611-71-2Relevant articles and documents
-
Lewkowitsch
, p. 1574,2722 (1883)
-
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
-
Ingersoll,Babcock,Burns
, p. 411,414 (1933)
-
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.
Designing of amino functionalized imprinted polymeric resin for enantio-separation of (±)-mandelic acid racemate
Alhawiti, Aliyah S.,Monier,Elsayed, Nadia H.
, (2021/02/12)
S-Mandelic acid (MA) enantio-selective resinous material functionalized with –NH2 groups has been developed and effectively utilized in chiral separation of (±)-MA racemate solution. S-MA has first combined with the polymerizable p-aminophenol and form the corresponding amide derivative, which was then polymerized with phenol/formalin using HCl as a catalyst. The stereo-selective –NH2 functionalized binding sites were then generated within the resin upon the alkaline degradation of the amide linkages followed by acidic treatments that will expel the resin incorporated S-MA out of the polymeric material to get the S-MA imprinted polymer (S-MAPR). The synthesized S-MA chiral amide derivative along with the developed polymeric resin was investigated by various techniques including FTIR and NMR spectra that confirmed the executed chemical modifications. In addition, the morphological appearance of the obtained resins were observed using SEM images. Moreover, the S-MAPR resin was examined to optimize the enantio-selective separation conditions and the studies indicated that the adsorption reached the highest value at pH 7 and the maximum capacity was 243 ± 1 mg/g. In addition, the chiral separation of (±)-MA racemic solution was successfully executed by the S-MAPR separation column with 55% and 82% enantiomeric excess of R- and S-MA within both the initial loading and recovery eluant solutions, respectively.
Method for synthesizing mandelic acid
-
Paragraph 0032; 0034-0035; 0037-0038; 0040-0041; 0043, (2021/02/06)
The invention relates to the technical field of compound preparation, and provides a method for synthesizing mandelic acid, which comprises the following steps: by using styrene as a basic raw material, trichloroisocyanuric acid as a chlorinating agent an