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Leukemia is one of the most frequent types of cancer. No effective treatment currently exists, driving a search for new compounds. Simple structural modifications were made to novel triterpenes isolated from Phoradendron wattii. Of the three resulting derivatives, 3α-methoxy-24-hydroxylup-20(29)-en-28-oic acid (T1m) caused a decrease in the median inhibitory concentration (IC50) on the K562 cell line. Its mode of action was apparently apoptosis, ROS generation, and loss of mitochondrial membrane potential (MMP). Molecular docking analysis showed T1m to produce lower binding energies than its precursor for the Bcl-2 and EGFR proteins. Small, simple, and viable modifications to triterpenes can improve their activity against leukemia cell lines. T1m is a potentially promising element for future research. Clarifying the targets in its mode of action will improve its applicability.

The use of natural products in fungal disease control is an approach to reduce the negative impact of synthetic fungicides in agriculture and the environment. Although there are many alternatives, beach-cast seaweeds are a natural source of novel compounds that can be useful against fungal phytopathogens. In this study, aqueous extracts (AEs) of five species of beach-cast seaweeds, Agardhiella subulata, Bryothamnion triquetrum, Codium isthmocladum, Dictyota dichotoma, and Halymenia floresii, collected in Yucatan, Mexico, were tested against Fusarium oxysporum, Colletotrichum gloeosporioides, and Pseudocercospora fijiensis by dilution assays. From these, only H. floresii AE showed antifungal activity against P. fijiensis (13.7 mg mL−1). Furthermore, the protein fraction isolated from this AE was also active against P. fijiensis at 0.625 μg mL−1. The chromatographic profile of H. floresii AE with antifungal activity showed three major peaks at retention times (tR) 1.6, 23.0, and 23.9 min, respectively. Analysis of solids in H. floresii AE after lyophilization revealed a possibly sulfated polysaccharide (carrageenan) derivative. The toxicity analysis on Artemia salina showed that this aqueous extract is safe.

The synthetic fungicides used in agriculture cause environmental and human health problems and favor the rise of resistant fungal strains. An alternative to decrease this negative impact is those products derived from native plants. Nevertheless, anthropogenic activities cause the loss of native plants with biotechnological potential, and the ex situ conservation is one way to protect them even though their biological activity may decrease in comparison with wild plants. Diospyros cuneata Standl., native species from the coastal dune of Yucatan, was collected in dry and rainy seasons from wild and nursery plants. The antifungal activity of its leaves aqueous extracts (AE) was tested against six phytopathogenic fungi through a dilution method, including four AE. The antifungal activity against Colletotrichum gloeosporioides of the AE of the dry season from wild and nursery plants was similar and higher than those of the rainy season. A liquid-liquid partition chromatographic technique was used to obtain organic fractions. The hexane fraction (HF) of wild and nursery plants of the dry season inhibited the germination of C. gloeosporioides and C. truncatum (Syn. C. capsici) spores. The chromatographic analysis of AE from the wild plant of the dry season indicated that the abundance of metabolites was the highest. The bioautography showed that in both fungi the most active zone corresponds to the HF of the nursery plants.

INTRODUCTION: (3S)‐16,17‐Didehydrofalcarinol (1) has been isolated from Tridax procumbens and has proved to have notorious bioactivity against Leishmania mexicana. In this study, hexane fractions obtained from the methanol extract of each plant part (roots, stems, leaves, flowers, and fruits) of T. procumbens collected monthly during a year were analysed in order to determine the quantity of 1 associated with biotic variables. OBJECTIVE: The aim of this study was to find the season of the year in which the bioactive metabolite 1 is at the highest concentration and to correlate it with temperature, length of day light, and rainfall. METHODS: Hexane fractions were obtained by liquid–liquid extraction and an accurate quantitation of 1 was performed using gas chromatography with a flame ionisation detector (GC‐FID) employing pelargonic acid vanillyl amide (2) as internal standard. Partial validation was based on linearity and precision. RESULTS: Our results indicated that the total content of 1 has significant variation (P ≤ 0.05) during the different collecting months. The total content of the metabolite reached its highest level in the roots of the plant during June in the rainfall season (0.0358 ± 0.001 mg/g), and its lowest values in February and March during the drought season (0.0015 ± 0.000 and 0.0008 ± 0.000 mg/g, respectively). CONCLUSION: Our study provided evidence that the content of 1 in roots is strongly influenced by the variables of the harvesting season, also indicating that the biosynthesis of the active metabolite is enhanced during the warm and rainy months.

© 2018 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Host–parasite associations facilitate the action of reciprocal selection and can drive rapid evolutionary change. When multiple host species are available to a single parasite, parallel specialization on different hosts may promote the action of diversifying natural selection and divergence via host race formation. Here, we examine a population of the kidnapper ant (Polyergus mexicanus) that is an obligate social parasite of three sympatric ant species: Formica accreta, F. argentea, and F. subaenescens (formerly F. fusca). Behavioral and ecological observations of P. mexicanus have shown that individual colonies parasitize only one species of host and that new Polyergus queens maintain host fidelity when establishing new colonies. To successfully adapt to a particular host, Polyergus ants may mimic or camouflage themselves with the species-specific chemical cues (cuticular hydrocarbons) that their hosts use to ascertain colony membership. To investigate the extent of host specialization, we collected both genetic and chemical data from P. mexicanus that parasitize each of the three different Formica species in sympatry. We show that host-associated genetic structure exists for both maternally inherited mitochondrial DNA data and biparentally inherited microsatellite markers. We also show that P. mexicanus can be distinguished by chemical profile according to host due to partial matching with their host. Our results support the hypothesis that host race formation is occurring among lineages of P. mexicanus that use different Formica hosts. Thus, this system may represent a promising model for illuminating the early steps of divergence, accumulation of reproductive isolation, and speciation.

A model polycyclic aromatic hydrocarbon (PAH) compound, anthracene, was incorporated into a thermosetting epoxy matrix as a reinforcing moiety via physical dispersion and/or chemical modification. In order to understand the “additive effect” of glass transition temperature (Tg) observed with the variation of free anthracene (AN) and bonded 2-aminoanthracene (2-AM) loading, the relaxation dynamics were investigated by broadband dielectric spectroscopy. Within the measurement range of 0.01 Hz–1 MHz and −60 to 130 °C, three relaxation processes, namely normal mode (n-mode) relaxation, α relaxation, and β relaxation, were observed for all epoxy composites with bonded and/or unbound anthracene. After eliminating the strong effect of ionic conduction by using the logarithmic derivative approximation e ' ' ∝ ∂ e ' ∂ ln ω , derived from the Kramers-Kronig relations, the n-mode relaxation occurring at low frequencies above Tg for the rigid epoxy system is revealed. The Arrhenius diagram showing the temperature dependence of each relaxation process for the PAH-epoxy composites was obtained after parametric fitting using the Havriliak-Negami (HN) function in the frequency domain. The segmental α relaxation was more strongly impacted than the long-range n-mode relaxation by the different reinforcing approaches. The correlation of Tg -scaled fragility to molecular structures reveals the different mechanisms for the retardation effects on cooperative segmental and chain relaxation time. The localized β relaxation below Tg was not seemingly affected by the incorporation of bound and/or unbound anthracenes as indicated by the characteristic relaxation time and the activation energy.

Five compounds were isolated from Bonellia macrocarpa roots: 1,3,5,6-tetramethoxy-8-methylnaphthalene (1), 3,5-dihydroxy-1,2,2-trimethyl-benzocyclobutane (2), 3-methoxy-5-octylphenol (3), 3-methoxy-2-methyl-5-pentylphenol (4), and protoprimulagenin A (5), being 1–3 new. Compound 5 showed the best effect, exhibiting cytotoxic activity on three of the cancer cell lines (HeLa, SiHa, and MCF-7) and antiproliferative activity against two cell lines (SiHa and DU-145). The isolated compounds were able to produce greater cytotoxic than antiproliferative effect; although their cytotoxic activity was not as potent, the cytotoxicity on Vero normal cell line was lower compared to that on cancer cell lines. This work contributes to the description of five compounds isolated from B. macrocarpa and highlights the biological potential of this species.

Two new 2-benzylbenzofurans, dorsjervin A (1) and dorsjervin B (2), were isolated together with other nine known compounds (3–11) from Dorstenia contrajerva. Structure elucidation of both compounds was done through UV, IR, 1D- and 2D-NMR experiments, and mass spectrometry. All of the isolated compounds were evaluated for an in vitro anti-leishmanial activity; compounds 7 and 8 were active, with IC50’s 4.9 and 2.9 μM, respectively. This is the first report on prenylated flavonoids (1, 2, and 7) isolated from a species of Dorstenia in the Americas.

A design of experiments and response surface modeling were performed to investigate the effects of formulation and proc- essing factors on the flexural moduli and strengths of vapor-grown carbon nanofiber (VGCNF)/vinyl ester (VE) nanocomposites. VGCNF type (pristine, surface-oxidized), use of a dispersing agent (no, yes), mixing method (ultrasonication, high-shear mixing, and a combination of both), and VGCNF weight fraction (0.00, 0.25, 0.50, 0.75, and 1.00 parts per hundred parts resin (phr)) were selected as independent factors. Response surface models were developed to predict flexural moduli and strengths as a continuous function of VGCNF weight fraction. The use of surface-oxidized nanofibers, a dispersing agent, and high-shear mixing at 0.48 phr of VGCNF led to an average increase of 19% in the predicted flexural modulus over that of the neat VE. High-shear mixing with 0.60 phr of VGCNF resulted in a remarkable 49% increase in nanocomposite flexural strength relative to that of the neat VE. This ar- ticle underscores the advantages of statistical design of experiments and response surface modeling in characterizing and optimizing polymer nanocomposites for automotive structural applications. Moreover, response surface models may be used to tailor the me- chanical properties of nanocomposites over a range of anticipated operating environments. V C 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2087-2099, 2013

The effects of moulding condition and curing atmosphere on the flexural properties of a neat 33 wt.%-styrene epoxy vinyl ester (VE) were investigated. Specimens were prepared using either open or closed moulds, and thermally cured under either air or nitrogen atmosphere. Four-point bending tests were performed with both the top (“air-side”) and the bottom (“mould-side”) surfaces of the cured specimens in tension. The mean flexural moduli for nitrogen-cured and closed-mould specimens were 3% and 9% higher than for air-cured specimens, respectively. However, the mean flexural strength for open-mould air-cured specimens with their air-sides loaded in tension were 65% lower than the mean flexural strengths of open-mould nitrogen-cured or closed-mould specimens. This likely resulted from partial VE resin curing inhibition due to oxygen diffusion into the free surface region of the open-mould air-cured specimens. This creates gradients in the local stiffness and strength in the near-surface region due to lower crosslink density. This effect may be particularly important for thin specimens. These results underscore the significance of exposure to air during open-mould curing on the cured VE flexural properties. Such assessments are crucial for composite part manufacturing utilizing VEs.

The effects of vapor-grown carbon nanofiber (VGCNF) weight fraction, high-shear mixing time, and ultrasonication time on the Izod impact strengths of VGCNF/vinyl ester (VE) nanocomposites were studied using a central composite design. A response surface model (RSM) for predicting impact strengths was developed using regression analysis. RSM predictions suggested that an 18% increase in impact strength was possible for nanocomposites containing only 0.170 parts per hundred parts resin (phr) of VGCNFs (∼0.1 v%) that were high-shear mixed for 100 min when compared to that of neat VE. In general, the predicted impact strengths increased for high-shear mixing times above 55 min and VGCNF weight fractions below 0.400 phr. The predicted strengths decreased as the VGCNF weight fraction was further increased. Scanning electron micrographs of the nanocomposite fracture surfaces showed that increased impact strength could be directly correlated to better nanofiber dispersion in the matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Aim We searched for evidence of floristic homogenization in widespread oceanic archipelagos. Location Twelve oceanic archipelagos in the Atlantic and Pacific oceans: Ascension, Azores, Canary, Cape Verde, Desventuradas, Easter, Galapagos, Hawaii, Juan Fernandez, Madeira, Puerto Rico and Savage. Methods By using Jaccard’s index, we established the floristic similarity between pairs of archipelagos at two stages: original (pre-European; Jo) and current flora (Jc). Then, we calculated ΔJ = Jc–Jo, where positive differences imply that similarity has increased floristic homogenization. Results We found that floristic similarity increased fourfold on average, from 1.6% to 6.3% for original and current floras, respectively. In fact, we recorded 64 cases in which floristic similarity increased and only two in which it decreased. The importance of invasions exceeds that of extirpations as a driver of biotic change by more than an order of magnitude (2679 versus 142 species, respectively). Main conclusions The vascular floras of these 12 insular oceanic systems have increased in compositional similarity, a phenomenon consistent with the trend towards biotic homogenization. It can be characterized as a teleconnected process that operates across vast geographical distances, driven by the unprecedented capacity of humans for translocation. Trends in biotic homogenization differ depending on the geographical location (i.e. Pacific island birds reported in a previous study), emphasizing the complexity of biotic change.

Oceanic islands have long been considered to be particularly vulnerable to biotic invasions, and much research has focused on invasive plants on oceanic islands. However, findings from individual islands have rarely been compared between islands within or between biogeographic regions. We present in this study the most comprehensive, standardized dataset to date on the global distribution of invasive plant species in natural areas of oceanic islands. We compiled lists of moderate (5–25% cover) and dominant (>25% cover) invasive plant species for 30 island groups from four oceanic regions (Atlantic, Caribbean, Pacific, and Western Indian Ocean). To assess consistency of plant behaviour across island groups, we also recorded present but not invasive species in each island group. We tested the importance of different factors discussed in the literature in predicting the number of invasive plant species per island group, including island area and isolation, habitat diversity, native species diversity, and human development. Further we investigated whether particular invasive species are consistently and predictably invasive across island archipelagos or whether island-specific factors are more important than species traits in explaining the invasion success of particular species. We found in total 383 non-native spermatophyte plants that were invasive in natural areas on at least one of the 30 studied island groups, with between 3 and 74 invaders per island group. Of these invaders about 50% (181 species) were dominants or co-dominants of a habitat in at least one island group. An extrapolation from species accumulation curves across the 30 island groups indicates that the total current flora of invasive plants on oceanic islands at latitudes between c. 35°N and 35°S may eventually consist of 500–800 spermatophyte species, with 250–350 of these being dominant invaders in at least one island group. The number of invaders per island group was well predicted by a combination of human development (measured by the gross domestic product (GDP) per capita), habitat diversity (number of habitat types), island age, and oceanic region (87% of variation explained). Island area, latitude, isolation from continents, number of present, non-native species with a known invasion history, and native species richness were not retained as significant factors in the multivariate models. Among 259 invaders present in at least five island groups, only 9 species were dominant invaders in at least 50% of island groups where they were present. Most species were invasive only in one to a few island groups although they were typically present in many more island groups. Consequently, similarity between island groups was low for invader floras but considerably higher for introduced (but not necessarily invasive) species – especially in pairs of island groups that are spatially close or similar in latitude. Hence, for invasive plants of natural areas, biotic homogenization among oceanic islands may be driven by the recurrent deliberate human introduction of the same species to different islands, while post-introduction processes during establishment and spread in natural areas tend to reduce similarity in invader composition between oceanic islands. We discuss a number of possible mechanisms, including time lags, propagule pressure, local biotic and abiotic factors, invader community assembly history, and genotypic differences that may explain the inconsistent performance of particular invasive species in different island groups.

Ants are among the most damaging invasive species, and their success frequently arises from the widespread cooperation displayed by introduced populations, often across hundreds of kilometers. Previous studies of the invasive Argentine ant (Linepithema humile) have shown that introduced populations on different continents each contain a single, vast supercolony and, occasionally, smaller secondary colonies. Here, we perform inter-continental behavioral analyses among supercolonies in North America, Europe, Asia, Hawaii, New Zealand and Australia and show that these far-flung supercolonies also recognize and accept each other as if members of a single, globally distributed supercolony. Furthermore, populations also possess similar genetic and chemical profiles. However, these ants do show aggression toward ants from South Africa and the smaller secondary colonies that occur in Hawaii and California. Thus, the largest and most dominant introduced populations are likely descended from the same ancestral colony and, despite having been established more than 100 years ago, have diverged very little. This apparent evolutionary stasis is surprising because, in other species, some of the most rapid rates of evolutionary change have occurred in introduced populations. Given the spatial extent of the Argentine ant society we report here, there can be little doubt that this intercontinental supercolony represents the most populous known animal society.

Resumen In Dosidicus gigas or jumbo squid, collagen plays an important role in squid swimming mechanisms. Scarce information is available on collagen. The content as well some physical and chemical properties of pepsin-soluble (PSC) and insoluble collagen (IC) were compared in mantle, arm, and fin from adult fresh jumbo squid. The total collagen content and SDS-electrophoresis profile were different in each anatomic part evaluated, the highest IC value was in arms. Scanning electron microscopy (SEM) studies showed same structural arrangement in the PSC from the three anatomical parts and different structural arrangement in the IC. DSC showed a very high transition at 115–120°C for PSC. The highest Tmax and ΔH was detected in arms collagen. This knowledge will aid to acquire a better understanding and to improve the commercial application of this economically important commodity. El colageno en el Dosidicus gigas o calamar gigante participa en los mecanismos natatorios del organismo. Sin embargo, ...

Argentine ants (Linepithema humile) in their native South American range, like most other ant species, form spatially restricted colonies that display high levels of aggression toward other such colonies. In their introduced range, Argentine ants are unicolonial and form massive supercolonies composed of numerous nests among which territorial boundaries are absent. Here we examine the role of cuticular hydrocarbons (CHCs) in nestmate recognition of this highly damaging invasive ant using three supercolonies from its introduced range. We conducted behavioral assays to test the response of Argentine ants to workers treated with colonymate or non-colonymate CHCs. Additionally, we quantified the amount of hydrocarbons transferred to individual ants and performed gas chromatography-mass spectrometry (GC/MS) to qualitatively characterize our manipulation of CHC profiles. The GC/MS data revealed marked differences in the hydrocarbon profiles across supercolonies and indicated that our treatment effectively masked the original chemical profile of the treated ants with the profile belonging to the foreign individuals. We found that individual workers treated with foreign CHCs were aggressively rejected by their colonymates and this behavior appears to be concentration-dependent: larger quantities of foreign CHCs triggered higher levels of aggression. Moreover, this response was not simply due to an increase in the amount of CHCs applied to the cuticle since treatment with high concentrations of nestmate CHCs did not trigger aggression.The results of this study bolster the findings of previous studies on social insects that have implicated CHCs as nestmate recognition cues and provide insight into the mechanisms of nestmate recognition in the invasive Argentine ant.

Capsaicinoids are a group of 12 or more related alkaloids responsible of the pungent sensation in fruits of the genus Capsicum. Capsaicin [(E)-N-(4-hydroxy-3-methoxybenzyl)-8-methyl-6-nonenamide] and dihydrocapsaicin are responsible for more than 90% of the pungency. This work describes the quantitative analyses by gas chromatography of the content of capsaicin and dihydrocapsaicin in the pericarp, placenta, and seeds of seven cultivars of chili peppers cultivated in the state of Yucatan, Mexico [chawa, dulce, sukurre, xcat’ik (Capsicum annuum L. var. annuum), maax (Capsicum annuum L. var. aviculare), and habanero orange and habanero white (Capsicum chinense Jacq.)]. Capsaicin content was higher, as expected, in the fruits of habanero orange and habanero white, followed by sukurre, chawa, xkat’ik, and maax. Dihydrocapsaicin content did not follow the same scheme, being higher in the fruits of sukurre, followed by chawa, habanero white, habanero orange, and maax. Xcat’ik showed minor quantities of dihydrocapsaicin, while dulce chili contained only traces of these two alkaloids.

The plant Aeschynomene fascicularis (Fabaceae) has been used in Mayan traditional medicine in the Yucatan peninsula. However, the compounds present in the plant responsible for its curative properties have not yet been investigated. Aeschynomene fascicularis root bark was extracted with 100% methanol to obtain a crude extract. The methanol extract was partitioned successively with solvents with increasing polarity to obtain the corresponding hexane (Hx), dichloromethane (DCM) and ethyl acetate fractions (EtOAc), as well as a residual water-alcoholic fraction. These fractions were tested for their cytotoxic activities using an MTT assay against Hep-2 cancer cell lines. The Hx fraction led to the isolation of spinochalcone C (1), spinochalcone A (2), isocordoin (3) and secundiflorol G (4). Their structures were identified based on spectroscopic evidence and chemical properties. All compounds were subjected to cytotoxicity and antiproliferative assays against a panel of seven cell lines, including one normal-type cell line. Spinochalcone A (2) exhibited cytotoxic activity against DU-145 cell line and antiproliferative activity against the KB cell line. Secundiflorol G (4) showed strong cytotoxic activity towards KB and Hep-2 cell lines. In addition, isocordoin (3) showed moderate activity on KB, Hep-2 and DU-145 cell lines. The active Compounds 2, 3 and 4 are potential therapeutic entities against cancer.

A new alkyl catechol (bonediol) was isolated from root bark of Bonellia macrocarpa. The structure of bonediol was characterized by spectral analysis (UV, IR, 1D and 2D NMR, and MS). Bonediol exhibited certain activity and selectivity on three cancer cell lines (KB, Hep-2, and SiHa).

Hayashi Fumiko, Diario de una vagabunda, trad. Virginia Meza, pról. Kayoko Takagi, Gijón, Satori Ediciones, colección Maestros de la Literatura Japonesa, 2013, 264 pp

In Manchester, a WG was set up to work on the implementation of the 9th catalogue of orbits of spectroscopic binaries (SB9), superseding the 8th release of Batten et al. (1989) (SB8). SB9 exists in electronic format only. The web site http://sb9.astro.ulb.ac.be was officially released during Summer 2001. This site is directly accessible from the Commission 26 web site, from BDB (in Besancon) and from the CDS (at least).

Calculations of HF vibrational relaxation times in He have been performed using a theoretical model which treats the HF molecule as a simple harmonic oscillator and approximates the He–HF interaction as a separable product of a Lennard‐Jones function of the intermolecular distance and an empirical exponential function of the internal molecular coordinate. When the two state formula for the relaxation time is used, the results agree with the experimental values of Bott and Cohen near 2600 °K but have a slightly greater slope.

The surface current injection technique can provide low cost, in situ EMP testing of aircraft systems. It has not provided adequate simulation quality in the past, however. This theoretical study was undertaken to find surface current injection technique configurations capable of quality simulation. A configuration capable of quality simulation was found. It compared favorably with conventional EMP simulation techniques when both were measured against theoretical threat aircraft responses. Some preliminary experimental results further confirm the capabilities of this configuration while validating the theoretical predictions.