Sustainable use of tropical fruits? Challenges and opportunities of applying the waste-to-value concept to international value chains.

Agriculture and food science literature on waste-to-value applications that allow upcycling of by-product ingredients is increasing. However, this stream of research rarely takes an international trade and sustainability systems perspective. This focused review defines the term of waste-to-value and the sustainable development goals connected to it, and points to the tensions and questions arising when international trade is involved. Further, it exemplifies the challenges and opportunities of waste-to-value in tropical fruit trade through five cases of tropical fruit from South America: Green coconut, açaí, maracujá, cambuci, and jabuticaba. We present a model of the international supply chain that indicates where the opportunities of waste-to-value applications in international tropical fruit trade are situated, and discuss which future research questions need to be addressed to tackle the challenges of waste-to-value in global tropical fruit chains. Establishing the waste-to-value approach in the export of yet-underused tropical fruits can amongst others improve local employment, preserve natural resources, allow favorable use of side-streams in local energy production, environmentally friendly packaging material for transport, and add health functionalities to the end-consumer products, but challenges have to be solved in order to ensure these environmental and social benefits materialize.

Acaricidal and anthelmintic action of ethanolic extract and essential oil of Achyrocline satureioides.

Although Brazilian livestock is considered one of the most productive in the world, the losses caused by parasites still greatly limit these activities and its incorrect control through traditional synthetic chemicals has caused problems such as parasitic resistance. The present study evaluated the anthelmintic and acaricidal action of ethanolic extract (EE) and essential oil (OE) obtained from Achyrocline satureioides inflorescences against an endo and an ectoparasite of great importance in sheep and cattle. The action against Haemonchus contortus was evaluated by the Larval Development Test (LDT) and the Egg Hatching Test (EHT), while the acaricidal potential against Rhipicephalus (Boophilus) microplus was evaluated by the Adult Immersion Test (AIT) and Larval Package Test (LPT). Chemical analyzes were performed by liquid chromatography coupled to mass of spectrometry (LC-MS) and gas chromatography coupled to mass spectrometry (GC-MS) in order to evaluate the chemical composition of EE and EO, respectively. Luteolin (m/z 285), quercetin (m/z 301) and methyl quercetin (m/z 315) were the major compounds detected in the A. satureioides EE, while 41 compounds were identified in EO. Among them, the major compounds were caryophyllene oxide (15.4%), limonene (10.9%), trans-calamenene + Î´-cadinene (8.0%), (E)-caryophyllene (5.5%), spathulenol (5.1%) and α-pinene (4.5%). Against H. contortus, by EHT, the EE and EO showed LC50 of 83.14 mg mL-1 and 10.42 mg mL-1, respectively. In LDT, LC50 were 0.16 mg mL-1 and 0.42 mg mL-1, respectively by EE and EO. In the AIT assay for R. (B.) microplus tick LC50 obtained for EE and EO were 76.43 mg mL-1 and 114.35 mg mL-1, respectively. EE at 100 mg mL-1 completely inhibited egg laying, while the EO at 50 mg mL-1 completely inhibited larval hatching. No significant larvicidal effect was observed in LPT for both extracts. The EE and EO presented a high efficacy at low concentrations in the inhibition of egg hatching and larval development of H. contortus. Although both extracts did not show consistent larvicidal action, the results were significant in inhibiting the oviposition of R. (B.) microplus engorged females.

Artemisia annua L. and photoresponse: from artemisinin accumulation, volatile profile and anatomical modifications to gene expression.

KEY MESSAGE: Blue and yellow light affected metabolism and the morphology. Blue and red promote the DOXP/MEP pathway. ADS gene expression was increased in plants cultivated under blue, promoting artemisinin content. Artemisinin-based combination therapies are the most effective treatment for highly lethal malaria. Artemisinin is produced in small quantities in the glandular trichomes of Artemisia annua L. Our aim was to evaluate the effect of light quality in A. annua cultivated in vitro under different light qualities, considering anatomical and morphological changes, the volatile composition, artemisinin content and the expression of two key enzymes for artemisinin biosynthesis. Yellow light is related to the increase in the number of glandular trichomes and this seemed to positively affect the molecular diversity in A. annua. Yellow light-stimulated glandular trichome frequency without triggered area enhancement, whereas blue light stimulated both parameters. Blue light enhanced the thickness of the leaf epidermis. The B-promoting effect was due to increased cell size and not to increased cell numbers. Green and yellow light positively influenced the volatile diversity in the plantlets. Nevertheless, blue and red light seemed to promote the DOXP/MEP pathway, while red light stimulates MVA pathway. Amorpha-4,11-diene synthase gene expression was significantly increased in plants cultivated under blue light, and not red light, promoting artemisinin content. Our results showed that light quality, more specifically blue and yellow light, positively affected secondary metabolism and the morphology of plantlets. It seemed that steps prior to the last one in the artemisinin biosynthesis pathway could be strongly influenced by blue light. Our work provides an alternative method to increase the amount of artemisinin production in A. annua without the use of transgenic plants, by the employment of blue light.

Collection and identification of an unknown component from Eugenia uniflora essential oil exploiting a multidimensional preparative three-GC system employing apolar, mid-polar and ionic liquid stationary phases.

The present research deals with the collection and structural elucidation of an unknown component, accounting for about 35% of the essential oil obtained upon distillation of the leaves of Eugenia uniflora L., harvested during summer (January, 2017) in Paraná State (Southern Brazil). A multidimensional gas chromatographic preparative system, based on the coupling of three GC systems equipped with apolar, PEG and ionic liquid-based stationary phases, was successfully applied for the isolation of the chromatographic band relative to the unknown molecule. The use of wide-bore columns allowed for an increased sample capacity compared to conventional micro-bore columns, thus the injection of a neat sample was feasible, greatly reducing the total collection time. A higher chromatographic efficiency was afforded by the use of a multidimensional approach in the heart-cut mode, exploiting the different selectivity of three stationary phases, which ensured the attainment of a highly pure fraction. In only five runs, more than 3 milligrams were collected, with an average purity greater then 95%. Finally, the unknown component was subjected to nuclear magnetic resonance spectroscopy, mass spectrometry and condensed phase Fourier-transform infrared spectroscopy, leading to the identification of 6-ethenyl-6-methyl-3,5-di(prop-1-en-2-yl)cyclohex-2-en-1-one. The presented approach has been demonstrated to be effective for the isolation and structural elucidation of unknown molecules in complex samples, which will allow for further in-depth studies, like biological evaluation or pharmacological tests.

Gas chromatography-mass spectrometry of sapucainha oil (Carpotroche brasiliensis) triacylglycerols comprising straight chain and cyclic fatty acids.

Sapucainha oil, which may be used to treat leprosy, comprises straight chain and cyclic fatty acids (FA), and triacylglycerols (TAG). The FA and TAG content of the oil sample was analysed using gas chromatography-electron ionisation mass spectrometry (GC-EIMS). FA analysis was performed after derivatisation to fatty acid methyl esters (FAME). For free FA and TAG analysis, the oil sample was dissolved in hexane and injected into a short, high-temperature column, for GC with MS analysis. Free FA and FAME were tentatively identified based on mass spectrum information of their molecular and fragment ions, as well as library matching. Overlapping TAG peaks were deconvoluted based on mass fingerprint data. The FA composition was utilised to predict possible TAG identities. FA residues of TAG were identified based on characteristic fragment ions, such as [M-RCO2]+, [RCO+128]+, [RCO+74]+ and RCO+ where R is the aliphatic hydrocarbon chain. FAME analysis showed that the cyclic FA hydnocarpic (36.1%), chaulmoogric (26.5%) and gorlic (23.6%) acids were the major components. In addition, straight chain FA such as palmitic, palmitoleic, stearic, oleic and linoleic acids were detected. Palmitic, oleic, hydnocarpic, chaulmoogric and gorlic acids were also detected as free FA in the oil sample. Six groups of TAG peaks were eluted from GC at temperatures ≥330 °C. After deconvolution and mass spectrum analysis, each TAG peak group was revealed to comprise 2 to 5 co-eluted TAG molecules; >18 TAG were identified. These TAG consisted of a mix of both cyclic and straight chain FA, but were mostly derived from cyclic FA.

Biodegradation of Organophosphorus Compounds Predicted by Enzymatic Process Using Molecular Modelling and Observed in Soil Samples Through Analytical Techniques and Microbiological Analysis: A Comparison.

Organophosphorus compounds (OP) are chemicals widely used as pesticides in different applications such as agriculture and public health (vector control), and some of the highly toxic forms have been used as chemical weapons. After application of OPs in an environment, they persist for a period, suffering a degradation process where the biotic factors are considered the most relevant forms. However, to date, the biodegradation of OP compounds is not well understood. There are a plenty of structure-based biodegradation estimation methods, but none of them consider enzymatic interaction in predicting and better comprehending the differences in the fate of OPs in the environment. It is well known that enzymatic processes are the most relevant processes in biodegradation, and that hydrolysis is the main pathway in the natural elimination of OPs in soil samples. Due to this, we carried out theoretical studies in order to investigate the interactions of these OPs with a chosen enzyme-the phosphotriesterase. This one is characteristic of some soils' microorganisms, and has been identified as a key player in many biodegradation processes, thanks to its capability for fast hydrolyzing of different OPs. In parallel, we conducted an experiment using native soil in two conditions, sterilized and not sterilized, spiked with specific amounts of two OPs with similar structure-paraoxon-ethyl (PXN) and O-(4-nitrophenyl) O-ethyl methylphosphonate (NEMP). The amount of OP present in the samples and the appearance of characteristic hydrolysis products were periodically monitored for 40 days using analytical techniques. Moreover, the number of microorganisms present was obtained with plate cell count. Our theoretical results were similar to what was achieved in experimental analysis. Parameters calculated by enzymatic hydrolysis were better for PXN than for NEMP. In soil, PXN suffered a faster hydrolysis than NEMP, and the cell count for PXN was higher than for NEMP, highlighting the higher microbiological toxicity of the latter. All these results pointed out that theoretical study can offer a better comprehension of the possible mechanisms involved in real biodegradation processes, showing potential in exploring how biodegradation of OPs relates with enzymatic interactions.

Ionic liquid capillary columns for analysis of multi-component volatiles by gas chromatography-mass spectrometry: performance, selectivity, activity and retention indices.

This study investigates applications and performance evaluation of SLB-IL60, SLB-IL76 and SLB-IL111 columns, in relation to a DB-Wax column, for the analysis of coffee volatile compounds. Both standards and an authentic coffee sample were analysed, with solid-phase microextraction (SPME) sampling of the latter. A cryofocusing method was applied to improve resolution of the earliest eluting peaks using splitless injection SPME sample analysis. The Grob test was used to verify the inertness and efficiency of the columns, helping to understand the interactions between analytes and stationary phases, particularly toward more polar coffee analytes. A DB-5 column was used only in analysis of n-alkanes and Grob test mixtures as an apolar reference. The evaluated ionic liquid columns showed a moderate acid-base character and low inertness for compounds with hydrogen bond capabilities, especially for the hydroxylated analytes, 2,3-butanediol in the Grob test, and furanones and acids in the coffee standards. The columns exhibiting the best resolution and efficiency were DB-Wax and SLB-IL60, both for samples and standards. Although the DB-Wax column is preferred for analysis of coffee volatiles, due to better inertness, the evaluated ionic liquid columns allowed identification of compounds that were not observed in separations with the Wax-phase column in this work. Among these compounds is 3,4-dimethyl-2,5-furandione, seldom reported in the literature of coffee. Proposed improvement by the manufacturer in the inertness of the columns evaluated in this study may lead to better results; so future versions of IL phases may be better applied in the separation of target analytes, especially those with basic character. Graphical abstract Illustrative representation of the sample (coffee) and the chemical structures of the stationary phases of the ionic liquid capillary columns used as object of study in the present work.

Chemical Composition and In vitro Anthelmintic Activity of Extracts of Tagetes patula Against a Multidrug-Resistant Isolate of Haemonchus contortus.

Sheep breeding has suffered economic losses due to parasitism by gastrointestinal nematodes, particularly Haemonchus contortus. The use of natural products, specifically Tagetes patula, has been suggested as an alternative method of combatting this issue. Chemical analyses of the extracts of this species described in the literature report the presence of important classes of secondary metabolites such as thiophenes, flavonoids, alkaloids, and benzofurans, some of which were identified and isolated in this study. The aim of this work was to test the effect of the essential oil (EO) and the ethanolic extract of the aerial parts (TpEtOH ) of T. patula on eggs and larvae of H. contortus, through an egg hatch test (EHT) and a larval development test (LDT). In the EHT, the EO showed 100% inhibition at 0.75 mg mL-1 (LC50 = 0.0780 mg mL-1 ), and the TpEtOH showed 100% inhibition at 100 mg mL-1 (LC50 = 12.8 mg mL-1 ). In the LDT, the EO showed 100% inhibition at 0.375 mg mL-1 (LC50 = 0.0400 mg mL-1 ), and the TpEtOH showed 100% inhibition at 1.56 mg mL-1 (LC50 = 0.340 mg mL-1 ). Compared to available literature data, the results presented here suggest that the crude extracts of T. patula have substantial potential for controlling this nematode by interrupting its life cycle and/or preventing it from reaching the infective stage.

Piper Essential Oils Inhibit Rhizopus oryzae Growth, Biofilm Formation, and Rhizopuspepsin Activity.

Piper is the largest genus of the Piperaceae family. The species of this genus have diverse biological activities and are used in pharmacopeia throughout the world. They are also used in folk medicine for treatment of many diseases in several countries including Brazil, China, India, Jamaica, and Mexico. In Brazil, Piper species are distributed throughout the national territory, making this genus a good candidate for biological activity screening. During our studies with Piper essential oils, we evaluated its activity against Rhizopus oryzae, the main agent of mucormycosis. The main compounds of seven Piper essential oils analyzed were Piper callosum-safrole (53.8%), P. aduncum-dillapiole (76.0%), P. hispidinervum-safrole (91.4%), P. marginatum-propiopiperone (13.2%), P. hispidum-γ-terpinene (30.9%), P. tuberculatum-(E)-caryophyllene (30.1%), and Piper sp.-linalool (14.6%). The minimum inhibitory concentration of Piper essential oils against R. oryzae ranged from 78.12 to >1250 µg/mL. The best result of total inhibition of biofilm formation was obtained with Piper sp. starting from 4.88 µg/mL. Considering the bioactive potential of EOs against planktonic cells and biofilm formation of R. oryzae could be of great interest for development of antimicrobials for therapeutic use in treatment of fungal infection.

Development and evaluation of an inhalation chamber for in vivo tests.

The bioavailability, toxicity, and therapeutic efficacy of a drug is directly related to its administration route. The pulmonary route can be accessed by inhalation after fumigation, vaporization or nebulization. Thus, pharmacological and toxicological evaluation accessed by an apparatus specifically designed and validated for this type of administration is extremely important. Based on pre-existing models, an inhalation chamber was developed. This presents a central structure with five animal holders. The nebulized air passes directly and continuously through these holders and subsequently to an outlet. Evaluation of its operation was performed using clove essential oil, a nebulizer, and a flow meter. The air within the chamber was collected by static headspace and analyzed by gas chromatography with a flame ionization detector. For this purpose, a 2.5 minutes chromatographic method was developed. The air flow in each of the five outputs was 0.92 liters per minute. During the first minute, the chamber became saturated with the nebulized material. Homogeneous and continuous operation of the chamber was observed without accumulation of volatile material inside it for 25 minutes. The inhalation chamber works satisfactorily for in vivo tests with medicines designed to be administrated by inhalation.

Growth Inhibition of Sulfate-Reducing Bacteria in Produced Water from the Petroleum Industry Using Essential Oils.

Strategies for the control of sulfate-reducing bacteria (SRB) in the oil industry involve the use of high concentrations of biocides, but these may induce bacterial resistance and/or be harmful to public health and the environment. Essential oils (EO) produced by plants inhibit the growth of different microorganisms and are a possible alternative for controlling SRB. We aimed to characterize the bacterial community of produced water obtained from a Brazilian petroleum facility using molecular methods, as well as to evaluate the antimicrobial activity of EO from different plants and their major components against Desulfovibrio alaskensis NCIMB 13491 and against SRB growth directly in the produced water. Denaturing gradient gel electrophoresis revealed the presence of the genera Pelobacter and Marinobacterium, Geotoga petraea, and the SRB Desulfoplanes formicivorans in our produced water samples. Sequencing of dsrA insert-containing clones confirmed the presence of sequences related to D. formicivorans. EO obtained from Citrus aurantifolia, Lippia alba LA44 and Cymbopogon citratus, as well as citral, linalool, eugenol and geraniol, greatly inhibited (minimum inhibitory concentration (MIC) = 78 µg/mL) the growth of D. alaskensis in a liquid medium. The same MIC was obtained directly in the produced water with EO from L. alba LA44 (containing 82% citral) and with pure citral. These findings may help to control detrimental bacteria in the oil industry.

Effects of 7-hydroxycalamenene isolated from Croton cajucara essential oil on growth, lipid content and ultrastructural aspects of Rhizopus oryzae.

The leaves and bark of Croton cajucara, a shrub from the Amazon region, have been used in folk medicine to treat diabetes, malaria, and gastrointestinal and liver disorders. The essential oil from the leaves, rich in linalool, presented antileishmanial and antimicrobial activities. A chemotype of this species was found with an essential oil rich in 7-hydroxycalamenene. During our studies of the C. cajucara essential oil, we isolated 7-hydroxycalamenene at > 98 % purity. The minimum inhibitory concentration of 7-hydroxycalamenene against Absidia cylindrospora, Cunninghamella elegans, Mucor circinelloides, Mucor circinelloides f. circinelloides, Mucor mucedo, Mucor plumbeus, Mucor ramosissimus, Rhizopus microsporus, Rhizopus oryzae, and Syncephalastrum racemosum ranged from 19.53 to 2500 µg/mL. The reference drug used, amphotericin B, presented a minimum inhibitory concentration ranging from 0.085 µg/mL to 43.87 µg/mL. 7-Hydroxycalamenene also altered spore differentiation and total lipid content. Ultrastructural analysis by transmission electron microscopy showed significant alterations in the cellular structure of R. oryzae.

In vitro cytocidal effects of the essential oil from Croton cajucara (red sacaca) and its major constituent 7- hydroxycalamenene against Leishmania chagasi.

BACKGROUND: Visceral leishmaniasis is the most serious form of leishmaniasis and can be lethal if left untreated. Currently available treatments for these parasitic diseases are frequently associated to severe side effects. The leaves of Croton cajucara are used as an infusion in popular medicine to combat several diseases. Previous studies have demonstrated that the linalool-rich essential oil from C. cajucara (white sacaca) is extremely efficient against the tegumentary specie Leishmania amazonensis. In this study, we investigated the effects of the 7-hydroxycalamenene-rich essential oil from the leaves of C. cajucara (red sacaca) against Leishmania chagasi, as well as on the interaction of these parasites with host cells. METHODS: Promastigotes were treated with different concentrations of the essential oil for determination of its minimum inhibitory concentration (MIC). In addition, the effects of the essential oil on parasite ultrastructure were analyzed by transmission electron microscopy. To evaluate its efficacy against infected cells, mouse peritoneal macrophages infected with L. chagasi promastigotes were treated with the inhibitory and sub-inhibitory concentrations of the essential oil. RESULTS: The minimum inhibitory concentrations of the essential oil and its purified component 7-hydroxycalamenene against L. chagasi were 250 and 15.6 µg/mL, respectively. Transmission electron microscopy analysis revealed important nuclear and kinetoplastic alterations in L. chagasi promastigotes. Pre-treatment of macrophages and parasites with the essential oil reduced parasite/macrophage interaction by 52.8%, while it increased the production of nitric oxide by L. chagasi-infected macrophages by 80%. CONCLUSION: These results indicate that the 7-hydroxycalamenene-rich essential oil from C. cajucara is a promising source of leishmanicidal compounds.

Antioxidant and antimicrobial activities of 7-hydroxy-calamenene-rich essential oils from Croton cajucara Benth.

Croton cajucara is a shrub native to the Amazon region locally known as "sacaca". Two morphotypes are known: white and red "sacaca". The essential oils (EO) obtained by hydrodistillation from leaves of the red morphotype were, in general, rich in 7-hydroxycalamenene (28.4%-37.5%). The effectiveness of these EO regarding the antimicrobial activity against pathogenic microorganisms was initially investigated by the drop test method, showing significant inhibition zones. Among the microorganisms tested, the essential oils rich in 7-hydroxycalamenene were more effective against methicillin resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, Mycobacterium tuberculosis, M. smegmatis, Mucor circinelloides and Rhizopus oryzae. The minimum inhibitory concentrations (MIC) of the oils were determined using the broth dilution assay. It was possible to observe that 7-hydroxycalamenene-rich oils presented high antimicrobial activity, with MIC of 4.76 × 10⁻³ µg/mL for MRSA, 4.88 µg/mL for M. tuberculosis, 39.06 µg/mL for M. smegmatis, and 0.152 µg/mL for R. oryzae and 3.63 × 10⁻8 µg/mL for M. circinelloides. The antioxidant activity of this EO suggests that 7-hydroxycalamenene provides more antioxidant activity according with EC(50) less than 63.59 µg/mL. Considering the bioactive potential of EOs and 7-hydroxycalamenene could be of great interest for development of antimicrobials for therapeutic use in treatment of bacterial and fungal infections in humans and/or veterinary practice.

Use and abuse of retention indices in gas chromatography.

The value of the concept of retention indices (RI) to the practice of gas chromatography (GC) is highlighted, where the RI of a compound is one component of the strategy to identify the compound. The widespread reliance on GC and then on mass spectrometry for 'identification', may result in inadequate confirmation of molecular identity. However, RI do provide a useful tentative indication of the possible molecule(s). Thus, the RI value is a useful first measure of the molecule identity, and shown here to be valuable provided limitations are recognised. An author has a responsibility to correctly calculate the index and then use the values for (tentative) identification. Tables of reference RI values are useful in this respect, but finding an 'exact match' RI value does not confirm the identity. Hence, it is necessary to understand how the RI value may be incorrectly used in this respect. The reviewer of written research is charged with ensuring the index values are applied in a rigorous manner. Selected case studies from our own work, support the care that must be exercised when reporting RI values. In terms of advanced GC operations, mention is made of multidimensional gas chromatography and comprehensive two-dimensional gas chromatography to acquire RI values on both the first and second columns in the two-column separation experiment.

Microencapsulation of marjoram essential oil as a food additive using sodium alginate and whey protein isolate.

Encapsulation techniques are generally used to preserve the volatile compounds of essential oils. This study aimed to evaluate the influence of process variables on the microencapsulation of marjoram essential oil (MEO) (Origanum majorana L.) by ionic gelation. The effect of sodium alginate concentration (0.5-2 g/100 mL), emulsifier concentration (0.5-2 g/100 mL whey protein isolate (WPI)), and cationic bath concentration (0.05-0.3 mol/L CaCl2) on the emulsions and beads properties were investigated, according to a rotatable central composite design. MEO chemical composition and antimicrobial activity were assessed. Emulsions were characterized for droplet size and viscosity, while the particles were analyzed for encapsulation efficiency, size and circularity, and morphology. High concentrations of alginate and WPI intensified the porous structure of the beads, reducing droplet mean diameter and encapsulation efficiency. High alginate concentrations also increased emulsion viscosity, affecting positively beads' circularity. The intermediate concentration of sodium alginate (1.25 g/100 mL), WPI (1.25 g/100 mL), and CaCl2 (0.175 mol/L) were selected as the most appropriate conditions to produce beads with satisfactory circularity and high encapsulation efficiency.

Synergism in Two-Component Insecticides with Dillapiole against Fall Armyworm.

The fall armyworm (Spodoptera frugiperda), a polyphagous insect pest, is a major threat to food production, rapidly spreading through all the tropical areas in the world. Resistance has developed to the control protocols used so far (pyrethroids, organophosphorus, and genetically modified plants), and alternative strategies must be found. The bioactivity in essential oils is usually associated with the major constituents, but synergistic interactions among the constituents (even minor ones) can improve the levels of activity considerably. Herein, we tested the insecticidal activity of several constituents of the essential oil from Piper aduncum, an Amazonian Piperaceae, both separately and as binary mixtures, through their application on the dorsal side of the larva pronotum. Dillapiole proved to be, isolated, the most active compound in this oil (LD50 = 0.35 ppm). In binary mixtures, a strong synergistic effect was observed for the pairs of dillapiole with ß-caryophyllene (LD50 = 0.03 ppm), methyl eugenol (LD50 = 0.05 ppm), and α-humulene (LD50 = 0.05 ppm). In some cases, however, antagonism was recorded, as for dillapiole + ß-pinene (LD50 = 0.44 ppm). The use of binary mixtures of essential oil constituents as low-environmental-toxicity insecticides allows a fine tuning of the insecticidal activity, and the exploitation of synergy effects.

In vitro efficacy of plant extracts and synthesized substances on Rhipicephalus (Boophilus) Microplus (Acari: Ixodidae).

Herbal drugs have been widely evaluated as an alternative method of parasite control, aiming to slow development of resistance and obtain low-cost biodegradable parasiticides. This study evaluated the in vitro efficacy on Rhipicephalus (Boophilus) microplus of extracts from Carapa guianensis seed oil, Cymbopogon martinii and Cymbopogon schoenanthus leaf essential oil, and Piper tuberculatum leaf crude extract and similar synthesized substances. In the immersion test, engorged females were evaluated in five dilutions ranging from 10% to 0.030625% concentration. In the larval test on impregnated filter paper, the concentration ranged from 10% to 0.02%. The treatments and controls were done in three replicates. Chemical analysis of the oils was performed by gas chromatography. The main compounds were oleic acid (46.8%) for C. guianensis and geraniol for C. martinii (81.4%), and C. schoenanthus (62.5%). The isolated and synthesized substances showed no significant effect on larvae and adult. C. martinii and P. tuberculatum showed the best efficacy on the engorged females. The LC(50) and LC(90) were 2.93% and 6.66% and 3.76% and 25.03%, respectively. In the larval test, the LC(50) and LC(90) obtained for C. martinii, P. tuberculatum, and C. schoenanthus were 0.47% and 0.63%, 0.41% and 0.79%, 0.57% and 0.96%, respectively. The fact that geraniol is present in greater quantities in C. martinii explains its higher activity in relation to C. shoenanthus. It is necessary to validate the in vivo use of safe and effective phytoparasiticidal substances. Efforts should be focused on developing formulations that enhance the efficacy in vivo and lengthen the residual period.

Antimicrobial activity of Paenibacillus kribbensis POC 115 against the dermatophyte Trichophyton rubrum.

In a search for an antifungal substance with activity against the dermatophyte fungus Trichophyton rubrum, strain POC 115 was chosen among different Paenibacillus strains for its phenotypic and genetic characterization and for preliminary characterization of its antimicrobial substance. Strain POC 115 was identified as belonging to Paenibacillus kribbensis. Physico-chemical characterization of the antimicrobial substance showed that it was not stable during heat and organic solvents treatments, but its activity was preserved at a wide range of pH and after treatment with pronase E, trypsin and DNase I. The crude concentrated supernatant of POC 115 culture was partially purified and the fraction presenting antimicrobial activity was further analyzed by UPLC/Mass Spectrometry. Two peaks were observed at 2.02 (mass 1,207 D) and 2.71 (mass 1,014 D) min in the mass chromatogram. The antimicrobial substance produced by POC 115 was correlated to iturin family compounds based on a set of primers designed for the amplification of PKS operon in the POC 115 genome. As happens with the mode of action of the antibiotics of the iturin group, the AMS produced by POC 115 caused the disruption of cytoplasmic membrane of T. rubrum and the subsequent withdraw of the intracellular material. This is the first report on the production of antimicrobial substances in P. kribbensis, and it may be of great relevance as an alternative or supplementary substance to antifungal drugs currently used against dermatophytes.

Immobilization of phosphonium-based ionic liquid stationary phases extends their operative range to routine applications in the flavor, fragrance and natural product fields.

Phosphonium-based ionic liquids (ILs) have proven to be successful stationary phases (SPs) for gas chromatography (GC) in several fields of application because of their unique selectivity and good chromatographic properties. This study focuses on the use of two ILs as GC SPs that are based on the phosphonium derivatives trihexyl(tetradecyl)phosphonium chloride ([P66614+] [Cl-]), and trihexyl(tetradecyl)phosphonium bis[(trifluoromethyl)sulfonyl]imide ([P66614+][NTf2-]), which have previously been shown to be complementary in terms of chromatographic selectivity and retention. Their application in routine analysis has been limited by their lower maximum allowable operating temperatures (MAOT) (200 °C for the [P66614+][Cl-] IL and 180 °C for [P66614+][NTf2-]), which restricts their use to samples that consist of analytes with relatively high volatility. A previous study carried out in the Authors' laboratory focused on extending the use of the [P66614+][Cl-] IL SP to the analysis of samples with analytes of medium-to-low volatility by optimizing column characteristics and operative conditions. This study addresses the immobilization of both the [P66614+][Cl-] and [P66614+][NTf2-] ILs to the inner wall of fused silica columns to increase their MAOT under soft and hard reaction conditions. The resulting MAOT depended on more or less drastic immobilization conditions, and reached 220 °C for soft immobilization (So-Im) and 240 °C for hard immobilization (Ha-Im) in the [P66614+][Cl-] IL columns, and 200 °C for So-Im and 220° for Ha-Im in columns coated with the [P66614+] [NTf2-] IL. The influence of immobilization on the separation power and performance of all the columns has been evaluated using i) the Grob test, ii) a model mixture of 41 compounds of different polarity, structure, and with different organic functional groups representative of the flavor and fragrance field, iii) a standard mixture of 37 fatty acid methyl esters, iv) the peppermint essential oil, v) two mixtures of sesquiterpenic alcohols (farnesols and santalols), and vi) a standard mixture of 16 pesticides. These test samples were also used to demonstrate the complementarity of the two phosphonium-based IL SPs in terms of selectivity and retention.