ‘relative antioxidant capacity index’ (RACI). The ethyl acetate fraction showed the highest RACI of +1.12. Analysis of the various fractions’ inhibitory ability against enzymes involved in diabetes (α-amylase and α-glucosidase), and against enzymes associated with Parkinson’s or Alzheimer’s diseases (acetylcholinesterase and butyrylcholinesterase) also suggested that the ethyl acetate fraction was the most active. Liquid chromatography–tandem mass spectrometry analysis of the ethyl acetate fraction showed more than 30 polyphenolic compounds, including triterpenes. The inhibitory cholinesterase effects of the triterpenes identified from M. diffusa were further analysed by in silico docking of these compounds into 3D-structures of acetylcholinesterase and butyrylcholinesterase. This is the first study on pharmacological activities and phytochemical profiling of the aerial parts of M. diffusa, showing that this plant, normally used as food in South America, is also rich in health-promoting phytochemicals.

New Products Generated from the Transformations of Ferulic Acid Dilactone

Various ferulic acid (FA) dimers occurring in plant cell walls, such as 8-5-, 8-O-4-, 5-5-, and 8-8- coupled dimers, are effective antioxidants and potential antimicrobials. It is necessary to access these diferulates as reference compounds to validate those isolated from plants. 3,6-bis(4-hydroxy-3-methoxyphenyl)-tetrahydrofuro-[3,4-c]furan-1,4-dione, a 8-8-coupled FA dilactone generated from ferulic acid via radical coupling, has been used to synthesize 8-8-coupled FA dimers although few reports investigated the distribution of products and mechanisms involved in the transformation of FA dilactone. In this work, the FA dilactone, obtained from FA by a peroxidase-catalyzed radical coupling, was reacted under various base/acid conditions. Effects of reaction conditions and workup procedures on the distribution of products were investigated by GC-MS. The isolated products from such treatments of FA dilactone were characterized by NMR. New derivatives of FA dimer including 2-(4-hydroxy-3-methoxybenzylidene)-3-(hydroxyl-(4-hydroxy-3-methoxyphenyl)methyl)succinic acid and 2-(bis(4-hydroxy-3-methoxyphenyl)-methyl)-succinic acid were produced from NaOH treatment. Another novel 8-8-coupled cyclic FA dimer, diethyl 6-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-methoxy-1,2-dihydronaphthalene-2,3-dicarboxylate was identified in products from FA dilactone treated by dry HCl in absolute ethanol. Mechanisms involved in such transformations were proposed.

Antibacterial Activity and Mode of Action of Dihydromyricetin from Ampelopsis grossedentata Leaves against Food-Borne Bacteria

Dihydromyricetin (DMY) has recently attracted increased interest due to its considerable health-promoting activities but there are few reports on its antibacterial activity and mechanism. In this paper, the activity and mechanisms of DMY from Ampelopsis grossedentata leaves against food-borne bacteria are investigated. Moreover, the effects of pH, thermal-processing, and metal ions on the antibacterial activity of DMY are also evaluated. The results show that DMY exhibits ideal antibacterial activity on five types of food-borne bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella paratyphi, and Pseudomonas aeruginosa). The activities of DMY against bacteria are extremely sensitive to pH, thermal-processing, and metal ions. The morphology of the tested bacteria is changed and damaged more seriously with the exposure time of DMY. Furthermore, the results of the oxidative respiratory metabolism assay and the integrity of the cell membrane and wall tests revealed that the death of bacteria caused by DMY might be due to lysis of the cell wall, leakage of intracellular ingredients, and inhibition of the tricarboxylic acid cycle (TCA) pathway.

Chemical constituents and antibacterial activities of Aspidistra typica

In the present investigation, we carried a phytochemical study of an ethanol-soluble extract from the root barks of Aspidistra typica Baill., a traditional food and herb medicine, leading to the isolation of four different kinds of compounds, including one benzene substituted coumarin, two organic phosphonic compounds, and one xanthone. The novel benzene substituted coumarin typicacoumarin A (1) was a new type of coumarin, and the two new organic phosphonic compounds, typicalphosphine A (2) and typicalphosphine B (3) were isolated for the first time, and their structures were elucidated by spectral techniques, viz.1D, 2D NMR spectra and HR-ESI-MS. The xanthone compound typicaxanthone A (4) was discovered from nature for the first time. The two new organic phosphonic chlorides (2, 3) showed stronger antibacterial activities, which were comparable to berberine hydrochloride. And typicaxanthone A (4) showed much stronger antibacterial activity against Escherichia coli ATCC-25922 bacterial strain, while typicacoumarin A (1) showed moderate antibacterial activities, weaker than berberine hydrochloride.

Antioxidant Capacity and Total Phenolic Content of Fresh, Oven-Dried and Stir-Fried Tamarind Leaves

The aim of this study was to compare the antioxidant capacity and total phenolic content as well as the chemical groups of fresh, oven-dried and stir-fried tamarind (Tamarindus indica L.) leaves. Methanol was used for extraction of fresh, oven-dried and stir-fried tamarind leaves. The stir-fried leaves were prepared using medium heat for 10 minutes prior to extraction and chemical analysis while dried leaves were obtained by oven drying at 60°C for 3 hours. The stir-fried leaves had significantly highest total phenolic content (TPC) (139.87 mg/g) and percentage DPPH radical-scavenging inhibition (69.92%) while the fresh leaves had the lowest TPC (39.31 mg/g) and antioxidant capacity (16.46%). The FTIR spectral data suggest that the heat treatment increased the amine groups as well as the antioxidant capacity of the tamarind leaves. To increase the antioxidant capacity, the tamarind leaves should be prepared in a stir-frying process.

Antibacterial activities of medicinal plants used in Mexican traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species.

MATERIALS AND METHODS

We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11,836 worldwide antibacterial patents prepared from different sources were recorded; only 36 antibacterial patents from plants were registered over the same time period. We offered some insights on the most important findings regarding the antibacterial effects, current state of the art, and research perspectives of top plant species with antibacterial activities in vitro.

CONCLUSIONS

Studies of the antibacterial in vitro activity of medicinal plants popularly used in Mexico to treat infections indicate that both the selection of plant material and the investigation methodologies vary. Standardized experimental procedures as well as in vivo pharmacokinetic studies to document the effectiveness of plant extracts and compounds are necessary. This review presents extensive information about the medicinal plants possessing antibacterial activity that has been scientifically studied and are popularly used in Mexico. We anticipate that this review will be of use for future studies because it constitutes a valuable information tool for selecting the most significant plants and their potential antibacterial properties.

The Phenolic Contents and Antioxidant Activities of Infusions of Sambucus nigra L

The aim of this work was to evaluate the antioxidant potential of teas prepared from twenty-four commercially available berries and flowers of Sambucus nigra L. in relation to their phenolic profile, as reflected by the most representative phenolic acids (caffeic, chlorogenic, p-coumaric, ferulic, gallic and syringic acids); flavonols (quercetin, kaempferol, myricetin and rutin); and total phenolic (TPC), phenolic acid (TAC) and flavonoid (TFC) contents. The infusions prepared from elderflowers contained more abundant phenolic compounds than the elderberry infusions. The TPC of these infusions ranged from 19.81 to 23.90 mg of gallic acid equivalents/g dry weight of sample (GAE/g DW) for elderberries and from 15.23 to 35.57 mg GAE/g DW for elderflowers, whereas the TFC ranged from 2.60 to 4.49 mg of rutin equivalents/g dry weight of sample (RUTE/g DW) in elderberry infusions and from 5.27 to 13.19 mg RUTE/g DW in elderflower infusions. Among the phenolic compounds quantified in this study, quercetin (2.07-9.48 mg/g DW) and myricetin (1.17-9.62 mg/g DW) had the highest concentrations in the teas prepared from berries and flowers, respectively. Moreover, the antioxidant potential of elder infusions assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and ferric reducing antioxidant power (FRAP) assays revealed that the teas prepared from flowers had higher mean DPPH and FRAP activities than the teas prepared from berries. Therefore, elder beverages could be important dietary sources of natural antioxidants that contribute to the prevention of diseases caused by oxidative stress.

Evaluation of the quality of herbal teas by DART/TOF-MS

The paper focuses on the optimization, settings and validation of direct analysis in real time coupled with time-of-flight detector when used for the evaluation of the quality of selected herbal teas (fennel, chamomile, nettle, linden, peppermint, thyme, lemon balm, marigold, sage, rose hip and St. John's wort). The ionization mode, the optimal ionization temperature and the type of solvent for sample extraction were optimized. The characteristic compounds of the analysed herbal teas (glycosides, flavonoids and phenolic and terpenic substances, such as chamazulene, anethole, menthol, thymol, salviol and hypericin) were detected. The obtained mass spectra were evaluated by multidimensional chemometric methods, such as cluster analysis, linear discriminate analysis and principal component analysis. The chemometric methods showed that the single variety herbal teas were grouped according to their taxonomic affiliation. The developed method is suitable for quick identification of herbs and can be potentially used for assessing the quality and authenticity of herbal teas. Direct analysis in real time/time-of-flight-MS is also suitable for the evaluation of selected substances contained in the mentioned herbs and herbal products. Copyright © 2017 John Wiley & Sons, Ltd.

ATIVIDADE ANTIMICROBIANA DA ERVA-MATE (Ilex paraguariensis) CONTRA MICRORGANISMOS ISOLADOS DA CARNE DE FRANGO

Resumo A erva-mate vem sendo estudada devido às diversas atividades biológicas já evidenciadas. Este estudo teve como objetivo avaliar o efeito antimicrobiano, pelo método de difusão em disco, da adição de extratos de erva-mate frente à Escherichia coli e ao Proteus mirabilis previamente isolados da carne de peito de frango. Foram utilizadas diferentes concentrações de extrato (125 mg/mL, 250 mg/mL, 550 mg/mL de extrato de erva-mate, controle negativo com solução salina 0,85% e erva-mate pura) em triplicata e os resultados analisados pelo SAS® 5.1. Quanto maior a concentração de extrato aplicada, maior (P<0,0001) foi o halo de inibição formado para as duas bactérias avaliadas, sendo que para a E. coli os halos foram menores quando comparados com os halos para o P. Mirabilis. Foi possível estimar a concentração de 400 mg/mL como sendo a mais eficiente frente ambas as bactérias avaliadas.

Polysaccharide extraction from Sphallerocarpus gracilis roots by response surface methodology

The extraction process of Sphallerocarpus gracilis root polysaccharides (SGRP) was optimized using response surface methodology with two methods [hot-water extraction (HWE) and ultrasonic-assisted extraction (UAE)]. The antioxidant activities of SGRP were determined, and the structural features of the untreated materials (HWE residue and UAE residue) and the extracted polysaccharides were compared by scanning electron microscopy. Results showed that the optimal UAE conditions were extraction temperature of 81°C, extraction time of 1.7h, liquid-solid ratio of 17ml/g, ultrasonic power of 300W and three extraction cycles. The optimal HWE conditions were 93°C extraction temperature, 3.6h extraction time, 21ml/g liquid-solid ratio and three extraction cycles. UAE offered a higher extraction yield with a shorter time, lower temperature and a lower solvent consumption compared with HWE, and the extracted polysaccharides possessed a higher antioxidant capacity. Therefore, UAE could be used as an alternative to conventional HWE for SGRP extraction.

Optimal Extraction of Gallic Acid fromSuaeda glaucaBge. Leaves and Enhanced Efficiency by Ionic Liquids

The ultrasound-assisted extraction (UAE) was initially applied to extract gallic acid fromSuaeda glaucaBge. using 70% ethanol as extraction solvent. Temperature, liquid-solid ratio, and extraction time were optimized by response surface methodology (RSM), obtaining maximum levels of gallic acid (6.30 mg·g−1) at 51°C, 19.52 mL·g−1, and 42.68 min, respectively. The obtained model was statistically significant (p<0.0001). The verification experiments at the optimum conditions yielded gallic acid for 6.21 mg·g−1. Subsequently, under optimal conditions, four ionic liquids were used to extract gallic acid fromSuaeda glaucaBge. The results indicated that the presence of 1-hexyl-3-methylimidazolium chloride allowed increasing the EE of gallic acid up to 8.90 mg·g−1. This might be interpreted in terms of the molecular interaction between ionic liquid and gallic acid. The use of ionic liquids involves a stronger gallic acid extraction capacity than conventional organic volatile solvents. A promising alternative process is proposed for the extraction of gallic acid ofSuaeda glaucaBge.

Effect of rosemary in combination with yeast extract on microbiology quality, oxidative stability and color of non-fermented cooked salami “Inovec”

The aim of this study was to determine antimicrobial and antioxidant effect of dried rosemary (1 g/kg) in combination with yeast extract 1 g/kg (1st experimental group) and 2 g/kg (2nd experimental group) in compare to control sample (without rosemary extract and treated with E316 and E621) in non-fermented heat-treated product Inovec salami. Inovec salami is a product produced all over the Slovakia. The similar product can be found in Polish (Polish salami) or in the Czech Republic (Vysocina salami). The samples were vacuum packaged and were kept at 4 °C for 30 days. Determination of psychrotrophic bacteria count (PBC), count of Enterobacteriaceae family (ETB), yeast and moulds, Lactobacillus spp. bacteria count (LAB) was done by cultivation methods. Oxidative stability was determined by TBARS value. Color spaces L*, a*, b* of Inovec salami was determined by CM 2600D spectrophotometer (Konica Minolta, Germany). It was found non-significant (p >0.05) color loss (decrease in redness) over time, and the treatments had a non-significant impact (p >0.05) on redness of the salami in compare to control sample. TBARS values of the rosemary treated cooked salami with different amount of yeasts extracts were significantly lower compare to control sample at the end of the shelf life. Also, lower value of TBARS was determined in salami with rosemary in combination with higher amount of yeast extract. The lowest count of PBC was determined in the second experimental group after 15 days. The rosemary extract in combination of yeast extract treatments were not able to influence the growth of the yeasts and moulds. It was found that rosemary extract in combination with yeast extract in the salami of the second experimental group after 15 days of storage significantly (p <0.05) decrease count of Lactobacillus bacteria.

Antioxidant activity and delayed aging effects of hot water extract from Chamaecyparis obtusa var. formosana leaves

The antioxidant activity and delayed aging effects of hot water extracts from leaves of Chamaecyparis obtusa var. formosana were investigated. Free radical, superoxide radical scavenging, and total phenolic content assays were employed to evaluate the in vitro activities of the extracts. In addition, in vivo assays using the nematode Caenorhabditis elegans were also performed in this study. The results showed that among all soluble fractions obtained from the extracts, the ethyl acetate-soluble fraction has the best in vitro and in vivo antioxidant activities. Moreover, it decreased significantly the deposition of lipofuscin (aging pigment) and extended the lifespan of C. elegans. Bioactivity-guided fractionation yielded six potent antioxidant constituents from the ethyl acetate-soluble fraction, namely, catechin, quercetin, quercetin-3-O-α-rhamnoyranoside, myricetin-3-O-α-rhamnoyranoside, vanillic acid, and 4-hydroxybenzoic acid. Quercetin-3-O-α-rhamnoyranoside pretreatment showed the highest survival of C. elegans upon juglone exposure. Taken together, the results revealed that hot water extracts from C. obtusa var. formosana leaves have the potential to be used as a source for antioxidant or delayed aging health food.

Antimicrobial activity of yerba mate (Ilex paraguariensis St. Hil.) against food pathogens

Yerba mate (Ilex paraguariensis St. Hil.) has been studied for its important biological activities mainly attributed to phenolic compounds. This study evaluated the antimicrobial activity of methanolic and ethanolic extracts of yerba mate against food pathogens, such as Staphylococcus aureus, Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli through minimum inhibitory (MIC) and bactericidal (MBC) concentrations, in addition to the determination of chemical composition by gas chromatography with mass spectrometry (GC-MS) and phenolic content. The most effective extract had its activity evaluated under different pH conditions by growth curve analysis. All microorganisms except E. coli were inhibited. The ethanolic extract showed the lowest MIC/MBC (0.78/0.78 mg/ml), the highest phenolic content (193.9 g.GAE/kg) and the presence of chlorogenic acid derivatives, especially 3-O-caffeoylquinic and caffeic acid. This extract was able to inhibit microbial growth at pH 7 and 8.

Correlation of total polyphenolic content with antioxidant and antibacterial activity of 24 extracts from Greek domestic Lamiaceae species

Lamiaceae family species are considered important because of their use in folk medicine, culinary and flavouring throughout the world. Their interesting bioactivities are attributed mainly to essential oils, polyphenols and terpenes. However, there are only few studies about polyphenolic extracts from Lamiaceae plants. Thus, 24 polyphenolic extracts from three Lamiaceae genera, Salvia, Mentha and Sideritis, collected in Greece were examined for antioxidant and antibacterial activity in correlation with their polyphenolic content. The results showed that the tested polyphenolic extracts had strong free radical scavenging activity against DPPH· and ABTS(+) radicals and protected from hydroxyl and peroxyl radical-induced DNA damage. Moreover, five extracts inhibited Staphylococcus aureus growth. Furthermore, the results showed that the total polyphenolic content is not correlated with the above activities, although this relation was different within each plant genus. This is the first study regarding the antioxidant and antibacterial activity of Salvia pomifera ssp. calycina, S. pomifera ssp. pomifera, Mentha microphylla and Sideritis raeseri ssp. attica species, and one of the few concerning protection from DNA damage and antibacterial activity of polyphenolic extracts from the rest of the tested species.

MECHANICAL PROPERTIES AND CURE TEST OF A NATURAL RUBBER/POLY(VINYL ALCOHOL) BLEND

Properties and antibacterial activity of polymer blend films prepared from polyvinyl alcohol (PVA) and natural rubber (NR) blends, in the presence of maleic acid as a cross-linking agent were studied. The effect of the maleic acid content, curing temperature, and curing time on the properties of the polymer blend was investigated. Cross-linking between PVA and maleic acid was observed by attenuated total reflection mode–Fourier transform infrared spectroscopy at 1152 cm−1. The swelling ratio of the polymer blend decreased as a function of the increase of the maleic acid content. The tensile strength of the polymer blend increased with an increase of both the maleic acid and the curing time. The highest tensile strength of the samples was observed with 40% w/w maleic acid after a 24 h curing time at 120 °C. The elongation at the break of 60/40 NR/PVA was ∼500% at 120 °C for 1 h. In addition, the polymer blend showed good antibacterial activity with Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, and Acinetobacter baumannii JVC 1053 and could find many applications.