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1.
Insects ; 12(12)2021 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-34940197

RESUMEN

The Formosan subterranean termite, Coptotermes formosanus Shiraki, is a highly destructive pest and a cosmopolitan invasive species. Sustainable termite management methods have been improving with the search for novel insecticides that are effective, safe, and cost efficient. Menadione, also known as vitamin K3, is a synthetic analogue and biosynthetic precursor of vitamin K with low mammalian toxicity. Menadione has shown insecticidal activity in several insects, presumably due to interference with mitochondrial oxidative phosphorylation. However, little is known about its effectiveness against termites. In this study, we evaluated the toxicity and repellency of menadione in C. formosanus. Our results showed that menadione affected the survival and feeding activity of termites both in filter paper and substrate (sand) treatments, and menadione influenced termite tunneling activity in treated sand. In a no-choice assay, ≥90% mortality after seven days and minimal or no food consumption were recorded when sand was treated with menadione at 6 to 600 ppm. In a two-choice assay with a combination of treated and untreated sand, termites were deterred by menadione at 6 to 600 ppm and exhibited low mortality (≤30%) over seven days, while tunneling activity was prevented with 60 to 600 ppm of menadione treatment. Overall, our study demonstrated dose-dependent toxicity and repellency of menadione in C. formosanus. The potential use of menadione as an alternative termite control agent is discussed.

4.
Chem Biol Interact ; 327: 109142, 2020 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-32610056

RESUMEN

Juglone and thymoquinone are cytotoxic to pancreatic cancer cells. The aim of this study was to investigate, using an analysis of isobolograms, the type and degree of interactions between juglone and thymoquinone on MIA PaCa-2 pancreatic cancer cells. Cell viability was evaluated using the MTT assay. Cell death was determined by flow cytometry. The IC50 value for juglone and TQ in combination was found to be 24.75 µM, which was higher than juglone or TQ alone. Juglone alone killed Mia Paca-2 cells by ferroptosis. At concentrations where 10, 20 or 50% of cells were affected, there existed a moderate antagonistic relationship between juglone and TQ as indicated by the combination index (CI) value determined by the Compusyn software. At concentrations that affected 75% and 90% of cells, there were nearly an additive effect with CI value of 1.09249 and 0.92391, respectively. Moderate synergism was only seen at concentration where 95% of cells were affected, and the corresponding concentration of juglone and TQ at that combination was 40.90 µM and 511.19 µM, respectively.


Asunto(s)
Antineoplásicos/farmacología , Benzoquinonas/farmacología , Naftoquinonas/farmacología , Neoplasias Pancreáticas/tratamiento farmacológico , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Sinergismo Farmacológico , Humanos
5.
J Insect Physiol ; 112: 1-8, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30445022

RESUMEN

Temperature is one of the most important abiotic factors influencing the adaptation and diversification of insects. Diverse and complex physiological mechanisms have evolved to help insects adapt to seasonal changes in temperature and prevent cold injury. Although the mechanisms of seasonal adaptation to low temperatures have been studied for insects in different taxa, none of these mechanisms have been investigated in scale insects in the superfamily Coccoidea. The crapemyrtle bark scale, Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), is a newly introduced scale pest of crapemyrtles, Lagerstroemia spp. (Myrtales: Lythraceae). Our previous study concerning the cold tolerance of this pest suggested that, from summer to winter, A. lagerstroemiae seasonally adapted to lower temperature with a 5 °C reduction of supercooling points. In addition, time required to achieve the same levels of mortality at lower temperatures also increased. In this study, we used A. lagerstroemiae as a model system to investigate the physiological mechanisms correlated with changes in cold tolerance in scale insects, by measuring water content, lipid content and fatty acid composition, and cryoprotective polyols and sugars every other month. Results suggested that water content was lower in winter and early spring than in summer and early fall (40.8% vs. 63.3%). The proportions of the fatty acids in PL were similar over seasons, but in TAG, shorter chain fatty acids (from C6:0 to C10:0) increased in winter as longer chain fatty acids (from C14:0 to C18:0) decreased. Among all measured polyols and sugars, including glycerol, d-mannitol, myo-inositol, and d-trehalose, the levels of d-mannitol were the highest in January 2016, which were 19-times of those in March 2016 and 4.5-times of those in September 2016. Results from this study provide a better understanding on how A. lagerstroemiae overwinters, which may give insights into the overwintering strategies of other scale insects.


Asunto(s)
Aclimatación , Hemípteros/metabolismo , Metabolismo de los Lípidos , Alcoholes del Azúcar/metabolismo , Animales , Frío , Ninfa/metabolismo , Estaciones del Año , Trehalosa/metabolismo , Agua/metabolismo
6.
Cell Chem Biol ; 25(12): 1519-1532.e5, 2018 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-30344053

RESUMEN

Metabolic decoys are synthetic analogs of naturally occurring biosynthetic acceptors. These compounds divert cellular biosynthetic pathways by acting as artificial substrates that usurp the activity of natural enzymes. While O-linked glycosides are common, they are only partially effective even at millimolar concentrations. In contrast, we report that N-acetylglucosamine (GlcNAc) incorporated into various thioglycosides robustly truncate cell surface N- and O-linked glycan biosynthesis at 10-100 µM concentrations. The >10-fold greater inhibition is in part due to the resistance of thioglycosides to hydrolysis by intracellular hexosaminidases. The thioglycosides reduce ß-galactose incorporation into lactosamine chains, cell surface sialyl Lewis-X expression, and leukocyte rolling on selectin substrates including inflamed endothelial cells under fluid shear. Treatment of granulocytes with thioglycosides prior to infusion into mouse inhibited neutrophil homing to sites of acute inflammation and bone marrow by ∼80%-90%. Overall, thioglycosides represent an easy to synthesize class of efficient metabolic inhibitors or decoys. They reduce N-/O-linked glycan biosynthesis and inflammatory leukocyte accumulation.


Asunto(s)
Adhesión Celular/efectos de los fármacos , Leucocitos/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Tioglicósidos/farmacología , Animales , Glicosilación/efectos de los fármacos , Células HL-60 , Humanos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Leucocitos/citología , Leucocitos/metabolismo , Ratones , Ratones Endogámicos C57BL , Estructura Molecular , Bibliotecas de Moléculas Pequeñas/química , Tioglicósidos/química
7.
Pest Manag Sci ; 73(10): 2039-2047, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28485048

RESUMEN

BACKGROUND: In experiments with Formosan subterranean termites (Coptotermes formosanus Shirakii), myo-inositol-2-monophosphate as the dicyclohexylammonium salt was tested among other sugar derivatives, and was found to be toxic to C. formosanus when added to a moistened filter paper food source in plastic Petri dishes. RESULTS: Curiously, over a nine-day period, the moniliform (beaded) antenna of C. formosanus deteriorated in a stepwise fashion with the most distal pseudosegment (bead) turning brown and falling off, followed by the penultimate pseudosegment, sequentially, until 7-9 days when only a stub of the antenna remained. Termites became increasingly moribund with the loss of antennae, and quit normal behavior including consuming cellulose food, and died. sn-Glycerol-3-phosphate as the dicyclohexylammonium salt also gave the same results. Dicyclohexylammonium hydrogen phosphate and monocyclohexylammonium dihydrogen phosphate were synthesized, to find a low-cost form for application to baits, both of which also showed similar toxicity. In a trial with Fibonacci series dilutions of neat cyclohexylamine, the antenna-affecting activity became apparent in the LD30 (14 days) to LD70 range of concentrations. At the higher concentrations, darkening of the most distal parts of leg extremities was noticed. CONCLUSION: Cyclohexylamine appears to be a novel termiticide with a previously unreported mechanism of toxicity. Its hydrogen phosphate salts retain the toxic effect and are inexpensive and easily synthesized. © 2017 Society of Chemical Industry.


Asunto(s)
Antenas de Artrópodos/efectos de los fármacos , Ciclohexilaminas , Control de Insectos , Insecticidas , Isópteros , Animales , Fosfatos
8.
J Diet Suppl ; 14(3): 264-277, 2017 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-27680107

RESUMEN

Epidemiological studies indicate that the increased consumption of sugars including sucrose and fructose in beverages correlate with the prevalence of obesity, type-2 diabetes, insulin resistance, hyperinsulinemia, hypertriglyceridemia, and hypertension in humans. A few reports suggest that fructose extends lifespan in Saccharomyces cerevisiae. In Anopheles gambiae, fructose, glucose, or glucose plus fructose also extended lifespan. New results presented here suggest that fructose extends lifespan in Caenorhabditis elegans (C. elegans) wild type (N2). C. elegans were fed standard laboratory food source (E. coli OP50), maintained in liquid culture. Experimental groups received additional glucose (111 mM), fructose (55 mM, 111 mM, or 555 mM), sucrose (55 mM, 111 mM, or 555 mM), glucose (167 mM) plus fructose (167 mM) (G&F), or high fructose corn syrup (HFCS, 333 mM). In four replicate experiments, fructose dose-dependently increased mean lifespan at 55 mM or 111 m Min N2, but decreased lifespan at 555 mM (P < 0.001). Sucrose did not affect the lifespan. Glucose reduced lifespan (P < 0.001). Equal amount of G&F or HFCS reduced lifespan (P < 0.0001). Intestinal fat deposition (IFD) was increased at a higher dose of fructose (555 mM), glucose (111 mM), and sucrose (55 mM, 111 mM, and 555 mM). Here we report a biphasic effect of fructose increasing lifespan at lower doses and shortening lifespan at higher doses with an inverse effect on IFD. In view of reports that fructose increases lifespan in yeast, mosquitoes and now nematodes, while decreasing fat deposition (in nematodes) at lower concentrations, further research into the relationship of fructose to lifespan and fat accumulation in vertebrates and mammals is indicated.


Asunto(s)
Caenorhabditis elegans/efectos de los fármacos , Fructosa/farmacología , Edulcorantes/farmacología , Tejido Adiposo/efectos de los fármacos , Animales , Caenorhabditis elegans/fisiología , Relación Dosis-Respuesta a Droga , Escherichia coli/efectos de los fármacos , Fructosa/administración & dosificación , Glucosa/administración & dosificación , Glucosa/farmacología , Intestinos , Longevidad/efectos de los fármacos , Sacarosa/administración & dosificación , Sacarosa/farmacología , Edulcorantes/administración & dosificación
9.
Front Nutr ; 3: 7, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27014695

RESUMEN

Lectins from dietary plants have been shown to enhance drug absorption in the gastrointestinal tract of rats, be transported trans-synaptically as shown by tracing of axonal and dendritic paths, and enhance gene delivery. Other carbohydrate-binding protein toxins are known to traverse the gut intact in dogs. Post-feeding rhodamine- or TRITC-tagged dietary lectins, the lectins were tracked from gut to dopaminergic neurons (DAergic-N) in transgenic Caenorhabditis elegans (C. elegans) [egIs1(Pdat-1:GFP)] where the mutant has the green fluorescent protein (GFP) gene fused to a dopamine transport protein gene labeling DAergic-N. The lectins were supplemented along with the food organism Escherichia coli (OP50). Among nine tested rhodamine/TRITC-tagged lectins, four, including Phaseolus vulgaris erythroagglutinin (PHA-E), Bandeiraea simplicifolia (BS-I), Dolichos biflorus agglutinin (DBA), and Arachis hypogaea agglutinin (PNA), appeared to be transported from gut to the GFP-DAergic-N. Griffonia Simplicifolia and PHA-E, reduced the number of GFP-DAergic-N, suggesting a toxic activity. PHA-E, BS-I, Pisum sativum (PSA), and Triticum vulgaris agglutinin (Succinylated) reduced fluorescent intensity of GFP-DAergic-N. PHA-E, PSA, Concanavalin A, and Triticum vulgaris agglutinin decreased the size of GFP-DAergic-N, while BS-I increased neuron size. These observations suggest that dietary plant lectins are transported to and affect DAergic-N in C. elegans, which support Braak and Hawkes' hypothesis, suggesting one alternate potential dietary etiology of Parkinson's disease (PD). A recent Danish study showed that vagotomy resulted in 40% lower incidence of PD over 20 years. Differences in inherited sugar structures of gut and neuronal cell surfaces may make some individuals more susceptible in this conceptual disease etiology model.

10.
Biomacromolecules ; 16(9): 3062-72, 2015 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-26270020

RESUMEN

Periodic patterns resembling spirals were observed to form spontaneously upon unassisted cooling of d-glucaric acid- and d-galactaric acid-based polyamide solutions in N-methyl-N-morpholine oxide (NMMO) monohydrate. Similar observations were made in d-galactaric acid-based polyamide/ionic liquid (IL) solutions. The morphologies were investigated by optical, polarized light and confocal microscopy assays to reveal pattern details. Differential scanning calorimetry was used to monitor solution thermal behavior. Small- and wide-angle X-ray scattering data reflected the complex and heterogeneous nature of the self-organized patterns. Factors such as concentration and temperature were found to influence spiral dimensions and geometry. The distance between rings followed a first-order exponential decay as a function of polymer concentration. Fourier-Transform Infrared Microspectroscopy analysis of spirals pointed to H-bonding between the solvent and the pendant hydroxyl groups of the glucose units from the polymer backbone. Tests on self-organization into spirals of ketal-protected d-galactaric acid polyamides in NMMO monohydrate confirmed the importance of the monosaccharide's pendant free hydroxyl groups on the formation of these patterns. Rheology performed on d-galactaric-based polyamides at high concentration in NMMO monohydrate solution revealed the optimum conditions necessary to process these materials as fibers by spinning. The self-organization of these sugar-based polyamides mimics certain biological materials.


Asunto(s)
Materiales Biomiméticos/química , Óxidos N-Cíclicos/química , Morfolinas/química , Nylons/química
11.
PLoS One ; 10(5): e0125376, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25978745

RESUMEN

Coptotermes formosanus is an imported, subterranean termite species with the largest economic impact in the United States. The frontal glands of the soldier caste termites comprising one third of the body mass, contain a secretion expelled through a foramen in defense. The small molecule composition of the frontal gland secretion is well-characterized, but the proteins remain to be identified. Herein is reported the structure and function of one of several proteins found in the termite defense gland secretion. TFP4 is a 6.9 kDa, non-classical group 1 Kazal-type serine protease inhibitor with activity towards chymotrypsin and elastase, but not trypsin. The 3-dimensional solution structure of TFP4 was solved with nuclear magnetic resonance spectroscopy, and represents the first structure from the taxonomic family, Rhinotermitidae. Based on the structure of TFP4, the protease inhibitor active loop (Cys(8) to Cys(16)) was identified.


Asunto(s)
Isópteros/química , Inhibidores de Serina Proteinasa/química , Animales , Secuencia de Bases , ADN Complementario/genética , Espectroscopía de Resonancia Magnética , Datos de Secuencia Molecular
12.
J Proteomics ; 112: 224-49, 2015 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-25175058

RESUMEN

Searchable mass spectral libraries for glycans may be enhanced using a B2 ion library. Using a quadrupole ion-trap mass spectrometer, successive fragmentations of sodiated oligosaccharides were carried out in the positive ion mode. In B,Y-type fragmentation, disaccharide B2 ions are generated which correspond to specific glycosidic linkages using progressive MS stages. Fragmentation of "B2 ions" corresponding to glycosidic linkages such as Hex-Fuc, Hex-Hex, Hex-HexNAc, HexNAc-Hex and HexNAc-HexNAc, were systematically studied in low energy CID and collected to form a "B2 library". Linkages produce characteristic fragmentation patterns in the absence of cross-ring fragmentation. Patterns of "B2 ions" rely on relative stability of glycosidic bonds and carbohydrate-metal complexes in the gas phase. MS(n) studies of linear, branched trisaccharides and tetrasaccharides show that isomers for which B2 ion information is not available are rarely a problem in practice by their absence in an isomeric sequence or by their scarcity in nature. This MS strategy for linkage determination of carbohydrates aided by a "B2 library" was developed with a scope for expansion, providing an improved tool for glycomics. We validated this method examining levels of expressed activities of two glycosyl transferases in cancer cell lines: ß3(B3GALNT2) and ß4GalNAcT(B4GALNT3&4) that generate GalNAcß3GlcNAcß and GalNAcß4GlcNAcß. BIOLOGICAL SIGNIFICANCE: Glycosylation is an important class of the "postranslationome", which includes manifold aspects of post-translational protein modification, affecting protein conformation, providing ligands for protein receptors [1-5], and encoding unique haptenic [6,7] or antigenic markers for oncology [8-11] and other applications. Identification of individual monomeric units, linkages, ring size, branching and anomerity has posed significant challenges to mass spectrometrists. MS(n) is a growing key instrumental method to differentiate among isomers [12]. While the potential isomers in oligosaccharides are impossibly large [12], likely possibilities can be limited by the biological system, including the expressed glycosyl transferases [13-20]. Mass spectra from sequential stages of collision activation (MS(n)) can supply structural details for precise characterization of linkage, monomer ID, substitutions, anomerity and branching [21-25]. There is a fundamental need for high throughput tools in glycomics to complement proteome studies. In that regard, nothing could be more important than searchable spectral library files for structural confirmation. The National Academy of Science (NAS) report (http://glyco.nas.edu) recommends the need of more than 10,000 synthetic structures of carbohydrates to advance the field of glycomics. This study demonstrates that the general reproducibility of ion trap spectra, and energy independence from modes of ionization and collisional activation, make compiling an MS(n) library for carbohydrate identification an achievable research target [26]. We intend to use the new B2 library for carbohydrate differences found on cancers, where we profile the glycosyltransferases to predict classes of potential structures, and use the library for MS identification of the expected cohort of altered structures.


Asunto(s)
Espectrometría de Masas/métodos , Oligosacáridos/química , Conformación de Carbohidratos
13.
J Econ Entomol ; 107(5): 1800-12, 2014 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-26309270

RESUMEN

Several rare and common monosaccharides were screened for toxic effects on the Formosan subterranean termite, Coptotermes formosanus Shiraki, with the aim of identifying environmentally friendly termiticides. myo-Inositol and phytic acid, which are nontoxic to mammals, were identified as potential termite control compounds. Feeding bioassays with termite workers, where both compounds were supplied on filter paper in concentrations from 160.2 to 1,281.7 µg/mm(3), showed concentration-dependent toxicity within 2 wk. Interestingly myo-inositol was nontoxic when administered to termites in agar (40 mg/ml) in the absence of a cellulosic food source, an unexplained phenomenon. In addition, decreased populations of termite hindgut protozoa were observed upon feeding on myo-inositol but not phytate-spiked filter paper. Radiotracer feeding studies using myo-inositol-[2-(3)H] with worker termites showed no metabolism after ingestion over a 2-d feeding period, ruling out metabolites responsible for the selective toxicity.


Asunto(s)
Inositol , Insecticidas , Isópteros , Ácido Fítico , Animales , Control de Insectos
14.
Otolaryngol Head Neck Surg ; 147(5): 943-9, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22687329

RESUMEN

OBJECTIVE: To investigate the improvement in histologic detection of fungi with Gomori methenamine silver (GMS) stain by trypsin predigestion in the mucus of patients with chronic rhinosinusitis (CRS). STUDY DESIGN: Prospective, single group, descriptive analysis. SETTING: Multi-institutional. SUBJECTS AND METHODS: Thirty-four sinus specimens from 12 surgical patients with CRS were stained with hematoxylin and eosin, GMS stain, GMS with trypsin digestion, immunofluorescence stains for chitinase, and anti-Alternaria. All patients received skin testing, total IgE serology, and radioallergosorbent tests (RAST) for 23 fungal-specific IgE antibodies. RESULTS: The conventional GMS stain detected fungi in only 9 of 34 (27%) specimens. Predigesting the specimen with trypsin dramatically improved the visualization of fungi (31/34, 91%). The chitinase immunofluorescence visualized fungi in 32 of 34 (94%), and anti-Alternaria visualized 33 of 34 specimens (97%). Only 8 of 12 (75%) patients had detectable allergies. CONCLUSIONS: This report describes a simple modification of the conventional GMS stain that can significantly improve the visualization of fungi on histology and explains the lack of detection in previous studies. These novel, more sensitive histologic methods reveal the presence of fungi within the eosinophilic mucin in allergic and also nonallergic CRS patients, further questioning a crucial role of an IgE-mediated pathophysiology.


Asunto(s)
Colorantes/química , Hongos/aislamiento & purificación , Metenamina , Moco/microbiología , Rinitis/microbiología , Sinusitis/microbiología , Adulto , Anciano , Enfermedad Crónica , Eosinófilos , Humanos , Persona de Mediana Edad , Mucinas , Estudios Prospectivos , Coloración y Etiquetado
15.
J Econ Entomol ; 103(5): 1647-56, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21061964

RESUMEN

In the interest of developing interventions to infestations by Formosan subterranean termites, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), several rare sugars were tested for effects on the termites and symbionts. Among these, the D-galactose analog, 2-deoxy-D-galactose (2deoxyGal) showed promise as a potential control chemical. At a test concentration of 2deoxyGal (320.4 microg/mm3) in water applied to 5-cm filter paper, in bioassays with 20 termite workers, we found that worker termite mortality was significantly affected over a 2-wk period. Subsequent dose-mortality feeding studies confirmed these findings. In addition, consumption of the sugar-treated filter paper by termites caused a significant decrease in hindgut protozoan populations. 2deoxyGal caused dose-dependent termite mortality, taking on average 1 wk to begin killing workers, indicating that it may have promise as a delayed action toxin, which, if added to baits, could allow time after bait discovery for an entire colony to be affected.


Asunto(s)
Fucosa/toxicidad , Insecticidas/toxicidad , Isópteros/efectos de los fármacos , Infestaciones por Ácaros/prevención & control , Animales , Relación Dosis-Respuesta a Droga , Femenino , Hexosas/toxicidad , Densidad de Población , Taiwán
16.
Pest Manag Sci ; 66(8): 875-8, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20602525

RESUMEN

BACKGROUND: Research has shown that the family of grapefruit flavors called nootkatones have significant repellant and toxic effects to Formosan subterranean termites (Coptotermes formosanus Shiraki). RESULTS: Nineteen synthetic nootkatone derivatives, along with three commercially available nootkatone derivatives, were tested for repellent activity against C. formosanus by a choice assay in a petri dish with a two-step triage procedure. Based on the repellency threshold value, the relationships between structure and activity are discussed. CONCLUSION: Four derivatives of nootkatone have very high repellency and toxicity to C. formosanus, 9 times the potency of the primary compound nootkatone. Four other compounds have between 2 and 3 times the repellency of nootkatones, and three compounds are equal in their repellency to nootkatone.


Asunto(s)
Repelentes de Insectos/química , Repelentes de Insectos/farmacología , Isópteros/efectos de los fármacos , Sesquiterpenos/química , Sesquiterpenos/farmacología , Animales , Sesquiterpenos Policíclicos , Relación Estructura-Actividad
17.
J Econ Entomol ; 103(6): 2132-9, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21309236

RESUMEN

In laboratory choice tests with either filter paper treatment or sand treatment, naphthalene and 10 derivatives were evaluated for their effects on the behavior of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). After 24-h exposure, workers avoided 50-microg/cm2-treated filter paper with 1'- and 2'-acetonaphthone. By day 8, feeding activity on filter paper treated with 1- and 2-methoxynaphthalene, 1'- and 2'-acetonaphthone were significantly reduced compared with the controls. Naphthalene and six other derivatives were not effective at 50-microg/cm2-treated filter paper. After 12-d exposure, tunnels constructed in sand treated with 1- and 2-methoxynaphthalene (0-3 cm2), 1'- and 2'-acetonaphthone (2-9 cm2), 2-naphthalene methanol (14-19 cm2), or 2-isopropylnaphthalene (16-19 cm2) at the rate of 100 mg/kg sand were significantly less than the controls (34 cm2). Consumption on filter paper placed on sand treated with 1- and 2-methoxynaphthalene and 1'- and 2'-acetonaphthone was significantly reduced (0-7 mg) compared with the controls (33-54 mg). 1-Methoxynaphthalene was the only treatment that caused significantly less feeding activity in the untreated sand chamber (0-6 mg) compared with the control (63-128 mg).


Asunto(s)
Conducta Alimentaria/efectos de los fármacos , Isópteros/efectos de los fármacos , Naftalenos/administración & dosificación , Animales , Celulosa , Dióxido de Silicio
18.
J Chromatogr B Analyt Technol Biomed Life Sci ; 877(27): 3175-80, 2009 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-19729350

RESUMEN

Juvenile hormone (JH) III is responsible for control of a variety of insect physiological and developmental states, including caste differentiation of the Formosan subterranean termite (Coptotermes formosanus Shiraki). We report here a simplified, efficient sample preparation and an optimized LC-ESI-MS method for quantifying JH III in whole body extracts. Sample preparation comprises hexane extraction (from termite whole bodies) and C18 cartridge purification. Previous LC-ESI-MS protocols exhibited the following two problems: (1) ion fragmentation differed when comparing spectra from insect samples and authentic JH III and (2) a JH III monitoring ion was not resolved from other unknown compounds in whole body samples from termites. To overcome these problems, we used a pentafluorophenyl LC column and water/acetonitrile containing ammonium acetate as solvent. In a mass chromatogram (m/z 235) of termite samples, a peak was detected at the retention time of authentic JH III, and MS(2) of this peak confirmed that the ion is a fragment of JH III, [M-CH(3)OH+H](+), being the base peak in both termites and authentic JH III samples. The protocol enables quantification of JH III in a single termite with signal/noise >10:1 and the limit of quantification is 21pg.


Asunto(s)
Cromatografía Liquida/métodos , Hormonas de Insectos/análisis , Isópteros/química , Sesquiterpenos/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos , Acetatos/química , Acetonitrilos/química , Animales , Fluorobencenos/química , Fenoles/química , Sensibilidad y Especificidad
19.
Org Lett ; 11(16): 3530-3, 2009 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-19630428

RESUMEN

A facile route to enantiomerically pure (+)-nootkatone and derivatives has been established through conjunctive stereoselective Grignard/anionic oxy-Cope (AOC) reactions.


Asunto(s)
Sesquiterpenos/síntesis química , Catálisis , Estructura Molecular , Sesquiterpenos Policíclicos , Sesquiterpenos/química , Estereoisomerismo
20.
J Lipid Res ; 48(3): 656-64, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17164223

RESUMEN

Of the lipid extracts of the defense secretion from the Formosan subterranean termite, Coptotermes formosanus Shiraki, on high-performance thin-layer chromatography analysis, no glycolipids or phospholipids were detected, but free fatty acids and three novel ceramides were found (termed TL-1, TL-2, and TL-3). Free fatty acids were confirmed to be lignoceric acid (C24:0) and hexacosanoic acid (C26:0), as described previously [Chen, J., G. Henderson, and R. A. Laine. 1999. Lignoceric acid and hexacosanoic acid: major components of soldier frontal gland secretions of the Formosan subterranean termite (Coptotermes formosanus). J. Chem. Ecol. 25: 817-824]. TL-1, TL-2, and TL-3 were characterized as ceramides differing in hydrophobicity based on results of matrix-assisted laser desorption-ionization time-of-flight mass spectrometry analysis, mild alkaline treatment, GC-MS analysis of fatty acid methylesters, and GC-MS analysis of sphingoid long-chain bases (LCBs) as trimethylsilyl derivatives. Fatty acids in TL-1 and TL-2 were C18:0, C20:0, and C22:0, and those in TL-3 were 2-hydroxy C18:0, C20:0, and C22:0. The most predominant LCB in TL-2 was a novel trihydroxy C(14)-sphingosine, 1,3,9-trihydroxy-2-amino-6-tetradecene. TL-3 contained C(18)-sphinganine and two kinds of novel sphingadienines, 1,3-dihydroxy-2-amino-7,10-hexadecadiene and 1,3-dihydroxy-2-amino-11,14-eicosadiene. Although examination of the biological activities of these novel ceramides was beyond the scope of these studies, because of the minuscule quantities available from termite secretions, it will be interesting in the future to synthesize these molecules for biological testing.


Asunto(s)
Ceramidas/análisis , Isópteros/química , Animales , Ceramidas/química , Ceramidas/metabolismo , Cromatografía en Capa Delgada , Ácidos Grasos no Esterificados/análisis , Cromatografía de Gases y Espectrometría de Masas , Isópteros/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
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