Engineering an Epoxide Hydrolase for Chemoenzymatic Asymmetric Synthesis of Chiral Triazole Fungicide ()- and ()-Flutriafol.

Flutriafol, a globally utilized triazole fungicide in agriculture, is typically applied as a racemic mixture, but its enantiomers differ in bioactivity and environmental impact. The synthesis of flutriafol enantiomers is critically dependent on chiral precursors: 2,2-bisaryl-substituted oxirane [(2-fluorophenyl)-2-(4-fluorophenyl)oxirane, ] and 1,2-diol [1-(2-fluorophenyl)-1-(4-fluorophenyl)ethane-1,2-diol, ]. Here, we engineered a epoxide hydrolase (EH), obtaining mutant / with a 6.

Correction: Coating effect of renatured triple-helix lentinan on the morphology and antimicrobial activity of ZnO synthesized by hydrothermal method.

[This corrects the article DOI: 10.1039/D4RA01590H.].

Coating effect of renatured triple-helix lentinan on the morphology and antimicrobial activity of ZnO synthesized by hydrothermal method.

Polysaccharides are considered to be ideal green raw materials for enhancing biocompatibility and dispersion effects of nanoparticles. In this study, we coated and dispersed ZnO nanoparticles (NPs) using the denaturation-renaturation process of a triple helix glucan lentinan (LNT), induced by changes in pH value within the reaction system. Various ZnO/LNT composites with different particle sizes and crystal morphologies were prepared and characterized.

Chemoenzymatic Asymmetric Synthesis of Chiral Triazole Fungicide ()-Tebuconazole in High Optical Purity Mediated by an Epoxide Hydrolase from .

Tebuconazole is a chiral triazole fungicide used globally in agriculture as a racemic mixture, but its enantiomers exhibit significant enantioselective dissimilarities in bioactivity and environmental behaviors. The steric hindrance caused by the -butyl group makes it a great challenge to synthesize tebuconazole enantiomers. Here, we designed a simple chemoenzymatic approach for the asymmetric synthesis of ()-tebuconazole, which includes the biocatalytic resolution of racemic epoxy-precursor (2--butyl-2-[2-(4-chlorophenyl)ethyl] oxirane, -) by / whole cells expressed epoxide hydrolase from (EH), followed by a one-step chemocatalytic synthesis of ()-tebuconazole.

Effect of Different Carbon Sources on Antioxidant Properties of Exopolysaccharides Produced by Scleroderma areolatum (Agaricomycetes).

Five kinds of exopolysaccharides (EPS) were obtained by fermentation of Scleroderma areolatum Ehrenb. with sucrose, glucose, maltose, lactose, and fructose as carbon sources. Antioxidant abilities of the obtained EPSs were evaluated by inhibiting AAPH, HO·, and glutathione (GS·) induced oxidation of DNA and quenching 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS· and galvinoxyl radicals.

Circ_0001861 facilitates trophoblast cell proliferation, migration, invasion and epithelial-mesenchymal transition via the miR-296-5p/forkhead box protein 1 pathway in preeclampsia.

Background: Preeclampsia (PE) is one of the leading causes of maternal mortality and placental trophoblastic disorders. Recent studies reported that circular RNAs (circRNAs) were involved in PE pathogenesis. However, the role of circ_0001861 in PE progression is largely unknown.

Structure Characterization and Anti-Inflammatory Activity of Polysaccharides from Lingzhi or Reishi Medicinal Mushroom Ganoderma lucidum (Agaricomycetes) by Microwave-Assisted Freeze-Thaw Extraction.

A water-soluble polysaccharide (GLP-2) was isolated and purified from Ganoderma lucidum by the microwave-assisted freeze-thaw method. Microwave-assisted rapid thawing treatment can greatly improve the extraction yield of polysaccharides. The chemical structure of GLP-2 was analyzed with FT-IR, HPLC, GC-MS, and NMR spectrometry.

Novel kojic acid derivatives with anti-inflammatory effects from Aspergillus versicolor.

Two novel kojic acid derivatives, kojicones A and B (1 and 2), along with the precursors kojic acid (3) and (2R,4R)-4-hydroxy-5-methoxy-2,4-dimethyl-2- [(2R)-2-methylbutyryloxy]-5-cyclohexen-1,3-dione (4), were isolated from a fungal strain Aspergillus versicolor. Their structures and absolute configurations were accurately confirmed by HRESIMS data, NMR analysis, and electronic circular dichroism (ECD) calculations. Kojicones A and B were the first examples of kojic acid adducts with cyclohexen-1,3-dione possessing unprecedented tricycle skeletons.

Effect of tween 40 and ethanol on the secretion, structure and antioxidant activities of exopolysaccharides from Inonotus rickii.

In this study, the effects of Tween 40 and ethanol supplementation on the secretion, structure and antioxidant activities of exopolysaccharide (EPS) from Inonotus rickii were investigated. It was observed that Tween 40 and ethanol displayed a stimulatory effect on EPS secretion. The EPSs obtained by the addition of Tween 40 (EPS-T), ethanol (EPS-E) and control (EPS-C) were purified by Sepharose CL-6B gel chromatography and molecular weights of EPS-T, EPS-E and EPS-C were estimated to be 22.

Effect of Carbon Source on Properties and Bioactivities of Exopolysaccharide Produced by Trametes ochracea (Agaricomycetes).

The effects of carbon source on properties and bioactivities of exopolysaccharide (EPS) produced by Trametes ochracea were investigated in this study. The results indicated that EPS production varied with five different carbon sources. After a fermentation period of 8 days, sucrose was the most suitable carbon source for biomass and EPS production.

Synthesis of gold-silver nanoalloys under microwave-assisted irradiation by deposition of silver on gold nanoclusters/triple helix glucan and antifungal activity.

Polysaccharides are ideal green synthetic raw materials to improve the biocompatibility of metal nanoparticles. However, polysaccharides generally have weak reducibilities, being challenging supports for the direct preparation of Ag nanoparticles. In this work, gold nanoclusters were prepared using a triple helix glucan (Lentinan) via microwave-assisted synthesis and subsequently employed as seeds for the synthesis of a series of Ag-Au alloy nanoparticles (Ag-AuNPs).

Antifungal Macrocyclic Trichothecenes from the Insect-Associated Fungus .

Three new macrocyclic trichothecenes possessing rare 6'-ketal moieties, roridoxins A-C (), and five known compounds () were isolated from the insect-associated fungus . Their structures were confirmed by a combination of NMR and HRESIMS data, while their absolute configurations were unambiguously determined by single-crystal X-ray analysis and electronic circular dichroism experiments. Trichothecenes and showed potent antifungal activities against four strains of phytopathogenic fungi.

Production, structural characterization, and antiproliferative activity of exopolysaccharide produced by Scleroderma areolatum Ehrenb with different carbon source.

The effects of different three carbon sources, that is, glucose, fructose, and sucrose, on production, molecular properties and antiproliferative activity of exopolysaccharide (EPS), were evaluated in the submerged culture of Scleroderma areolatum Ehrenb. Among carbon sources examined, the addition of sucrose maximizes the mycelia production, while fructose could maximize the EPS yield. Although the predominant carbohydrate compositions identified were gluconic acid and mannose, the monosaccharide composition of EPSs was also different significantly.

Antioxidant coumarin and pyrone derivatives from the insect-associated fungus .

Two new compounds, versicolones A and B ( and ), and three known pyrone derivatives (-) were isolated from the insect-associated fungus . Their structures were elucidated through a combination of HRESIMS and NMR spectroscopic analysis. Versicolone A () was revealed as a coumarin derivative with the rare 5-alkyl side chain substitution.

Characterization and Antioxidant Activity of an Exopolysaccharide Produced by Rigidoporus microporus (Agaricomycetes).

In this investigation we developed an optimal fermentation medium to produce an exopolysaccharide (EPS) with antioxidant activity from Rigidoporus microporus. Lactose and tryptone were chosen as the optimal carbon and nitrogen sources, respectively, for EPS production, with a 6-day cultivation cycle. After removing proteins through the use of the Sevag method, one EPS fraction was purified from the culture filtrates by gel filtration chromatography on a Sepharose CL-6B column.

Effect of carbon source on production, characterization and bioactivity of exopolysaccharide produced by Phellinus vaninii Ljup.

The effect on different three carbon source (i.e. glucose, fructose and sucrose) on production, chemical characterization and antioxidant activity of exopolysaccharide (EPS) produced by Phellinus vaninii Ljup was investigated in this study.

Molecular Characterization of Two Polysaccharides from Phellinus vaninii Ljup and their Cytotoxicity to Cancer Cell Lines.

Background: Phellinus vaninii, a medicinal basidiomycete fungus, is often confused with Phellinus igniarius and Phellinus linteus. Polysaccharides extract from P. igniarius and P.

Sulfation of the Extracellular Polysaccharide Produced by the King Oyster Culinary-Medicinal Mushroom, Pleurotus eryngii (Agaricomycetes), and Its Antioxidant Properties In Vitro.

Extracellular polysaccharide from Pleurotus eryngii was sulfated; the optimum reaction conditions used pyridine as the reaction solvent, a temperature of 80°C, and a reaction time of 90 minutes. The structure and antioxidant activity of the sulfated and original polysaccharides (designated as SF-1 and Fr-1, respectively) were investigated. The main functional groups of polysaccharides were determined by Fourier transform infrared, and the chain conformation was determined by size-exclusion chromatography with laser light scattering and viscometry.

Optimization, Purification, Characterization, and Antioxidant Activity of Exopolysaccharide Produced by the Northern Tooth Mushroom, Climacodon septentrionalis (Basidiomycota).

The optimization, purification, and characterization of exopolysaccharide (EPS) from Climacodon septentrionalis were investigated. The results showed that the optimal incubation time was 8 days for EPS production by C. septentrionalis; maltose and soy extract were the best carbon and nitrogen sources, respectively.

Construction of selenium nanoparticles/β-glucan composites for enhancement of the antitumor activity.

We report on a green procedure for the stabilization of selenium nanoparticles (SeNPs) by a naturally occurring β-glucan with triple helical conformation known as Lentinan (t-LNT) in water after denaturing into single chains (s-LNT) at 140 °C. The results demonstrated that the s-LNT can interact with SeNPs through Se-O-H interaction. Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectra, UV/vis, X-ray diffraction (XRD) and dynamic light scattering (DLS) showed that s-LNT coated SeNPs to form a stable nano-composite Se/s-LNT, leading to good dispersion of SeNPs.

Synthesis and stabilization of gold nanoparticles induced by denaturation and renaturation of triple helical β-glucan in water.

We report on a green procedure for the synthesis and stabilization of gold nanoparticles (AuNPs) from chlorauric acid (HAuCl4) with the use of a β-glucan known as Lentinan (LNT) without external reducing or stabilizing agents in aqueous medium. LNT adopted triple helical conformation in water, which was first denatured into single chains (s-LNT) at a high temperature of 140 °C before mixing with HAuCl4. Results from UV-vis absorption spectroscopy, transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) spectra suggested that AuCl4(-) was rapidly reduced to AuNPs by s-LNT.

Effects of calcium carbonate polymorph on the structure and properties of soy protein-based nanocomposites.

Novel protein-based nanocomposites were well prepared by in vivo synthesis and co-precipitation of soy protein isolate (SPI) with calcium carbonate (CaCO3) in an aqueous solution. The resultant CaCO3 in the nanocomposites was identified as calcite- and aragonite-type, respectively. The morphology and structure of the CaCO3/SPI composites were investigated by means of wide-angle X-ray diffraction, Fourier transform infrared spectra, scanning electron microscopy, and high-resolution transmission electron microscopy.