Isobutyl amides - potent compounds for controlling Diatraea saccharalis

BACKGROUND: A dichloromethane-methanol extract of the seeds of Piper tuberculatum Jacq. (Piperaceae) and two isobutyl amides, 4,5-dihydropiperlonguminine (1) and pellitorine (2), which were isolated by chromatographic methods, were assayed for their lethality against the sugarcane borer Diatraea saccharalis F. (Lepidoptera: Pyralidae). RESULTS: Bioassays were carried out with fourth-instar caterpillars through topical application of test solutions to the dorsal surface of the prothorax, and dose-response correlations were determined. Significant insect mortalities were observed 24, 48 and 72 h after treatment at concentrations of >= 100 mu g insect(-1). The LD(50) and LD(90) values for compound 1 were 92.83 and 176.50 mu g insect(-1), and for compound 2 they were 91.19 and 184.56 mu g insect(-1). CONCLUSION: According to the LD(50) and LD(90) for compounds 1 and 2, it can be inferred that the values reflect an acute lethal response to both compounds, based on interaction(s) of the toxicants with a primary target or series of targets. Thus, the amides were demonstrated to have potential value in the control of the sugarcane borer. (C) 2008 Society of Chemical Industry

A Validated Reverse-phase HPLC Analytical Method for the Quantification of Phenolic Compounds in Baccharis dracunculifolia

Introduction - Baccharis dracunculifolia, which has great potential for the development of new phytotherapeutic medicines, is the most important botanical source of the southeastern Brazilian propolis, known as green propolis on account of its color. Objective - To develop a reliable reverse-phase HPLC chromatographic method for the analysis of phenolic compounds in both B. dracunculifolia raw material and its hydroalcoholic extracts. Methodology - The method utilised a C(18) CLC-ODS (M) (4.6 x 250 mm) column with nonlinear gradient elution and UV detection at 280 nm. A procedure for the extraction of phenolic compounds using aqueous ethanol 90%, with the addition of veratraldehyde as the internal standard, was developed allowing the quantification of 10 compounds: caffeic acid, coumaric acid, ferulic acid, cinnamic acid, aromadendrin-4`-methyl ether, isosakuranetin, drupanin, artepillin C, baccharin and 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran acid. Results - The developed method gave a good detection response with linearity in the range 20.83-800 mu g/mL and recovery in the range 81.25-93.20%, allowing the quantification of the analysed standards. Conclusion - The method presented good results for the following parameters: selectivity, linearity, accuracy, precision, robustness, as well as limit of detection and limit of quantitation. Therefore, this method could be considered as an analytical tool for the quality control of B. dracunculifolia raw material and its products in both cosmetic and pharmaceutical companies. Copyright (C) 2008 John Wiley & Sons, Ltd.

Antileishmanial, antimalarial and antimicrobial activities of the extract and isolated compounds from Austroplenckia populnea (Celastraceae)

Austroplenckia populnea (Celastraceae), known as ""marmelinho do campo"", is used in Brazilian folk medicine as antimicrobial, anti-inflammatory, and antitumoural agent. The aim of the present work was to evaluate the antimicrobial. antileishmanial and antimalarial activities of the crude hydroalcoholic extract of A. populnea (CHE) and some of its isolated compounds. The phytochemical study of the CHE was carried Out affording the isolation of methyl populnoate (1), populnoic acid (2), and stigmast-5-en-3-O-beta-(D-glucopyranoside) (3). This is the first time that the presence of compound 3 in A. populnea is reported. The results showed that the CHE presents antifungal and antibacterial activities, especially against Candida glabrata and Candida albicans, for which the CHE showed IC(50) values of 0.7 mu g mL(-1) and 5.5 mu g mL(-1), respectively, while amphotericin B showed an IC(50) value of 0.1 mu g mL(-1) against both microorganisms. Compounds 1-3 were inactive against all tested microorganisms. In the antileishmanial activity test against Leishmania donovani, the CHE showed an IC(50) value of 52 mu g mL(-1), while compounds 2 and 3 displayed an IC(50) value of 18 mu g mL(-1). In the antimalarial assay against Plasmodium falciparum (D6 and W2 clones), it was observed that all evaluated samples were inactive. In order to compare the effect on the parasites with the toxicity to mammalian cells, the cytotoxicity activity of the isolated compounds was evaluated against Vero cells, showing that all evaluated samples exhibited no cytotoxicity at the maximum dose tested.

Antimicrobial activity of the extract and isolated compounds from Baccharis dracunculifolia D. C. (Asteraceae)

Baccharis dracunculifolia D. C. (Asteraceae) is the most important plant source of the Brazilian green propolis. Since propolis is known for its antimicrobial activity, the aim of this work was to evaluate the showed that the leaves extract of B. dracunculifolia (BdE) presents antifungal and antibacterial activities, especially against Candida krusei and Cryptococcus neoformans, for which the BdE showed IC50 values of 65 mu g mL(-1) and 40 mu g mL(-1), respectively In comparison to the BdE, it was observed that the green propolis extract (GPE) showed better antimicrobial activity, displaying an IC50 value of 9 mu g mL(-1) against C krusei. Also, a phytochemical study of the BdE was carried out, affording the isolation of ursolic acid (1), 2 alpha-hydroxy-ursolic acid (2), isosakuranetin (3), aromadendrin-4`-methylether (4), baccharin (5), viscidone (6), hautriwaic acid lactone (7), and the clerodane diterpene 8. This is the first time that the presence of compounds 1, 2, and 8 in B. dracunculifolia has been reported. Among the isolated compounds, 1 and 2 showed antibacterial activity against methicillin-resistant Staphylococcus aureus, displaying IC50 values of 65 mu g mL(-1) and 40 mu g mL(-1), respectively. 3 was active against C neoformans, showing an IC50 value of 15 mu g mL(-1) and a MIC value of 40 mu g mL(-1), while compounds 4-8 were inactive against all tested microorganisms. The results showed that the BdE, similar to the GPE, displays antimicrobial activity, which may be related to the effect of several compounds present in the crude extract.

Schistosomicidal Evaluation of Zanthoxylum naranjillo and its Isolated Compounds against Schistosoma mansoni Adult Worms

Chemical investigation of the EtOAc fraction (EF) obtained from the ethanolic extract of Zanthoxylum naranjillo (Rutaceae) leaves (EE) by preparative HPLC resulted in the isolation of protocatechuic acid (1), gallic acid (2), p-hydroxybenzoic acid (3), and 5-O-caffeoylshikimic acid (4). This is the first time that the presence of compounds 1-4 in Z. naranjillo has been reported. Compounds 1-4, the EE, and EF were tested in vitro against Schistosoma mansoni adult worms. The results showed that the S. mansoni daily egg production decreased by 29.8%, 13.5% 28.4%, 17.7%, 16.3%, and 6.4%, respectively. Compounds 1 and 3 were also able to separate adult worm pairs into male and female. This activity may be correlated with the reduction in egg production, since 1 and 3 showed better inhibitory properties compared with 2 and 4.

Seasonal Variation of the (E)-Nerolidol and Other Volatile Compounds Within Ten Different Cultivated Populations of Baccharis dracunculifolia DC (Asteraceae)

Initially, the seeds of Baccharis dracunculifolia were collected from populations of 10 different regions, and the cultivation experiment was carried out in an experimental area of 1,800 m(2) by cultivating 100 individuals of each population. The essential oil analyses were performed on both GC-FID and GUMS, which allowed the identification of 14 compounds. The oil yield varied from 0.31% to 0.70% among populations and season. The major oxygenated sesquiterpenes in the cultivated experiment were (E)-nerolidol (32%) and spathulenol (17%). The mean concentration in the plant of (E)-nerolidol was five times higher in March (136.53 mg/100 g of plant) than it was in July (25.03 mg/100 g of plant). The mean concentration of spathulenol increased about three fold from July (16.25 mg/100 g of plant) to April (47.50 mg/100 g of plant).

Enzymatic inhibitory activity and trypanocidal effects of extracts and compounds from Siphoneugena densiflora O. Berg and Vitex polygama Cham.

Hexanic, methanolic, and hydroalcoholic extracts, and 34 isolated compounds from Vitex polygama Cham. (Lamiaceae, formely Verbenaceae) and Siphoneugena densiflora O. Berg (Myrtaceae) were screened for their trypanocidal effects on bloodstream forms of Trypanosoma cruzi and T brucei, as well as for their enzymatic inhibitory activities on glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) and trypanothione reductase (TR) enzymes from T cruzi and adeninephosphoribosyl transferase (APRT) enzyme from Leishmania tarentolae. In general, polar extracts displayed strong effects and some of the tested compounds have shown good results in comparison to positive controls of the bioassays.

A chemometric study on the analgesic activity of cannabinoid compounds using SDA, KNN and SIMCA methods

The supervised pattern recognition methods K-Nearest Neighbors (KNN), stepwise discriminant analysis (SDA), and soft independent modelling of class analogy (SIMCA) were employed in this work with the aim to investigate the relationship between the molecular structure of 27 cannabinoid compounds and their analgesic activity. Previous analyses using two unsupervised pattern recognition methods (PCA-principal component analysis and HCA-hierarchical cluster analysis) were performed and five descriptors were selected as the most relevants for the analgesic activity of the compounds studied: R (3) (charge density on substituent at position C(3)), Q (1) (charge on atom C(1)), A (surface area), log P (logarithm of the partition coefficient) and MR (molecular refractivity). The supervised pattern recognition methods (SDA, KNN, and SIMCA) were employed in order to construct a reliable model that can be able to predict the analgesic activity of new cannabinoid compounds and to validate our previous study. The results obtained using the SDA, KNN, and SIMCA methods agree perfectly with our previous model. Comparing the SDA, KNN, and SIMCA results with the PCA and HCA ones we could notice that all multivariate statistical methods classified the cannabinoid compounds studied in three groups exactly in the same way: active, moderately active, and inactive.

(FAB07_002) From the 'Curry to the 'Weal: Aboriginal town camps and compounds of the back-blocks

My involvement with Aboriginal people began in 1972 in my final year of architecture, when a small group of students were asked to advise on some Aboriginal building projects in Mt Isa and Cloncurry. This led to my Doctoral research and grew into the Aboriginal Environments Research Centre now well established at the university of Queensland. Although the personnel of this Centre have completed over 140 field trips in the last 20 years, it is a set of data collected largely from the first ten field trips in 1972-76 that will be presented in this paper.

Adsorption characteristics of phenolic compounds onto coal-reject-derived adsorbents

Carbonaceous adsorbents were prepared by heat treatment of coal reject at 600 degrees C, after chemical treatment in HNO3, H2SO4, and NaOH at 25 and 75 degrees C. Pore structure characterization and the phenol adsorption capacities of the adsorbents showed that nitric acid pretreatment significantly enhanced the surface properties, consequently the adsorption capacities of the adsorbents. A number of samples were subsequently prepared by carbonizing coal reject at 600 degrees C, after pretreatment in HNO3 under various conditions. The acid concentration, residence time, and reaction temperature were varied to obtain adsorbents with various pore structures. The adsorption capacities of the derived adsorbents for phenol, p-nitrophenol, and benzene were measured to gain further insights into the pore structure evolution. Adsorption isotherms of phenol, p-nitrophenol, and p-chlorophenol on the best adsorbent prepared were determined and correlated with theoretical isotherm equations, such as the Langmuir, Freundlich, and Redlich-Peterson equations.

The effect of grain refinement and silicon content on grain formation in hypoeutectic Al-Si alloys

The effect of increasing the amount of added grain refiner on grain size and morphology has been investigated for a range of hypoeutectic Al-Si alloys. The results show a transition in grain size at a silicon concentration of about 3 wt% in unrefined alloys; the grain size decreasing with silicon content before the transition, and increasing beyond the transition point. A change in morphology also occurs with increased silicon content. The addition of grain refiner leads to greater refinement for silicon contents below the transition point than for those contents above the transition point, while the transition point seems to remain unchanged. The slope of the grain size versus silicon content curve after the transition seems to be unaffected by the degree of grain refinement. The results are related to the competitive processes of nucleation and constitutional effects during growth and their impact on nucleation kinetics. (C) 1999 Elsevier Science S.A. All rights reserved.

Oxidation of oxa and thia fatty acids and related compounds catalysed by 5-and 15-lipoxygenase

The modified fatty acids, (Z,Z,Z)-(octadeca-6,9,12-trienyloxy)acetic acid, (Z,Z,Z)-(octadeca-9,12,15-trienyloxy)acetic acid, (all-Z)-(eicosa-5,8,11,14-tetraenyloxy)acetic acid, (all-Z)-(eicosa-5,8,11,14-tetraenylthio)acetic acid, 3-[(all-Z)-(eicosa-5,8,11,14-tetraenylthio)]propionic acid, (all-Z)-(eicosa-5,8,11,14-tetraenylthio)succinic acid, N-[(all-Z)-(eicosa-5,8,11,14-tetraenoyl)]glycine and N-[(all-Z)-(eicosa-5,8,11,14-tetraenoyl)]aspartic acid, all react with soybean 15-lipoxygenase. The products were treated with triphenylphosphine to give alcohols, which were isolated using HPLC. Analysis of the alcohols using negative ion tandem electrospray mass spectrometry, and by comparison with compounds obtained by autoxidation of arachidonic acid, shows that each enzyme catalysed oxidation occurs at the omega -6 position of the substrate. In a similar fashion, it has been found that (Z,Z,Z)-(octadeca-6,9,12-trienyloxy)acetic acid, (Z,Z,Z)-(octadeca-9,12,15-trienyloxy)acetic acid, (all-Z)-(eicosa-5,8,11,14-tetraenylthio)acetic acid and N-[(all-Z)-(eicosa-5,8, 11.14-tetraenylthio)]propionic acid each undergoes regioselective oxidation at the carboxyl end of the polyene moiety on treatment with potato 5-lipoxygenase. Neither (all-Z)-(eicosa-5,8,11,14-tetraenylthio)succinic acid nor N-[(all-Z)-(eicosa-5,8,11,14-tetraenoyl)]aspartic acid reacts in the presence of this enzyme, while N-[(all-Z)-(eicosa-5,8,11,14-tetraenoyl)]glycine affords the C11' oxidation product. The alcohol derived from (Z,Z,Z)-(octadeca-6,9, 12-trienyloxy)acetic acid using the 15-lipoxygenase reacts at the C6' position with the 5-lipoxygenase. (C) 2001 Elsevier Science Ltd. All rights reserved.

Identification of trail pheromone compounds from the labial glands of the stingless bee Geotrigona mombuca

Foragers of several species of stingless bees deposit pheromone spots in the vegetation to guide recruited nestmates to a rich food source. Recent studies have shown that Trigona and Scaptotrigona workers secrete these pheromones from their labial glands. An earlier report stated that species within the genus Geotrigona use citral from their mandibular glands for scent marking. Since convincing experimental proof for this conjecture is lacking, we studied the glandular origin of the trail pheromone of Geotrigona mombuca. In field bioassays, newly recruited bees were diverted by artificial scent trails that branched off from the natural scent trail deposited by their nestmates only when they were baited with extracts from the foragers` labial glands. Compounds extracted from the mandibular glands, however, did not release trail following behavior. This demonstrates that the trail pheromone of G. mombuca is produced in the labial glands, as in Trigona and Scaptotrigona. Furthermore, in chemical analyses citral was identified exclusively in the foragers` mandibular glands, which disproves its supposed role as a trail pheromone. The labial glands contained a series of terpene- and wax type esters, with farnesyl butanoate as major constituent. We, therefore, postulate that the trail pheromone of G. mombuca is composed of a blend of esters.

Modification-related porosity formation in hypoeutectic aluminum-silicon alloys

A series of aluminum-10 wt pet silicon castings were produced in sand molds to investigate the effect of modification on porosity formation. Modification with individual additions of either strontium or sodium resulted in a statistically significant increase in the level of porosity compared to unmodified castings. The increase in porosity with modification is due to the presence of numerous dispersed pores, which were absent in the unmodified casting. It is proposed that these pores form as a result of differences in size of the aluminum-silicon eutectic grains between unmodified and modified alloys. A geometric model is developed to show how the size of eutectic grains can influence the amount and distribution of porosity. Unlike traditional feeding-based models, which incorporate the effect: of microstructure on permeability, this model considers what happens when liquid is isolated from the riser and can no longer flow. This simple isolation model complements rather than contradicts existing theories on modification-related porosity formation and should be considered in the development of future comprehensive models.