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Lipoteichoic acid isolated from Lactobacillus plantarum K8 (pLTA) alleviates lipopolysaccharide (LPS)-induced excessive inflammation through inhibition of TNF-α and interleukin (IL)-6. In addition, pLTA increases the survival rate of mice in a septic shock model. In the current study, we have found that pLTA contributes to homeostasis through regulation of pro- and anti-inflammatory cytokine production. In detail, pLTA decreased the production of IL-10 by phorbol-12-myristate-13-acetate (PMA)-differentiated THP-1 cells stimulated with prostaglandin E2 (PGE-2) and LPS. However, TNF-α production which was inhibited by PGE-2+LPS increased by pLTA treatment. The regulatory effects of IL-10 and TNF-α induced by PGE-2 and LPS in PMA-differentiated THP-1 cells were mediated by pLTA, but not by other LTAs isolated from either Staphylococcus aureus (aLTA) and L. sakei (sLTA). Further studies revealed that pLTA-mediated IL-10 inhibition and TNF-α induction in PGE-2+LPS-stimulated PMA-differentiated THP-1 cells were mediated by dephosphorylation of p38 and phosphorylation of c-Jun N-terminal kinase (JNK), respectively. Reduction of pLTA-mediated IIL-10 inhibited the metastasis of breast cancer cells (MDA-MB-231), which was induced by IL-10 or conditioned media prepared from PGE-2+LPS-stimulated PMA-differentiated THP-1 cells. Taken together, our data suggest that pLTA contributes to inflammatory homeostasis through induction of repressed pro-inflammatory cytokine as well as inhibition of excessive anti-inflammatory cytokine.

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Due to high peak capacity and separation efficiency, multidimensional separation strategies have become an established tool in qualitative and quantitative analysis of proteomes. The recent technological developments in multidimensional separation strategies mainly focus on the improvement of separation resolution (peak capacity), analysis throughput and sensitivity. The aim of this review is to provide these informative resources, which might be helpful to those in proteomics community who are interested in improving MDLC performance or using them for novel proteomic applications. This review will summarize the recent advances of such techniques, and highlight their important biological applications in proteomic study over the past 2 years.

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Three varieties of honey of different dominant floral origin were found to attract social Hymenoptera, including large earth bumble bee, Bombus terrestris in a New Zealand’s mountain beech forest. This study was undertaken to identify volatile organic compounds that induce the attraction of bumble bees to honeybee (Apis mellifera) honey. We have analyzed the chemical composition of the volatile organic compounds produced in three distinct varieties of honey (i.e. mānuka, honeydew and clover honey). The composition of the chemical profile of the three honey varieties differed in the quality and in the ratio of compounds in the headspace. Ortho-methoxyacetophenone was the main compound in the headspace of all three honey varieties. Among the forty compounds identified in the headspace in the three varieties, only seven shared compounds (i.e. benzaldehyde, benzyl alcohol, phenylacetaldehyde, 2-phenylethanol, isophorone, 4-oxoisophorone, and ortho-methoxyacetophenone) were present in the headspace of the three honey varieties. The relative attractiveness of various blends of the seven common compounds found in the three honey varieties was tested for the attraction to bumble bees in a mountain beech forest. A binary blend of isophorone and 4-oxoisophorone at a ratio of 90:10 was the most attractive blend for both bumble bee workers and queens. A small number of honey bee workers were also attracted to the former binary blend. Our study represents the first identification of a honey-derived attractant for bumble bees and honey bees. The potential application of our finding for monitoring of bumble bees or to enhance crop pollination and help to tackle the current concern of a global pollination crisis is discussed.

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The hyphenation of high-performance thin-layer chromatography (HPTLC) with enzyme inhibition assays followed by high-resolution mass spectrometry (HRMS) represents a targeted profiling required in the development of new natural pharmaceuticals, functional food and cosmetics. This direct combination of a chromatogram with an enzymatic assay substantially extents the understanding of inhibitor properties in vitro. For the first time, a straightforward workflow was established for estimating the equivalency of unknown inhibitors directly in the autogram. Exemplarily, lipopeptides produced as secondary metabolites by five different Bacillus strains were analyzed by HPTLC hyphenated with the tyrosinase and acetylcholinesterase (AChE) assays. Lipopeptides that showed an inhibition were characterized by HPTLC-HRMS. Among the many reports about the biological properties of lipopeptides, their enzyme inhibitory properties are new. The most intense inhibitors were identified as surfactin and iturin A according to reference substances and exact masses. Three further inhibitors were supposedly assigned as fengycin, iturin C, and surfactin methyl ester according to their exact masses. The inhibitory activities of surfactin and iturin A were quantitatively compared with kojic acid and piperine, as references for common natural inhibitors. Their equivalently calculated tyrosinase inhibition showed that 1 µg kojic acid was equal to 1.8 µg and 3.2 µg of iturin A and surfactin, respectively; regarding to AChE inhibition, 1 µg piperine was equal to 1.7 µg and 0.6 µg of iturin A and surfactin, respectively. Further unknown enzyme inhibitors found in the sample were exemplarily calculated as surfactin, iturin A, kojic acid and piperine equivalents to estimate their importance.

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We prepared photoresponsive actuators as both hydrogels and dry gels consisting of 4-arm poly(ethylene glycol) (PEG) cross-linked by a [c2]daisy chain, which is a double-threaded [2]rotaxane dimer with α-cyclodextrin (αCD) and stilbene. The obtained gels showed fast and large deformation triggered by UV irradiation in both wet and dry states. The UV/Vis spec-troscopy results, NMR measurements and tensile tests on the gels revealed that the actuation is driven by photoisomeriza-tion of the stilbene unit in the [c2]daisy chain. The responsiveness of these gels depends on the molecular weight of the 4-arm PEG. These results suggest that αCD recognizes trans-stilbene prior to UV irradiation to maintain the length of the PEG chain in the polymer network and that photoisomerization allows αCD to leave the cis-stilbene moiety and move onto the PEG chain because the association constant of αCD with cis-stilbene is quite low. Thus, the sliding motion of the αCD unit shrinks the [c2]daisy chain, leading to the contraction of the gels. In both wet and dry states, these actuations are repeatable through reversible photoisomerization of the stilbene moiety using different wavelengths of UV-light irradiation and can be used to perform bending and lifting actions (for 15 times heavier weight compared to the dry gel).

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It remains inconclusive regarding the dose-dependent effect of egg consumption on plasma cholesterol in humans. It is unknown if egg white consumed in a normal amount can reduce plasma cholesterol. We used hamsters as a model to (i) investigate the dose-dependent effect of consuming 0 to 5 whole eggs on plasma total cholesterol (TC), and (ii) examine if egg white equivalent to 1-5 eggs possessed any reducing effect on plasma TC. In experiment 1, hamsters were divided into 6 groups (n=8 each) and fed either a control diet or five experimental diets supplemented with whole egg powders equivalent to 1 to 5 eggs/2000 kcal. Results showed that supplementation of one egg increased plasma TC by 25% compared with the control (226±16 versus 282±56 mg/dL, p<0.05), while supplementation of 2-5 eggs did not significantly produce additional raising effect on plasma cholesterol. However, supplementation of 1-5 eggs in diets caused a dose-dependent accumulation of cholesterol in liver from 21.5±4.4 to 71.3±7.3 mg/g (p<0.01). In the second experiment, hamsters were divided into 6 groups and fed either a high cholesterol control diet or five experimental diets supplemented with egg white powders from 1-5 eggs. Results showed that egg white powders affected neither plasma nor liver. The egg white powder did not affect fecal sterol excretion, suggesting it had no effect on the cholesterol absorption. It was therefore concluded that consumption of 2-5 eggs did not significantly produce additional raising effect on plasma cholesterol, while egg white did not possess a plasma cholesterol-lowering activity if it was consumed at the amount similar to a normal human diet.

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Formation of glutathionic conjugates with quinonoid forms generated through oxidation of betanidin and gomphrenin obtained from fruits of Basella alba L. was studied by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) and high-resolution mass spectrometry (LCMS-IT-TOF). The conjugates were studied for the aim of trapping of the formed quinonoids by glutathione which would indicate a presence of specific quinonoid structures in reaction products of the pigments with ABTS cation radicals. The structure of betanidin conjugate, which was formed with high efficiency, was established by NMR analysis. In the case of gomphrenin conjugate, its structure was tentatively indicated by analogous to betanidin conjugate MSn fragmentation paths. In contrast, no detectable glutathionic conjugate of betanin quinonoid (quinone methide) was present in similar betanin reaction mixtures. As a result of additional experiments performed during oxidation of gomphrenin by ABTS cation radicals in the absence of glutathione, except of decarboxylated and dehydrogenated gomphrenin derivatives, generation of betanidin and its derivatives was observed which indicated that the subsequent dopachromic intermediate rearrangement affected hydrolysis of the glucosidic bond. This is in contrast to betanin which is not deglucosylated in the same conditions during the oxidation. Obtained results shed some light on the oxidation pathways of various glycosylated betacyanins with gomphrenin being presumably the most potent antioxidant ascertained in this group of pigments.

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Framework nitrogen atoms of carbon nitride (C3N4) can coordinate with and activate metal sites for catalysis. In this study, C3N4 was employed to harvest visible light and activate Co2+ sites, without the use of additional ligands, in photochemical CO2 reduction. Photocatalysts containing single Co2+ sites on C3N4 were prepared by a simple deposition method and demonstrated excellent activity and product selectivity towards CO formation. A turnover number of more than 200 was obtained for CO production using the synthesized photocatalyst under visible-light irradiation. Inactive cobalt oxides formed at relatively high cobalt loadings but did not alter product selectivity. Further studies with X-ray absorption spectroscopy confirmed the presence of single Co2+ sites on C3N4 and their important role in achieving selective CO2 reduction.

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The antiproliferative antimicrobial fungal metabolites known as the myrocins have been proposed to cross-link DNA by double nucleotide addition. However, the nature of the DNA-reactive species is ambiguous, as myrocins have been isolated as functionally-distinct 5-hydroxy-γ-lactone and diosphenol isomers. Based on computational studies and literature precedent, we hypothesized that the diosphenol 7 (assigned here the trivial name myrocin G) is the biologically-active form of the representative isolate (+)-myrocin C (1). To probe this, we developed a short enantioselective route to 7. A powerful fragment coupling reaction that forms the central ring of the target in 38% yield and in a single step was developed. In support of our hypothesis, 7 was efficiently transformed to the bis(sulfide) 6, a product previously isolated from reactions of 1 with benzenethiol. This work provides the first direct access to the diosphenol 7, sets the stage for elucidating the mode of interaction of the myrocins with DNA, and provides a foundation for the synthesis of other pimarane diterpenes.

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We present a parameterized analytic statistical model of the thermodynamics of alchemical molecular binding within the solvent potential of mean force formalism. The model describes the free energy profiles of linear single-decoupling alchemical binding free energy calculations accurately. The parameters of the model, which are physically motivated, are derived by maximum likelihood inference from data obtained from alchemical molecular simulations. The validity of the model has been assessed on a set of host-guest complexes. The model faithfully reproduces both the binding free energy profiles and the probability densities of the perturbation energy as a function of the alchemical progress parameter. The model offers a rationalization for the characteristic shape of binding free energy profiles. The parameters obtained from the model are potentially useful descriptors of the association equilibrium of molecular complexes. Potential applications of the model for the classification of molecular complexes and the design of alchemical molecular simulations are envisioned.