Antimicrobial Activity and Phytochemical Characterization of Baccharis concava Pers., a Native Plant of the Central Chilean Coast.

Few sclerophyllous plants from the central coast of Chile have been systematically studied. This work describes the phytochemical composition and antimicrobial properties of Baccharis concava Pers. (sin. B. macraei), a shrub found in the first line and near the Pacific coast. B. concava has been traditionally used by indigenous inhabitants of today's central Chile for its medicinal properties. Few reports exist regarding the phytochemistry characterization and biological activities of B. concava. A hydroalcoholic extract of B. concava was prepared from leaves and small branches. Qualitative phytochemical characterization indicated the presence of alkaloids, steroids, terpenoids, flavonoids, phenolic, and tannin compounds. The antimicrobial activity of this extract was assessed in a panel of microorganisms including Gram-positive bacteria, Gram-negative bacteria, and pathogenic yeasts. The extract displayed an important antimicrobial effect against Gram-positive bacteria, Candida albicans, and Cryptococcus neoformans but not against Gram-negatives, for which an intact Lipopolysaccharide is apparently the determinant of resistance to B. concava extracts. The hydroalcoholic extract was then fractionated through a Sephadex LH-20/methanol-ethyl acetate column. Afterward, the fractions were pooled according to a similar pattern visualized by TLC/UV analysis. Fractions obtained by this criterion were assessed for their antimicrobial activity against Staphylococcus aureus. The fraction presenting the most antimicrobial activity was HPLC-ESI-MS/MS, obtaining molecules related to caffeoylquinic acid, dicaffeoylquinic acid, and quercetin, among others. In conclusion, the extracts of B. concava showed strong antimicrobial activity, probably due to the presence of metabolites derived from phenolic acids, such as caffeoylquinic acid, and flavonoids, such as quercetin, which in turn could be responsible for helping with wound healing. In addition, the development of antimicrobial therapies based on the molecules found in B. concava could help to combat infection caused by pathogenic yeasts and Gram-positive bacteria, without affecting the Gram-negative microbiota.

Oxidation of chlortetracycline and its isomers by Botrytis aclada laccase in the absence of mediators: pH dependence and identification of transformation products by LC-MS.

Tetracyclines are antibiotics considered emerging pollutants and currently, wastewater treatment plants are not able to remove them efficiently. Laccases are promising enzymes for bioremediation because they can oxidize a wide variety of substrates. The aim of this study was to evaluate the Botrytis aclada laccase for the oxidation of chlortetracycline and its isomers in the absence of a mediator molecule, at a pH range between 3.0 to 7.0, and to characterize the transformation products by LC-MS. Chlortetracycline and three isomers were detected in both, controls and reaction mixtures at 0 h and in controls after 48 h of incubation but in different proportions depending on pH. An additional isomer was also detected, but only in the presence of BaLac. Based on the transformation products identified in the enzymatic reactions and information from literature, we assembled a network of transformation pathways starting from chlortetracycline and its isomers. The spectrometric analysis of the products indicated the probable occurrence of oxygen insertion, dehydrogenation, demethylation and deamination reactions. Four new products were identified, and we also described a novel transformation product without the chloro group. We observed that increasing pH led to higher diversity of main products. This is the first study using the laccase from fungi Botrytis aclada to oxidate chlortetracycline and its isomers and it can be considered as an ecological alternative to be used in bioremediation processes such as wastewater.

Effect of Structured Phenolic Lipids with EPA/DHA and Gallic Acid against Metabolic-Associated Fatty Liver Disease (MAFLD) in Mice.

Obesity is the leading risk factor for developing metabolic (dysfunction)-associated fatty liver disease (MAFLD). The food industry has an essential role in searching for new strategies to improve primary food sources to revert some of the metabolic alterations induced by obesity. There is consistent evidence that long-chain polyunsaturated fatty acids (n-3 LCPUFA) belonging to the n-3 series, i.e., eicosapentaenoic (20:5n-3, EPA) and docosahexaenoic (22:6n-3, DHA) acids, could revert some alterations associated with obesity-induced metabolic diseases. A relevant tool is the synthesis of structured acylglycerols (sAG), which include EPA or DHA at the sn-2 position. On the other hand, it has been reported that a crucial role of antioxidants is the reversion of MAFLD. In this work, we studied the effects of new molecules incorporating gallic acid (GA) into EPA/DHA-rich structured lipids. Mice were fed with a high-fat diet (60%) for three months and were then divided into five groups for supplementation with sAG and sAG structured with gallic acid (structured phenolic acylglycerols, sPAG). sPAG synthesis was optimized using a 2²-screening factorial design based on the response surface methodology (RSM). Our results show that treatment of sPAG was effective in decreasing visceral fat, fasting glycemia, fasting insulin, suggesting that this new molecule has a potential use in the reversal of MAFLD-associated alterations.

Carotenoid Cocktail Produced by An Antarctic Soil Flavobacterium with Biotechnological Potential.

Carotenoids are highly important in pigmentation, and its content in farmed crustaceans and fish correlates to their market value. These pigments also have a nutritional role in aquaculture where they are routinely added as a marine animal food supplement to ensure fish development and health. However, there is little information about carotenoids obtained from Antarctic bacteria and its use for pigmentation improvement and flesh quality in aquaculture. This study identified carotenoids produced by Antarctic soil bacteria. The pigmented strain (CN7) was isolated on modified Luria-Bertani (LB) media and incubated at 4 °C. This Gram-negative bacillus was identified by 16S rRNA analysis as Flavobacterium segetis. Pigment extract characterization was performed through high-performance liquid chromatography (HPLC) and identification with liquid chromatography-mass spectrometry (LC-MS). HPLC analyses revealed that this bacterium produces several pigments in the carotenoid absorption range (six peaks). LC-MS confirms the presence of one main peak corresponding to lutein or zeaxanthin (an isomer of lutein) and several other carotenoid pigments and intermediaries in a lower quantity. Therefore, we propose CN7 strain as an alternative model to produce beneficial carotenoid pigments with potential nutritional applications in aquaculture.

A phenolic-rich extract from Ugni molinae berries reduces abnormal protein aggregation in a cellular model of Huntington's disease.

Accumulation of misfolded proteins in the brain is a common hallmark of most age-related neurodegenerative diseases. Previous studies from our group identified the presence of anti-inflammatory and antioxidant compounds in leaves derived from the Chilean berry Ugni molinae (murtilla), in addition to show a potent anti-aggregation activity in models of Alzheimer´s disease. However, possible beneficial effects of berry extracts of murtilla was not investigated. Here we evaluated the efficacy of fruit extracts from different genotypes of Chilean-native U. molinae on reducing protein aggregation using cellular models of Huntington´s disease and assess the correlation with their chemical composition. Berry extraction was performed by exhaustive maceration with increasing-polarity solvents. An unbiased automatic microscopy platform was used for cytotoxicity and protein aggregation studies in HEK293 cells using polyglutamine-EGFP fusion proteins, followed by secondary validation using biochemical assays. Phenolic-rich extracts from murtilla berries of the 19-1 genotype (ETE 19-1) significantly reduced polyglutamine peptide aggregation levels, correlating with the modulation in the expression levels of autophagy-related proteins. Using LC-MS and molecular network analysis we correlated the presence of flavonoids, phenolic acids, and ellagitannins with the protective effects of ETE 19-1 effects on protein aggregation. Overall, our results indicate the presence of bioactive components in ethanolic extracts from U. molinae berries that reduce the load of protein aggregates in living cells.

Effects of elderflower extract enriched with polyphenols on antioxidant defense of salmon leukocytes

BACKGROUND: In fish farming, the plant extracts containing antioxidant compounds have been added to the diet for enhancing pathogen resistance. In vitro studies evaluating the antioxidant effect of herbal extracts on fish cell models have focused on ROS production and the respiratory burst mechanism. However, the effects on enzymatic antioxidant defense on salmon leukocytes have not been evaluated. This study aims to evaluate the enzymatic antioxidant defense and ROS-induced cell damage in Salmon Head Kidney-1 (SHK-1) cell line exposed to polyphenol-enriched extract from Sambucus nigra flowers. RESULTS: Firstly, the Total Reactive Antioxidant Power (TRAP) assay of elderflower polyphenol (EP) was evaluated, showing 459 and 489 times more active than gallic acid and butyl hydroxy toluene (BHT), respectively. The toxic effect of EP on salmon cells was not significant at concentrations below 120 mg/ mL and no hemolysis activity was observed between 20 and 400 mg/mL. The treatment of SHK-1 cell line with EP decreased both the lipid peroxidation and protein oxidation induced by H2O2, which could be associated with decreasing oxidative stress in the SHK-1 cells since the GSH/GSSG ratio increased when only EP was added. CONCLUSIONS: These results suggest that plant extracts enriched with polyphenols could improve the enzymatic antioxidant defense of salmon leukocytes and protect the cells against ROS-induced cell damage

Synthesis of EPA- and DHA-Enriched Structured Acylglycerols at the sn-2 Position Starting from Commercial Salmon Oil by Enzymatic Lipase Catalysis under Supercritical Conditions.

There is consistent evidence that long-chain polyunsaturated fatty acids (LCPUFA) belonging to the n-3 series, i.e., eicosapentaenoic (20:5n-3, EPA) and docosahexaenoic (22:6n-3, DHA) acids, decrease the risk of heart, circulatory and inflammatory diseases. Furthermore, the bioavailability of such fatty acids has been shown to depend on their location in triacylglycerol (TG) molecules at the sn-2 position. Consequently, great attention has been accorded to the synthesis of structured acylglycerols (sAG), which include EPA or DHA at the sn-2 position. The aim of this work was to synthesize sAG starting from deodorized refined commercial salmon oil. For this, immobilized lipase B from Candida antarctica (nonspecific) was used as a catalyst for the intra-interesterification process under CO2 supercritical conditions (CO2SC). According to the CO2SC reaction time, three different fractions including sAG compounds were obtained. The location of EPA and DHA at the sn-2 position in the resulting glycerol backbone was identified by mass spectrometry (MALDI-TOF) analysis. In all fractions obtained, a marked decrease in the starting TG content was observed, while an increase in the DHA content at the sn-2 position was detected. The fraction obtained after the longest reaction time period (2 h) led to the highest yield of sn-2 position DHA in the resulting sAG molecule.

Comparative characterization of the hemocyanin-derived phenol oxidase activity from spiders inhabiting different thermal habitats.

Enzymes adapted to cold temperatures are commonly characterized for having higher Michaelis-Menten constants (KM) values and lower optimum and denaturation temperature, when compared to other meso or thermophilic enzymes. Phenoloxidase (PO) enzymes are ubiquitous in nature, however, they have not been reported in spiders. It is the oxygen carrier protein hemocyanin (Hc), found at high concentrations in their hemolymph, which displays an inducible PO activity. Hence, we hypothesize that Hc-derived PO activity could show features of cold adaptation in alpine species. We analyzed the Hc from two species of Theraphosidae from different thermal environments: Euathlus condorito (2400 m a.s.l.) and Grammostola rosea (500 m a.s.l.). Hc was purified from the hemolymph of both spiders and was characterized by identifying subunit composition and measuring the sodium dodecyl sulfate (SDS)-induced PO activity. The high-altitude spider Hc showed higher PO activity under all conditions and higher apparent Michaelis-Menten constant. Moreover, the optimum temperature for PO activity was lower for E. condorito Hc. These findings suggest a potential adaptation at the level of Hc-derived PO activity in Euathlus condorito, giving insights on possible mechanisms used by this mygalomorph spider to occupy extremes and variable thermal environments.

In vitro biotransformation of OA-group and PTX-group toxins in visceral and non-visceral tissues of Mytilus chilensis and Ameghinomya antiqua.

Lipophilic marine toxins (LMTs) are made up of multiple groups of toxic analogues, which are characterised by different levels of cellular and toxic action. The most prevalent groups in the southern Pacific zone are: a) okadaic acid group (OA-group) which consists of okadaic acid (OA) and dinophysistoxin-1 (DTX-1); and, b) pectenotoxin-2 (PTX2) group which consists of pectenotoxin-2 (PTX-2). The main objective of our study was to examine in vitro biotransformation of OA-group and PTX-group in the tissues of two endemic species of bivalves from southern Chile; blue mussels (Mytilus chilensis) and clams (Ameghinomya antiqua). The biotransformation processes of both groups were only detected in the digestive glands of both species using LC-MS/MS. The most frequently detected analogues were acyl derivatives (≈2.0 ± 0.1 µg ml-1) for OA-group and PTX-2SA (≈1.4 ± 0.1 µg ml-1) for PTX-group, with a higher percentage of biotransformation for OA-group (p < .001). In addition, simultaneous incubations of the different analogues (OA/PTX-2; DTX-1/PTX-2 and OA/DTX-1/PTX-2) did not show any interaction between the biotransformation processes. These results show that the toxicological variability of endemic species leads to biotransformation of the profile of toxins, so that these new analogues may affect people's health.

Inhibition of ß-amyloid Aggregation of Ugni molinae Extracts.

The ß-amyloid peptide (1-42) is a molecule capable of aggregating into neurotoxic structures that have been implicated as potential etiological factors of Alzheimer's Disease. The aim of this study was to evaluate the inhibition of ß-amyloid aggregation of ethyl acetate and ethanolic extracts obtained from Ugni molinae leaves on neurotoxic actions of ß-amyloid aggregates. Chemical analyses were carried out with the extracts in order to determine their phenolic profile and its quantification. Both extracts showed a tendency to reduce neuronal deaths caused by ß-amyloid. This tendency was inversely proportional to the evaluated concentrations. Moreover, the effect of EAE and ETE on ß-amyloid aggregation was studied by fluorimetric T Thioflavin assay and transmission electronic microscopy (TEM); the extracts showed a modulation in the aggregation process. Partly, it is believed that these effects can be attributed to the polyphenolic compounds present in the extracts.

Inhibition of Soybean 15-Lipoxygenase and Human 5-Lipoxygenase by Extracts of Leaves, Stem Bark, Phenols and Catechols Isolated From Lithraea caustica (Anacardiaceae).

Lithraea caustica (Molina) Hook. and Arn. (Anacardiaceae), common name Litre, is an evergreen endemic plant used in the Mapuche Chilean folk medicine. The stem juice of L. caustica mixed with Rubus ulmifolius (blackberry) is used to treat cough and the infusion of leaves is used in baths to treat joint inflammations. In this study, the activities of 3-n-alk(en)yl-catechols, obtained from the dichloromethane extract of the epicuticular compounds of fresh leaves (DCME), stem bark petroleum ether extract (PEE), fractions of phenols and phenol-acid compounds obtained from the methanolic extract (methanolic extract) of defatted leaves and aqueous infusion (AE) from fresh leaves, were evaluated as in vitro inhibitors of soybean 15-lipoxygenase (15-sLOX) and human 5-lipoxygenase (5-hLOX), one of the inflammation pathways. The 3-n-alk(en)yl-catechols were characterized by gas chromatography-mass spectrometry and 1D and 2D nuclear magnetic resonance analysis as mixtures of 3-[(10E)-pentadec-10'-en-1-yl]-catechol, 3-[(10Z)-pentadec-10'-en-1-yl]-catechol and 3-n-pentadecylcatechol. In addition, two fractions, obtained from MeOHE, were characterized by liquid chromatography electrospray ionization tandem mass spectrometric as complex mixtures of known acids and phenolic compounds. DCME, MeOHE and ethyl acetate extract (AcOEtE) extracts showed inhibition against 15-sLOX, and the AE of fresh leaves, showed the best inhibition against 5-hLOX. The mixture of 3-n-alk(en)yl-catechols showed inhibition of 15-sLOX and 5-hLOX. The compounds 3-[(10Z)-pentadec-10'-en-1-yl]-catechol (IC50 2.09 µM) and 3-n-pentadecylcatechol (IC50 2.74 µM) showed inhibition against 5-hLOX. The inhibition values obtained for the 3-n-alk(en)yl-catechols are in the range of well-known inhibitors of 5-hLOX. Acetylation of the 3-n-alk(en)yl-catechols blocks the inhibitory activity, indicating that the free catechol function is necessary for the enzyme inhibition. In addition, the fractions of phenols and phenol-acid compounds showed inhibitory activity against 15-sLOX and the AE, showed a good inhibition against 5-hLOX. These results would be in agreement with the use of L. caustica, as an anti-inflammatory in Mapuche ethnomedicine.

Antihyperalgesic Activity of Quillaic Acid Obtained from Quillaja Saponaria Mol.

BACKGROUND: Quillaja saponaria Mol. bark contains a high concentration of triterpene saponins that have been used for centuries as a cleansing, antiinflammatory and analgesic agent in Chilean folk medicine. In earlier studies, in mice, both the anti-inflammatory as well as the antinociceptive effect of the major sapogenin, quillaic acid have been demonstrated (QA). OBJECTIVE: To determine the antihyperalgesic effect of QA one and seven days after itpl administration of complete Freund's adjuvant (CFA) in male mice using the hot plate test in the presence of complete Freund's adjuvant (HP/CFA) as an acute and chronic skeletal muscle pain model. METHODS: The present study evaluated the antihyperalgesic activity of QA against acute and chronic skeletal muscle pain models in mice using the hot plate test in the presence of complete Freund's adjuvant (HP/CFA), at 24 h (acute assay) and 7 days (chronic assay) , with dexketoprofen (DEX) as the reference drug. RESULTS: In acute and chronic skeletal muscle pain assays, QA at 30 mg/kg ip elicited its maximal antihyperalgesic effects (65.0% and 53.4%) at 24 h and 7 days, respectively. The maximal effect of DEX (99.0 and 94.1 at 24 h and 7 days, respectively) was induced at 100 mg/kg. CONCLUSION: QA and DEX elicit dose-dependent antihyperalgesic effects against acute and chronic skeletal muscle pain, but QA is more potent than DEX in the early and late periods of inflammatory pain induced by CFA.

Identification of Peptides in Flowers of Sambucus nigra with Antimicrobial Activity against Aquaculture Pathogens.

The elder (Sambucus spp.) tree has a number of uses in traditional medicine. Previous studies have demonstrated the antimicrobial properties of elderberry liquid extract against human pathogenic bacteria and also influenza viruses. These properties have been mainly attributed to phenolic compounds. However, other plant defense molecules, such as antimicrobial peptides (AMPs), may be present. Here, we studied peptide extracts from flowers of Sambucus nigra L. The mass spectrometry analyses determined peptides of 3 to 3.6 kDa, among them, cysteine-rich peptides were identified with antimicrobial activity against various Gram-negative bacteria, including recurrent pathogens of Chilean aquaculture. In addition, membrane blebbing on the bacterial surface after exposure to the cyclotide was visualized by SEM microscopy and SYTOX Green permeabilization assay showed the ability to disrupt the bacterial membrane. We postulate that these peptides exert their action by destroying the bacterial membrane.

Prevalence and factors associated with a higher risk of neck and back pain among permanent wheelchair users: a cross-sectional study.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To determine the prevalence of, and factors associated with, spinal pain among wheelchair users. SETTING: Four Spanish hospitals specialized in providing care for wheelchair users. METHODS: Persons who had used a wheelchair for a median (IRQ) of 10 (5;19) years, 27% of them due to reasons other than spinal cord injury, were recruited consecutively (n = 750). Data on 43 demographic, psychosocial, ergonomic, and clinical variables were collected, and analyzed. Main outcome measures were: point prevalence of neck (NP), thoracic (TP), low back pain (LBP), and pain at any spinal level (PASL); and factors associated with them. RESULTS: Point prevalence was 56% for NP, 54% for TP, 45% for LBP, and 76% for PSAL. PASL was associated with a lower quality of life (OR (95% CI) 0.91 (0.86; 0.97)). Multivariable regression models showed that the main factors associated with significant pain (≥1.5 VAS points) were: (a) For NP: cervical spinal injury and wheelchair seat cushion thickness, (b) For TP: thoracic spinal injury and sagittal index, (c) For LBP: thoracic or lumbar spinal injury, with some sensitivity remaining, (d) For PASL: being female, living alone, and using a non-power wheelchair. Discrimination (AUC) of these models ranged between 0.638 and 0.818. p-values in the Hosmer-Lemeshow test ranged between 0.420 and 0.701. CONCLUSIONS: Prevalence of spinal pain among wheelchair users is high. It is associated with a lower quality of life. Future studies should assess whether using a power wheelchair affects PASL, and if the thickness of seat cushion affects NP. SPONSORSHIP: Spanish Back Pain Research Network.

Thermal stability of oils added with avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) leaf extracts during the French potatoes frying.

Effect of the addition of avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) hydroalcoholic leaf extracts (AHE and OHE, respectively) on thermal stability of canola oil (CO) and high oleic sunflower oil (HOSO) during French potatoes frying at 180°C was studied. The extracts were characterized by the total phenolic content, phenol chromatographic profiles and antioxidant activity. B-type trimer procyanidins were the major phenolic compounds identified in AHE. OHE showed higher phenol content, antioxidant activity regarding AHE. CO+OHE and HOSO+OHE decreased the formation of polar compounds and showed an anti-polymeric effect with respect to oils without extracts, whereas AHE extract showed a prooxidant effect on HOSO. Therefore, OHE showed an antioxidant effect on HOSO and CO under the studied conditions. In addition, all systems (CO+AHE, HOSO+AHE, CO+OHE and HOSO+OHE) increased the retention of tocopherols. These results demonstrate the potential utility of OHE as natural antioxidant for oils.

Phenolic composition and antioxidant capacity of Ugni molinae Turcz. leaves of different genotypes.

Ugni molinae Turcz. is a native shrub of Chile, known for its edible berries and its leaves, which have been the focus of recent attention, as a good source of phenolic compounds to be used in cosmetics and food products. The aim of this study was to assess the differences in the phenolic composition and antioxidant capacity of the ethanolic extracts from the leaves of 10 genotypes of U. molinae, that were cultivated under the same soil, climate and agronomical management. Antioxidant activity was assessed by complementary methods (ORAC-Fl, FRAP and DPPH assay), phenolic composition of each extract was analyzed by LC-MS. Phenolic and flavonoid total contents were determined by Folin-Ciocalteu and AlCl3 methods. Significative differences were found by these methods, and ellagitannins, gallic acid derivatives and flavonols were identified as responsible for these differences, showing the influence of the genotype on the phenolic composition of U. molinae leaves.

New visible and selective DNA staining method in gels with tetrazolium salts.

DNA staining in gels has historically been carried out using silver staining and fluorescent dyes like ethidium bromide and SYBR Green I (SGI). Using fluorescent dyes allows recovery of the analyte, but requires instruments such as a transilluminator or fluorimeter to visualize the DNA. Here we described a new and simple method that allows DNA visualization to the naked eye by generating a colored precipitate. It works by soaking the acrylamide or agarose DNA gel in SGI and nitro blue tetrazolium (NBT) solution that, when exposed to sunlight, produces a purple insoluble formazan precipitate that remains in the gel after exposure to light. A calibration curve made with a DNA standard established a detection limit of approximately 180 pg/band at 500 bp. Selectivity of this assay was determined using different biomolecules, demonstrating a high selectivity for DNA. Integrity and functionality of the DNA recovered from gels was determined by enzymatic cutting with a restriction enzyme and by transforming competent cells after the different staining methods, respectively. Our method showed the best performance among the dyes employed. Based on its specificity, low cost and its adequacy for field work, this new methodology has enormous potential benefits to research and industry.

Chemical properties and assessment of the antioxidant capacity of native species from the genus Ugni / Características químicas y evaluación de la capacidad antioxidante de especies del género Ugni

Introduction: Ugni molinae Turcz., Ugni candollei Barn. (Berg) and Ugni selkirkii (Hook. et Arn.) Berg are Chilean species that share morphological characteristics and they are distributed in geographic locations with very diverse habitats. Its is considered important for the characterization of the Chilean flora to determine if there are similarities in the sort of chemical compounds among species with close morphological relations, growing in different habitats and their consequent biological activity. Objective: to assess the chemical composition and the antioxidant capacity of leaf extracts from the Chilean species of the genus Ugni, and to compare with the U. molinae characteristics. Methods: composition of chemical compounds was determined by chromatographic methods (HPLC-ESI-MS). The antioxidant capacity was assessed by DPPH, ABTS and by stabilization of the hydroxyl radical. Results: as expected, given the great morphological similarity existing among the three species of Ugni that grow in Chile, similarities were found in their chemical composition. Nevertheless, it was also expectable to find variations among them. Thus, U. candollei and U. selkirkii are the species that present greater content and variety of phenolic and terpenic compounds. These species exert greater antioxidant capacity in comparison toU. molinae. U. candollei hightlights for its flavonoid content such as glycosides and quercetin derivatives, and the species U. selkirkii, is important in galotannins. U. molinae is characterized in ellagic acids derivatives. Conclusion: these data and the morphological characteristics could become a useful toll in order to determine the closeness degree among these species(AU

Introducción: Ugni molinae Turcz., Ugni candollei (Barn.) Berg y Ugni selkirkii (Hook. et Arn.) Berg son especies chilenas que comparten características morfológicas y se distribuyen en lugares geográficos con muy diversos hábitats. Se considera importante para la caracterización de la flora chilena determinar si hay similitudes en el tipo de compuestos químicos entre especies con relaciones morfológicas cercanas, que crecen en diferentes hábitats y su actividad biológica consecuente. Objetivo: evaluar la composición química y la capacidad antioxidante de extractos de hojas de las especies chilenas del género Ugni, y compararlas con las características de la especie U. molinae. Métodos: la composición química se determinó por métodos cromatográficos (HPLC-ESI-MS). La capacidad antioxidante se evaluó por los métodos DPPH, ABTS, y la estabilización del radical hidroxilo. Resultados: como era de esperar, dada la gran similitud morfológica existente entre las tres especies de Ugni que crecen en Chile, se encontraron similitudes en su composición química. Sin embargo, también era esperable encontrar variaciones entre ellas. Por lo tanto, U. candollei y U. selkirkii son las especies que presentan mayor contenido y variedad de compuestos fenólicos y terpénicos. Estas especies ejercen una mayor capacidad antioxidante en comparación con U. molinae. U. candollei se caracteriza por su contenido en flavonoides como quercetina glucósidos y sus derivados, y la especie U. selkirkii, por la presencia de galotaninos. U. molinae se caracteriza por contener derivados del ácido elágico. Conclusión: estos datos y las características morfológicas podrían convertirse en una herramienta útil para determinar el grado cercanía entre estas especies(AU)

Protonation Sites, Tandem Mass Spectrometry and Computational Calculations of o-Carbonyl Carbazolequinone Derivatives.

A series of a new type of tetracyclic carbazolequinones incorporating a carbonyl group at the ortho position relative to the quinone moiety was synthesized and analyzed by tandem electrospray ionization mass spectrometry (ESI/MS-MS), using Collision-Induced Dissociation (CID) to dissociate the protonated species. Theoretical parameters such as molecular electrostatic potential (MEP), local Fukui functions and local Parr function for electrophilic attack as well as proton affinity (PA) and gas phase basicity (GB), were used to explain the preferred protonation sites. Transition states of some main fragmentation routes were obtained and the energies calculated at density functional theory (DFT) B3LYP level were compared with the obtained by ab initio quadratic configuration interaction with single and double excitation (QCISD). The results are in accordance with the observed distribution of ions. The nature of the substituents in the aromatic ring has a notable impact on the fragmentation routes of the molecules.

Morphological Effects and Antioxidant Capacity of Solanum crispum (Natre) In Vitro Assayed on Human Erythrocytes.

In order to gain insight into the molecular mechanism of the antioxidant properties of Solanum crispum, aqueous extracts of its leaves were assayed on human erythrocytes and molecular models of its membrane. Phenolics and alkaloids were detected by HPLC-MS. Scanning electron and defocusing microscopy showed that S. crispum changed erythrocytes from the normal shape to echinocytes. These results imply that molecules present in the aqueous extracts were located in the outer monolayer of the erythrocyte membrane. Dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE) were chosen as representative of phospholipid classes located in the outer and inner monolayers of the erythrocyte membrane, respectively. X-ray diffraction showed that S. crispum preferentially interacted with DMPC bilayers. Experiments regarding its antioxidant properties showed that S. crispum neutralized the oxidative capacity of HClO on DMPE bilayers; defocusing microscopy and hemolysis assays demonstrated the protective effect of S. crispum against the oxidant effects of HClO on human erythrocytes.