J Fungi (Basel)
November 2024
In this paper, we present a novel class of hybrid polyketides, tenuazamines A-H (-), which exhibit a unique tautomeric equilibrium from FL7. The elucidation of the structures was achieved through a diverse combination of NMR, HR-ESIMS, and ECD methods, with a focus on extensive spectroscopic data analysis. Notably, compounds , , - exhibited potent toxic effects on the growth of .
View Article and Find Full Text PDFPlumerianoids A-D (1-4) with a new intact spirocyclic iridoid alkaloid skeleton, along with a new degraded alkaloid 8--plumerianine (5), and a known one (6), were isolated and characterized from . The structure of 6 was revised as (8,13)-plumerianine. These alkaloids consist of three epimeric pairs (1/2, 3/4, and 5/6), exhibiting virtually identical NMR spectra within each pair.
View Article and Find Full Text PDFMetallic atoms within metal-organic framework (MOF) materials exhibit a distinctive and adaptable coordination structure. The three-dimensional (3D) pore configuration of MOFs enables the complete exposure of metal active sites, rendering them prevalent in various catalytic reactions. In this study, zinc (Zn) atoms within Zn-based MOF materials, characterized by an abundance of valence electrons, are utilized for the transesterification of dimethyl carbonate (DMC).
View Article and Find Full Text PDFHerein, we report an extensive phytochemical study on the whole plant of , which led to the isolation of ten new orbitides, named drymariamides A-J (-). Compounds , , and incorporate rare residues of noncanonical amino acids of kynurenine (Kyn) or 3a-hydroxypyrroloindoline (HPI). Their structures with absolute configurations were elucidated by a combination of spectroscopic analysis, advanced Marfey's method, X-ray diffraction, and electronic circular dichroism analysis.
View Article and Find Full Text PDFCopper nanoparticle-based catalysts have been extensively applied in industry, but the nanoparticles tend to sinter into larger ones in the chemical atmospheres, which is detrimental to catalyst performance. In this work, we used dealuminated Beta zeolite to support copper nanoparticles (Cu/Beta-deAl) and showed that these particles become smaller in methanol vapor at 200°C, decreasing from ~5.6 to ~2.
View Article and Find Full Text PDFThe thermocatalytic conversion of carbon dioxide (CO) into high value-added chemicals provides a strategy to address the environmental problems caused by excessive carbon emissions and the sustainable production of chemicals. Significant progress has been made in the CO hydrogenation to long chain α-olefins, but controlling C-O activation and C-C coupling remains a great challenge. This review focuses on the recent advances in catalyst design concepts for the synthesis of long chain α-olefins from CO hydrogenation.
View Article and Find Full Text PDFA non-spore-forming, Gram-stain-positive, short rod-shaped strain, designated SJQ22, was isolated from a paddy soil sample collected in Shanghai, PR China. A comparative analysis of 16S rRNA gene sequences showed that strain SJQ22 fell within the genus , forming a clear cluster with the type strains of (98.6 % sequence similarity) and (98.
View Article and Find Full Text PDFHere, we report a Na-promoted FeCu-based catalyst with excellent liquid hydrocarbon selectivity and catalytic activity. The physiochemical properties of the catalysts were comprehensively characterized by various characterization techniques. The characterization results indicate that the catalytic performance of the catalysts was closely related to the nature of the metal promoters.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2023
The conversion of CO into ethanol with renewable H has attracted tremendous attention due to its integrated functions of carbon elimination and chemical synthesis, but remains challenging. The electronic properties of a catalyst are essential to determine the adsorption strength and configuration of the key intermediates, therefore altering the reaction network for targeted synthesis. Herein, we describe a catalytic system in which a carbon buffer layer is employed to tailor the electronic properties of the ternary ZnO -Fe C -Fe O , in which the electron-transfer pathway (ZnO →Fe species or carbon layer) ensures the appropriate adsorption strength of -CO* on the catalytic interface, facilitating C-C coupling between -CH * and -CO* for ethanol synthesis.
View Article and Find Full Text PDFThe process of Fischer-Tropsch synthesis is commonly described as a series of reactions in which CO and H are dissociated and adsorbed on the metals and then rearranged to produce hydrocarbons and HO. However, CO dissociation adsorption is regarded as the initial stage of Fischer-Tropsch synthesis and an essential factor in the control of catalytic activity. Several pathways have been proposed to activate CO, namely direct CO dissociation, activation hydrogenation, and activation by insertion into growing chains.
View Article and Find Full Text PDFCatalytic conversion of CO to long-chain hydrocarbons with high activity and selectivity is appealing but hugely challenging. For conventional bifunctional catalysts with zeolite, poor coordination among catalytic activity, CO selectivity and target product selectivity often limit the long-chain hydrocarbon yield. Herein, we constructed a singly cobalt-modified iron-based catalyst achieving 57.
View Article and Find Full Text PDFContinued efforts to expand the structural diversity of dichapetalins and explore further the cytotoxic structure-activity relationships have led to the isolation of 17 undescribed analogues, dichapelonins A-Q (-), and three known compounds (-) from the twigs of . Compounds - comprise five compound classes as classified by varied C6-C2 conjugates at the A ring of the 13,30-cyclodammarane skeleton, and their structures were determined by spectroscopic data analysis, experimental electronic circular dichroism measurements, and X-ray crystallography. Biological tests revealed compounds - with a phenyl-butadiene appendage to be the most potent cytotoxic compound type of those evaluated.
View Article and Find Full Text PDFBiodiesel is generally produced from vegetable oils and methanol, which also generates glycerol as byproduct. To improve the overall economic performance of the process, the selective formation of methanol from glycerol is important in biodiesel production. In the present study, a CaO modified HZSM-5 zeolite was prepared by an impregnation method and used for the conversion of glycerol to methanol.
View Article and Find Full Text PDFGermanium (Ge) has a high specific capacity when used as an alloying anode in lithium-ion batteries. However, a large volume of expansion that occurs during charging and discharging hampers its practical applications. In order to improve the stability of the alloying anode, a three-dimensional (3D) germanium/carbon porous composite was produced.
View Article and Find Full Text PDFACS Appl Mater Interfaces
July 2022
Flexible bioelectric dry electrodes are an important part of long-term medical healthcare monitoring systems. In this study, a new method is proposed for the preparation of dry electrodes with micronanopillar arrays structured by designing dimensionally tunable anodized aluminum oxide (AAO) templates, by which polyaniline/thermoplastic polyurethane single-layer micronanopillar array structured dry electrodes (PANI/TPU-SE) and polyaniline/thermoplastic polyurethane double-layer micronanopillar array structured dry electrodes (PANI/TPU-DE) are prepared. Compared with the planar structure, the micronanopillar array structure can reduce the contact gap between the electrode and skin and increase the contact area, thus exhibiting lower contact impedance and higher signal quality.
View Article and Find Full Text PDFg-CN-based materials show potential for photoreduction of CO to oxygenates but are subjected to fast recombination of photogenerated charge carriers. Here, a novel Cu-dispersive protonated g-CN (PCN) metal-semiconductor (m-s) heterojunction from thermal reduction of a CuO/PCN precursor was prepared and characterized using in situ X-ray diffraction, scanning transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible (UV-vis) spectra, photoluminescence (PL) spectra, transient photocurrent response, and electrochemical impedance spectroscopy (EIS). The Cu amount in Cu/PCN and the reduction temperature affected the generation of CHOH and CHOH from the photoreaction of CO-aerated HO.
View Article and Find Full Text PDFAdopting the concurrent reduction of CuO during hydrothermal preparation of ZnVO, metal-semiconductor heterojunction Cu/ZnVO nanorods were synthesized and applied to the catalytic generation of methanol and ethanol from CO aerated water under UV-vis light irradiation. 10Cu/ZnVO obtained from 10 wt % composite amount of CuO exhibited a total carbon yield of 6.49 μmol·g·h.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
September 2021
Strain SJQ9, an aerobic bacterium isolated from a soil sample collected in Shanghai, PR China, was characterized using a polyphasic approach. It grew optimally at pH 7.0, 30-35 °C and in the presence of 1 % (w/v) NaCl.
View Article and Find Full Text PDFChemical studies on have afforded 18 highly modified complex triterpenoids belonging to four compound classes as defined by the newly adapted functional motifs associated with the A ring of the molecules. Their structures were determined by solid data acquired by diverse methods. The biosynthetic pathway for the four compound classes was rationalized cascade modifications involving diverse chemical events.
View Article and Find Full Text PDFEven though the transformation of syngas into aromatics has been realized a methanol-mediated tandem process, the low product yield is still the bottleneck, limiting the industrial application of this technology. Herein, a tailor-made zeolite capsule catalyst with Ga doping and SiO coating was combined with the methanol synthesis catalyst CrO to boost the synthesis of value-added aromatics, especially -xylene, from syngas. Multiple characterization studies, control experiments, and density functional theory (DFT) calculation results clarified that Ga doped zeolites with strong CO adsorption capability facilitated the transformation of the reaction intermediate methanol by optimizing the first C-C coupling step under a high-pressure CO atmosphere, thereby driving the reaction forward for aromatics synthesis.
View Article and Find Full Text PDFHerein, a simple and green quasi-solid-phase (QSP) method for facile synthesis of proton-type ZSM-5 avoiding use of excessive water, dry gel, Na cation and fluoride is reported. Crystallization by using the stoichiometric amount of TPAOH (tetrapropylammonium hydroxide) at 180 °C for only 12 h gave well-structured HZSM-5 crystals with high specific surface area of 429 m g and high thermal stability. 5MRs was observed to closely relate the formation of MFI structure and QSP method exhibits shorter induction period (t ), higher nucleation rate (V ), and faster growth rate (V ).
View Article and Find Full Text PDFExcellent comprehensive dielectric properties (including dielectric constant and loss) are essential for electromechanical transducers. This work introduced a bimodal network composite with poly(dimethyl siloxane) (PDMS) and delaminated TiCT sheets (-TiCT) modified with hyperbranched polysiloxane (HPSi) (referred to as HPSi--TiCT). Before the final cross-linking, HPSi--TiCT, trapped with short-chain PDMS (C-PDMS) and long-chain PDMS (C-PDMS), was pre-reacted, which formed a distinct bimodal network structure.
View Article and Find Full Text PDFThe suadimins A-C (-) from are the first example of monoterpenoid quinoline alkaloid dimers featuring an unprecedented carbon skeleton. Their structures and absolute configurations were established on the basis of extensive spectroscopic analyses, electric circular dichroism (ECD), and X-ray crystallography. Suadimin A showed significant antimycobacterial activity in vitro with an MIC of 6.
View Article and Find Full Text PDFWe previously isolated a monocrotophos-degrading strain Starkeya sp. YW6, which could also degrade propham. Here, we show that strain YW6 metabolizes propham via a pathway in which propham is initially hydrolyzed to aniline and then converted to catechol, which is then oxidized via an ortho-cleavage pathway.
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