We report the novel synthesis of azetidin-2-one derivatives containing aryl sulfonate moiety from the reaction of 2-hydroxy benzaldehyde with p-toluene sulfonyl chloride afforded firstly 2-formylphenyl 4-methylbenzene...We report the novel synthesis of azetidin-2-one derivatives containing aryl sulfonate moiety from the reaction of 2-hydroxy benzaldehyde with p-toluene sulfonyl chloride afforded firstly 2-formylphenyl 4-methylbenzene sulfonate (2). The compound (2) on reaction with p-aminobenzoic acid or 2-aminopyridine gave the corresponding aldimines (3). Furthermore, the aldimines are on reaction with chloroacetyl chloride gives corresponding azetidin-2-ones in good to moderate yield. Among the eight synthesized azetidin-2-ones, five selected compounds have been screened for the an-ti-inflammatory activity, few of them showed good anti-inflammatory activity compared with standard drugs. Anti- microbial activity of all synthesized compounds has been tested and most of the compounds showed good anti-bacterial and anti-fungal activities.展开更多
In the presence of catalytic amount of In（OTf）3 （10 mol%）, a series of aldimines reacted with tetraallyltin in a 2：1 molar ratio to afford the corresponding homoallylic amines in good yields. The good atom effici...In the presence of catalytic amount of In（OTf）3 （10 mol%）, a series of aldimines reacted with tetraallyltin in a 2：1 molar ratio to afford the corresponding homoallylic amines in good yields. The good atom efficiency was achieved under mild reaction conditions and a new protocol （allyl）4Sn/In（OTf）3 for simple imines was developed.展开更多
A series of structurally related diphenol aldimines (DPAs) were synthesized. These aldimines involve different substitution patterns of their phenolic groups, for the purpose of optimizing their ability to inhibit ATP...A series of structurally related diphenol aldimines (DPAs) were synthesized. These aldimines involve different substitution patterns of their phenolic groups, for the purpose of optimizing their ability to inhibit ATP synthase. The inhibitory effects of these DPA compounds were evaluated using purified F1 and membrane-bound F1F0 E. coli ATP synthase. Structure-activity relationship studies of these di-phenol compounds showed that maximum inhibition was achieved when both phenolic groups are either in the meta-positions (DPA-7, IC50 = 2.0 μM), or in the ortho-positions (DPA-9, IC50 = 5.0 μM). The lowest ATP synthase inhibition was found to be when the phenolic groups are both in the para-positions (DPA-2, IC50 = 100.0 μM). Results also show that the inhibitory effects of these compounds on ATPase are completely reversible. Identical inhibition patterns of both the purified F1 and the membrane bound F1F0 enzyme were observed. Study of E. coli cell growth showed that these diphenol aldimines effectively inhibit both ATP synthesis and cell growth.展开更多
L-Aspartateβ-decarboxylase from Acinetobacter radioresistens(ArASD)has been modifed to convert 3-methylaspartic acid into 2-aminobutyric acid,which activated a novel process for biosynthesis of 2-aminobutyric acid.Ho...L-Aspartateβ-decarboxylase from Acinetobacter radioresistens(ArASD)has been modifed to convert 3-methylaspartic acid into 2-aminobutyric acid,which activated a novel process for biosynthesis of 2-aminobutyric acid.However,the process is limited by the low activity of the ArASD.Here,the activity of ArASD was signifcantly improved by modifcation based on sequence alignment and structural analysis.The 38th residue of ArASD is speculated to be the key residue for regulating the conformation of the internal aldimine,and site-directed mutagenesis on R38 residue was carried out.A variant,K18A/R38K/V287I,with 2.2 times higher specifc activity was isolated.Molecular dynamics simulation indicated that the torsion angle of the imine bond of the variant decreased,which was benefcial to the protonation of the internal aldimine and the increase in the initial energy of the enzyme.Therefore,the energy barrier of the transition state was reduced,resulting in improved catalytic activity toward 3-methylaspartic acid.These results provide a reference and a new point of view for enzyme modifcation by increasing the energy of the initial state.展开更多
The rapid alkylation of methyl N-benzylidene glycinate with halides under microwave irradiation using solid-liquid phase transfer condition without solvent has been achieved wilhin only one minute. After hydrolysis o... The rapid alkylation of methyl N-benzylidene glycinate with halides under microwave irradiation using solid-liquid phase transfer condition without solvent has been achieved wilhin only one minute. After hydrolysis of alkylated products the corresponding α-amino acids were obtained in overall yield 43.6～62.5%.展开更多
文摘We report the novel synthesis of azetidin-2-one derivatives containing aryl sulfonate moiety from the reaction of 2-hydroxy benzaldehyde with p-toluene sulfonyl chloride afforded firstly 2-formylphenyl 4-methylbenzene sulfonate (2). The compound (2) on reaction with p-aminobenzoic acid or 2-aminopyridine gave the corresponding aldimines (3). Furthermore, the aldimines are on reaction with chloroacetyl chloride gives corresponding azetidin-2-ones in good to moderate yield. Among the eight synthesized azetidin-2-ones, five selected compounds have been screened for the an-ti-inflammatory activity, few of them showed good anti-inflammatory activity compared with standard drugs. Anti- microbial activity of all synthesized compounds has been tested and most of the compounds showed good anti-bacterial and anti-fungal activities.
基金the National Natural Science Foundation of China(Nos.20421202,20372033)for financialsupport.
文摘In the presence of catalytic amount of In（OTf）3 （10 mol%）, a series of aldimines reacted with tetraallyltin in a 2：1 molar ratio to afford the corresponding homoallylic amines in good yields. The good atom efficiency was achieved under mild reaction conditions and a new protocol （allyl）4Sn/In（OTf）3 for simple imines was developed.
文摘A series of structurally related diphenol aldimines (DPAs) were synthesized. These aldimines involve different substitution patterns of their phenolic groups, for the purpose of optimizing their ability to inhibit ATP synthase. The inhibitory effects of these DPA compounds were evaluated using purified F1 and membrane-bound F1F0 E. coli ATP synthase. Structure-activity relationship studies of these di-phenol compounds showed that maximum inhibition was achieved when both phenolic groups are either in the meta-positions (DPA-7, IC50 = 2.0 μM), or in the ortho-positions (DPA-9, IC50 = 5.0 μM). The lowest ATP synthase inhibition was found to be when the phenolic groups are both in the para-positions (DPA-2, IC50 = 100.0 μM). Results also show that the inhibitory effects of these compounds on ATPase are completely reversible. Identical inhibition patterns of both the purified F1 and the membrane bound F1F0 enzyme were observed. Study of E. coli cell growth showed that these diphenol aldimines effectively inhibit both ATP synthesis and cell growth.
基金This work was supported by National Key R&D Program of China(2017YFE0129600)the National Natural Science Foundation of China(21878125)the Priority Academic Program Development of Jiangsu Higher Education Institutions,the 111 Project(No.111-2-06).
文摘L-Aspartateβ-decarboxylase from Acinetobacter radioresistens(ArASD)has been modifed to convert 3-methylaspartic acid into 2-aminobutyric acid,which activated a novel process for biosynthesis of 2-aminobutyric acid.However,the process is limited by the low activity of the ArASD.Here,the activity of ArASD was signifcantly improved by modifcation based on sequence alignment and structural analysis.The 38th residue of ArASD is speculated to be the key residue for regulating the conformation of the internal aldimine,and site-directed mutagenesis on R38 residue was carried out.A variant,K18A/R38K/V287I,with 2.2 times higher specifc activity was isolated.Molecular dynamics simulation indicated that the torsion angle of the imine bond of the variant decreased,which was benefcial to the protonation of the internal aldimine and the increase in the initial energy of the enzyme.Therefore,the energy barrier of the transition state was reduced,resulting in improved catalytic activity toward 3-methylaspartic acid.These results provide a reference and a new point of view for enzyme modifcation by increasing the energy of the initial state.
文摘 The rapid alkylation of methyl N-benzylidene glycinate with halides under microwave irradiation using solid-liquid phase transfer condition without solvent has been achieved wilhin only one minute. After hydrolysis of alkylated products the corresponding α-amino acids were obtained in overall yield 43.6～62.5%.
