Production of Fumaric Acid by Bioconversion of Corncob Hydrolytes Using an Improved <Emphasis Type="Italic">Rhizopus oryzae</Emphasis> Strain

The use of microorganism fermentation for production of fumaric acid (FA), which is widely used in food, medicine, and other fields, can provide technical support for the FA industry. In this study, we aimed to increase the titer of FA production by using an improved Rhizopus oryzae WHT5, which was domesticated to obtain a furfural-resistant strain in corncob hydrolytes. The metabolic pathways and metabolic network of this strain were investigated, and the related enzymes and metabolic flux were analyzed. Metabolic pathway analysis showed that the R. oryzae WHT5 strain produced FA mainly through two pathways. One occurred in the cytoplasm and the other was a mitochondrial pathway. The key parameters of the fermentation process were analyzed. The FA titer was 49.05 g/L from corncob hydrolytes using R. oryzae WHT5 in a 7-L bioreactor. The use of a furfural-resistant strain developed through domestication effectively increased the titer of FA. This capacity of the microorganisms to produce high amounts of FA by bioconverting corncob hydrolyte can be further applied for industrial production of FA.     

Formal [4 + 1] cycloaddition strategy for the synthesis of dihydrobenzofurans via Michael addition of 2-(2-nitrovinyl)-phenols and malonate esters (C1 synthon) and subsequent iodine-catalyzed oxidative annulation

A novel [4 + 1] cycloaddition protocol for the synthesis of dihydrobenzo(naphtho)furan skeletons from readily available 2-(2-nitrovinyl)-phen(naphth)ols and malonate esters via a tandem Michael addition/iodine-catalyzed oxidative annulation has been developed. This method provides a new and facile application of malonate esters as 1,1-nucleophilic/electrophilic type C1 synthons without a pre-functionalization step and the plausible reaction mechanism is proposed.     

Determination of Pharmaceuticals by Dynamic Cell Membrane Chromatography Coupled with High-Performance Liquid Chromatography

As a biological affinity chromatographic method, cell membrane chromatography (CMC) using a silica stationary phase covered with specific cell membrane has been used in screening active components. The innovation of this work is that the bioactive cell membrane and the chromatographic packing are mixed and absorbed for the first time to form the pre-column. The pre-column was placed in front of a C₁₈ column to create dynamic CMC online high-performance liquid chromatography (HPLC) system. The retention behavior and dynamic changes of pharmaceuticals were studied for this system. The results indicate that the retention time of the drug was increased and the symmetry factor reached the analytical level after the addition of the dynamic cell membrane pre-column. Therefore, the dynamic CMC coupled with HPLC system may be a potentially rapid and efficient drug analysis approach for the interaction of drug molecule and receptor on red blood cell membranes.     

Regioselective addition of Ti enolates to conjugated enones: New insights into the mechanism based on experimental and DFT investigation

The regioselective addition mechanism of the Ti(IV) enolates derived from α-diazo-β-keto carbonyl compounds and α-diazo-β-keto phosphonates to conjugated enones has been studied on the basis of a hypothetical bridging chloride-controlled theory, by density functional theory (DFT), and experimentally. The DFT results indicate that, for the Ti(IV) enolate 3 derived from α-diazo-β-keto carbonyl compounds, the free energy of the bridging chloride-controlled 1,2-addition transition state is 2.4 kcal/mol higher than that of 1,4-addition, and the calculated enthalpies of 1,2-addition is 4.36 kcal/mol more than that of 1,4-addition. For the Ti(IV) enolate 4 derived from α-diazo-β-keto phosphonates, in contrary, the free energy of the bridging chloride-controlled 1,2-addition transition state is 1.1 kcal/mol lower than that of 1,4-addition, and the calculated enthalpy of 1,2-addition is 3.46 kcal/mol less than that of 1,4-addition. Our findings demonstrate that the nucleophilic addition of these Ti(IV) enolates to conjugated enones was carried out not only kinetically but also irreversibly for the first time.     

K3PO4 promoted dipolar [3+3] cyclization: Direct synthesis of pyrazino[2,1-a]isoquinoline derivatives

A K₃PO₄ promoted dipolar [3+3] cyclization of dihydroisoquinoline imines and arylacyl bromides has been developed. This process realized the direct synthesis of pyrazino[2,1-a]isoquinoline derivatives in 44–69% yields. A head to tail dimerization was proposed as key step for this procedure.     

基于环己酮氧化脱氢构建碳-碳与碳-杂键

环己酮是一种廉价易得的大宗有机化工产品,被广泛用作有机合成反应的原料和中间体。脱氢芳构化是合成功能化芳烃的有效途径,使用环己酮作为反应底物,经过亲核加成、脱水和催化脱氢可以将非芳香的有机分子转化为芳香化合物。与传统的芳基化反应相比,该策略避免了苛刻的反应条件和含卤化合物的生产,克服了化学和区域选择性难以控制的难题,为功能化芳烃的合成提供了一条温和、环保的途径。本文就近年来以环己酮为原料,进行氧化脱氢、直接构建碳-碳和碳-杂键,及通过碳-杂键的形成合成杂环化合物的研究现状进行介绍。     

A Universal Organic Cathode for Ultrafast Lithium and Multivalent Metal Batteries

Low‐cost multivalent battery chemistries (Mg²⁺, Al³⁺) have been extensively investigated for large‐scale energy storage applications. However, their commercialization is plagued by the poor power density and cycle life of cathodes. A universal polyimides@CNT (PI@CNT) cathode is now presented that can reversibly store various cations with different valences (Li⁺, Mg²⁺, Al³⁺) at an extremely fast rate. The ion‐coordination charge storage mechanism of PI@CNT is systemically investigated. Full cells using PI@CNT cathodes and corresponding metal anodes exhibit long cycle life (>10000 cycles), fast kinetics (>20 C), and wide operating temperature range (?40 to 50 °C), making the low‐cost industrial polyimides universal cathodes for different multivalent metal batteries. The stable ion‐coordinated mechanism opens a new foundation for the development of high‐energy and high‐power multivalent batteries.     

5-二乙胺基-2-(吡啶-2’-亚氨甲基)苯酚的合成及其对Zn2+的识别

本文利用2-氨基吡啶与4-二乙胺基水杨醛反应合成了5-二乙胺基-2-(吡啶-2’-亚氨甲基)苯酚(探针L),对其结构进行了表征。在DMSO/Tris(6:4, v/v, pH =7.4)溶液中,探针L高选择性荧光“关-开”识别Zn₂₊,在365 nm紫外灯照射下,由无荧光变成蓝色荧光。实验表明,探针L与Zn₂₊的结合比为1:1,结合常数为2.6×10₃ L. mol_-1,检测限为 9.39×10_-7mol/L,pH适用范围为7-11,并可检测水样中的Zn₂₊。     

In vitro evaluation of secoiridoid glucosides from the fruits of Ligustrum lucidum as antiviral agents.

Six secoiridoid glucosides, lucidumoside C (1), oleoside dimethylester (2), neonuezhenide (3), oleuropein (4), ligustroside (5) and lucidumoside A (6), isolated from the fruits of Ligustrum lucidum (Oleaceae), were examined in vitro for their activities against four strains of pathogenic viruses, namely herpes simplex type I virus (HSV-1), influenza type A virus (Flu A), respiratory syncytial virus (RSV) and parainfluenza type 3 virus (Para 3). Antiviral activities were evaluated by the cytopathic effect (CPE) inhibitory assay. The purpose was to check if the antioxidative potency of these glucosides correlated with their antiviral potency. Results showed that none of the glucosides had any significant activity against HSV-1 and Flu A. Oleuropein, however, showed significant antiviral activities against RSV and Para 3 with IC50 value of 23.4 and 11.7 microg/ml, respectively. Lucidumoside C, oleoside dimethylester and ligustroside showed potent or moderate antiviral activities against Para 3 with IC50 values of 15.6-20.8 microg/ml. These results also documented that the anti-oxidative potency of these secoiriodoid glucosides was not directly related to their antiviral effects.