Effect of montmorillonite modified straw biochar on transfer behavior of lead and copper in the historical mining areas of dry-hot valleys.

Due to the rapid development of human beings, heavy metals are occurred in the Yunnan-Guizhou Plateau and Panxi Plateau, the special dry and hot climate areas. Pb and Cu can be quickly transferred through water-plant-animal, further harm to human health by food chain. Therefore, the study of heavy metal treatment is imminent. In this study, Biochar-montmorillonite composites were prepared by co-pyrolysis and characterized, and their ability to remove lead and copper from water-soil process were tracked. And their effectiveness in remediating soil contaminated by lead and copper was documented. The composite material has the rich pore structure, large specific surface area (81.5 m2/g) and a variety of surface functional groups such as C-C, CO, ester-metal and metal-oxygen bonds. Pb and Cu can be effectively adsorbed and fixed to the level of no harm to human health. The adsorption reaction of lead and copper on the Biochar-montmorillonite composites is more suitable to be described by Langmuir adsorption and pseudo-second-order kinetics models. The saturation adsorption capacity of the composite for Pb was measured as 212.5 mg/g. For Cu, it was 136.5 mg/g. The data were fitted by a two-compartment first-order kinetic model. ffast for Pb and Cu is estimated to be 0.81 and 0.78, respective. Fast adsorption is dominant and belongs to typical chemical adsorption, which is consistent with the second-order kinetic results. With 5 % of the composite, approximately 80 % of exchangeable heavy metals in those soils collected from the Yunnan-Guizhou Plateau and Panxi Plateau were reduced. The biochar-montmorillonite composites made Pb and Cu change to stable residual state, up to 35 %. Besides, it effectively restored the activity of urease and sucrase in soils. Results indicated that biochar-montmorillonite composites can be effectively used as an environment-friendly adsorbent or passivator to purify heavy metals in soils.

Auto-tuning numerical method for acoustic wave simulation using analytical solution.

Numerical wavefield simulation such as commercial simulation software enables an optimal design of an ultrasound computed tomography (USCT) system for clinical purpose of before prototyping. Such simulator, not developed for optimal design though, can provide rapid implementation for acoustic wave propagation but may lead to unexpected errors during the establishment of numerical model. Here, we propose an auto-tuning numerical method (ATNM), aiming to optimize physical parameters (e.g. grid size, Courant-Friedrichs-Lewy (CFL) number, perfectly matched layer (PML) absorption coefficient, etc) such that the enumerated wavefield computed on those converges to the corresponding analytical solution derived from acoustic scattering theory. We use genetic algorithm (GA) to automatically calibrate numerical wavefield. Our preliminary test is to investigate the best design of PML absorption coefficient for USCT to minimize mean relative error (MRE) between the k-Wave simulation and the analytic model and show its efficacy. The experimental results verify our hypothesis that this calibrated numerical simulator on a simple physical domain is generalizable to any other domains.

The effect of shear wave elastography in the diagnosis of delaminated partial-thickness rotator cuff tears.

AIM: To assess the effectiveness of shear wave elastography (SWE) in diagnosing delaminated partial-thickness rotator cuff tears (DPT-RCT). MATERIAL AND METHODS: A retrospective study was carried out on 137 patients with DPT-RCT. The study included complete clinical data, including the images of conventional ultrasound (US), SWE, Magnetic Resonance Imaging (MRI) and shoulder arthroscopic surgery. The features of US, SWE, and MRI were evaluated. The study analysed the Shear-Wave Velocity (SWV) among three types of DPT-RCT, and between the regions of tears, normal contralateral, and affected unilateral supraspinatus tendon. Furthermore, receiver operating characteristic (ROC) curves were evaluated. RESULTS:  The SWE detection rate was significantly higher (91.2%) compared to US (73.7%) and MRI (87.6%) for the overall diagnosis of DPT-RCT. Similarly, SWE yielded higher rates of detection for types 1 (89.5%) and 2 (92.3%) of DPT-RCT as compared to US (71.7%, 69.2%) and MRI (81.6%, 94.9%), respectively. However, there was no significant difference in the accuracy of diagnosing type 3 among the three methods. The SWV of the 137 supraspinatus tendon tears was 3.64±0.60 m/s, which was higher than that of the normal supraspinatus tendon (2.43±0.47 m/s, p<0.01) as well as the region of tears (1.61±0.54 m/s, p<0.01). Nevertheless, there was no significant difference in SWV among the three types of DPT-RCT. The cutoff thresholds of SWV for identifying normal tendon from DPT-RCT and for identifying DPT-RCT from the region of tears were 2.96m/s and 2.39m/s, respectively. CONCLUSIONS: SWE with SWV can provide both quantitative and qualitative diagnostic information for DPT-RCT, which can be used as a crucial supplement imaging method.

Structural optimization method of rice precision direct seed-metering device based on multi-index orthogonal experimental.

Introduction: To improve the mechanization level of rice planting, a new type of direct seeding device for rice was designed. The device's structural properties will be crucial in determining its seeding performance. Structure optimization in the current seed metering device design process focuses on a single or few indexes, resulting in improved individual performance but imbalanced overall performance. Therefore, a structure optimization method of the direct seeding device based on a multi-index orthogonal experiment was proposed in this study. Methods: First, the DEM-MBD coupling method observed the factors and levels that affected the performance overall. Second, a test platform based on the electric drive control model was constructed, and a multi-index orthogonal test was devised. Finally, the structural parameters of the seed metering devices were optimized based on matrix analysis. Results: From the results, the primary and secondary levels of significance of factors were just as follows: hole diameter > hole number > adjustment angle. The following are the optimal parameters found by optimization analysis: the diameter of the hole was 12 mm, the number of holes was 10, and the adjustment angle was 80°. Validation tests were carried out and analyzed based on the optimal structural parameter combination. The qualification rate of seeds per hole, empty hole rate, average seed number, coefficient of variation of seed number, average hole spacing, and the variance coefficient of hole spacing are 93.07%, 0%, 9.39,14.04%, 22.84 cm, and 9.14%, respectively. Discussion: In comparison to traditional design and structural parameter optimization methods for rice precision seed metering device, this study not just to provides an optimization scheme for improving the overall performance of rice precision seed metering device, but also serves as a technical reference for the development and design of new rice precision seed metering device.

Aniline-induced production of aniline-containing polyketides and related bicyclic polyketides by the Yellow River wetland-derived fungus Talaromyces funiculosus.

Introduction and Methods: Silencing gene activation can effectively enrich the diversity of fungal secondary metabolites. Results and Discussion: Cultivation of the Yellow River wetland-derived fungus Talaromyces funiculosus HPU-Y01 with aniline led to the isolation of one new aniline-containing polyketide tanicutone A (1), two new bicyclic polyketides tanicutones B-C (2-3), a new related trienoic acid 8-methyldeca-2,4,6-trienoic acid (5), and a known compound 4. The planar structures and configurations of 1-5 were determined by NMR, MS, and ECD calculations. Compound 2 featured a key aldehyde group and showed promising inhibitory activity against Vibrio parahaemolyticus with a minimum inhibitory concentration (MIC) value of 0.17 µg/mL. This is a rare report of aniline-induced fungal production of tetrahydronaphthone polyketides.

Efficient production of icariin and baohuoside I from Epimedium Folium flavonoids by fungal α-L-rhamnosidase hydrolysing regioselectively the terminal rhamnose of epimedin C.

Industrial application of icariin and baohuoside I has been hindered by the short supply to a great extent. In this work, a novel GH78 α-L-rhamnosidase AmRha catalyzed the bioconversion of low-value epimedin C in crude Epimedium Folium flavonoids (EFs) to icariin and baohuoside I was developed. Firstly, the high-level expression of AmRha in Komagataella phaffii GS115 attained an enzyme activity of 571.04 U/mL. The purified recombinant AmRha could hydrolyze α-1,2-rhamnoside bond between two rhamnoses (α-Rha(2 → 1)α-Rha) in epimedin C to produce icariin with a molar conversion rate of 92.3%, in vitro. Furtherly, the biotransformation of epimedin C to icariin by the recombinant Komagataella phaffii GS115 cells was also investigated, which elevated the EFs concentration by fivefold. In addition, biotransformation of epimedins A-C and icariin in the raw EFs to baohuoside I was fulfilled by a collaboration of AmRha and ß-glucosidase/ß-xylosidase Dth3. The results obtained here provide a new insight into the preparation of high-value products icariin and baohuoside I from cheap raw EFs.

Synthesis of Aminoalkyl Sclareolide Derivatives and Antifungal Activity Studies.

Sclareolide was developed as an efficient C-nucleophilic reagent for an asymmetric Mannich addition reaction with a series of N-tert-butylsulfinyl aldimines. The Mannich reaction was carried out under mild conditions, affording the corresponding aminoalkyl sclareolide derivatives with up to 98% yield and 98:2:0:0 diastereoselectivity. Furthermore, the reaction could be performed on a gram scale without any reduction in yield and diastereoselectivity. Additionally, deprotection of the obtained Mannich addition products to give the target sclareolide derivatives bearing a free N-H group was demonstrated. In addition, target compounds 4-6 were subjected to an antifungal assay in vitro, which showed considerable antifungal activity against forest pathogenic fungi.

Filamentous Fungi-Derived Orsellinic Acid-Sesquiterpene Meroterpenoids: Fungal Sources, Chemical Structures, Bioactivities, and Biosynthesis.

Fungi-derived polyketide-terpenoid hybrids are important meroterpenoid natural products that possess diverse structure scaffolds with a broad spectrum of bioactivities. Herein, we focus on an ever-increasing group of meroterpenoids, orsellinic acid-sesquiterpene hybrids comprised of biosynthetic start unit orsellinic acid coupling to a farnesyl group or/and its modified cyclic products. The review entails the search of China National Knowledge Infrastructure (CNKI), Web of Science, Science Direct, Google Scholar, and PubMed databases up to June 2022. The key terms include "orsellinic acid", "sesquiterpene", "ascochlorin", "ascofuranone", and "Ascochyta viciae", which are combined with the structures of "ascochlorin" and "ascofuranone" drawn by the Reaxys and Scifinder databases. In our search, these orsellinic acid-sesquiterpene hybrids are mainly produced by filamentous fungi. Ascochlorin was the first compound reported in 1968 and isolated from filamentous fungus Ascochyta viciae (synonym: Acremonium egyptiacum; Acremonium sclerotigenum); to date, 71 molecules are discovered from various filamentous fungi inhabiting in a variety of ecological niches. As typical representatives of the hybrid molecules, the biosynthetic pathway of ascofuranone and ascochlorin are discussed. The group of meroterpenoid hybrids exhibits a broad arrange of bioactivities, as highlighted by targeting hDHODH (human dihydroorotate dehydrogenase) inhibition, antitrypanosomal, and antimicrobial activities. This review summarizes the findings related to the structures, fungal sources, bioactivities, and their biosynthesis from 1968 to June 2022.

Dothideomins A-D, Antibacterial Polycyclic Bisanthraquinones from the Endophytic Fungus Dothideomycetes sp. BMC-101.

Four new bisanthraquinones, dothideomins A-D (1-4), were identified from Dothideomycetes sp. BMC-101, an endophytic fungus isolated from Magnolia grandiflora L. leaves. Their chemical structures were established by NMR analysis, single-crystal X-ray crystallography, and ECD analysis. Dothideomins A-D (1-4) were characterized by an unusual 6/6/6/5/6/3/6/6 octocyclic scaffold (1 and 2) and a 6/6/6/5/6/6/6 heptacyclic scaffold (3 and 4), respectively. All compounds, especially 1 and 3, exhibited potent antibacterial activity with MIC values ranging from 0.4 to 0.8 µg/mL.

Identification and Characterization of a Cryptic Bifunctional Type I Diterpene Synthase Involved in Talaronoid Biosynthesis from a Marine-Derived Fungus.

We report the identification of the tnd biosynthetic cluster from the marine-derived fungus Aspergillus flavipes and the in vivo characterization of a cryptic type I diterpene synthase. The heterologous expression of the bifunctional terpene synthase led to the discovery of a diterpene backbone, talarodiene, harboring a benzo[a]cyclopenta[d]cyclooctane tricyclic fused ring system. The conversion of geranylgeranyl diphosphate to talarodiene was investigated using 13C-labeling studies, and stable isotope tracer experiments showed the biotransformation of talarodiene into talaronoid C.

Production of Multiple Talaroenamines from Penicillium malacosphaerulum via One-Pot/Two-Stage Precursor-Directed Biosynthesis.

Nineteen new talaroenamine derivatives, talaroenamines F1-F19 (1-19), were isolated from the Yellow River wetland derived Penicillium malacosphaerulum HPU-J01 by use of a one-pot/two-stage precursor-directed biosynthesis approach. During this approach, the initial precursor p-methylaniline was first used as a carrier to capture the biologically synthesized cyclohexanedione to produce talaroenamine F, and then the other aniline derivatives were employed to replace the p-methylaniline fragment of talaroenamine F to generate the final products. LC-MS analysis showed that only four compounds (2, 8, 10, and 12) could be produced by the traditional precursor-directed biosynthesis in which the aniline precursors were added simultaneously. Compound 14 was cytotoxic against the K562 cell line with an IC50 value of 2.2 µM. This work demonstrated the one-pot/two-stage precursor-directed biosynthesis could improve substrate acceptance leading to the production of diverse talaroenamines.

Nonenzymatic Self-Assembly Access to Diverse ortho-Quinone Methide-Based Pseudonatural Products.

A nonenzymatic self-assembly program was introduced to explore diverse clavatol-based pseudonatural products (PNPs) in a marine-derived fungus. Intermolecular couplings of the chemoreactive ortho-quinone methide of clavatol with native acceptors led to 14 clavatol-based PNPs with five categories, and compounds 1, 2, 5-10, and 12 are new. In particular, 1 and 2 possessed an unprecedented oxa-angular tetracyclic scaffold with highly oxidized modification and exhibited cytotoxicity. Such a program is proven to be of great advantage in constructing bioactive PNPs.

Mimicking DNA Periodic Docking Grooves for Adaptive Identification of l-/d-Tryptophan in a Biological Metal-Organic Framework.

Bioinspired metal-organic frameworks (MOFs) serve as suitable crystalline models for recognition and sensing of biomolecules mimicking natural processes, providing new ideas and concepts for cutting-edge biomedical applications. Here, we have successfully prepared a robust biological metal-organic framework with periodic docking grooves resembling the major and minor grooves in the DNA double helix structure, which can be used as unique recognition sites for selectively identifying l-/d-tryptophan (l-/d-Trp). Notably, successful encapsulation of Trp could be observed by single-crystal X-ray diffraction for the first time. Trp has matched size and shape to fit snugly into the major groove. Combined with isothermal titration calorimetry, it was found that ZnBTCHx could spontaneously capture l-/d-Trp through two different thermodynamic pathways: enthalpy-driven for encapsulating l-Trp and entropy-driven for uptaking d-Trp. Furthermore, molecular dynamics and density functional theory verified the role of hydrogen bonding and π-π/C-H···π interactions in the host-guest interface. This work provides unique insight for the construction of bionic models to mimic the natural binding properties, which is of great significance for the fields of pharmaceutical chemistry and biomedical science.

Combination Strategy of Genetic Dereplication and Manipulation of Epigenetic Regulators Reveals a Novel Compound from Plant Endophytic Fungus.

The strategies of genetic dereplication and manipulation of epigenetic regulators to activate the cryptic gene clusters are effective to discover natural products with novel structure in filamentous fungi. In this study, a combination of genetic dereplication (deletion of pesthetic acid biosynthetic gene, PfptaA) and manipulation of epigenetic regulators (deletion of histone methyltransferase gene PfcclA and histone deacetylase gene PfhdaA) was developed in plant endophytic fungus Pestalotiopsis fici. The deletion of PfptaA with PfcclA and/or PfhdaA led to isolation of 1 novel compound, pestaloficiol X (1), as well as another 11 known compounds with obvious yield changes. The proposed biosynthesis pathway of pestaloficiol X was speculated using comparative analysis of homologous biosynthetic gene clusters. Moreover, phenotypic effects on the conidial development and response to oxidative stressors in the mutants were explored. Our results revealed that the new strain with deletion of PfcclA or PfhdaA in ΔPfptaA background host can neutralise the hyperformation of conidia in the PfptaA mutant, and that the ΔPfptaA ΔPfhdaA mutant was generally not sensitive to oxidative stressors as much as the ΔPfptaA ΔcclA mutant in comparison with the single mutant ΔPfptaA or the parental strains. This combinatorial approach can be applied to discover new natural products in filamentous fungi.

Oriented Deep Eutectic Solvents as Efficient Approach for Selective Extraction of Bioactive Saponins from Husks of Xanthoceras sorbifolia Bunge.

The husks of Xanthoceras sorbifolia Bunge (X. sorbifolia), as by-products of industrial production, have brought a severe burden to the environment and caused an enormous waste of resources. Bioactive triterpenoid saponins are rich in the husks. To reuse the husks and gain high-quality saponin products, saponin-oriented deep eutectic solvents (DESs), as an efficient and selective extraction strategy from X. sorbifolia husks, were designed for the first time. The enhancement of the extraction rate was investigated by screening solvents from acidic DESs and response surface methodology (RSM) optimization. As a result, the tetrapropylammonium bromide-lactic acid (TPMBr-La) was the most efficient DESs, with an extraction efficiency of up to 135% higher than 70% ethanol. A maximum extraction rate of 72.11 ± 0.61 mg Re/g dw was obtained under the optimized parameters. Scanning electron microscope graphs revealed that damage to the microstructure caused by DESs enhanced the extraction efficiency. Moreover, the recovery of total saponins with D101 macroporous resin was consistent with the pseudo-second-order kinetic model. Seven saponins were also identified by HPLC-MS analysis. Finally, TPMBr-La extracts exhibited 92.30 ± 1.10% DPPH radical scavenging rate at 100 µg/mL, and 92.20 ± 0.30% ABTS radical scavenging rate at 1200 µg/mL. Our current research proposes a selective and high-efficiency substitute for the extraction of saponins and might contribute to further DESs application in the recycling of by-products.

Transcriptional Differences Guided Discovery and Genetic Identification of Coprogen and Dimerumic Acid Siderophores in Metarhizium robertsii.

Siderophores are small molecular iron chelators and participate in the multiple cellular processes in fungi. In this study, biosynthesis gene clusters of coprogens and dimerumic acids were identified by transcriptional level differences of genes related to iron deficiency conditions in Metarhizium robertsii. This leads to the characterization of new coprogen metachelin C (1) and five known siderophores metachelin A (2), metachelin A-CE (3), metachelin B (4), dimerumic acid 11-mannoside (5), and dimerumic acid (6). The structure of metachelin C (1) was elucidated by NMR spectroscopy and HR-ESI-MS analysis. Genetic deletions of mrsidA, and mrsidD abolished the production of compounds 1-6 that implied their involvement in the biosynthesis of coprogen and dimerumic acid. Interestingly, NRPS gene mrsidD is responsible for biosynthesis of both coprogen and dimerumic acid, thus we proposed plausible biosynthetic pathways for the synthesis of coprogen and dimerumic acid siderophores. Therefore, our study provides the genetic basis for understanding the biosynthetic pathway of coprogen and dimerumic acid in Metarhizium robertsii.

Construction of a Luminescent Cadmium-Based Metal-Organic Framework for Highly Selective Discrimination of Ferric Ions.

Fluorescent metal-organic frameworks (MOFs) are ideal materials for sensors because of their adjustable pore size and functional groups, which provide them with favorable metal ion selective recognition. In this paper, a new cadmium-based MOF was synthesized using Cd(NO3)2·4H2O and 3,3',5,5'-biphenyltetracarboxylic acid by solvothermal method. CdBPTC owned three types of channels with dimensions of approximately 8.4 × 8.3 Å, 6.0 × 5.2 Å, 9.7 × 8.4 Å along a, b, and c axis, respectively. This MOF has high selectivity to ferric ions and shows excellent anti-inference ability toward many other cations. The results indicate that the fluorescence quenching efficiency of CdBPTC is close to 100% when the concentration of Fe3+ reaches 1.0 × 10-3 mol·L-1. Moreover, the luminescent intensity at 427 nm presents a linear relationship at a concentration range of 2.0 × 10-4~7.0 × 10-4 mol·L-1, which can be quantitatively expressed by the linear Stern-Volmer equation I0/I = 8489 [Fe3+] - 0.1400, which is comparable to the previously reported better-performing materials. Competitive energy absorption and ion exchange may be responsible for the variation in fluorescence intensity of CdBPTC in different Fe3+ concentrations.

Emerimicins V-X, 15-Residue Peptaibols Discovered from an Acremonium sp. through Integrated Genomic and Chemical Approaches.

Fermentation of Acremonium tubakii W. Gams isolated from a soil sample collected from the University of Utah led to the isolation and characterization of six new linear pentadecapeptides, emerimicins V-X (1-6). Peptaibols containing 15-residues are quite rare, with only 22 reported. Genome mining and bioinformatic analysis were used to identify the emerimicin 60 kbp eme biosynthetic cluster harboring a single 16-module hybrid polyketide-nonribosomal peptide synthetase. A detailed bioinformatic investigation of the corresponding 15 adenylation domains, combined with 1D and 2D NMR experiments, LC-MS/MS data, and advanced Marfey's method, allowed for the elucidation and absolute configuration of all proteinogenic and nonproteinogenic amino acid residues in 1-6. As some peptaibols possess cytotoxic activity, a zebrafish embryotoxicity assay was used to evaluate the toxicity of the six emerimicins and showed that emerimicin V (1) and VI (2) exhibit the most potent activity. Additionally, out of the six emerimicins, 1 displayed modest activity against Enterococcus faecalis, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococcus faecium with MIC values of 64, 32, and 64 µg/mL, respectively.

Antifungal natural products.

Natural products are specialized small molecules produced in Nature and play pivotal roles in many cellular processes. These compounds possess exquisite chemical diversity and represent some of the most important pharmaceutical agents in human health care. With the rampant rise of fungal pathogens that are becoming resistant to nearly all clinically available antibiotics, there is an increased urgency to find new antifungal therapies with novel modes of action. To meet this need, we must be able to quickly identify new bioactive chemical scaffolds within complex natural extracts, determine their mechanisms of action, and generate appreciable yields for preclinical studies. In this review, we will highlight naturally derived antifungal agents of clinical importance as well as those with strong potential as leads in drug development.

Discovery and characterization of a cytochalasan biosynthetic cluster from the marine-derived fungus Aspergillus flavipes CNL-338.

Cytochalasans are a large family of well-studied cytotoxic molecules isolated from fungi. Investigation into the organic extract of the marine-derived fungal strain Aspergillus flavipes CNL-338 led to the isolation of seven leucine-containing cytochalasans. Genome mining allowed for the identification of the ffs biosynthetic gene cluster, and genetic inactivation studies verified its involvement in cytochalasan biosynthesis. In addition, comparative analysis of key residues in the binding pocket of core cytochalasan biosynthetic enzymes revealed significant similarities among fungal adenylation domains despite differences in substrate preference. We report the identification of leucine-containing cytochalasans from the marine-derived A. flavipes CNL-338 and the characterization of the ffs biosynthetic cluster as verified by genetic inactivation studies.