Redox-enzyme‐mediated electrochemical processes such as hydrogen production,nitrogen fixation,and CO_(2) reduction are at the forefront of the green chemistry revolution.To scale up,the inefficient two‐dimensional(2...Redox-enzyme‐mediated electrochemical processes such as hydrogen production,nitrogen fixation,and CO_(2) reduction are at the forefront of the green chemistry revolution.To scale up,the inefficient two‐dimensional(2D)immobilization of redox enzymes on working electrodes must be replaced by an efficient dense 3D system.Fabrication of 3D electrodes was demonstrated by embedding enzymes in polymer matrices.However,several requirements,such as simple immobilization,prolonged stability,and resistance to enzyme leakage,still need to be addressed.The study presented here aims to overcome these gaps by immobilizing enzymes in a supramolecular hydrogel formed by the self‐assembly of the peptide hydrogelator fluorenylmethyloxycarbonyldiphenylalanine.Harnessing the self‐assembly process avoids the need for tedious and potentially harmful chemistry,allowing the rapid loading of enzymes on a 3D electrode under mild conditions.Using the[FeFe]hydrogenase enzyme,high enzyme loads,prolonged resistance against electrophoresis,and highly efficient hydrogen production are demonstrated.Further,this enzyme retention is shown to arise from its interaction with the peptide nanofibrils.Finally,this method is successfully used to retain other redox enzymes,paving the way for a variety of enzyme‐mediated electrochemical applications.展开更多
An efficient greener one pot synthesis of dimethyl-dihydro-7H-chromeno[3, 2-h]quinolin-8(9H)-one derivatives has been synthesized through cyclization of aromatic aldehyde, dimidone and 8-hydroxy-quinoline through one-...An efficient greener one pot synthesis of dimethyl-dihydro-7H-chromeno[3, 2-h]quinolin-8(9H)-one derivatives has been synthesized through cyclization of aromatic aldehyde, dimidone and 8-hydroxy-quinoline through one-pot condensation method is described. The synthesized compounds are screened for further biological activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Bacillus using cut plate method and disc diffusion method.展开更多
文摘目的:观察加参方浸膏对过氧化氢(H_2O_2)诱导的H9c2心肌细胞凋亡的干预作用,并探讨其作用机制。方法:采用MTT法,考察400、200、100、50、25μmol/L的H_2O_2与3.0、1.8、0.9、0.3、0.1 mg/m L加参方浸膏对H9c2心肌细胞活性的影响。将H9c2心肌细胞分为正常组、模型组、加参方组,除正常组细胞加入相应培养基外,模型组、加参方组细胞均采用50μmol/L H_2O_2处理以诱导细胞发生氧化应激损伤,加参方组在模型组基础上加入0.3 mg/m L加参方浸膏干预处理。采用DAPI染色法,在荧光显微镜下观察细胞形态学变化;采用流式细胞仪检测细胞凋亡率;采用荧光定量逆转录-聚合酶链式反应法测定细胞中胱天蛋白酶3(Caspase-3)、Bax、Bcl-2 m RNA表达水平,Western Blot法测定Caspase-3、Bax、Bcl-2蛋白表达水平。结果:50μmol/L为H_2O_2最适造模浓度,0.3 mg/m L为加参方浸膏最适药物干预浓度。与模型组比较,加参方组细胞的形态改善,细胞凋亡率显著降低(P<0.05);Caspase-3、Bax m RNA及蛋白表达水平显著降低,Bcl-2 m RNA及蛋白表达水平显著升高(P<0.05)。结论:加参方浸膏对H_2O_2诱导的H9c2心肌细胞凋亡有显著的抑制作用,其机制可能与下调细胞中Caspase-3、Bax表达,上调Bcl-2表达有关。
基金Ministry of Energy,Israel,Grant/Award Numbers:219‐11‐120,222‐11‐065Israel Science Foundation,Grant/Award Number:GA 2185/17。
文摘Redox-enzyme‐mediated electrochemical processes such as hydrogen production,nitrogen fixation,and CO_(2) reduction are at the forefront of the green chemistry revolution.To scale up,the inefficient two‐dimensional(2D)immobilization of redox enzymes on working electrodes must be replaced by an efficient dense 3D system.Fabrication of 3D electrodes was demonstrated by embedding enzymes in polymer matrices.However,several requirements,such as simple immobilization,prolonged stability,and resistance to enzyme leakage,still need to be addressed.The study presented here aims to overcome these gaps by immobilizing enzymes in a supramolecular hydrogel formed by the self‐assembly of the peptide hydrogelator fluorenylmethyloxycarbonyldiphenylalanine.Harnessing the self‐assembly process avoids the need for tedious and potentially harmful chemistry,allowing the rapid loading of enzymes on a 3D electrode under mild conditions.Using the[FeFe]hydrogenase enzyme,high enzyme loads,prolonged resistance against electrophoresis,and highly efficient hydrogen production are demonstrated.Further,this enzyme retention is shown to arise from its interaction with the peptide nanofibrils.Finally,this method is successfully used to retain other redox enzymes,paving the way for a variety of enzyme‐mediated electrochemical applications.
文摘An efficient greener one pot synthesis of dimethyl-dihydro-7H-chromeno[3, 2-h]quinolin-8(9H)-one derivatives has been synthesized through cyclization of aromatic aldehyde, dimidone and 8-hydroxy-quinoline through one-pot condensation method is described. The synthesized compounds are screened for further biological activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Bacillus using cut plate method and disc diffusion method.
