4199-09-1Relevant articles and documents
Engineering of an epoxide hydrolase for efficient bioresolution of bulky pharmaco substrates
Kong, Xu-Dong,Yuan, Shuguang,Li, Lin,Chen, She,Xu, Jian-He,Zhou, Jiahai
, p. 15717 - 15722 (2014)
Optically pure epoxides are essential chiral precursors for the production of (S)-propranolol, (S)-alprenolol, and other β-adrenergic receptor blocking drugs. Although the enzymatic production of these bulky epoxides has proven difficult, here we report a method to effectively improve the activity of BmEH, an epoxide hydrolase from Bacillus megaterium ECU1001 toward α-naphthyl glycidyl ether, the precursor of (S)-propranolol, by eliminating the steric hindrance near the potential product-release site. Using X-ray crystallography, mass spectrum, and molecular dynamics calculations, we have identified an active tunnel for substrate access and product release of this enzyme. The crystal structures revealed that there is an independent product-release site in BmEH that was not included in other reported epoxide hydrolase structures. By alanine scanning, two mutants, F128A and M145A, targeted to expand the potential product-release site displayed 42 and 25 times higher activities toward α-naphthyl glycidyl ether than the wild-type enzyme, respectively. These results show great promise for structure-based rational design in improving the catalytic efficiency of industrial enzymes for bulky substrates. epoxide hydrolase X-ray crystallography protein engineering product release bulky substrate We are grateful for access to beamline BL17U1 at Shanghai Synchrotron Radiation Facility and thank the beamline staff for technical support. We also thank Dr. Peter K. Park and Profs. Zhihong Guo and Ran Hong for helpful discussions. This work was supported by National Program on Key Basic Research of China Grant 2011CB710800 (to J.-H.X. and J.Z.), National Grand Project for Medicine Innovation Grant 2012ZX10002006 (to J.Z.), National Natural Science Foundation of China Grant 21276082 (to J.-H.X.), and a grant from the Open Fund from the State Key Laboratory of Bioreactor Engineering (to J.Z.).
Optical resolution and optimization of (R, S) - Propranolol using dehydroabietic acid via diastereomeric crystallization
Ge, Li,Zhao, Qiongqiong,Yang, Kedi,Liu, Shishi,Xia, Fan
, p. 131 - 136 (2015)
The optical resolution of (R, S)-propranolol by the diastereomeric crystallization method was successfully performed using dehydroabietic acid (DHAA) as the resolving agent in methanol. The three important parameters: DHAA amount, solvent (methanol) amount, and crystallization temperature of diastereomeric salts were optimized employing the response surface methodology (RSM). When maintaining a lower limit of 95% for the purity of (S)-propranolol, the optimal resolution conditions were a DHAA/(R, S)-propranolol molar ratio of 1.1, solvent/(R, S)-propranolol ratio of 16.2 mL.g-1, and crystallization temperature of -5°C. The desired (S)-propranolol was prepared with 94.8% optical purity and 72.2% yield under the optimal conditions.
Kinetic resolution of propranolol by a lipase-catalyzed N-acetylation
Chiou, Tzyy-Wen,Chang, Cheng-Chi,Lai, Chung-Torr,Tai, Dar-Fu
, p. 433 - 436 (1997)
An enzymatic method for the direct resolution of propranolol is described. Candida cylindracea lipase enantioselectively catalyzed N-acetylation of S-propranolol with isopropenyl acetate in isopropyl ether. The ee values of the two enantiomers of N-acetylpropranolol were determined by an HPLC equipped with a chiral column. The effects of organic solvent nature and substrate concentration on enantioselectivity were also studied.
THE SYNTHESIS OF E-(2S,3S)-3-TRIMETHYLSILYLGLYCIDOL AND ITS CONVERSION TO (-)-PROPRANOLOL
Katsuki, Tsutomu
, p. 2821 - 2822 (1984)
(-)-Propranolol was synthesized in a highly enantio- and regioselective manner by using titanium mediated asymmetric epoxidation via the key intermediate, E-(2S,3S)-3-trimethylsilylglycidol.
Preparation of a novel hydroxypropyl-γ-cyclodextrin functionalized monolith for separation of chiral drugs in capillary electrochromatography
Deng, Miaoduo,Xue, Mengyao,Liu, Yanru,Zhao, Min
, p. 188 - 195 (2021/02/26)
In this study, a novel hydroxypropyl-γ-cyclodextrin (HP-γ-CD) functionalized monolithic capillary column was prepared by one-pot sequential strategy and used for chiral separation in capillary electrochromatography for the first time. In one pot, GMA-HP-γ-CD as functional monomer was allowed to be formed via the ring opening reaction between HP-γ-CD and glycidyl methacrylate (GMA) catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and then copolymerized directly with ethylene dimethacrylate (EDMA) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) in the presence of porogenic solvents via thermally initiated free radical polymerization. The preparation conditions of monoliths were optimized. Enantiomer separations of six chiral drugs including pindolol, clorprenaline, tulobuterol, clenbuterol, propranolol, and tropicamide were achieved on the monolith. Among them, pindolol, clorprenaline, and tropicamide were baseline separated with resolution values of 1.62, 1.73, and 1.55, respectively. The mechanism of enantiomer separation was discussed by comparison of the HP-γ-CD and HP-β-CD functionalized monoliths.
Preparation and evaluation of a triazole-bridged bis(β-cyclodextrin)–bonded chiral stationary phase for HPLC
Shuang, Yazhou,Liao, Yuqin,Wang, Hui,Wang, Yuanxing,Li, Laisheng
, p. 168 - 184 (2019/11/25)
A triazole-bridged bis(β-cyclodextrin) was synthesized via a high-yield Click Chemistry reaction between 6-azido-β-cyclodextrin and 6-propynylamino-β-cyclodextrin, and then it was bonded onto ordered silica gel SBA-15 to obtain a novel triazole-bridged bis (β-cyclodextrin)–bonded chiral stationary phase (TBCDP). The structures of the bridged cyclodextrin and TBCDP were characterized by the infrared spectroscopy, mass spectrometry, elemental analysis, and thermogravimetric analysis. The chiral performance of TBCDP was evaluated by using chiral pesticides and drugs as probes including triazoles, flavanones, dansyl amino acids and β-blockers. Some effects of the composition in mobile phase and pH value on the enantioseparations were investigated in different modes. The nine triazoles, eight flavanones, and eight dansyl amino acids were successfully resolved on TBCDP under the reversed phase with the resolutions of hexaconazole, 2′-hydroxyflavanone, and dansyl-DL-tyrosine, which were 2.49, 5.40, and 3.25 within 30 minutes, respectively. The ten β-blockers were also separated under the polar organic mode with the resolution of arotinolol reached 1.71. Some related separation mechanisms were discussed preliminary. Compared with the native cyclodextrin stationary phase (CDSP), TBCDP has higher enantioselectivity to separate more analytes, which benefited from the synergistic inclusion ability of the two adjacent cavities and bridging linker of TBCDP, thereby enabling it a promising prospect in chiral drugs and food analysis.
Enantioseparation of mandelic acid on vancomycin column: Experimental and docking study
Shahnani, Mostafa,Sefidbakht, Yahya,Maghari, Shokoofeh,Mehdi, Ahmad,Rezadoost, Hassan,Ghassempour, Alireza
supporting information, p. 1289 - 1298 (2020/08/19)
So far, no detailed view has been expressed regarding the interactions between vancomycin and racemic compounds including mandelic acid. In the current study, a chiral stationary phase was prepared by using 3-aminopropyltriethoxysilane and succinic anhydride to graft carboxylated silica microspheres and subsequently by activating the carboxylic acid group for vancomycin immobilization. Characterization by elemental analysis, Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance, and thermogravimetric analysis demonstrated effective functionalization of the silica surface. R and S enantiomers of mandelic acid were separated by the synthetic vancomycin column. Finally, the interaction between vancomycin and R/S mandelic acid enantiomers was simulated by Auto-dock Vina. The binding energies of interactions between R and S enantiomers and vancomycin chiral stationary phase were different. In the most probable interaction, the difference in mandelic acid binding energy was approximately 0.2 kcal/mol. In addition, circular dichroism spectra of vancomycin interacting with R and S enantiomers showed different patterns. Therefore, R and S mandelic acid enantiomers may occupy various binding pockets and interact with different vancomycin functions. These observations emphasized the different retention of R and S mandelic acid enantiomers in vancomycin chiral column.
Preparation of polar group derivative β-cyclodextrin bonded hydride silica chiral stationary phases and their chromatography separation performances
Zhao, Baojing,Li, Lan,Wang, Yuting,Zhou, Zhiming
, p. 643 - 649 (2018/11/27)
Three novel β-cyclodextrin compounds derived with piperidine which is flexible, L-proline containing a chiral center, ionic liquid with 3,5-diamino-1,2,4-triazole as the cation were designed and synthesized as chiral selectors for enantiomer separation, whose name were (mono-6-deoxy-6-(piperidine)-β-cyclodextrin, mono-6-deoxy-6-(L-proline)-β-cyclodextrin, mono-6-deoxy-6-(3,5-diamino-1,2,4-triazole)-β-cyclodextrin, multi-substituted 3,5-diamino-1,2,4- triazole-(p-toluenesulfonic)-β-cyclodextrin), respectively. In addition, to enhance the polarity of chiral stationary phases, hydrosilylation and silylation reactions were implemented to derive ordinary silica, the common used selector carrier, to hydride silica, whose surface is covered with proton. 31 pyrrolidine compounds and some chiral drugs were tested in both polar organic mobile phase mode and normal mobile phase mode. 6-Deoxy-6-L-proline-β-cyclodextrin-CSP showed satisfactory separations in polar organic mobile phase mode and exihibited a strong separation capability in different pH values; multi-substituted 3,5-diamino-1,2,4-triazole-(p-toluenesulfonic)-β-cyclodextrin-CSP can separate pyrrolidine compounds in both mobile phase modes with high resolutions and separation efficiency compared to commercially available CSPs, making it to be the most valuable object to study. The composition of mobile phase, type of stationary phase as well as the peak problem of chromatograms was discussed deeply.
Enantioseparation of chiral pharmaceuticals by vancomycin-bonded stationary phase and analysis of chiral recognition mechanism
Li, Jiaxi,Liu, Ruixia,Wang, Liyang,Liu, Xiaoling,Gao, Hongjie
, p. 236 - 247 (2019/02/01)
The drug chirality is attracting increasing attention because of different biological activities, metabolic pathways, and toxicities of chiral enantiomers. The chiral separation has been a great challenge. Optimized high-performance liquid chromatography (HPLC) methods based on vancomycin chiral stationary phase (CSP) were developed for the enantioseparation of propranolol, atenolol, metoprolol, venlafaxine, fluoxetine, and amlodipine. The retention and enantioseparation properties of these analytes were investigated in the variety of mobile phase additives, flow rate, and column temperature. As a result, the optimal chromatographic condition was achieved using methanol as a main mobile phase with triethylamine (TEA) and glacial acetic acid (HOAc) added as modifiers in a volume ratio of 0.01% at a flow rate of 0.3?mL/minute and at a column temperature of 5°C. The thermodynamic parameters (eg, ΔH, ΔΔH, and ΔΔS) from linear van 't Hoff plots revealed that the retention of investigated pharmaceuticals on vancomycin CSP was an exothermic process. The nonlinear behavior of lnk′ against 1/T for propranolol, atenolol, and metoprolol suggested the presence of multiple binding mechanisms for these analytes on CSP with variation of temperature. The simulated interaction processes between vancomycin and pharmaceutical enantiomers using molecular docking technique and binding energy calculations indicated that the calculated magnitudes of steady combination energy (ΔG) coincided with experimental elution order for most of these enantiomers.
HPLC with cellulose Tris (3,5-DimethylPhenylcarbamate) chiral stationary phase: Influence of coating times and coating amount on chiral discrimination
Wei, Qiuhong,Su, Hongjiu,Gao, Diannan,Wang, Shudong
, p. 164 - 173 (2019/01/18)
Coating cellulose tris (3,5-dimethylphenylcarbamate) (CDMPC) on silica gels with large pores have been demonstrated as an efficient way for the preparation of chiral stationary phase (CSP) for high-performance liquid chromatography (HPLC). During the process, a number of parameters, including the type of coating solvent, amount of coating, and the method for subsequent solvent removing, have been proved to affect the performance of the resultant CSPs. Coating times and the concentration of coating solution, however, also makes a difference to CSPs' performance by changing the arrangement of cellulose derivatives while remaining the coating amount constant, have much less been studied before, and thereby, were systematically investigated in this work. Results showed that CSPs with more coating times exhibited higher chiral recognition and column efficiency, suggesting that resolution was determined by column efficiency herein. Afterwards, we also investigated the effect of coating amount on the performance of CSPs, and it was shown that the ability of enantio-recognition did not increase all the time as the coating amount; and four of seven racemates achieved best resolution when the coating amount reached to 18.37%. At the end, the reproducibility of CDMPC-coated CSPs were further confirmed by two methods, ie, reprepared the CSP-0.15-3 and reevaluated the effect of coating times.
