Search

Isoquercetin and D-allulose have diverse applications and significant value in antioxidant, antibacterial, antiviral, and lipid metabolism. Isoquercetin can be synthesized from quercetin, while D-allulose is converted from D-fructose. However, their production scale and overall quality are relatively low, leading to high production costs. In this study, we have devised a cost-effective one-pot method for biosynthesizing isoquercetin and D-allulose using a whole-cell biocatalyst derived from quercetin and sucrose. To achieve this, the optimized isoquercetin synthase and D-allulose-3-epimerase were initially identified through isofunctional gene screening. In order to reduce the cost of uridine diphosphate glucose (UDPG) during isoquercetin synthesis and ensure a continuous supply of UDPG, sucrose synthase is introduced to enable the self-circulation of UDPG. At the same time, the inclusion of sucrose permease was utilized to successfully facilitate the catalytic production of D-allulose in whole cells. Finally, the recombinant strain BL21/UGT-SUS+DAE-SUP, which overexpresses Mi F3GTMUT, Gm SUS, Ec SUP, and DAEase, was obtained. This strain co-produced 41±2.4 mg/L of isoquercetin and 5.7±0.8 g/L of D-allulose using 120 mg/L of quercetin and 20 g/L of sucrose as substrates for 5 h after optimization. This is the first green synthesis method that can simultaneously produce flavonoid compounds and rare sugars. These findings provide valuable insights and potential for future industrial production, as well as practical applications in factories. • Simultaneous production of isoquercitrin and allulose using a single strain of recombinant E.coli. • Whole-cell catalysis as a green and efficient method with future industrial prospects. • Constructed self-recycling of UDPG(uridine diphosphate glucose) cofactors to reduce UDPG costs. • Whole-cell catalysis of sucrose by introduction of sucrose permease. [ABSTRACT FROM AUTHOR]

Zika virus (ZIKV) is a single-stranded RNA flavivirus transmitted by mosquitoes. Its infection is associated with neurological complications such as neonatal microcephaly and adult Guillain–Barré syndrome, posing a serious threat to the health of people worldwide. Therefore, there is an urgent need to develop effective anti-ZIKV drugs. Atranorin is a lichen secondary metabolite with a wide range of biological activities, including anti-inflammatory, antibacterial and antioxidant, etc. However, the antiviral activity of atranorin and underlying mechanism has not been fully elucidated. We aimed to determine the anti-ZIKV activity of atranorin in human glioma cell line SNB-19 and investigate the potential mechanism from the perspective of viral life cycle and the host cell functions. We first established ZIKV-infected human glioma cells (SNB-19) model and used Western Blot, RT-qPCR, immunofluorescence, fluorescence-activated cell sorting (FACS) and plaque assay to evaluate the anti-ZIKV activity of atranorin. Then we assessed the regulation effect of atranorin on ZIKV induced IFN signal pathway activation by RT-qPCR. Afterward, we introduced time-of-addition assay, viral adsorption assay, viral internalization assay and transferrin uptake assay to define which step of ZIKV lifecycle is influenced by atranorin. Finally, we performed virus infectivity assay, molecular docking and thermal shift assay to uncover the target protein of atranorin on ZIKV. Our study showed that atranorin could protect SNB-19 cells from ZIKV infection, as evidenced by inhibited viral protein expression and progeny virus yield. Meanwhile, atranorin attenuated the activation of IFN signal pathway and downstream inflammatory response that induced by ZIKV infection. The results of time-of-addition assay indicated that atranorin acted primarily by disturbing the viral entry process. After ruling out the effect of atranorin on AXL receptor tyrosine kinase (AXL) dependent virus adsorption and clathrin-mediated endocytosis, we confirmed that atranorin directly targeted the viral envelope protein and lowered ZIKV infectivity by thermal shift assay and virus infectivity assay respectively. We found atranorin inhibits ZIKV infection in SNB-19 cells via targeting ZIKV envelope protein. Our study provided an experimental basis for the further development of atranorin and a reference for antiviral drug discovery from natural resources. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper presents a new way to calculate productivity of five-spot pattern at high water cut stages. In low permeability reservoirs, it is difficult for the reservoir fluid to flow, and the recovery factor is very low. Being based on the non-Darcy flow in low permeability reservoir, taking threshold pressure gradient into consideration, a new method to calculate the well pattern was built. This method is based on the two-parameter continuous model, and the method of flow line integrals and the numerical integration were used to build the productivity model. Productivity for the new method is validated by comparing with the actual data from field, and both the seepage theory and the reservoir engineering illustrate the correctness of the new method in this paper. The fracture length and pressure difference between the injection well and the production well have a significant effect on the productivity of the fractured five-point well pattern. The greater the length of the fracture is, the higher the productivity of the fractured five-point well pattern is. The greater the pressure difference is, the higher the productivity of the fractured five-point well pattern is. [ABSTRACT FROM AUTHOR]

Melatonin (MT) has been implicated in the plant response to phosphorus (P) stress; however, the precise molecular mechanisms involved remain unclear. This study investigated whether MT controls internal P distribution and root cell wall P remobilization in rice. Rice was treated with varying MT and P levels and analyzed using biochemical and molecular techniques to study phosphorus utilization. The results demonstrated that low P levels lead to a rapid increase in endogenous MT levels in rice roots. Furthermore, the exogenous application of MT significantly improved rice tolerance to P deficiency, as evidenced by the increased biomass and reduced proportion of roots to shoots under P‐deficient conditions. MT application also mitigated the decrease in P content regardless in both the roots and shoots. Mechanistically, MT accelerated the reutilization of P, particularly in the root pectin fraction, leading to increased soluble P liberation. In addition, MT enhanced the expression of OsPT8, a gene involved in root‐to‐shoot P translocation. Furthermore, we observed that MT induced the production of nitric oxide (NO) in P‐deficient rice roots and that the mitigating effect of MT on P deficiency was compromised in the presence of the NO inhibitor, c‐PTIO, implying that NO is involved in the MT‐facilitated mitigation of P deficiency in rice. Overall, our findings highlight the potential of MT as a promising strategy for enhancing rice tolerance to P deficiency and improving P use efficiency in agricultural practices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Interfacial heterogeneous Ni(OH) 2 /Ni 2 P microstructures are constructed on nickel foam. • Ni(OH) 2 /Ni 2 P/NF exhibits excellent HER, HzOR and hydrazine-assisted water splitting activity. • The heterogeneous interfaces contribute to the enhanced activity. • An innovative intermittent hydrazine-assisted water splitting electrolysis system is proposed. Hydrazine oxidation reaction (HzOR) has been proposed to replace the sluggish oxygen evolution reaction (OER) for energy-saving hydrogen generation. However, the rational design of bifunctional electrocatalysts that can simultaneously accelerate HER/HzOR kinetics and the source of the hydrazine chemical substrate are still challenging. Herein, interfacial heterogeneous nickel hydroxide/nickel phosphide microstructures are in-situ grown on nickel foam (Ni(OH) 2 /Ni 2 P/NF) via a combined electrodeposition-phosphorization-electrodeposition strategy. After Ni(OH) 2 modification, a charge redistribution is triggered between Ni(OH) 2 and Ni 2 P, reducing the charge-transfer resistance and optimizing the adsorption energy of reaction intermediates. Ni(OH) 2 /Ni 2 P/NF thus yields an impressive bifunctional electrocatalytic activity for HER and HzOR with potentials of −72 and −14 mV at 10 mA cm−2, respectively. When using Ni(OH) 2 /Ni 2 P/NF as both electrodes, decreased cell voltage of 0.357 V is required to drive a current density of 100 mA cm−2 in 0.5 M hydrazine-containing alkaline electrolyte. Furthermore, an intermittent hydrazine-assisted water electrolysis system is proposed to make the combination of hydrazine sewage purification and energy-saving hydrogen production realistic. [ABSTRACT FROM AUTHOR]