127036-18-4Relevant academic research and scientific papers
Modeling and optimization of lipase-catalyzed hydrolysis for production of (S)-2-phenylbutyric acid enhanced by hydroxyethyl-β-cyclodextrin
Zhang, Panliang,Cheng, Qing,Xu, Weifeng,Tang, Kewen
, p. 96 - 103 (2019/05/27)
An efficient reactive system was established to produce (S)-2-phenylbutyric acid (2-PBA) through the enzymatic enantioselective hydrolysis of 2-phenylbutyrate ester (2-PBAE) in aqueous medium. Lipase CALA from Canadian antarctica and hexyl 2-phenylbutyrate (2-PBAHE) were identified upon screening as the best enzyme and substrate, respectively. Adding hydroxyethyl-β-cyclodextrin (HE-β-CD) to improve the solubility of the substrate resulted in a 1.5 times increase in substrate conversion while retaining a high enantioselectivity compared with that when HE-β-CD was not added. The effects of lipase concentration, substrate concentration and HE-β-CD concentration, temperature, pH, and reaction time on enantiomeric excess and conversion rate were investigated, and the optimal conditions were identified using response surface methodology (RSM). Under the optimal conditions, namely 50 mg/mL lipase CALA, 30 mmol/L substrate, 60 mmol/L HE-β-CD, pH of 6.5, temperature of 83 °C and reaction time of 18 h, the enantiomeric excess and overall conversion rate were 96.05% and 27.28%, respectively. This work provides an efficient alternative method for improving the conversion of aromatic ester substrates by including β-cyclodextrin in an aqueous hydrolysis reaction system.
Disulfide symmetric dimers as stable pre-hapten forms for bioconjugation: A strategy to prepare immunoreagents for the detection of sulfophenyl carboxylate residues in environmental samples
Estevez, M.-Carmen,Galve, Roger,Sanchez-Baeza, Francisco,Marco, M.-Pilar
experimental part, p. 1906 - 1917 (2009/04/08)
A convenient, generic synthesis of bioconjugates from haptens with a thiol group has been established. The corresponding haptens are synthesized as stable symmetric dimmers through a disulfide bond that is reduced immediately before conjugation with the a
Nucleophilic Additions to Ketenes by (Trimethylsilyl)lithium and by Enolates
Gong, Leyi,Leung-Toung, Regis,Tidwell, Thomas T.
, p. 3634 - 3639 (2007/10/02)
Reaction of t-Bu2C=C=O (5) with Me3SiLi at -78 deg C followed by trapping of the intermediate enolate with Ac2O gave t-Bu2C=C(OAc)SiMe3 (9).Other ketenes gave similar products.Reaction of ketenes PhCR=C=O (R = Me, 13; R = Et, 3) with enolates CH2=C(OLi)R1 (R1 = H, Me, t-Bu, Ph) at -78 deg C followed by warming to 25 deg C and hydrolysis gave vinyl esters PhCHRCO2C(R1)=CH2, along with 10 percent PhCHMeCOCH2COPh for R = Me, R1 = Ph.Under the same conditions the ketenes PhCR=C=O with enolates CH2=C(OK)R1 (R1 = Me, t-Bu, Ph) gave only 1,3-diketones PhCHRCOCH2COR1, but vinyl esters were the major products if the reactions were quenched at -78 deg C.It is proposed that enolates undergo preferential O-acylation by ketenes in a kinetically favored process, but that these intermediates can revert to thermodynamically more stable C-acylated products.
