611-71-2Relevant articles and documents
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Lewkowitsch
, p. 1574,2722 (1883)
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Process Development for the Production of (R)-(-)-Mandelic Acid by Recombinant Escherichia coli Cells Harboring Nitrilase from Burkholderia cenocepacia J2315
Wang, Hualei,Fan, Haiyang,Sun, Huihui,Zhao, Li,Wei, Dongzhi
, p. 2012 - 2016 (2015)
(R)-(-)-Mandelic acid is an important chiral building block that is widely used in pharmacy and the production of fine chemicals. A more advanced method for obtaining (R)-(-)-mandelic acid is direct hydrolysis of the corresponding racemic mandelonitrile. In order to develop a cost-effective process, a highly efficient enantioselective nitrilase BCJ2315 from Burkholderia cenocepacia J2315 was used for the biotransformation of mandelonitrile to (R)-(-)-mandelic acid. The recombinant Escherichia coli M15/BCJ2315 showed high substrate tolerance and could completely hydrolyze up to 250 mM of mandelonitrile. A fed-batch reaction was performed by periodically or continuously dosing the substrate into the reactor to alleviate substrate inhibition in a monophasic buffer system. Finally, the highest substrate loading (2.9 M) was achieved in the continuous fed batch reaction mode, giving (R)-(-)-mandelic acid at the highest concentration (2.3 M, 350 g/L) with 97.4% ee ever reported. The hydrolysis process was easily scaled up to 2 and 10 L, indicating the potential for the industrial production of optically pure (R)-(-)-mandelic acid.
Highly efficient resolution of mandelic acid using lipase from Pseudomonas stutzeri LC2-8 and a molecular modeling approach to rationalize its enantioselectivity
Cao, Yan,Wu, Shanshan,Li, Jiahuang,Wu, Bin,He, Bingfang
, p. 108 - 113 (2014)
Mandelic acid, a key precursor of chiral synthons, was successfully acylated in diisopropyl ether. The reaction was catalyzed by the lipase from Pseudomonas stutzeri LC2-8, and vinyl acetate was employed as acyl donor. Under the optimized reaction conditions, a resolution of 180 mM (55 g/L) mandelic acid was achieved. (S)-O-Acetyl mandelic acid was enantioselectivity formed in >99% ee at a yield close to the maximum theoretical value for kinetic resolution (50%). The highly substrate tolerable and enantioselective nature of lipase LC2-8 suggests that it is of great potential for the practical resolution of racemic mandelic acid. Additionally, the high enantiopreference of lipase LC2-8 toward (S)-mandelic acid in acetylation was also rationalized through molecular docking and molecular dynamics simulations.
Optical Resolution of Phenylalanine and Mandelic Acid
Yamamoto, Yasushi,Kato, Shinji,Yamashita, Hiroshi,Maekawa, Takashi
, p. 3149 - 3152 (1992)
The optical resolutions of phenylalanine and mandelic acid were performed by complex formation with Cu2+, D- and L-mandelic acids were completely resolved by forming a complex with L-phenylalanine, while the maximum optical purity of D- and L-p
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Ingersoll,Babcock,Burns
, p. 411,414 (1933)
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Surface functionalization of chitosan-coated magnetic nanoparticles for covalent immobilization of yeast alcohol dehydrogenase from Saccharomyces cerevisiae
Li, Gui-Yin,Zhou, Zhi-De,Li, Yuan-Jian,Huang, Ke-Long,Zhong, Ming
, p. 3862 - 3868 (2010)
A novel and efficient immobilization of yeast alcohol dehydrogenase (YADH, EC1.1.1.1) from Saccharomyces cerevisiae has been developed by using the surface functionalization of chitosan-coated magnetic nanoparticles (Fe 3O4/KCTS) as support. The magnetic Fe3O 4/KCTS nanoparticles were prepared by binding chitosan alpha-ketoglutaric acid (KCTS) onto the surface of magnetic Fe3O 4 nanoparticles. Later, covalent immobilization of YADH was attempted onto the Fe3O4/KCTS nanoparticles. The effect of various preparation conditions on the immobilized YADH process such as immobilization time, enzyme concentration and pH was investigated. The influence of pH and temperature on the activity of the free and immobilized YADH using phenylglyoxylic acid as substrate has also been studied. The optimum reaction temperature and pH value for the enzymatic conversion catalyzed by the immobilized YADH were 30 °C and 7.4, respectively. Compared to the free enzyme, the immobilized YADH retained 65% of its original activity and exhibited significant thermal stability and good durability.
Constituents of Prunus zippeliana leaves and branches
Kitajima,Tanaka
, p. 2007 - 2009 (1993)
The following substances were identified in the fresh leaves and branches of Prunus zippeliana MIQ.: 22-dehydroclerosteryl acetate, stigmasteryl acetate, β-sitosterol, stigmasterol, clerosterol, 22-dehydroclerosterol, β- sitosterol and stigmasterol 3-O-β-D-glucopyranoside, ursolic acid, oleanolic acid, 2α-hydroxyursolic acid, tormentic acid, methyl linolate, phytol, prunasin, dl-mandelic acid, kaempferol 3-O-[O-α-L-rhamnopyranosyl-(1 → 6)- β-D-glucopyranoside] and d-mandelic acid β-D-glucopyranoside. Worthy of note is that 24α-ethylsterols (β-sitosterol and stigmasterol) and 24β- ethylsterols (clerosterol and 22-dehydroclerosterol) were obtained together from the leaves of a higher plant.
Gene cloning, expression, and characterization of a nitrilase from Alcaligenes faecalis ZJUTB10
Liu, Zhi-Qiang,Dong, Li-Zhu,Cheng, Feng,Xue, Ya-Ping,Wang, Yuan-Shan,Ding, Jie-Nv,Zheng, Yu-Guo,Shen, Yin-Chu
, p. 11560 - 11570 (2011)
Nitrilases are important industrial enzymes that convert nitriles directly into the corresponding carboxylic acids. In the current work, the fragment with a length of 1068 bp that encodes the A. faecalis ZJUTB10 nitrilase was obtained. Moreover, a catalytic triad was proposed and verified by site-directed mutagenesis, and the detailed mechanism of this nitrilase was clarified. The substrate specificity study demonstrated that the A. faecalis ZJUTB10 nitrilase belongs to the family of arylacetonitrilases. The optimum pH and temperature for the purified nitrilase was 7-8 and 40 °C, respectively. Mg2+ stimulated hydrolytic activity, whereas Cu2+, Co2+, Ni2+, Ag+, and Hg2+ showed a strong inhibitory effect. The Km and vmax for mandelonitrile were 4.74 mM and 15.85 μmol min-1 mg-1 protein, respectively. After 30 min reaction using the nitrilase, mandelonitrile at the concentration of 20 mM was completely hydrolyzed and the enantiomeric excess against (R)-(-)-mandelic acid was >99%. Characteristics investigation indicates that this nitrilase is promising in catalysis applications.
Synthesis of α-hydroxycarboxylic acids from various aldehydes and ketones by direct electrocarboxylation: A facile, efficient and atom economy protocol
Singh, Kishanpal,Sohal, Harvinder Singh,Singh, Baljit
, p. 839 - 845 (2021/04/09)
In present work, the formation of α-hydroxycarboxylic acids have been described from various aromatic aldehydes and ketones via direct electrocarboxylation method with 80-92% of yield without any side product and can be purified by simple recrystallization using sacrificial Mg anode and Pt cathode in an undivided cell, CO2at (1 atm) was continuously bubbled in the cell throughout the reaction using tetrapropylammonium chloride as a supporting electrolyte in acetonitrile. The synthesized compounds obtained in fair to excellent yield with a high level of purity. The characterization of electrocarboxylated compounds was done with spectroscopic techniques like IR, NMR (1H & 13C), mass and elemental analysis.
High-yield DL-mandelic acid synthesis process
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, (2021/09/04)
The invention provides a high-yield DL-mandelic acid synthesis process. The synthesis process specifically comprises the following steps: 1, treating benzaldehyde by using sodium hydrogen sulfite to obtain benzaldehyde sodium hydrogen sulfite; 2, extracting the benzaldehyde sodium hydrogen sulfite by using an organic solvent, recovering unreacted benzaldehyde in the benzaldehyde sodium hydrogen sulfite, and adding sodium cyanide after the extraction is completed to prepare mandelonitrile; 3, adding an inorganic acid, and then carrying out heating and pressure maintaining treatment to hydrolyze the mandelonitrile so as to obtain mandelic acid; and 4, purifying the mandelic acid. According to the method, the step of extracting the p-benzaldehyde sodium hydrogen sulfite salt is added, so that the probability that the product purity is reduced due to benzoin condensation is reduced, the recycled benzaldehyde can be returned to the raw material for use, and the yield can be increased in multiple rounds of reactions; and the hydrolysis process of the mandelonitrile adopts heating and pressure maintaining treatment, so that consumption of inorganic acid can be reduced, and the hydrolysis efficiency is improved.
Enantioseparation of mandelic acid and substituted derivatives by high-performance liquid chromatography with hydroxypropyl-β-cyclodextrin as chiral mobile additive and evaluation of inclusion complexes by molecular dynamics
Shi, Jie-Hua,Lin, Zhen-Yi,Kou, Song-Bo,Wang, Bao-Li,Jiang, Shao-Liang
supporting information, p. 675 - 684 (2021/08/16)
The enantioseparation and resolution mechanism of mandelic acid (MA), 4-methoxymandelic acid (MMA), and 4-propoxymandelic acid (PMA) were investigated by reversed-phase high-performance liquid chromatography (HPLC) with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) as a chiral mobile-phase additive and molecular dynamics simulation. The suitable chromatographic conditions for the enantioseparation of MA, MMA, and PMA were obtained. Under the selected chromatographic conditions, these enantiomers could achieve baseline separation. The results of thermodynamic parameter analysis revealed that the main driven forces for the enantioseparation of MA, MMA, and PMA could be van der Waals forces and hydrogen-bonding interactions and the chromatographic retention of these chiral compounds was an enthalpy-driven process. The results of the molecular simulation revealed that their chiral resolution mechanism on HP-β-CD was responsible for the formation of inclusion complexes of enantiomers with HP-β-CD with different conformations and binding energies. And the binding energy of HP-β-CD with (S)-isomer was larger than that with (R)-isomer, which is consistent with the experimental results of the first elution of (S)-isomer. Additionally, it is also confirmed that the interaction energies included the van der Waals energy (?Evdw), electrostatic energy (?Eelec), polar solvation energy, and SASA energy (?Esasa), and the separation factor (α) was closely connected with the disparity in the binding energies of optical isomers and HP-β-CD complexes. Meanwhile, from molecular dynamics simulation, it can be found that the ?(?Ebinding), (?(?Ebinding) = ?Ebinding,R ? ?Ebinding,S) value was in order of MA–HP-β-CD complex > MMA–HP-β-CD complex > PMA–HP-β-CD complex, which was consistent with the order of Δ(ΔG) values obtained from van't Hoff plot. This indicated that the molecular dynamics simulation has predictive function for chiral resolution.