A facile procedure for the synthesis of 3-（2′-amino-3′-cyano-4′-arylpyrid-6′-yl） coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out...A facile procedure for the synthesis of 3-（2′-amino-3′-cyano-4′-arylpyrid-6′-yl） coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out on microwave irradiation in good yield with short time and easy work-up. The structures of all the compounds have been confirmed on the basis of their analytical, IR, ^1H NMR, and mass spectral data.展开更多
Coumarins occupy an important place in the realm of natural products and synthetic organic chemistry. A fast and highly efficient green method for synthesizing 3-aryl coumarin derivatives from salicylaldehyde and phen...Coumarins occupy an important place in the realm of natural products and synthetic organic chemistry. A fast and highly efficient green method for synthesizing 3-aryl coumarin derivatives from salicylaldehyde and phenyl acetyl chloride in the presence of tetrahydrofuran and K2CO3 using ultrasound irradiation is reported. Ultrasound assisted reactions have resulted in better yields and faster reaction time of the desired products than when prepared under conventional conditions. The resulting coumarin derivatives were characterized by IR spectrum.展开更多
A new angelol-type coumarin glucoside, 6-[（1R,2R）-1, 2-dihydroxy-3-β-D-glucosyloxy-3-methylbutyl]-7-methoxycoumarin, was isolated from the roots of Angelica pubescens. Its structure was elucidated on the basis of s...A new angelol-type coumarin glucoside, 6-[（1R,2R）-1, 2-dihydroxy-3-β-D-glucosyloxy-3-methylbutyl]-7-methoxycoumarin, was isolated from the roots of Angelica pubescens. Its structure was elucidated on the basis of spectral analysis.展开更多
AIM： To compare three kinds of fluorescent probes for in vitro labeling and in vivo tracking of endothelial progenitor cells（EPCs） in a mouse model of laser-induced retinal injury.METHODS： EPCs were isolated from ...AIM： To compare three kinds of fluorescent probes for in vitro labeling and in vivo tracking of endothelial progenitor cells（EPCs） in a mouse model of laser-induced retinal injury.METHODS： EPCs were isolated from human umbilical cord blood mononuclear cells and labeled with three different fluorescent probes： 5-（and-6）-carboxyfluorescein diacetate succinimidyl ester（CFSE）, 1,1′-dilinoleyl-3,3,3′,3′-tetramethylindo-carbocyanine perchlorate linked acetylated low-density lipoprotein（Di I-Ac LDL）, and green fluorescent protein（GFP）. The fluorescent intensity of EPCs was examined by confocal microscopy. Survival rate of labeled EPCs was calculated with trypan blue staining, and their adhesive capability was assessed. A mouse model of retinal injury was induced by laser, and EPCs were injected into the vitreous cavity. Frozen section and fluorescein angiography on flat-mounted retinal samples was employed to track the labeled EPCs in vivo.RESULTS： EPCs labeled with CFSE and Di I-Ac LDL exhibited an intense green and red fluorescence at the beginning; the fluorescence intensity decreased gradually to 20.23% and 49.99% respectively, after 28 d. On the contrary, the florescent intensity of GFP-labeled EPCs increased in a time-dependent manner. All labeled EPCs showed normal morphology and no significant change in survival and adhesive capability. In the mouse model, transplantation of EPCs showed a protective effect against retinal injury. EPCs labeled with CFSE and Di I-Ac LDL were successfully tracked in mice during the development of retinal injury and repair; however, GFP-labeled EPCs were not detected in the laser-injured mouse retina.CONCLUSION： The three fluorescent markers used in this study have their own set of advantages and disadvantages. CFSE and Di I-Ac LDL are suitable for short-term EPClabeling, while GFP should be used for long-term labeling. The choice of fluorescent markers should be guided by the purpose of the study.展开更多
Lysine-ε-acetylation(Kac)is a post-translational modification(PTM)that is critical for metabolic regulation and cell signaling in mammals.However,its prevalence and importance in plants remain to be determined.Employ...Lysine-ε-acetylation(Kac)is a post-translational modification(PTM)that is critical for metabolic regulation and cell signaling in mammals.However,its prevalence and importance in plants remain to be determined.Employing high-resolution tandem mass spectrometry,we analyzed protein lysine acetylation in five representative Arabidopsis organs with 2~3 biological replicates per organ.A total of 2887 Kac proteins and 5929 Kac sites were identified.This comprehensive catalog allows us to analyze proteome-wide features of lysine acetylation.We found that Kac proteins tend to be more uniformly expressed in different organs,and the acetylation status exhibits little correlation with the gene expression level,indicating that acetylation is unlikely caused by stochastic processes.Kac preferentially targets evolutionarily conserved proteins and lysine residues,but only a small percentage of Kac proteins are orthologous between rat and Arabidopsis.A large portion of Kac proteins overlap with proteins modified by other PTMs including ubiquitination,SUMOylation and phosphorylation.Although acetylation,ubiquitination and SUMOylation all modify lysine residues,our analyses show that they rarely target the same sites.In addition,we found that“reader”proteins for acetylation and phosphorylation,i.e.,bromodomain-containing proteins and GRF(General Regulatory Factor)/14-3-3 proteins,are intensively modified by the two PTMs,suggesting that they are main crosstalk nodes between acetylation and phosphorylation signaling.Analyses of GRF6/14-3-3λreveal that the Kac level of GRF6 is decreased under alkaline stress,suggesting that acetylation represses plant alkaline response.Indeed,K56ac of GRF6 inhibits its binding to and subsequent activation of the plasma membrane H+-ATPase AHA2,leading to hypersensitivity to alkaline stress.These results provide valuable resources for protein acetylation studies in plants and reveal that protein acetylation suppresses phosphorylation output by acetylating GRF/14-3-3 proteins.展开更多
基金the Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials for financial support(No.JSKC07041).
文摘A facile procedure for the synthesis of 3-（2′-amino-3′-cyano-4′-arylpyrid-6′-yl） coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out on microwave irradiation in good yield with short time and easy work-up. The structures of all the compounds have been confirmed on the basis of their analytical, IR, ^1H NMR, and mass spectral data.
文摘Coumarins occupy an important place in the realm of natural products and synthetic organic chemistry. A fast and highly efficient green method for synthesizing 3-aryl coumarin derivatives from salicylaldehyde and phenyl acetyl chloride in the presence of tetrahydrofuran and K2CO3 using ultrasound irradiation is reported. Ultrasound assisted reactions have resulted in better yields and faster reaction time of the desired products than when prepared under conventional conditions. The resulting coumarin derivatives were characterized by IR spectrum.
基金the Jiangsu Province Basic Facility Project(Nos.:BM2006104,BM2006507).
文摘A new angelol-type coumarin glucoside, 6-[（1R,2R）-1, 2-dihydroxy-3-β-D-glucosyloxy-3-methylbutyl]-7-methoxycoumarin, was isolated from the roots of Angelica pubescens. Its structure was elucidated on the basis of spectral analysis.
基金Supported by the National Natural Science Foundation of China(No.81400403)the International Science and Technology Cooperation Program of Jilin Province(No.20110733)the Technology Program of Soochow City(No.SYS201375)
文摘AIM： To compare three kinds of fluorescent probes for in vitro labeling and in vivo tracking of endothelial progenitor cells（EPCs） in a mouse model of laser-induced retinal injury.METHODS： EPCs were isolated from human umbilical cord blood mononuclear cells and labeled with three different fluorescent probes： 5-（and-6）-carboxyfluorescein diacetate succinimidyl ester（CFSE）, 1,1′-dilinoleyl-3,3,3′,3′-tetramethylindo-carbocyanine perchlorate linked acetylated low-density lipoprotein（Di I-Ac LDL）, and green fluorescent protein（GFP）. The fluorescent intensity of EPCs was examined by confocal microscopy. Survival rate of labeled EPCs was calculated with trypan blue staining, and their adhesive capability was assessed. A mouse model of retinal injury was induced by laser, and EPCs were injected into the vitreous cavity. Frozen section and fluorescein angiography on flat-mounted retinal samples was employed to track the labeled EPCs in vivo.RESULTS： EPCs labeled with CFSE and Di I-Ac LDL exhibited an intense green and red fluorescence at the beginning; the fluorescence intensity decreased gradually to 20.23% and 49.99% respectively, after 28 d. On the contrary, the florescent intensity of GFP-labeled EPCs increased in a time-dependent manner. All labeled EPCs showed normal morphology and no significant change in survival and adhesive capability. In the mouse model, transplantation of EPCs showed a protective effect against retinal injury. EPCs labeled with CFSE and Di I-Ac LDL were successfully tracked in mice during the development of retinal injury and repair; however, GFP-labeled EPCs were not detected in the laser-injured mouse retina.CONCLUSION： The three fluorescent markers used in this study have their own set of advantages and disadvantages. CFSE and Di I-Ac LDL are suitable for short-term EPClabeling, while GFP should be used for long-term labeling. The choice of fluorescent markers should be guided by the purpose of the study.
基金supported by National Natural Science Foundation of China(31922008)the Strategic Priority Research Program of CAS(XDB27040108)+1 种基金Chinese Academy of Sciences(YIPA Y201844)Shanghai Municipal Science and Technology Commission(17391900200 and 18395801200)to Heng Zhang.
文摘Lysine-ε-acetylation(Kac)is a post-translational modification(PTM)that is critical for metabolic regulation and cell signaling in mammals.However,its prevalence and importance in plants remain to be determined.Employing high-resolution tandem mass spectrometry,we analyzed protein lysine acetylation in five representative Arabidopsis organs with 2~3 biological replicates per organ.A total of 2887 Kac proteins and 5929 Kac sites were identified.This comprehensive catalog allows us to analyze proteome-wide features of lysine acetylation.We found that Kac proteins tend to be more uniformly expressed in different organs,and the acetylation status exhibits little correlation with the gene expression level,indicating that acetylation is unlikely caused by stochastic processes.Kac preferentially targets evolutionarily conserved proteins and lysine residues,but only a small percentage of Kac proteins are orthologous between rat and Arabidopsis.A large portion of Kac proteins overlap with proteins modified by other PTMs including ubiquitination,SUMOylation and phosphorylation.Although acetylation,ubiquitination and SUMOylation all modify lysine residues,our analyses show that they rarely target the same sites.In addition,we found that“reader”proteins for acetylation and phosphorylation,i.e.,bromodomain-containing proteins and GRF(General Regulatory Factor)/14-3-3 proteins,are intensively modified by the two PTMs,suggesting that they are main crosstalk nodes between acetylation and phosphorylation signaling.Analyses of GRF6/14-3-3λreveal that the Kac level of GRF6 is decreased under alkaline stress,suggesting that acetylation represses plant alkaline response.Indeed,K56ac of GRF6 inhibits its binding to and subsequent activation of the plasma membrane H+-ATPase AHA2,leading to hypersensitivity to alkaline stress.These results provide valuable resources for protein acetylation studies in plants and reveal that protein acetylation suppresses phosphorylation output by acetylating GRF/14-3-3 proteins.
