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In this study, polydopamine and silver-modified graphene oxide (Ag/PGO) were prepared using a one-step method, and the effects of Ag/PGO as a lubricating oil additive on the viscosity, thermal conductivity, and lubricating performance of lubricating oil were studied. The influence of additive lubricating oil on the temperature increase and vibration of a high-speed motorized spindle was studied through a motorized spindle experiment. The results showed that the addition of Ag/PGO nanocomposites could improve the thermophysical properties and lubricating properties of the lubricating oil. The Ag/PGO nanoparticles deposited on the friction surface formed a friction protective film, which prevented direct contact between the friction pairs and effectively reduced the heat generated through friction and micro-peak collision during bearing operation. The lubricating oil containing Ag/PGO had high thermal conductivity and a good heat dissipation effect in convection heat transfer in the bearing cavity. The deposition and repair of nanoparticles could improve the micro-morphology of the friction surface and reduce the high-frequency amplitude of the motorized spindle.

Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers, which are of growing concern due to their endocrine-disrupting effects, developmental toxicity, and potential carcinogenicity. However, data on human exposure to OPEs is still scarce. In this study, a relatively simple and efficient method with less serum consumption for the detection of OPEs in human serum was developed and validated. Nine OPEs in 200 μL of human serum were extracted by an acetonitrile–formic acid system and analyzed using ultra-high-performance liquid chromatography–quadrupole tandem time-of-flight high-resolution mass spectrometry. Several experiments were conducted to optimize the chromatographic and mass spectrometric conditions as well as sample preparation to obtain a more sensitive and efficient analytical protocol. The proposed method was examined in terms of its linearity, accuracy, precision, detection limit, and matrix effect. The matrix-spiked recoveries of the target OPEs ranged from 83.3% to 111.1%, with relative standard deviations between 2.7% and 16.6%. The detection limits were within (0.002 to 0.029) ng mL−1, while the quantification limits were within (0.007 to 0.098) ng mL−1. The internal standard-corrected matrix effects varied from 82.7% to 113.9%. Finally, the method was applied to detect OPEs in actual human serum samples. All nine OPEs were detected in 269 serum samples to varying degrees, with the average concentrations ranging from (0.08 to 1.77) ng mL−1. After validation, the method was found to be simple in pretreatment, high in sensitivity, good in practicality, and suitable for exposure evaluation of OPEs in populations.

Eleven new phenyltetracenoid polyketides, streptovertimycins U (1) and V (2), 14-bromo-streptovertidione (3), streptovertimycins W–Y (4–6), and streptovertimycins Z1–Z5(7–11), together with the known congeners fasamycins R (12) and S (13) and accramycins A (14) and B (15), were isolated from the NaBr-supplemented rice-grown cultures of Streptomyces morookaenseSC1169. Their structures were elucidated by extensive spectroscopic analysis, single-crystal X-ray diffraction analysis, and theoretical computations of ECD spectra. Compounds 1and 2are methylene-bridged dimers of accramycin A, and compounds 3and 7–11are brominated fasamycin congeners. Compounds 5and 8–14exhibited activity against the drug-resistant bacteria MRSA and VRE (MIC = 0.6–5.0 μg/mL), and the dimer 1displayed activity against MRSA (MIC = 2.5 μg/mL). Compounds 6–15showed cytotoxicity against the human carcinoma A549, HeLa, HepG2, and MCF-7 cells in the IC50range between 1.7 and 9.2 μM.

The actinopyrone biosynthetic gene cluster (atpn) lacks glycosyl- and methyltransferase genes, yet its product clearly calls for such enzymes. Using bioinformatics and biochemical methods, we confirmed that the mt3913and gt723genes, well beyond the atpncluster boundaries, encode methyltransferase and glycosyltransferase, respectively. Moreover, homologous protein GT1507 enabled us to produce 14 non-natural actinopyrone analogues. PM050463 (3) was found to display potent anti-Helicobacter pyloriactivity and no signs of cytotoxicity.

•A site-specific recombinant strategy guarantees the precise structural and functional optimization of CD19/CD22/CD3 trispecific antibody.•The optimized CD19/CD22/CD3 exhibited impressive activities in overcoming immune escape and enhancing clearance of B-cell malignancies.

Cell-type-specific domains are the anatomical domains in spatially resolved transcriptome (SRT) tissues where particular cell types are enriched coincidentally. It is challenging to use existing computational methods to detect specific domains with low-proportion cell types, which are partly overlapped with or even inside other cell-type-specific domains. Here, we propose De-spot, which synthesizes segmentation and deconvolution as an ensemble to generate cell-type patterns, detect low-proportion cell-type-specific domains, and display these domains intuitively. Experimental evaluation showed that De-spot enabled us to discover the co-localizations between cancer-associated fibroblasts and immune-related cells that indicate potential tumor microenvironment (TME) domains in given slices, which were obscured by previous computational methods. We further elucidated the identified domains and found that Srgnmay be a critical TME marker in SRT slices. By deciphering T cell-specific domains in breast cancer tissues, De-spot also revealed that the proportions of exhausted T cells were significantly increased in invasive vs. ductal carcinoma.

Three new actinopyrone derivatives, actinopyrones E–G (1, 3, and 4), together with three known analogues, PM050463 (2), actinopyrone D (5), and PM050511 (6), were isolated from Streptomycessp. SCSIO ZS0520 derived from a deep-sea hydrothermal vent. Their structures, complete with absolute configurations, were elucidated using extensive spectroscopic analyses combined with Mosher’s method, ECD calculations, and bioinformatics analyses. These findings corrected the absolute configurations of previously reported actinopyrone analogues 2, 5, and 6at C-3, C-9, and C-10. Notably, compound 6displayed notable cytotoxicity against six human cell lines with IC50values of 0.26–2.22 μM. A likely biosynthetic pathway and annotations of protein function are proposed on the basis of bioinformatics analyses. Genes coding for methyltransferase and glycosyltransferase tailoring chemistries needed to generate final structures were notably absent from the biosynthetic gene cluster. Taken together, these results enable further bioengineering of the actinopyrones and related congeners as potential antitumor agents.

Multilayer commingled production is the most efficient development technique of coalbed methane under the condition of multiple coal seams. However, due to the differences in physical properties between multilayer superimposed gas-bearing systems, interlayer interference severely limits coalbed methane development in commingled production. To achieve multilayer-commingled production, interlayer interference must be reduced and the combination of production layers must be optimized. Physical simulations are an effective measure to achieve this goal. According to the characteristics of multiple thin interbeds, strong reservoir heterogeneity and interlayer pressure difference in the Surat basin, a physical model is established to simulate the multilayer-commingled production process of coalbed methane reservoirs and the gas production contribution, and a pressure change of each layer is analyzed. The greater the interlayer pressure difference, the more obvious the early backflow phenomenon of the low-pressure layer, the more obvious the difference of layered production contribution in the later stage, the lower the degree of commingled production and recovery, and the stronger the interlayer interference. In view of these, this study proposes a new experimental method named the succession production. The novelty of this method is to control the commingled production time, that is, the high-pressure layer is produced first, and the low-pressure layer is combined when the interlayer pressure is consistent. The results show that this method can eliminate the early backflow phenomenon of the low-pressure layer and reduce interlayer interference. Furthermore, the characteristics of interlayer interference and the change law of multilayer-commingled production capacity of succession and commingled production are clarified, providing theoretical and technical support for reducing interlayer interference and optimizing production layer combination to promote the efficient development of multiple thin interbedded coalbed methane reservoirs.

Formicapyridine-type racemates, streptovertidines A (1) and B (2), a 7,24-seco-fasamycin, streptovertidione (3), and the fasamycin-type streptovertimycins I–T (4–15), together with 13 known fasamycin congeners (16–28), were isolated from soil-derived Streptomyces morookaenseSC1169. Their structures were elucidated by extensive spectroscopic analysis and theoretical computations of ECD spectra. The fasamycin-type compounds 5, 8–12, 14, and 15exhibited activity against the drug-resistant bacteria MRSA and VRE (MIC: 1.25–10.0 μg/mL). All isolates, except 3, 4, 10, and 24, displayed cytotoxicity against at least one of the human carcinoma A549, HeLa, HepG2, and MCF-7 cells (IC50< 10.0 μM), of which some were also cytotoxic to the noncancerous Vero cells. Taken together, the activity data demonstrated that the fasamycin-type compounds were more selective to the tested bacteria over the mammalian cells. Structure–activity relationship analysis suggested that chlorination at C-2 in antibacterial fasamycin-type compounds improves the activity and selectivity to the bacteria. Theoretical simulations of reaction paths and chemical reactions for conversion of 3to 1were carried out and supported that the pyridine ring formation in formicapyridines proceeds nonenzymatically via 1,5-dicarbonyl condensation with ammonia.

Eight new β-resorcylic acid lactones (RALs), including the hypothemycin-type compounds paecilomycins N–P (1–3) and the radicicol-type metabolites dechloropochonin I (4), monocillins VI (5) and VII (6), 4′-hydroxymonocillin IV (7), and 4′-methoxymonocillin IV (8), along with nine known RALs (9–17), were isolated from the cultures of Paecilomycessp. SC0924. Compounds 1and 2feature a novel 6/11/5 ring system, and 3is the first 5′-keto RAL. The structures of 1–8were elucidated on the basis of extensive spectroscopic analysis, X-ray diffraction analysis, and theoretical calculations of ECD spectra. Compounds 3, 5, and 6exhibit cytotoxicity against MCF-7, A549, and HeLa cells, and compounds 5and 7display antifungal activity against Peronophythora litchii.

Schistosomiasis poses a serious threat to human health and remains a major tropical and parasitic disease in more than 70 countries. Praziquantel (PZQ) has been the primary treatment for schistosomiasis for nearly 4 decades.

The low-temperature nitrogen adsorption measurement is commonly used to describe the pore structure of porous medium, while the role of degassing temperature in the low-temperature nitrogen adsorption measurement does not attract enough attention, various degassing temperatures may lead to the different pore structure characterization for the same coal. In this study, the low-rank coal collected from Binchang mining area, southwest of Ordos Basin was launched the low-temperature nitrogen adsorption measurement under seven various degassing temperatures (120 °C, 150 °C, 180 °C, 210 °C, 240 °C, 270 °C and 300 °C), respectively, the dynamic change of the pore structure under refined upgrading degassing temperatures are studied, and it was also quantitative evaluated with the multi-fractal theory. The results show that the pore specific surface area and pore volume decrease linearly with the increased degassing temperatures, ranges from 12.53 to 2.16 m2/g and 0.01539 to 0.00535 cm3/g, respectively. While the average pore aperture features the contrary characteristics (various from 4.9151 to 9.9159 nm), indicating the pore structure has been changed during the refined upgrading degassing temperatures. With the upgrading degassing temperatures, the sizes of hysteresis loop decrease, and the connectivity of pore structure enhanced. The multi-fractal dimension and multi-fractal spectrum could better present the partial abnormal of pore structure during the refined upgrading degassing temperatures, and the quality index, Dqspectrum, D−10–D10and multi-fractal spectrum could describe the homogeneity and connectivity of the pores finely. The degassing temperatures of 150 °C, 180 °C and 270 °C are selected as three knee points, which can reflect the partial abnormal of the pore structure during the refined upgrading degassing temperatures. Under the lower degassing temperature (< 150 °C), the homogeneity and connectivity of the pore feature a certain increase, following that it presents stable when the degassing temperatures various from 150 to 180 °C. The homogeneity and connectivity of the pore would further enhanced until the degassing temperature reaches to 270 °C. Because of the melting of the pore when the degassing temperature exceeds 270 °C, the complexity of pore structure increased. In this study, we advise the degassing temperature for low-temperature nitrogen adsorption measurement of low-rank coal should not exceed 120 °C.

Combinatorial biosynthesis with fungal polyketide synthases (PKSs) promises to produce unprecedented bioactive “unnatural” natural products (uNPs) for drug discovery. Genome mining of the dothideomycete Rhytidhysteron rufulumuncovered a collaborating highly reducing PKS (hrPKS)–nonreducing PKS (nrPKS) pair. These enzymes produce trace amounts of rare S-type benzenediol macrolactone congeners with a phenylacetate core in a heterologous host. However, subunit shuffling and domain swaps with voucher enzymes demonstrated that all PKS domains are highly productive. This contradiction led us to reveal novel programming layers exerted by the starter unit acyltransferase (SAT) and the thioesterase (TE) domains on the PKS system. First, macrocyclic vs linear product formation is dictated by the intrinsic biosynthetic program of the TE domain. Next, the chain length of the hrPKS product is strongly influenced in transby the off-loading preferences of the nrPKS SAT domain. Last, TE domains are size-selective filters that facilitate or obstruct product formation from certain priming units. Thus, the intrinsic programs of the SAT and TE domains are both part of the extrinsic program of the hrPKS subunit and modulate the observable metaprogram of the whole PKS system. Reconstruction of SAT and TE phylogenies suggests that these domains travel different evolutionary trajectories, with the resulting divergence creating potential conflicts in the PKS metaprogram. Such conflicts often emerge in chimeric PKSs created by combinatorial biosynthesis, reducing biosynthetic efficiency or even incapacitating the system. Understanding the points of failure for such engineered biocatalysts is pivotal to advance the biosynthetic production of uNPs.

Two pairs of salicylaldehyde derivative enantiomers, euroticins A and B (1and 2), were isolated from a marine-derived fungus Eurotiumsp. SCSIO F452. Compound 1possesses a highly constructed 6/6/6/5/7 pentacyclic structure featuring an unprecedented 2,11-dioxatricyclo[5.3.1.04,8]undecane core. Compound 2represents the first example of 6/6/6/6 tetracyclic salicylaldehyde derivative. Their structures were established by spectroscopic analyses, X-ray diffraction, and electronic circular dichroism (ECD) and 13C NMR calculations. Compounds (+)-2and (−)-2exhibited remarkable antioxidative activities.

Eight new polyhydroxanthones, penicixanthones A–H (1–8), including four monomers (1–4) and four dimers (5–8), were isolated from solid cultures of Penicillium purpurogenumSC0070. Their structures were elucidated by extensive spectroscopic analysis, X-ray single-crystal diffraction, and theoretical computations of ECD spectra. Penicixanthone B (2) has a hexahydroxanthone structure featuring an unusual oxygen bridge between C-6 and C-8a. Penicixanthone D (4) is distinct from other penicixanthones in stereochemistry, and its biosynthetic mechanism was proposed based on theoretical simulations for the reaction pathway of C-10a epimerization. Penicixanthone G (6) exhibited the most potent cytotoxicity (IC50: 0.3–0.6 μM) when tested against human carcinoma A549, HeLa, and HepG2 cells, whereas it was nontoxic to the normal Vero cells (IC50> 50 μM). It also displayed the strongest antibacterial activity (MIC: 0.4 μg/mL) against both Staphylococcus aureusand the methicillin-resistant strain MRSA.

In this article, nano-sized calcium perrhenate was prepared using the microemulsion reaction method. By the aid of surfactant, the calcium perrhenate was suspended in pentaerythritol ester base oil to serve as a lubricating additive. The tribological performances of the oil containing calcium perrhenate at elevated temperatures were investigated by four-ball tests and ball-on-disk reciprocating sliding tests. The underlying lubricating mechanism of the calcium perrhenate additive was explored using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry/thermogravimetry, Raman spectroscopy, and X-ray photoelectron spectroscopy. The four-ball test results indicated that the oil containing calcium perrhenate featured lower friction coefficients, smaller wear scar diameters, and lower temperature rising performance than the base oil under an applied load of 392N. The optimum lubricating property was obtained when the additive was at a concentration of 0.05wt%. The tribological performance in a wide temperature range results showed that the friction coefficients of the oil containing calcium perrhenate were slightly lower than those of the base oil at a relatively low temperature range, and decreased as the temperature increased within a high range. The improved tribological performances owed to the formation of a protective layer, which consisted of the shear-susceptible calcium perrhenate additive as well as some native metal oxides that enhanced the layer carrying capacity during rubbing after chemical degradation of base oil. This protective layer acted as a barrier between the rubbing surfaces, preventing them from directly contacting each other at elevated temperatures.

Atrovimycin (1), a cyclodepsipeptide containing a unique vicinal-hydroxylated cinnamic acyl chain, was isolated and elucidated from Streptomyces atrovirensLQ13. The biosynthetic pathway of 1was achieved, revealing cytochrome P450 (Avm43) and epoxide hydrolase (Avm29) enzymes constructing the vicinal-dihydroxy substitution, as well as a tailoring P450 (Avm28) enzyme catalyzing β-hydroxylation of the l-Phe moiety. Atrovimycin shows in vitro antifungal activity and antitubercular activity against Mycobacterium tuberculosisH37Rv both in vitro(with MIC of 2.5 μg/mL) and in vivo.

As an efficient, safe, and environmentally friendly technology, semiconductor photocatalysis has been widely used in the removal of antibiotics from wastewater. In this work, a novel Ag/BiOI/g‐C3N4composite photocatalytic material, BiOI/g‐C3N4, g‐C3N4, and BiOI are prepared as the photocatalysts. The morphologies, chemical properties, and photocatalytic performances of the photocatalysts are characterized using scanning electron microscope, transmission electron microscope, X‐ray diffraction, X‐ray photoelectron spectroscopy, Fourier‐transform infrared spectrometer, ultraviolet–visible spectroscopy (UV–Vis) diffuse reflectance spectra, and photoluminescence spectra. In addition, tetracycline hydrochloride (TC) and ceftiofur sodium aqueous solutions are used to simulate wastewater and the photocatalytic degradation performances of the photocatalysts are investigated and compared under visible light. Compared to g‐C3N4, BiOI, and BiOI/g‐C3N4, the Ag/BiOI/g‐C3N4demonstrates superior performance, increasing the removal rates of TC and ceftiofur sodium to 85.6% and 90.2%, respectively. The photocatalytic mechanism of the Ag/BiOI/g‐C3N4may involve the promotion of the visible light–harvesting ability and inhibition of the recombination of photogenerated electron/hole pairs. Furthermore, the primary active groups in the system are identified as superoxide radicals (·O2−) and hydroxyl radicals (·OH). Herein, some valuable insights into the development of innovative photocatalytic materials are offered for the effective removal of antibiotics from water. A novel Ag/BiOI/g‐C3N4ternary composite is successfully synthesized for the first time. Compared with intrinsic g‐C3N4, intrinsic BiOI, and BiOI/g‐C3N4, it has higher photocatalytic degradation ability of antibiotics.

Four new cyclodepsipeptides, dinghupeptins A–D (1–4), possessing a rare N5-(2-hydroxylethyl)glutamine moiety, were isolated from cultures of the soil-derived Streptomycessp. SC0581. Their structures were elucidated by spectroscopic and advanced Marfey’s amino acid analysis, and their 3D structures were established by theoretical conformational analysis. Compounds 1and 2, containing a 3-amino-6-hydroxypiperidone unit, displayed selective inhibition of chymotrypsin with IC50values of 2.1 and 1.1 μM, respectively. Enzyme kinetic analysis and molecular docking experiments revealed they are competitive inhibitors binding to the active site of chymotrypsin.

Three new abyssomicin monomers designated neoabyssomicins D (1), E (2), and A2 (3) and the two dimeric neoabyssomicins F (4) and G (5) were discovered from the marine-derived Streptomyces koyangensisSCSIO 5802, and their structures rigorously elucidated. Neoabyssomicin D (1) possesses an unprecedented 8/5/5/7 ring skeleton, the biosynthesis of which (as well as 2) is proposed herein. Additionally, dimeric agents 4and 5were found to be active against methicillin-resistant Staphylococcus aureusand vesicular stomatitis virus, respectively.

Three pairs of spirocyclic diketopiperazine enantiomers, variecolortins A–C (1–3), were isolated from marine-derived fungus Eurotiumsp. SCSIO F452. Compound 1possesses an unprecedented highly functionalized seco-anthronopyranoid carbon skeleton featuring a 2-oxa-7-azabicyclo[3.2.1]octane core. Compounds 2and 3represent rare examples of a 6/6/6/6 tetracyclic cyclohexene–anthrone carbon scaffold. Their structures were determined by spectroscopic analyses, X-ray diffraction, and ECD calculations. Their enantiomers exhibited different antioxidative and cytotoxic activities, and their modes of action were investigated.

Tetrahydrocurcumin (THC) is a major metabolite of curcumin and plays an important role in curcumin-induced biological effects. THC is a promising preventive and chemotherapeutic agent for cancer. A series of new pyrazole derivatives of THC have been synthesized as potent anticancer agents. Direct condensation of THC with various substituted hydrazines leads to new pyrazole derivatives of THC (1–18). The prepared compounds have been evaluated via in vitro MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay for their cell proliferation-inhibitory activity against human lung adenocarcinoma (A549), human cervical carcinoma (HeLa) and human breast carcinoma (MCF-7) cells. Most derivatives show significantly higher anticancer activity against all three tested cancer cell lines than the parent compound THC. Several compounds (7, 8, 12, 13and 15) display promising anticancer activity against MCF-7 cell line with IC50values ranging from 5.8 to 9.3 µM. The most active compound (8) is substituted with 4-bromophenyl group at the pyrazole ring and inhibits the growth of all three tested cancer cell lines with an IC50values of (8.0 µM, A549), (9.8 µM, HeLa) and (5.8 µM, MCF-7). The obtained compounds can be a good starting point for the development of new lead molecules in the fight against cancer.

Thirteen new pentacyclic triterpenoids, cleistocalyxic acids A–K (1, 2, 4, 5, and 7–13) and cleistocalyxolides A (3) and B (6), and 15 known analogues (14–28), based on taraxastane, oleanane, ursane, multiflorane, and lupane skeletons, were isolated from the leaves of Cleistocalyx operculatus. The structures of 1–13were elucidated by analysis of their spectroscopic data and ECD/TDDFT computations. Cleistocalyxolide A (3), presumed to be derived from the known taraxastane-type compound 14, has a rare rearranged triterpenoid backbone. Cleistocalyxic acid B (2) displayed cytotoxicity against HepG2, NCI-N87, and MCF-7 cancer cell lines with IC50values ranging from 3.2 to 6.5 μM, and cleistocalyxic acid D (5) was active against HepG2 and NCI-N87 cells with values around 5.0 μM. The noncytotoxic cleistocalyxic acid E (7) inhibited production of IL-6 by 68.1% and TNF-α by 53.7% in LPS-induced RAW 264.7 macrophages at a concentration of 2 μM.

Five new highly oxygenated α-pyrone merosesquiterpenoids, ochraceopones A–E (1–5), together with one new double bond isomer of asteltoxin, isoasteltoxin (6), and two known asteltoxin derivatives, asteltoxin (7) and asteltoxin B (8), were isolated from an Antarctic soil-derived fungus, Aspergillus ochraceopetaliformisSCSIO 05702. Their structures were determined through extensive spectroscopic analysis, CD spectra, quantum mechanical calculations, and X-ray single-crystal diffraction. Ochraceopones A–D (1–4) are the first examples of α-pyrone merosesquiterpenoids possessing a linear tetracyclic carbon skeleton, which has not been previously described. All the isolated compounds were tested for their antiviral, cytotoxic, antibacterial, and antitubercular activities. Among these compounds, ochraceopone A (1), isoasteltoxin (6), and asteltoxin (7) exhibited antiviral activities against the H1N1 and H3N2 influenza viruses with IC50values of >20.0/12.2 ± 4.10, 0.23 ± 0.05/0.66 ± 0.09, and 0.54 ± 0.06/0.84 ± 0.02 μM, respectively. A possible biosynthetic pathway for ochraceopones A–E (1–5) was proposed.

Paeciloketals (1–3), new benzannulated spiroketal derivatives, were isolated from the marine fungus Paecilomyces variotiiderived from the giant jellyfish Nemopilema nomurai. Compound 1was present as a racemate and was resolved into enantiopure 1aand 1bby chiral-phase separation on a cellulose column. Compounds 2and 3, possessing a novel benzannulated spiroketal skeleton, were rapidly interconvertible and yielded an equilibrium mixture on standing at room temperature. The relative and absolute configurations of compounds 2and 3were determined by NOESY analysis and ECD calculations. Compound 1showed modest antibacterial activity against the marine pathogen Vibrio ichthyoenteri.

Four dimeric acremines, bisacremines A–D (1–4), with a novel carbon skeleton and a new monomer, acremine T (5), were obtained from cultures of the soil-derived fungus Acremonium persicinumSC0105. Their structures were characterized by analysis of spectroscopic data, ECD/TDDFT computations, and X-ray diffraction. Compounds 1and 2exhibited weak cytotoxicity against HeLa cells, and 2also showed modest activity against A549 and HepG2 cells.

Two new polycyclic tetramate macrolactams, lysobacteramides A (1) and B (2), together with HSAF (heat-stable antifungal factor, 3), 3-dehydroxy HSAF (4), and alteramide A (5) were isolated from a culture of Lysobacter enzymogenesC3 in nutrient yeast glycerol medium. Their structures were determined by MS and extensive NMR analysis. The absolute configurations of 1–5were assigned by theoretical calculations of their ECD spectra. Although HSAF and analogues were reported from several microorganisms, their absolute configurations had not been established. The isolation and the absolute configurations of these compounds revealed new insights into the biosynthetic mechanism for formation of the polycycles. Compounds 1–4exhibited cytotoxic activity against human carcinoma A549, HepG2, and MCF-7 cells with IC50values ranging from 0.26 to 10.3 μM. Compounds 2and 3showed antifungal activity against Fusarium verticillioideswith IC50value of 47.9 and 6.90 μg/mL, respectively.

Six new quinone sesquiterpenes, myrothecols A–F (1–6), and hymenopsin B (7) were isolated from cultures of Myrotheciumsp. SC0265 by bioassay-guided fractionation. Their structures were elucidated on the basis of 1D and 2D NMR and MS data. The absolute configurations of the new compounds were assigned by CD/TDDFT calculations, and that of and hymenopsin B was confirmed by X-ray diffraction analysis. Compounds 1–5and hymenopsin demonstrated cytotoxic activity against human carcinoma A549, HeLa, and HepG2 cells. Compounds 1–5also exhibited antibacterial activity against Staphylococcus aureusand Bacillus cereus.

Ustilaginoidea virensis a pathogenic fungus that causes false smut disease in rice during the flowering stage through stamen filaments. Currently, there is a need to develop safe and effective antifungal agents for the control of this disease. In our preliminary experiments, we found that MTE-1, a new trisaccharide ester, exhibits significant inhibitory activity against U. virens. Hence, the effects and inhibitory mechanism of MTE-1 in U. virenswere investigated. Results showed that the MTE-1 inhibited the hyphae growth of U. virenswith an IC50of 5.67 μg/mL. Similarly, MTE-1 disrupted the endomembrane system in U. virens, especially the plasma membrane, mitochondria, and lipidosome. Moreover, transcriptome and proteome analysis indicated that MTE-1 inhibited the growth of U. virensby inhibiting the synthesis of lipids, altering the primary metabolic pathways including carbohydrates and amino acid metabolism, and affecting the intracellular redox dyshomeostasis, thus leading to the disorder of active oxygen metabolism. These findings lay the foundation for the future application of MTE-1-derived agents in the management of antifungal diseases.

Four new cyclic diarylheptanoids, casuarinols A–C (1–3) and casuarinolide A (4), together with six known ones (5–10), were isolated from the roots of Casuarina equisetifolia. Structures were elucidated by extensive spectroscopic analysis, theoretical conformational, and electronic circular dichroism analyses. Casuarinol C (3) is a novel cyclic diarylheptanoid-aldehyde adduct. Casuarinolide A (4) represents the first structure of a seco-cyclic diarylheptanoid. Compounds 1–9were evaluated for their anti-influenza A virus (IAV) activity against A/WSN/33 (H1N1). (−)-(M)-11-Oxo-3,12R,17-trihydroxy-9-ene-[7,0]-metacyclophane (5) displayed significant anti-IAV activity with an IC50value of 8.64 ± 2.49 μM and a CC50higher than 100 μM.

Four new dammarane-type saponins, operculinosides A–D (1–4), were isolated from the aerial parts of Operculina turpethum, of which 1and 2are the first two dammarane-type triterpenoids having an oxymethyl group at C-24. Their structures were determined by spectroscopic analysis and acid hydrolysis. The absolute configuration of operculinoside A (1) was confirmed by X-ray crystallography. Compounds 1and 3showed significant protective activities against d-galactosamine-induced toxicity in L-02 human hepatic cells.

Six new β-resorcylic acid lactones (1−6), named paecilomycins A−F, and five known compounds, aigilomycin B (7), zeaenol (8), aigialomycin D (9), aigialomycin F (10), and aigialospirol, were isolated from the mycelial solid culture of Paecilomycessp. SC0924. Their structures were elucidated by extensive NMR analysis, single-crystal X-ray study, and chemical correlations. Compounds 5and 10exhibited antiplasmodial activity against Plasmodium falciparumline 3D7 with IC50values of 20.0 and 10.9 nM, respectively, and compounds 5−7showed moderate activity against the P. falciparumline Dd2.

Seven structurally related new polyoxygenated methyl cyclohexanoids, ampelomins A−G (1−7), were isolated from the mycelial solid culture of a soil-derived Ampelomycesfungus. Their structures were determined by spectroscopic and chemical means. Ampelomins A (1), C (3), E (5), and G (7) exhibited weak activity against α-glucosidase with IC50values of 1.74−5.93 mM, and ampelomin A (1) showed moderate antibacterial activity with MIC90values ranging from 202.4 to 1015.9 μM. A plausible polyketide biogenetic pathway is postulated for these compounds.

Two new sulfur-containing phenolic compounds, 7-hydroxy-5-hydroxymethyl-2H-benzo[1,4]thiazin-3-one (1) and 2,5-dihydroxy-3-methanesulfinylbenzyl alcohol (2), along with two known compounds, 3-chloro-2,5-dihydroxybenzyl alcohol (3) and 2-hydroxy-6-methylbenzoic acid (4), were isolated from the mycelial solid culture of a soil-derived Ampelomycesfungus by antibacterial assay-guided fractionation. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 1–3showed structure and microbial dependent antibacterial activities.

Two 2-phenylbenzofurans, lespedezavirgatol ( 1) and lespedezavirgatal ( 2), and a coumestan, lespedezacoumestan ( 3), were isolated from the aerial parts of Lespedeza virgata, together with nine known flavonoids. Their structures were determined on the basis of spectroscopic data. The three new compounds showed strong oxygen radical absorbance capacity and potent inhibition toward lipid peroxidation in both plasma and kidney homogenate of renal failure rats.

An on‐line SPE–HPLC method, using a monolithic poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) (poly(GMA‐EDMA)) based weak cation‐exchange (WCX) column, was developed for simultaneous determination of α1‐adrenergic receptor antagonists in human plasma. The monolithic WCX column was prepared by anin‐situ polymerization protocol and modified stepwise with ethylenediamine and chloroacetic acid. On connecting this column to an injection valve, an on‐line SPE protocol could be established for removal of matrices (mainly proteins and lipids) and preconcentration of four α1‐adrenergic receptor antagonists in human plasma. This method was validated and then used for determination of terazosin, alfuzosin, prazosin, and doxazosin in clinical plasma samples. For all analytes, each calibration curve was found to be linear over a range of 0.005–5 μg/mL (R>0.997), and the limit of detection for each analyte was 0.5 ng/mL. Recovery (> 80%) and precision (RSD <15%) for inter‐ and intra‐day assay were tested at three concentration levels of each analyte and showed acceptable results for quantitative assay. Real samples from hypertensive patients were monitored and results were in agreement with those of the conventional liquid–liquid extraction‐HPLC method. Furthermore, due to its good permeability and biocompatibility, the monolithic WCX sorbent could be reused more than 300 times. The proposed method was especially appropriate for multi‐analyte monitoring in plasma samples.

Three new photoactivated insecticidal thiophene derivatives, xanthopappins A−C (1−3), were isolated from Xanthopappus subacaulis, along with three known thiophene acetylenes, 5-hydroxymethyl-2-(E)-hept-5-ene-1,3-diynylthiophene (4), 5-(1,2-dihydroxyethyl)-2-(E)-hept-5-ene-1,3-diynylthiophene (5), and 5-(1,2-diacetoxyethyl)-2-(E)-hept-5-ene-1,3-diynylthiophene (6). The structures of 1−3were elucidated by spectroscopic methods. Compounds 1−6exhibited significant photoactivated insecticidal activity against the fourth-instar larvae of the Asian tiger mosquito.

Abstract Phytotoxicity-directed extraction and fractionation of the aerial parts of Mikania micrantha H.B.K. led to the isolation and identification of three sesquiterpenoids: dihydromikanolide, deoxymikanolide, and 2,3-epoxy-1-hydroxy-4,9-germacradiene-12,8:15,6-diolide. These sesquiterpenoids inhibited both germination and seedling growth of tested species with deoxymikanolide possessing the strongest phytotoxicity. In a bioassay against lettuce (Lectuca sativa L.), deoxymikanolide reduced radicle elongation at low concentration (IC50 = 47 µg/ml); dihydromikanolide showed a weaker effect (IC50 = 96 µg/ml), and 2,3-epoxy-1-hydroxy-4,9-germacradiene-12,8:15,6-diolide exhibited the least effect (IC50 = 242 µg/ml). Deoxymikanolide caused yellowish lesions at the root tips of lettuce at a concentration of 50 µg/ml, and a 250 µg/ml solution killed lettuce seedlings. A bioassay against the monocot ryegrass (Lolium multiforum) revealed similar results on radicle elongation, which implied that the growth inhibition by these compounds was not selective. To evaluate their phytotoxicity to plants in natural habitats, three common companion tree species in south China, Acacia mangium, Eucalyptus robusta, and Pinus massoniana, were also tested and similar results were obtained. This is the first report on the isolation of 2,3-epoxy-1-hydroxy-4,9-germacradiene-12,8:15,6-diolide as a naturally occurring product.

Two new monoterpenoid indole alkaloid derivatives, turpiniside (1) and 11-methoxyjavaniside (2), along with the known alkaloids, vincosamide (3), (3R)-pumiloside (4), and paratunamide C (5), were isolated from the leaves of Turpinia arguta (Lindl.) Seem. Their structures were determined on the basis of spectroscopic data. Compounds 1 and 3–5 were found to effect relaxation of the supercoiled pBR322 plasmid DNA in the presence of Cu2+. [ABSTRACT FROM AUTHOR]

To investigate the influence of particle size of pineapple leaf fiber (PALF) powders on their structure, bioactive components and antioxidant activities, different sized PALF powders were prepared using superfine grinding. Particle sizes and surface morphology of PALF powders were examined with laser diffraction instrument and scanning electron microscopy (SEM) respectively. Meanwhile, the contents of polyphenols and flavonoids in PALF powders were determined by UV method, and the antioxidant capacity was investigated. During the superfine grinding process, as the time prolonged, the particle size of PALF powders sharply decreased and the surface area increased. When the grinding time reached to 60 min, PALF superfine powder having a median diameter of 18.209 um was obtained. Scanning electron micrograph displayed that the shape and particle size of superfine powders were uniform. After superfine pulverization, the bioactive components of PALF can be well preserved. The total polyphenols content of PALF superfine powder was 2.347 mg GAE/g DW and the total flavonoids content was 0.227 mg RE/g DW. Therefore, the antioxidant capacity of PALF superfine powder remains high level, including DPPH radical scavenging rate (0.167 mg GAE/g DW), ABTS radical scavenging rate (0.105 mg GAE/g DW) and total antioxidant activity (67.379 unit/g DW). The results demonstrated that PALF superfine powder has good potential to be used in functional food, cosmetics and biomedical materials.

In order to analyze the influence of different storage temperature on the storability and postharvest quality attributes of custard apple, the postharvest custard apple were stored at 4, 15 or 20-28degC (room temperature) by measuring the change of weight loss rate, firmness, content of total soluble solid (TSS) and titratable acid (TA). By 4, 7, 10 d with 22-28degC(room temperature), 15degC, 4degC, the weight loss of custard apple was about 1.97%, 2.21%, 1.04%, respectively. The firmness decreased gradually during the whole storage time with 22-28degC, 15degC, but the firmness of custard apple increased rapidly from 5.53 N to 9.11 N at 4degC, within 1 to 10 days of storage. TSS content increased gradually in the early stage of storage and then decreased. TA content decreased continuously during the whole storage time. Slight decline in pH of the all the products was observed during postharvest storage. The result showed that the shelf life of fruits were 4, 7, 10 d with 22-28degC(room temperature), 15degC, 4degC, respectively.

A new amide glycoside, 3-α-glucopyranosyloxy-N-methyl-3-phenylpropanamide (1), and a new cyclodipeptide, (3S,6S)-3,6-bis(4-acetamidobutyl)piperazine-2,5-dione (2), were isolated from the solid culture of Streptomycetes michiganensisstrain SC0642. Their structures were elucidated by spectroscopic methods.

Two new metabolites, 4R*-hydroxy-3,5R*-dimethoxycyclohex-2-enone (1) and 2-hydroxy-N-(2-hydroxyphenyl)propionamide (2), were isolated from solid cultures of the phytopathogen Peronophythora litchii, along with 4-hydroxybenzyl alcohol (3) and methyl D-indole-3-lactate (4). Their structures were elucidated on the basis of spectroscopic and spectrometric data. These metabolites were not toxic to brine shrimps (LC50> 500 μg/mL).

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

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A new amide, 5,8-dimethoxynaphthalene-2-carboxamide (1), together with 2-phenylacetamide (2), 4-methoxybenzamide (3), 3,4-dimethoxybenzamide (4), 3,4-dimethoxycinnamamide (5), and 4,6-diacetylaminoresorcinol (6), was isolated from the solid culture of Streptoverticillium morookaense. The structure was elucidated by spectroscopic methods. The antifungal activity of the isolated amides was assessed against Peronophythora litchii.

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