611-71-2Relevant articles and documents
Enantioseparation of Mandelic Acid Enantiomers with Magnetic Nano-Sorbent Modified by a Chiral Selector
Tarhan, Tuba,Tural, Bilsen,Tural, Servet,Topal, Giray
, p. 835 - 842 (2015)
In this study, R(+)-α-methylbenzylamine-modified magnetic chiral sorbent was synthesized and assessed as a new enantioselective solid phase sorbent for separation of mandelic acid enantiomers from aqueous solutions. The chemical structures and magnetic pr
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.
An organic solvent and thermally stable lipase from Burkholderia ambifaria YCJ01: Purification, characteristics and application for chiral resolution of mandelic acid
Yao, Changjin,Cao, Yan,Wu, Shanshan,Li, Shuang,He, Bingfang
, p. 105 - 110 (2013)
A solvent-tolerant bacterium Burkholderia ambifaria YCJ01 was newly isolated by DMSO enrichment of the medium. The lipase from the strain YCJ01 was purified to homogeneity with apparent molecular mass of 34 kDa determined by SDS-PAGE. The purified lipase exhibited maximal activity at a temperature of 60 °C and a pH of 7.5. The lipase was very stable below 55 °C for 7 days (remaining 80.3% initial activity) or at 30 °C for 60 days. PMSF significantly inhibited the lipase activity, while EDTA had no effect on the activity. Strikingly, the lipase showed distinct super-stability to the most tested hydrophilic and hydrophobic solvents (25%, v/v) for 60 days, and different optimal pH in contrast with the alkaline lipase from B. cepacia S31. The lipase demonstrated excellent enantioselective transesterification toward the S-isomer of mandelic acid with a theoretical conversion yield of 50%, eep of 99.9% and ees of 99.9%, which made it an exploitable biocatalyst for organic synthesis and pharmaceutical industries.
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.
R-mandelic acid production with immobilized recombinant Escherichia coli cells in a recirculating packed bed reactor
Zhang, Xin-Hong,Liu, Zhi-Qiang,Xue, Ya-Ping,Yang, Bo,Xu, Ming,Zheng, Yu-Guo
, p. 205 - 211 (2016)
A recirculating packed bed reactor (RPBR) was used for efficient production of R-mandelic acid (R-MA) by kinetic resolution of racemic R,S-mandelonitrile (R,S-MN) using the recombinant E. coli cells crosslinked with diatomite (DA)/glutaraldehyde (GA)/polyethyleneimine (PEI). The performance and productivity of RPBR were evaluated by several parameters, including cell load, substrate feeding rate, height diameter (H/D) ratio, reactor structures, and operation stability. The kinetic resolution process showed higher initial reaction rate (1.52 mM/min) and yield (100%) by recycling 100 mL of substrate solution (70 mM) through RPBR packed with 6.0 g immobilized cells at a substrate-feeding rate of 19 mL/min while the H/D ratio was 2.8. The immobilized cells were successfully applied into kinetic resolution of R,S-MN in the RPBR for 50 batches with an average productivity of 4.12 g/L/h for R-MA with >99% of enantiomeric excess.
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
Screening for enantioselective nitrilases: Kinetic resolution of racemic mandelonitrile to (R)-(-)-mandelic acid by new bacterial isolates
Kaul, Praveen,Banerjee, Anirban,Mayilraj,Banerjee, Uttam C.
, p. 207 - 211 (2004)
Several new microorganisms have been isolated with high nitrilase activity against (RS)-mandelonitrile using the enrichment culture technique. The organisms were cultivated in liquid culture and the enzyme activity was determined at different phases of growth. The organisms having high enzyme titre were further grown and used as catalysts for the transformation of mandelonitrile to mandelic acid. The percentage conversion was checked with RP-HPLC and the enantiomeric excess was determined on a chiral column. Three isolates gave the desired product, (R)-(-)-mandelic acid with high ee (%) and were identified as Pseudomonas putida, Microbacterium paraoxydans and Microbacterium liquefaciens. All three isolates showed good specific activity (0.33-0.50U/mgmin) with high ee (>93%) and E values. The conversion of racemic mandelonitrile to mandelic acid by these isolates was compared: P. putida was found to be the most suitable biocatalyst for further studies as it showed higher reaction rate (kRxn), lower Km, better growth rate (μ), good yield and ee values and higher stability compared to the other two microorganisms.
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.
Nucleation and growth kinetics of (R)-mandelic acid from aqueous solution in the presence of the opposite enantiomer
Zhang, Yan,Mao, Shimin,Ray, Ajay K.,Rohani, Sohrab
, p. 2879 - 2887 (2010)
Resolution of mandelic acid (MA), a racemic compound, is presented in this article using direct crystallization from enantiomeric enriched water solutions. Final crystals with enantiomeric excess (ee) of (R)-MA higher than 96.4% were obtained. Because of
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.
