A new free recoverable and reusable mono-alkaloid-type ligand has been synthesized by a simple method. With highly polar groups, the ligand can be recycled and reused eight times to prepare ethyl （2R,3S）-2,3-dihydro...A new free recoverable and reusable mono-alkaloid-type ligand has been synthesized by a simple method. With highly polar groups, the ligand can be recycled and reused eight times to prepare ethyl （2R,3S）-2,3-dihydroxy-3-phenylpropionate with high yield and ee via asymmetric dihydroxylation （AD） reaction. C 2009 Sheng Yong Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
（R）-2-hydroxy-3-phenylpropionic acid （PIP,） is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bi...（R）-2-hydroxy-3-phenylpropionic acid （PIP,） is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bioconversion of phenylpyruvate （PPA） to PLA using whole recombinant Escherichia coli cells in a series of buffer/organic solvent systems. Octane was found to be the best organic solvent. The optimum volume ratio of the water phase to the n-octane phase, conversion temperature, substrate concentration, and cell concentration were 6：4, 40 ℃, 12.5 g/L, and 30 g/L wet cells, respectively. Under the optimized conditions, the average PLA productivity in the aqueous/ n-octane system was 30.69% higher than that in the aqueous system, and 32.31 g/L PLA was obtained with the use of a stirred reactor （2-L scale）. Taken together, our findings indicated that PLA biosynthesis was more efficient in an aqueous/n-octane biphasic system than in a monophasic aqueous system. The proposed biphasic system is an effective strategy for enhancing PLA yield and the biosynthesis of its analogues.展开更多
The chiral compound 5H-imidazol[2,3-b]isoquinoline-l-ethanol-5-one-1,2, 3, 10b-tetrahydro- β（S）-phenyl-3（S）-phenyl was synthesized from the direct condensation of 2- cyanophenyacetonitrile with optically active ...The chiral compound 5H-imidazol[2,3-b]isoquinoline-l-ethanol-5-one-1,2, 3, 10b-tetrahydro- β（S）-phenyl-3（S）-phenyl was synthesized from the direct condensation of 2- cyanophenyacetonitrile with optically active （S）-（＋）-2-phenylglycinol in chlorobenzene under dry, anaerobic conditions. ZnCl2 was used as a Lewis acid catalyst in this reaction, and the structure of this compound was determined by X-ray diffraction, NMR, MS and IR. Crystal data of the title compound： C25H22N2O2, Mr = 382.45, P 21 21 21, a = 5.341（5）, b = 16.735（5）, c = 22.129（5） A, γ = 90°, V = 1978（2）A^3, Z = 4, Dc = 1.284 g/cm^3, the final R = 0.0321 for 2269 observed reflections with I 〉 2 σ（I） and Rw = 0.0771 for all data.展开更多
基金supported by the National Natural Science Foundation of China(No.20572131,20842007)Natural Science Basic Research Plan in Shaanxi Province of China(No.SJ08-ZT02) for financial support.
文摘A new free recoverable and reusable mono-alkaloid-type ligand has been synthesized by a simple method. With highly polar groups, the ligand can be recycled and reused eight times to prepare ethyl （2R,3S）-2,3-dihydroxy-3-phenylpropionate with high yield and ee via asymmetric dihydroxylation （AD） reaction. C 2009 Sheng Yong Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金Project supported by the National Natural Science Foundation of China(Nos.31470092 and 31501459)the Natural Science Youth Foundation of Jiangsu Province(No.BK20130380)China
文摘（R）-2-hydroxy-3-phenylpropionic acid （PIP,） is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bioconversion of phenylpyruvate （PPA） to PLA using whole recombinant Escherichia coli cells in a series of buffer/organic solvent systems. Octane was found to be the best organic solvent. The optimum volume ratio of the water phase to the n-octane phase, conversion temperature, substrate concentration, and cell concentration were 6：4, 40 ℃, 12.5 g/L, and 30 g/L wet cells, respectively. Under the optimized conditions, the average PLA productivity in the aqueous/ n-octane system was 30.69% higher than that in the aqueous system, and 32.31 g/L PLA was obtained with the use of a stirred reactor （2-L scale）. Taken together, our findings indicated that PLA biosynthesis was more efficient in an aqueous/n-octane biphasic system than in a monophasic aqueous system. The proposed biphasic system is an effective strategy for enhancing PLA yield and the biosynthesis of its analogues.
文摘The chiral compound 5H-imidazol[2,3-b]isoquinoline-l-ethanol-5-one-1,2, 3, 10b-tetrahydro- β（S）-phenyl-3（S）-phenyl was synthesized from the direct condensation of 2- cyanophenyacetonitrile with optically active （S）-（＋）-2-phenylglycinol in chlorobenzene under dry, anaerobic conditions. ZnCl2 was used as a Lewis acid catalyst in this reaction, and the structure of this compound was determined by X-ray diffraction, NMR, MS and IR. Crystal data of the title compound： C25H22N2O2, Mr = 382.45, P 21 21 21, a = 5.341（5）, b = 16.735（5）, c = 22.129（5） A, γ = 90°, V = 1978（2）A^3, Z = 4, Dc = 1.284 g/cm^3, the final R = 0.0321 for 2269 observed reflections with I 〉 2 σ（I） and Rw = 0.0771 for all data.
