Chemoenzymatic Synthesis of Enantiopure Amino Alcohols from Simple Methyl Ketones

This study highlights the straight-forward synthesis of substituted 1,2-amino alcohols from simple and readily available aromatic methyl ketones. Starting from acetophenone derivatives, the straight-forward synthesis strategy involved an initial bromination of the alpha-positioned methyl group in the first step, followed by a simple hydrolysis to the hydroxyketone (2-hydroxyacetophenone). The hydroxylated intermediate was subsequently converted from Silicibacter pomeroyi to the final 1,2-amino alcohol by using the transaminase. The transaminase-catalyzed reaction proceeded with yields up to 62 % and always excellent enantiomeric excess of >99 %. Interestingly, the keto-enol-tautomerism of the hydroxyl ketone yields an unexpected amino alcohol isomer.     

PCCP-Catalyzed Synthesis of Tetrasubstituted Allenes Bearing Heteroaromatic Sulfenyl Group**

We report a Brønsted acid-catalyzed synthesis of tetrasubstituted allenyl compounds decorated with heterocyclic sulfenyl group. The reaction proceeds readily from available propargylic alcohols in the presence of pentacarboxycyclopenatadienes (PCCPs) as organocatalysts. The developed strategy provides tetrasubstituted allene derivatives in high yields (from 55 to 98 %) and under mild reaction conditions.     

Super-Strong Hydrogel Composites Reinforced with PBO Nanofibers for Cartilage Replacement

Cartilage replacement materials exhibiting a set of demanding properties such as high water content, high mechanical stiffness, low friction, and excellent biocompatibility are quite difficult to achieve. Here, poly(p-phenylene-2,6-benzobisoxazole) (PBO) nanofibers are combined with polyvinyl alcohol (PVA) to form a super-strong structure with a performance that surpasses the vast majority of previously existing hydrogels. PVA–PBO composites with water contents in the 59–76% range exhibit tensile and compressive moduli reaching 20.3 and 4.5 MPa, respectively, and a coefficient of friction below 0.08. Further, they are biocompatible and support the viability of chondrocytes for 1 week, with significant improvements in cell adhesion, proliferation, and differentiation compared to PVA. The new composites can be safely sterilized by steam heat or gamma radiation without compromising their integrity and overall performance. In addition, they show potential to be used as local delivery platforms for anti-inflammatory drugs. These attractive features make PVA–PBO composites highly competitive engineered materials with remarkable potential for use in the design of load-bearing tissues. Complementary work has also revealed that these composites will be interesting alternatives in other industrial fields where high thermal and mechanical resistance are essential requirements, or which can take advantage of the pH responsiveness functionality.     

Catalytic transfer hydrogenation of biomass-derived furfural to furfuryl alcohol with formic acid as hydrogen donor over CuCs-MCM catalyst

Catalytic transfer hydroge nation(CTH) of furfural(FF) to furfu ryl alcohol(FFA) has received great intere st in recent years.He rein,Cu-Cs bimetallic supported catalyst,CuCs(2)-MCM,was developed for the CTH of FF to FFA using formic as hydrogen donor.CuCs(2)-MCM achieved a 99.6% FFA yield at an optimized reaction conditions of 170℃,1 h.Cu species in CuCs(2)-MCM had dual functions in catalytically decomposing formic acid to generate hydrogen and hydrogenating FF to FFA.The doping of Cs made the size of Cu particles smaller and improved the dispersion of the Cu active sites.Impo rtantly,the Cs species played a favorable role in enhancing the hydrogenation activity as a promoter by adjusting the surface acidity of Cu species to an appropriate level.Correlation analysis showed that surface acidity is the primary factor to affect the catalytic activity of CuCs(2)-MCM.     

CBS还原合成手性1-苯乙醇实验设计*

将学科热点之一催化不对称合成策略引入实验教学中,通过CBS还原制备手性醇。实验以苯乙酮为原料,还原得到粗产物手性1-苯乙醇,经制备色谱仪分离提纯,气相色谱和自动旋光仪表征产物的光学性质。实验为综合型有机化学实验,通过此实验,学生在掌握手性醇合成原理与方法的同时,进一步学习手套箱、气相色谱、制备色谱仪、自动旋光仪等新技术,以提升学生综合科研素质。     

Enhanced Electrocatalytic Activity of Methanol and Ethanol Oxidation in Alkaline Medium at Bimetallic Nanoparticles Electrochemically Decorated Fullerene-C60 Nanocomposite Electrocatalyst: An Efficient Anode Material for Alcohol Fuel Cell Applications

Direct alcohol fuel cells (DAFCs) have been recently playing a pivotal role in electrochemical energy sources and portable electronics. Research in DAFCs has proceeded to engage major attention due to their high catalytic activity, long-term stability, portability, and low cost. Herein, we present a facile surfactant-free route to anchor bimetallic Pd−W nanoparticles supported fullerene-C₆₀ catalyst (Pd-W@Fullerene-C₆₀) for high-performance electrooxidation of alcohols (methanol & ethanol) for DAFCs applications. Structural, elemental composition, and morphological analysis of the proposed catalyst were carried out using UV-Vis spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy-dispersive x-ray spectroscopy (EDX). Electrochemical properties such as electrochemical activity, electrochemical active surface area (ECSA), and long-term stability of the Pd-W@Fullerene-C₆₀ catalyst for ethanol and methanol oxidation in the alkaline medium were explored by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA). Results revealed that the proposed catalyst showed enlarged ECSA, tremendous electrocatalytic activity, high poison tolerance limit, good reproducibility, and enhanced long-term stability as compared to the monometallic catalyst and commercially available catalyst (Pt/C) towards ethanol and methanol oxidation reaction. This enhanced potentiality of the Pd-W@Fullerene-C₆₀ catalyst is due to the synergistic effect of W−Pd nanoparticles and excellent electron kinetic from fullerene support material. These findings strongly suggest the Pd-W@Fullerene-C₆₀ catalyst as potential anode material for the alcohol oxidation reaction.     

A Novel Dual Drug Approach That Combines Ivermectin and Dihydromyricetin (DHM) to Reduce Alcohol Drinking and Preference in Mice

Alcohol use disorder (AUD) affects over 18 million people in the US. Unfortunately, pharmacotherapies available for AUD have limited clinical success and are under prescribed. Previously, we established that avermectin compounds (ivermectin [IVM] and moxidectin) reduce alcohol (ethanol/EtOH) consumption in mice, but these effects are limited by P-glycoprotein (Pgp/ABCB1) efflux. The current study tested the hypothesis that dihydromyricetin (DHM), a natural product suggested to inhibit Pgp, will enhance IVM potency as measured by changes in EtOH consumption. Using a within-subjects study design and two-bottle choice study, we tested the combination of DHM (10 mg/kg; i.p.) and IVM (0.5–2.5 mg/kg; i.p.) on EtOH intake and preference in male and female C57BL/6J mice. We also conducted molecular modeling studies of DHM with the nucleotide-binding domain of human Pgp that identified key binding residues associated with Pgp inhibition. We found that DHM increased the potency of IVM in reducing EtOH consumption, resulting in significant effects at the 1.0 mg/kg dose. This combination supports our hypothesis that inhibiting Pgp improves the potency of IVM in reducing EtOH consumption. Collectively, we demonstrate the feasibility of this novel combinatorial approach in reducing EtOH consumption and illustrate the utility of DHM in a novel combinatorial approach.     

从《世阿弥传书》到《匠明》:能乐观演空间尺度体系的传承与演变

利用酰胺化反应在2,2,6,6-四甲基哌啶-1-氧自由基(TEMPO)分子的4位引入乙酰氨基和异烟酰氨基分别获得Acet-TEMPO和isoNTA-TEMPO分子.将Acet-TEMPO、 isoNTA-TEMPO和TEMPO分别与MIL-101(Fe)组成共催化体系,以苯甲醇选择性氧化为苯甲醛做模型反应,研究上述3种催化体系的催化性能.催化结果表明3种催化体系的催化活性顺序为:MIL-101(Fe)/isoNTA-TEMPO MIL-101(Fe)/Acet-TEMPOMIL-101(Fe)/TEMPO.通过对比实验和吸附实验表明isoNTA-TEMPO的吡啶官能团与MIL-101(Fe)的Fe簇配位作用是提高体系催化性能的关键因素.MIL-101(Fe)/isoNTA-TEMPO催化体系对各种芳香醇均表现出较好的催化性能,且催化剂能循环回收利用.     

芳烃酰基化后还原制备芳香醇的工艺进展

芳烃制备高附加值精细化学品芳香醇(9-芴甲醇),一直以来存在产物选择性低以及合成成本高等问题。基于此,本文主要综述了芳烃酰基化后还原合成芳香醇的工艺,包括第一步采用Friedel-Crafts酰基化反应、Vilsmeier-Haack反应、Reimer-Tiemann反应、Duff反应等过程将芳烃酰基化合成芳香醛/酮;第二步通过金属氢化物还原、催化加氢还原、活泼金属还原、Cannizarro反应、Meerwein-Ponndorf-Verley还原反应等过程将芳香醛/酮还原合成芳香醇。在总结和归纳各种工艺过程优缺点的基础上,提出了合理的芳香醇制备工艺,为9-芴甲醇产业化制备技术的开发提供帮助。     

Anti-atherosclerotic activity of Betulinic acid loaded polyvinyl alcohol/methylacrylate grafted Lignin polymer in high fat diet induced atherosclerosis model rats

Betulinic acid is one such natural pentacyclic triterpenoid compound, holding various pharmacological properties but its poor bioavailability is the only limitation. One of the biological macromolecules such as Lignin is a plant-derived aromatic, eco-friendly and low-cost polymer that certainly self-assembles into nano-sized colloids. Therefore, onto the current investigation, we increased the bioavailability of betulinic acid by coating on to a nanopolymer prepared with poly vinyl alcohol, lignins and methyl acrylate. Betulinic acid loaded polyvinyl alcohol/ethylacrylate grafted Lignin polymer (PVA/Lig-g-MA) nanoformulation was characterized using FTIR, XRD, SEM and TEM analysis and also the drug entrapment, in vitro drug releasing capacity was done to examine the efficiency of the nanoformulation of a drug. The MTT assay was evaluated the cytotoxicity of synthesized nanoformulation against normal endothelial cells HUVEC and HAPEC to confirm the side effects of the drug. The anti-atherosclerotic property of the nanoformulation was ascertained in both in vitro condition (with HUVEC and HPAEC) and in vivo studies (with Wistar rats). As a result, the characterization studies and in vitro studies clearly confirmed the Betulinic acid loaded PVA/Lig-g-MA nanoformulation is an ideal nanopolymer and it doesn’t cause any cytotoxic effect in normal endothelial cells. It also decreased the lipopolysaccharides induced inflammation through the down-regulation of NFκB and MAP/JNK signaling molecule expressions. Following in vivo results confirmed the synthesized nanoformulation effectively decreased the hyperchlostremia, inflammation and vasoconstriction, which induced over high fat diet. The results of histopathological analysis of cardiac tissues also confirmed the cardioprotective role of synthesized nanoformulation. Overall, both the in vitro and in vivo studies authentically proven the Betulinic acid loaded PVA/Lig-g-MA nanoformulation would be a potent cost effective anti-atherosclerotic nanodrug.