Substituent, temperature and solvent effects on tautomeric equilibria in several β-ketoamides have been investigated by means of nuclear magnetic resonance spectroscopy (NMR). Keto-enol equilibrium predominates over ...Substituent, temperature and solvent effects on tautomeric equilibria in several β-ketoamides have been investigated by means of nuclear magnetic resonance spectroscopy (NMR). Keto-enol equilibrium predominates over the amide-imidol one. The relative stability of the individual tautomers and the corresponding equilibrium shifts are explained considering electronic and steric effects and tautomer stabilization via internal hydrogen bonds. In solution, these compounds exist mainly as ketoamide and Z-enolamide tautomers, both presenting intramolecular hydrogen bonds.展开更多
Peroxynitrite(ONOO^(-))contributes to oxidative stress and neurodegeneration in Parkinson's disease(PD).Developing a peroxynitrite probe would enable in situ visualization of the overwhelming ONOO^(-)flux and unde...Peroxynitrite(ONOO^(-))contributes to oxidative stress and neurodegeneration in Parkinson's disease(PD).Developing a peroxynitrite probe would enable in situ visualization of the overwhelming ONOO^(-)flux and understanding of the ONOO^(-)stress-induced neuropathology of PD.Herein,a novelα-ketoamide-based fluorogenic probe(DFlu)was designed for ONOO^(-)monitoring in multiple PD models.The results demonstrated that DFlu exhibits a fluorescence turn-on response to ONOO^(-)with high specificity and sensitivity.The efficacy of DFlu for intracellular ONOO^(-)imaging was demonstrated systematically.The results showed that DFlu can successfully visualize endogenous and exogenous ONOO^(-)in cells derived from chemical and biochemical routes.More importantly,the two-photon excitation ability of DFlu has been well demonstrated by monitoring exogenous/endogenous ONOO^(-)production and scavenging in live zebraflsh PD models.This work provides a reliable and promisingα-ketoamide-based optical tool for identifying variations of ONOO^(-)in PD models.展开更多
A new series of quinoxaline 1,4-di-N-oxides were synthesized and evaluated for their antibacterial and antifungal activities. The best result was demonstrated by 3-amino-N-(4-methoxyphenyl)-2-quinoxalinecarboxamide 1,...A new series of quinoxaline 1,4-di-N-oxides were synthesized and evaluated for their antibacterial and antifungal activities. The best result was demonstrated by 3-amino-N-(4-methoxyphenyl)-2-quinoxalinecarboxamide 1,4-di-N-oxide 4e, MIC (0.24 μg/ml) against Aspergillus fumigatus, and (0.12 μg/ml) against Streptococcus pneumonia.展开更多
文摘Substituent, temperature and solvent effects on tautomeric equilibria in several β-ketoamides have been investigated by means of nuclear magnetic resonance spectroscopy (NMR). Keto-enol equilibrium predominates over the amide-imidol one. The relative stability of the individual tautomers and the corresponding equilibrium shifts are explained considering electronic and steric effects and tautomer stabilization via internal hydrogen bonds. In solution, these compounds exist mainly as ketoamide and Z-enolamide tautomers, both presenting intramolecular hydrogen bonds.
基金supported by the National Natural Science Foundation of China(22077101)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF023)+4 种基金Natural Science Foundation of Shaanxi Province(2022JM-130)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-008,2020GXLH-Z-021,2020GXLH-Z-023)the China Postdoctoral Science Foundation(2022M711595,2022M722595)Postdoctoral Research Funding Schemes of Jiangsu Province(2021K036A)The Natural Science Foundation of Ningbo(202003N4049,202003N4065).
文摘Peroxynitrite(ONOO^(-))contributes to oxidative stress and neurodegeneration in Parkinson's disease(PD).Developing a peroxynitrite probe would enable in situ visualization of the overwhelming ONOO^(-)flux and understanding of the ONOO^(-)stress-induced neuropathology of PD.Herein,a novelα-ketoamide-based fluorogenic probe(DFlu)was designed for ONOO^(-)monitoring in multiple PD models.The results demonstrated that DFlu exhibits a fluorescence turn-on response to ONOO^(-)with high specificity and sensitivity.The efficacy of DFlu for intracellular ONOO^(-)imaging was demonstrated systematically.The results showed that DFlu can successfully visualize endogenous and exogenous ONOO^(-)in cells derived from chemical and biochemical routes.More importantly,the two-photon excitation ability of DFlu has been well demonstrated by monitoring exogenous/endogenous ONOO^(-)production and scavenging in live zebraflsh PD models.This work provides a reliable and promisingα-ketoamide-based optical tool for identifying variations of ONOO^(-)in PD models.
文摘A new series of quinoxaline 1,4-di-N-oxides were synthesized and evaluated for their antibacterial and antifungal activities. The best result was demonstrated by 3-amino-N-(4-methoxyphenyl)-2-quinoxalinecarboxamide 1,4-di-N-oxide 4e, MIC (0.24 μg/ml) against Aspergillus fumigatus, and (0.12 μg/ml) against Streptococcus pneumonia.
