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. The results demonstrated that renatured LNT (r-LNT) effectively encapsulated the {101̄0} crystal planes of ZnO, preventing crystal growth during the renaturation process and resulting in smaller, uniformly dispersed nanoparticles. Among the samples, ZnO/r-LNT-2 exhibited significantly higher antimicrobial activity, and it had a certain inhibitory effect on various plant pathogens. It also displayed the highest inhibitory effect against Candida albicans, with a minimum inhibitory concentration (MIC) of up to 8 µg mL-1. Consistently, ZnO/r-LNT-2 generated the highest amount of reactive oxygen species (ROS), thus exhibiting the most effective antimicrobial activity. However, excessive introduction of the dispersant LNT may reduce these activities. This study provides a foundation for further exploring the detailed mechanism of ROS generation catalyzed by ZnO and for harnessing the full potential of this type of antimicrobial agent.

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

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 tert-butyl group makes it a great challenge to synthesize tebuconazole enantiomers. Here, we designed a simple chemoenzymatic approach for the asymmetric synthesis of (R)-tebuconazole, which includes the biocatalytic resolution of racemic epoxy-precursor (2-tert-butyl-2-[2-(4-chlorophenyl)ethyl] oxirane, rac-1a) by Escherichia coli/Rpeh whole cells expressed epoxide hydrolase from Rhodotorula paludigensis (RpEH), followed by a one-step chemocatalytic synthesis of (R)-tebuconazole. It was observed that (S)-1a was preferentially hydrolyzed by E. coli/Rpeh, whereas (R)-1a was retained with a specific activity of 103.8 U/g wet cells and a moderate enantiomeric ratio (E value) of 13.4, which was remarkably improved to 43.8 after optimizing the reaction conditions. Additionally, a gram-scale resolution of 200 mM rac-1a was performed using 150 mg/mL E. coli/Rpeh wet cells, resulting in the retention of (R)-1a in a 97.0% ees, a 42.5% yields, and a 40.5 g/L/d space-time yield. Subsequently, the synthesis of highly optical purity (R)-tebuconazole (>99% ee) was easily achieved through the chemocatalytic ring-opening of the epoxy-precursor (R)-1a with 1,2,4-triazole. To elucidate insight into the enantioselectivity, molecular docking simulations revealed that the unique L-shaped substrate-binding pocket of RpEH plays a crucial role in the enantioselective recognition of bulky 2,2-disubstituted oxirane 1a.

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. The effects of carbon sources on the antioxidant properties of EPSs could be examined. The results showed that five EPSs can effectively inhibit radicals induced oxidation of DNA, and the thiobarbituric acid reactive substances (TBARS) percentages were 44.7%-80.8%, 52.3%-77.5%, and 44.7%-73.3% in inhibiting AAPH, HO·, and GS· induced oxidation of DNA, respectively. All five EPSs could scavenge ABTS· and galvinoxyh, and exhibit superior activity in scavenging free radicals. Antioxidant abilities of EPS with fructose as carbon source were highest among five EPS.

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. METHODS: The RNA expression of circ_0001861, forkhead box protein 1 (FOXP1) and microRNA-296-5p (miR-296-5p) was detected by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Western blot assay was performed to examine the protein levels of FOXP1 and epithelial-mesenchymal transition (EMT) markers. Cell viability, proliferation, migration and invasion were detected by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, and transwell assays. Luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation (RIP) assay were conducted to explore the interaction between miR-296-5p and circ_0001861 or FOXP1. RESULTS: Circ_0001861 and FOXP1 were downregulated but miR-296-5p was upregulated in PE placenta. Upregulation of circ_0001861 facilitated trophoblast cell proliferation, migration, invasion and EMT. Mechanistically, circ_0001861 sponged miR-296-5p to elevate FOXP1 expression, thus promoting trophoblast cell progression. CONCLUSION: The circ_0001861/miR-296-5p/FOXP1 axis plays a critical role in trophoblast cell proliferation, migration, invasion and EMT, which may provide a novel insight into developing potential therapeutic targets for PE.

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

ABSTRACT 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. Amongst carbon sources examined, glucose and sucrose were favorable for the mycelia growth, while the maximum EPS yield was achieved when sucrose was employed. The predominant carbohydrate compositions in EPSs identified were gluconic acid, glucose, mannose and galactose acid. Then, FT-IR spectral analysis revealed prominent characteristic groups in EPSs. EPSs molecule exist as nearly globular shape form in aqueous solution. The variation also affects antioxidant activities by investigated by using hydroxyl and DPPH radical scavenging assay. Sucrose was best carbon source from the viewpoint of antioxidant activity due to the relatively high contents of galactose in the EPS with moderate molecular weight and polydispersity.