Surgical timing prevails as the main factor over morphologic characteristics in the reduction by ligamentotaxis of thoracolumbar burst fractures.

BACKGROUND: thoracolumbar burst fractures are associated with spinal canal occupation. The indirect decompression of the spinal canal and reduction of the fragment can be achieved with the distraction of the middle column and ligamentotaxis. Nevertheless, the factors that influence the effectiveness of this procedure and its temporality are controversial. METHODS: The aim of this observational, cross-sectional study was to evaluate the effectiveness of indirect reduction by ligamentotaxis in thoracolumbar burst fractures according to the fracture's radiologic characteristics and the procedure's temporality. Patients diagnosed with a thoracolumbar burst fracture between 2010 and 2021 were submitted to indirect reduction by distraction and ligamentotaxis. A retrospective analysis of radiologic characteristics and temporality of the procedure was performed with an independent sample t-test or Pearson's correlation coefficient, as required. RESULTS: A total of 58 patients were included in the analysis. Postoperatively, ligamentotaxis significantly improved all radiologic parameters (canal occupation, endplates distance, and vertebra height). Still, none of the radiological characteristics of the fracture (width, height, position, sagittal angle) were associated with the postoperative change in canal occupation. The endplates distance and the temporality of ligamentotaxis significantly predicted the reduction of the fracture. CONCLUSION: Fragment reduction effectiveness is more significant when performed as early as possible and adequate distraction is achieved using the internal fixator system. The radiologic characteristics of the fractured fragment do not determine its reduction capacity.

Unitary rotation of pixellated polychromatic images.

Unitary rotations of polychromatic images on finite two-dimensional pixellated screens provide invertibility, group composition, and thus conservation of information. Rotations have been applied on monochromatic image data sets, where we now examine closer the Gibbs-like oscillations that appear due to discrete "discontinuities" of the input images under unitary transformations. Extended to three-color images, we examine here the display of color at the pixels where, due to oscillations, some pixel color values may fall outside their required common numerical range [0,1], between absence and saturation of the red, green, and blue formant colors we choose to represent the images.

Insecticidal, Repellent and Antifeedant Activity of Essential Oils from Blepharocalyx cruckshanksii (Hook. & Arn.) Nied. Leaves and Pilgerodendron uviferum (D. Don) Florin Heartwood against Horn Flies, Haematobia irritans (Diptera: Muscidae).

Haematobia irritans is a cosmopolitan obligate blood-feeding ectoparasite of cattle and is the major global pest of livestock production. Currently, H. irritans management is largely dependent on broad-spectrum pesticides, which has led to the development of insecticide resistance. Thus, alternative control methods are needed. Essential oils have been studied as an alternative due to their wide spectrum of biological activities against insects. Thus, the main aim of this study was to evaluate the insecticidal, repellent and antifeedant activity of the essential oils from Blepharocalyx cruckshanksii leaves and Pilgerodendron uviferum heartwood against horn flies in laboratory conditions. The composition of the essential oils was analyzed using gas chromatography coupled to mass spectrometry. Accordingly, α-pinene (36.50%) and limonene (20.50%) were the principal components of the B. cruckchanksii essential oil, and δ-cadinol (24.16%), cubenol (22.64%), 15-copaenol (15.46%) and δ-cadinene (10.81%) were the most abundant compounds in the P. uviferum essential oil. Mortality of flies and feeding behavior were evaluated by non-choice tests, and olfactory response was evaluated using a Y-tube olfactometer. Both essential oils were toxic to horn flies, with LC50 values for B. cruckchanksii essential oil of 3.58 µL L-1 air at 4 h, and for P. uviferum essential oil of 9.41 µL L-1 air and 1.02 µL L-1 air at 1 and 4 h, respectively. Moreover, the essential oils exhibited spatial repellency in the olfactometer using only 10 µg of each oil, and these significantly reduced the horn fly feeding at all doses evaluated. Although further laboratory and field studies related to the insectistatic and insecticide properties of these essential oils against H. irritans are necessary, B. cruckshanksii leaves and P. uviferum heartwood essential oils are promising candidates for horn fly management.

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.

Light propagation in inhomogeneous media, coupled quantum harmonic oscillators and phase transitions.

This contribution has two main purposes. First, using classical optics we show how to model two coupled quantum harmonic oscillators and two interacting quantized fields. Second, we present classical analogs of coupled harmonic oscillators that correspond to anisotropic quadratic graded indexed media in a rotated reference frame, and we use operator techniques, common to quantum mechanics, to solve the propagation of light through a particular type of graded indexed medium. Additionally, we show that the system presents phase transitions.

Essential Oil, Extracts, and Sesquiterpenes Obtained From the Heartwood of Pilgerodendron uviferum Act as Potential Inhibitors of the Staphylococcus aureus NorA Multidrug Efflux Pump.

Staphylococcus aureus is a serious human pathogen that is highly adaptive to environmental conditions and rapidly develops antibiotic resistance. The use of efflux pumps to reduce antibiotic concentrations at the intracellular level is one of the main mechanisms by which bacteria develop antibiotic resistance. The management of efflux pumps, specifically NorA, which is expressed by S. aureus strains, is a valuable strategy for restoring susceptibility in strains resistant to antibacterial agents. In recent years, many studies have focused on searching for natural substances that can reverse efflux pump-mediated resistance in S. aureus. Extracts and compounds obtained from plants can be efficient efflux pump inhibitors (EPIs) and represent a potentially patient-friendly strategy for controlling S. aureus. In the present study, we evaluated the ability of essential oils, petroleum ether extracts, dichloromethane extract (DCME) and six compounds isolated from the heartwood of Pilgerodendron uviferum (Cupressaceae) and two synthetic derivatives to inhibit efflux in NorA pumps in the following three S. aureus strains: K2378, which overexpressed the norA gene (norA++), K1902 (norA-deleted, ΔnorA) and the parental strain, NCTC 8325-4. Efflux activity was evaluated using a fluorometric method that measured the accumulation of the universal efflux pump substrate ethidium bromide (EtBr). Only DCME and the compounds 15-copaenol and epi-cubenol inhibited EtBr efflux by K2378. Even the lowest concentration of 15-copaenol exhibited a stronger inhibitory effect than carbonyl cyanide m-chlorophenyl hydrazone on EtBr efflux by K2378. 15-copaenal only showed inhibition of EtBr efflux in K2378 cells at 125 µg/mL, but not superior to the control inhibitor and 15-copaenyl acetate exerted no intrinsic EPI activity against K2378. Fractional inhibitory concentration index (FICI) values obtained in the checkerboard assays, indicated that all combinations between DCME, epi-cubenol and 15-copaenol, and tested antibiotics showed a synergistic effect in wild type, norA ++ and ΔnorA strains. Moreover, those were not toxic for the HeLa cell line at concentrations in which the synergistic effect and inhibitory activity of efflux pumps was determined. Other extracts and compounds obtained from P. uviferum did not display EtBr efflux-inhibiting activity against the evaluated S. aureus strains.

Antifungal activity against Botrytis cinerea of labdane-type diterpenoids isolated from the resinous exudate of Haplopappus velutinus Remy (Asteraceae).

Two labdane diterpenoids were isolated, from the resinous exudate of Haplopappus velutinus Remy (Asteraceae); the main compound was identified as 7,13-(E)-labdadien-15,18-dioic-acid-18-methyl ester (1) and the minor compound identified as 7-labden-15,18-dioic-acid-18-methyl ester (2). Their structures were obtained using FTIR, MS, HRMS and NMR data: 1D NMR (1H, 13C and DEPT-135), 2D homonuclear NMR (COSY and NOESY) and heteronuclear NMR (HSQC and HMBC). The trans stereochemistry of the decalin moiety of compounds 1 and 2 was established through NOESY experiments of the reduction product of 1; 7-labden-15,18-diol (1a). Diterpenoids 1 and 1a are described for the first time and showed antifungal activity, inhibiting approximately 40% mycelial growth of Botrytis cinerea.

Antifeedant Effects of Essential Oil, Extracts, and Isolated Sesquiterpenes from Pilgerodendron uviferum (D. Don) Florin Heartwood on Red Clover Borer Hylastinus obscurus (Coleoptera: Curculionidae).

The beetle Hylastinus obscurus Marsham (Coleoptera: Curculionidae), endemic to Europe and Northern Africa, is one of the most important red clover pests in Chile. As commercial insecticides are less effective against this pest, plant secondary metabolites have been considered as an alternative for its control. Here, we have investigated the chemical composition of essential oil (EO), petroleum ether extract (PEE), and dichloromethane extract (DCME) from Pilgerodendron uviferum heartwood. Additionally, the effects of EO and extracts on the feeding behavior (% of weight shift) of H. obscurus have been evaluated. The composition of EO, PEE, and DCME were analyzed using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The results showed the presence of a similar mixture of sesquiterpenes in the essential oil and in both of the extracts, which accounted for circa 60% of the total mixture. Sesquiterpenes were further isolated using chromatographic methods and were structurally characterized by optical rotation, GC⁻MS, FTIR, and 1D and 2D NMR experiments. The physicochemical properties of the isolated sesquiterpenes, including lipophilicity and vapor pressure, were also determined. The sesquiterpenes were identified as the following: (-)-trans-calamenene (1), cadalene (2), (-)-cubenol (3), (-)-epi-cubenol (4), (-)-torreyol (5), and (-)-15-copaenol (6). The antifeedant activity of EO, extracts, and isolated sesquiterpenes were evaluated using artificial diets in a non-choice test. Relative to the control, the EO, DCME extract, and the isolated sesquiterpenes, namely, (-)-trans-calamenene (1), cadalene (2), and (5) torreyol, were found to be the most effective treatments against H. obscurus. Our study showed that the compounds occurring in P. uviferum heartwood were effective in reducing the adult growth of H. obscurus. The physicochemical properties of the isolated sesquiterpenes might have been associated with antifeedant effects.

Plant Flavonoid Content Modified by Domestication.

Plant domestication can modify and weaken defensive chemical traits, reducing chemical defenses in plants and consequently their resistance against pests. We characterized and quantified the major defensive flavonols and isoflavonoids present in both wild and cultivated murtilla plants (Ugni molinae Turcz), established in a common garden. We examined their effects on the larvae of Chilesia rudis (Butler) (Lepidoptera: Arctiidae). Insect community and diversity indices were also evaluated. We hypothesized that domestication reduces flavonoid contents and modifies C. rudis preference, the insect community, and diversity. Methanolic extracts were obtained from leaves of U. molinae plants and analyzed by high performance liquid chromatography. Results showed higher insect numbers (86.48%) and damage index (1.72 ± 0.16) in cultivated plants. Four new first records of insects were found associated with U. molinae. Diversity indices, such as Simpson, Shannon, and Margalef, were higher in cultivated plants than in wild plants. Furthermore, eight isoflavonoids were identified in U. molinae leaves for the first time. The five flavonols showed higher concentrations in wild U. molinae leaves (89.8 µg/g) than in cultivated plants (75.2 µg/g); however, no differences were found in isoflavonoids between wild and cultivated plants. The larvae of C. rudis consumed more leaf material of cultivated plants than wild plants in choice (3.8 vs. 0.8 mm2) and no-choice (7.5 vs. 3.0 mm2) assays. Our study demonstrates that domestication in U. molinae reduces the amount of flavonoids in leaves, increasing the preference of C. rudis and the insect community.

Uses of hazardous medicinal plants: composition of the essential oil of Clinopodium gilliesii (Benth. ) Kuntze (Lamiaceae), collected in Chile / Uso de plantas medicinales peligrosas: composición del aceite esencial de Clinopodium gilliesii (Benth. ) Kuntze (Lamiaceae), recolectada en Chile

Clinopodium gilliesii (Benth.) Kuntze, harvested in the Chilean highlands, contains a surprising 93.87% of the toxic monoterpene pulegone in the essential oil. These results show remarkable differences with studies of the same species carried out in Argentina and Peru. These dissimilarities in the monoterpene composition of essential oils should be associated with differences in toxicity and biological activity of this medicinal plant used in ethnomedicine in different countries for the treatment of similar discomforts and diseases. These results are discussed considering the risk of consuming C. gilliesii, without clear recommendations and control of at least pulegone content in essential oils.

Clinopodium gilliesii (Benth.) Kuntze, recolectada en el altiplano chileno, contiene un sorprendente 93,87% del monoterpeno toxico pulegona, en el aceite esencial. Estos resultados muestran diferencias notables con estudios de la misma especie realizados en Argentina y Perú. Estas disimilitudes, en la composición de los aceites esenciales deben estar asociadas con diferencias en la toxicidad y actividad biológica de esta especie medicinal que se utiliza en etnomedicina en diferentes lugares para el tratamiento de molestias y enfermedades similares. Estos resultados se discuten considerando el riesgo de consumir C. gilliesii, sin recomendaciones claras y control de al menos el contenido de pulegona en los aceites esenciales.

Enhanced Antibacterial Activity of Ent-Labdane Derivatives of Salvic Acid (7α-Hydroxy-8(17)-ent-Labden-15-Oic Acid): Effect of Lipophilicity and the Hydrogen Bonding Role in Bacterial Membrane Interaction.

In the present study, the antibacterial activity of several ent-labdane derivatives of salvic acid (7α-hydroxy-8(17)-ent-labden-15-oic acid) was evaluated in vitro against the Gram-negative bacterium Escherichia coli and the Gram-positive bacteria Staphylococcus aureus and Bacillus cereus. For all of the compounds, the antibacterial activity was expressed as the minimum inhibitory concentration (MIC) in liquid media and minimum inhibitory amount (MIA) in solid media. Structure activity relationships (SAR) were employed to correlate the effect of the calculated lipophilicity parameters (logPow) on the inhibitory activity. Employing a phospholipidic bilayer (POPG) as a bacterial membrane model, ent-labdane-membrane interactions were simulated utilizing docking studies. The results indicate that (i) the presence of a carboxylic acid in the C-15 position, which acted as a hydrogen-bond donor (HBD), was essential for the antibacterial activity of the ent-labdanes; (ii) an increase in the length of the acylated chain at the C-7 position improved the antibacterial activity until an optimum length of five carbon atoms was reached; (iii) an increase in the length of the acylated chain by more than five carbon atoms resulted in a dramatic decrease in activity, which completely disappeared in acyl chains of more than nine carbon atoms; and (iv) the structural factors described above, including one HBD at C-15 and a hexanoyloxi moiety at C-7, had a good fit to a specific lipophilic range and antibacterial activity. The lipophilicity parameter has a predictive characteristic feature on the antibacterial activity of this class of compounds, to be considered in the design of new biologically active molecules.

Structure-Activity and Lipophilicity Relationships of Selected Antibacterial Natural Flavones and Flavanones of Chilean Flora.

In this study, we tested eight naturally-occurring flavonoids-three flavanones and five flavones-for their possible antibacterial properties against four Gram-positive and four Gram-negative bacteria. Flavonoids are known for their antimicrobial properties, and due their structural diversity; these plant-derived compounds are a good model to study potential novel antibacterial mechanisms. The lipophilicity and the interaction of antibacterial compounds with the cell membrane define the success or failure to access its target. Therefore, through the determination of partition coefficients in a non-polar/aqueous phase, lipophilicity estimation and the quantification of the antibacterial activity of different flavonoids, flavanones, and flavones, a relationship between these parameters was assessed. Active flavonoids presented diffusion coefficients between 9.4 × 10-10 and 12.3 × 10-10 m²/s and lipophilicity range between 2.0 to 3.3. Active flavonoids against Gram-negative bacteria showed a narrower range of lipophilicity values, compared to active flavonoids against Gram-positive bacteria, which showed a wide range of lipophilicity and cell lysis. Galangin was the most active flavonoid, whose structural features are the presence of two hydroxyl groups located strategically on ring A and the absence of polar groups on ring B. Methylation of one hydroxyl group decreases the activity in 3-O-methylgalangin, and methylation of both hydroxyl groups caused inactivation, as shown for 3,7-O-dimethylgalangin. In conclusion, the amphipathic features of flavonoids play a crucial role in the antibacterial activity. In these compounds, hydrophilic and hydrophobic moieties must be present and could be predicted by lipophilicity analysis.

Unitary rotation and gyration of pixelated images on rectangular screens.

In the two space dimensions of screens in optical systems, rotations, gyrations, and fractional Fourier transformations form the Fourier subgroup of the symplectic group of linear canonical transformations: U(2)F⊂Sp(4,R). Here, we study the action of this Fourier group on pixelated images within generic rectangular Nx×Ny screens; its elements here compose properly and act unitarily, i.e., without loss of information.

Repellent Activity of the Essential Oil from the Heartwood of Pilgerodendron uviferum (D. Don) Florin against Aegorhinus superciliosus (Coleoptera: Curculionidae).

The weevil Aegorhinus superciliosus Guérin (Coleoptera: Curculionidae), which is endemic to Central-Southern Chile and Argentina, is one of the major berry pests in Chile and the most important pest in the La Araucanía Region (38°44'9″S, 72°35'25″W). Due to the poor effectiveness and problems surrounding the implementation of the traditional control methods using organophosphate and carbamate insecticides, new strategies for controlling this pest are needed. In this communication, we evaluated the behavioral responses of male and female A. superciliosus to volatile compounds released from the essential oil (EO) obtained from the heartwood of Pilgerodendron uviferum (D. Don) Florin using olfactometric bioassays. The composition of the EO was analyzed using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). According to these analyses, δ-cadinol (24.16%), cubenol (22.64%), 15-copaenol (15.46%) and δ-cadinene (10.81%) were the principal components of the EO. The Pilgerodendron uviferum EO, which is almost exclusively composed of sesquiterpenes (99.5%), exhibited a repellent effect against A. superciliosus adults, regardless of the sex or concentration used (56.6 mg/cm³ and 1.58 × 10(-2) mg/cm³). The EO has low volatility and greater persistence than the EOs composed of monoterpenes and is considered a good model in the search for raspberry weevil repellents.

Antibacterial Activity of Alkaloid Fractions from Berberis microphylla G. Forst and Study of Synergism with Ampicillin and Cephalothin.

Berberis microphylla is a native plant that grows in Patagonia and is commonly used by aboriginal ethnic groups in traditional medicine as an antiseptic for different diseases. The present study evaluated the antibacterial and synergistic activity of alkaloid extracts of B. microphylla leaves, stems and roots used either individually or in combination with antibiotics against Gram-positive and Gram-negative bacteria. The in vitro antibacterial activities of leaf, stem and root alkaloid extracts had significant activity only against Gram-positive bacteria. Disc diffusion tests demonstrated that the root extract showed similar activity against B. cereus and S. epidermidis compared to commercial antibiotics, namely ampicillin and cephalothin, and pure berberine, the principal component of the alkaloid extracts, was found to be active only against S. aureus and S. epidermidis with similar activity to that of the root extract. The minimum inhibitory concentrations (MICs) of the alkaloid extracts ranged from 333 to 83 µg/mL, whereas minimum bactericidal concentrations (MBCs) varied from 717 to 167 µg/mL. In addition, synergistic or indifferent effects between the alkaloid extracts and antibiotics against bacterial strains were confirmed.

Risk factors for the need of surgical treatment of a first recurrent lumbar disc herniation.

PURPOSE: A recurrent lumbar disc herniation (RLDH) is the most prevalent cause for new radicular pain after surgery for disc herniation-induced sciatica. Reported risk factors include age, gender and smoking, while its surgical treatment is associated to a higher rate of complications and costs. The purpose of this study is to identify factors that increase the risk of requiring surgical treatment for a first RLDH in workers' compensation patients. METHODS: Nested case-control: 109 patients operated for an RLDH (cases) between June 1st 1994 and May 31st 2011 (minimum follow-up 1 year) and 109 randomly selected patients operated for a first disc herniation with no recurrence during the study period (controls). Age, gender, smoking status, type of work and MRI characteristics of the index herniation were statistically evaluated as potential risk factors. RESULTS: Patient's age of less than 35 years (p = 0.001) and a subligamentous herniation (p < 0.05) at the time of the index surgery were identified as risk factors for requiring surgical treatment of a first RLDH. No statistical differences were observed between both groups regarding the other evaluated variables. CONCLUSION: A subligamentous disc herniation and patient's age inferior to 35 years at the time of the first surgery are risk factors for requiring surgical treatment of a first RLDH among workers' compensation patients.

Temporal Variation of Aristolochia chilensis Aristolochic Acids during Spring.

In this communication, we report the springtime variation of the composition of aristolochic acids (AAs) in Aristolochia chilensis leaves and stems. The dominant AA in the leaves of all samples, which were collected between October and December, was AA-I (1), and its concentration varied between 212.6±3.8 and 145.6±1.2 mg/kg and decreased linearly. This decrease occurred in parallel with the increase in AA-Ia (5) concentration from 15.9±0.8 mg/kg at the beginning of October to 96.8±7.8 mg/kg in mid-December. Both acids are enzymatically related by methylation-demethylation reactions. Other AAs also showed important variations: AA-II (2) significantly increased in concentration, reaching a maximum in the first two weeks of November and subsequently decreasing in mid-December to approximately the October levels. The principal component in the AA mixture of the stems was also AA-I (1); similar to AA-II (2), its concentration increased beginning in October, peaked in the second week of November and subsequently decreased. The concentrations of AA-IIIa (6) and AA-IVa (7) in the leaves and stems varied throughout the study period, but no clear pattern was identified. Based on the variation of AAs in A. chilensis leaves and stems during the study period, the reduced contents of non-phenolic AAs and increased concentrations of phenolic AAs are likely associated with a decrease in this plant's toxicity during the spring.

A rapid preparative-TLC/GC-MS methodology for discriminating between two filmy ferns (Hymenophyllaceae) native from the temperate rain forest of Southern Chile based on their soluble carbohydrates / Una metodología de CCF-preparativa/CG-EM rápida para discriminar entre dos helechos película(Hymenophyllaceae) nativos del bosque templado del sur de Chile basada en sus hidratos de carbono

Filmy ferns are a conspicuous epiphytic component of the temperate rain forest of southern Chile and the more abundant genus is Hymenophyllum represented by 19 species, they are a primitive fern family sharing their limited water lost control (poikilohydricity) with lower non-vascular plants, such as bryophytes and lichens. Because, carbohydrate accumulation is a desiccation tolerance mechanism proposed for desiccation-tolerant vascularized plants, the aim of this investigation was to propose a methodology for soluble carbohydrate analysis in native ferns. Preparative- TLC showed to be a simple and rapid technique for separating Hymenophyllum sugars. GC-MS analysis allowed identifying glucitol (2.0 percent), sucrose (2.0 percent), alpha or beta-melibiose (5.0 percent) and salidroside (4.4 percent) in H. cruentum carbohydrate profile from H. dentatum showed significant differences presenting only two sugars sucrose (1.4 percent) and alpha or beta-melibiose (3.2 percent). Furthermore, salidroside, an antioxidant compound, was identified only in H. cruentum. Our results suggest that H. cruentum, has higher preventive mechanisms than H. dentatum; that would allow delay the effects of desiccation (prevent a rapid dehydration) and thus survive to short periods of drought present in the study area. Due to the presence of salidroside in H. cruentum this species should be more resistant to oxidative stress that H. dentatum.

Los helechos película se pueden encontrar en el bosque templado lluvioso del sur de Chile, siendo el género más abundante Hymenophyllum representado con 19 especies. Son una familia de helechos primitivos que comparten la limitación de control de pérdida de agua (poiquilohidrícos) con plantas no vasculares, tales como briófitas y líquenes. Como el contenido de hidratos de carbono ha sido asociado a la protección de la planta durante la desecación, su análisis es una herramienta importante para dilucidar el mecanismo asociado a este fenómeno. El objetivo de esta investigación fue proponer una metodología fácil y rápida para el análisis de hidratos de carbono en helechos nativos. La CCF-preparativa permitió la separación de hidratos de carbono presentes en plantas del género Hymenophyllum. El análisis por GC-MS logró identificar glucitol (2,0 por ciento), sacarosa (2,0 por ciento), alfa o Beta-melibiosa (5.0 por ciento) y salidrosido (4,4 por ciento) en H. cruentum. El perfil de hidratos de carbono de H. dentatum mostró diferencias significativas, mostrando sólo dos compuestos sacarosa (1,4 por ciento) y alfa o beta- melibiosa (3.2 por ciento). Además, salidrosido, un compuesto antioxidante, sólo fue identificado en H. cruentum. Nuestros resultados sugieren que ante la menor tolerancia a la desecación observada previamente en H. cruentum, esta especie presenta mecanismos que le permitirían retardar los efectos de la desecación (prevención de una rápida pérdida de agua) y así sobrevivir a los periodos cortos de sequía presentes en la zona de estudio. Debido a La presencia de salidrosido en H. cruentum, esta especie debería ser más resistente al estrés oxidativo que H. dentatum.

Insecticidal effect of Cryptocarya alba essential oil on the housefly, Musca domestica L / Efecto insecticida del aceite esencial de Cryptocarya alba en la mosca doméstica, Musca domestica L

The composition of the essential oil (EO) from Cryptocarya alba obtained by hydro distillation of fresh leaves was analyzed using gas chromatography (GC) and gas chromatography/mass spectrosmetry (GC/MS). The insecticidal effect of the oil on the house fly Musca domestica was evaluated by placing flies in a sealed glass jar containing a piece of EO-treated cotton yarn. The dose necessary to kill 50 percent of flies (LC50) in 0.5 and 1 h was determined at 26 +/- 1 °C. The essential oil from Cryptocarya alba showed significant insecticidal properties [33.56 (7.06-159.50) mg/dm3 (0.5 h) and 15.07 (5.29-42.91) mg/dm3 (1 h)]. According to GC and GC/MS analysis a total of 38 compounds were identified. The composition of the Cryptocarya alba essential oil reported in this study is different to that reported in other publications with 4-terpineol (17.48 percent) ; 4- (3,3-dimethyl-but-1-ynyl) -4-hydroxy-2,6,6-trimethylcyclohex-2-enone (12.84 percent); 1,8-cineole (7.90 percent); p-cymene (7.11 percent) and sabinene (6.80 percent), accounting for 52.13 percent of the EO. The EO from Cryptocarya alba appears promising as a natural insecticide against houseflies.

La composición del aceite esencial (AE), obtenido por hidrodestilación de hojas frescas de Cryptocarya alba se analizó mediante cromatografía de gases (CG) y cromatografía de gases/espectrometría de masas (CG/EM). La actividad insecticida del aceite contra la mosca doméstica, Musca domestica se evaluó colocando las moscas en un frasco de vidrio sellado con un trozo de hilo de algodón tratado con diferentes cantidades de AE. La dosis necesaria para matar el 50 por ciento de las moscas (LC50) en 0,5 y 1 hora se determinó a 26 +/- 1 oC. El aceite esencial de Cryptocarya alba mostró un buen efecto insecticida [33,56 (7,06-159,50) mg/dm3 (0,5 h) and 15,07 (5,29-42,91) mg/dm3 (1 h)]. La composición del aceite esencial de Cryptocarya alba encontrada en este trabajo es diferente al informado en otras publicaciones, con 4-terpineol (17,48 por ciento); 4-(3,3-dimetil-but-1-inil)-4-hidroxi-2,6,6-trimetilciclohex-2-enona (12.84 por ciento); 1,8-cineole (7,90 por ciento); p-cimeno (7,11 por ciento) y sabineno (6,80 por ciento), lo que representa el 52.13 por ciento del AE. El AE de Cryptocarya alba parece prometedor como un insecticida natural contra la mosca doméstica.

Identification of isoquinoline alkaloids from Berberis microphylla by HPLC ESI-MS/MS / Identificación de alcaloides isoquinolínicos en Berberis microphylla G. Forst mediante CLAE IES-MS/MS

Berberis microphylla (G. Forst) is a native plant growing in Patagonia. In recent years Patagonia Berberis are becoming important due to their interesting biological properties related to their alkaloids content. The aim of this study was determine the distribution and proportion of isoquinoline alkaloids in leaves, stems and roots of B. microphylla collected in two different climatic zones from Chilean Patagonia. Using by HPLC ESI-MS/MS isocorydine, jatrorrhizine, palmatine, reticuline, scoulerine, tetrahydroberberine and thalifendine were detected for the first time in this specie, and the presence of allocryptopine, berberine, calafatine and protopine, previously isolated in B. microphylla was corroborated. The alkaloids profile showed differences of compounds in samples collected in two climatic zones, where more compounds were detected in plants from Lago Deseado than Cerro Sombrero. Furthermore, a greater number of alkaloids were found in stem and root extracts and berberine and thalifendine were detected in higher proportion in these structures.

Berberis microphylla (G. Forst) es un arbusto nativo que crece en la Patagonia. Actualmente, esta planta ha sido foco de estudio dada las propiedades biológicas que presenta, atribuidas principalmente al contenido de alcaloides. El objetivo de este estudio fue determinar la distribución y proporción de alcaloides isoquinolínicos en hojas, tallos y raíces de B. microphylla colectadas en dos zonas climáticas de la Patagonia chilena. Mediante CLAE IES-MS/MS se informa por primera vez la presencia de isocoridina jatrorrizina, palmatina, reticulina, escoulerina, tetrahidroberberina y talifendina en esta especie y se confirma la presencia de allocriptopina, berberina, calafatina y protopina, identificados previamente en B. microphylla. El perfil de alcaloides mostró diferencias en la presencia de compuestos en las muestras colectas en las dos zonas climáticas, observándose un mayor número de compuestos en plantas provenientes de Lago Deseado. Además, un mayor número de compuestos se identificó en extractos de tallos y raíces donde berberina y talifendina fueron detectados en mayor proporción.