1.Preparation of surface imprinted material of single enantiomer of mandelic acid with a new surface imprinting technique and study on its chiral recognition and resolution properties.
Gao B1, Chen L2, Li Y3. J Chromatogr A. 2016 Apr 22;1443:10-20. doi: 10.1016/j.chroma.2016.03.018. Epub 2016 Mar 15.
A surface imprinted material of the single enantiomer of mandelic acid with high performance was successfully prepared with a new surface imprinting technique of synchronously graft-polymerizing and molecule imprinting, and its enantiomeric recognition and resolution properties were investigated. Micro-sized silica gel particles were first modified with coupling agent γ-mercaptopropyl trimethoxysilane (MPMS), obtaining the modified particles MPMS-SiO2 on which mercapto groups were introduced. A surface initiating system of -SH/BPO was constituted with the mercapto group (-SH) on MPMS-SiO2 particles and dibenzoyl peroxide (BPO) in N,N-dimethyl formamide (DMF) solution. In DMF solution, (R)-mandelic acid molecule was used as the template and the functional monomer hydroxyethyl methylacrylate (HEMA) were combined together by right of multi-site hydrogen bonds. The free radicals produced on MPMS-SiO2 particles initiate HEMA molecules around (R)-mandelic acid molecules and the crosslinking agent N,N'-Methylenebisacrylamide (MBA) to produce graft/crosslinking-polymerization.
2.Characterization of pharmaceutically active compounds in Dongting Lake, China: Occurrence, chiral profiling and environmental risk.
Ma R1, Wang B2, Lu S3, Zhang Y1, Yin L1, Huang J1, Deng S1, Wang Y1, Yu G1. Sci Total Environ. 2016 Mar 23;557-558:268-275. doi: 10.1016/j.scitotenv.2016.03.053. [Epub ahead of print]
Twenty commonly used pharmaceuticals including eight chiral drugs were investigated in Dongting Lake, China. The contamination level was relatively low on a global scale. Twelve pharmaceuticals were identified. The most abundant compound was caffeine followed by diclofenac, DEET, mefenamic acid, fluoxetine, ibuprofen and carbamazepine with mean concentrations from 2.0 to 80.8ngL-1. Concentrations between East and West Dongting Lake showed spatial difference, with the West Dongting Lake less polluted. The relatively high ratio of caffeine versus carbamazepine (over 50) may indicate there was possible direct discharge of domestic wastewater into the lake. This is the first study presenting a survey allowing for comprehensive analysis of multiclass achiral and chiral pharmaceuticals including beta-blockers, antidepressants and anti-inflammatory drugs in freshwater lake. The enantiomeric compositions presented racemic to weakly enantioselective, with the highest enantiomeric fraction (EF) of 0.
3.Synthesis of nano-sized stereoselective imprinted polymer by copolymerization of (S)-2-(acrylamido) propanoic acid and ethylene glycol dimethacrylate in the presence of racemic propranolol and copper ion.
Alizadeh T1, Bagherzadeh A2, Shamkhali AN2. Mater Sci Eng C Mater Biol Appl. 2016 Jun 1;63:247-55. doi: 10.1016/j.msec.2016.02.077. Epub 2016 Feb 27.
A new chiral functional monomer of (S)-2-(acrylamido) propanoic acid was obtained by reaction of (l)-alanine with acryloyl chloride. The resulting monomer was characterized by FT-IR and HNMR and then utilized for the preparation of chiral imprinted polymer (CIP). This was carried out by copolymerization of (l)-alanine-derived chiral monomer and ethylene glycol dimethacrylate, in the presence of racemic propranolol and copper nitrate, via precipitation polymerization technique, resulting in nano-sized networked polymer particles. The polymer obtained was characterized by scanning electron microscopy and FT-IR. The non-imprinted polymer was also synthesized and used as blank polymer. Density functional theory (DFT) was also employed to optimize the structures of two diasterometric ternary complexes, suspected to be created in the pre-polymerization step, by reaction of optically active isomers of propranolol, copper ion and (S)-2-(acrylamido) propanoic acid.
4.Ketamine: A Review of Clinical Pharmacokinetics and Pharmacodynamics in Anesthesia and Pain Therapy.
Peltoniemi MA1, Hagelberg NM2, Olkkola KT3, Saari TI2. Clin Pharmacokinet. 2016 Mar 30. [Epub ahead of print]
Ketamine is a phencyclidine derivative, which functions primarily as an antagonist of the N-methyl-D-aspartate receptor. It has no affinity for gamma-aminobutyric acid receptors in the central nervous system. Ketamine shows a chiral structure consisting of two optical isomers. It undergoes oxidative metabolism, mainly to norketamine by cytochrome P450 (CYP) 3A and CYP2B6 enzymes. The use of S-ketamine is increasing worldwide, since the S(+)-enantiomer has been postulated to be a four times more potent anesthetic and analgesic than the R(-)-enantiomer and approximately two times more effective than the racemic mixture of ketamine. Because of extensive first-pass metabolism, oral bioavailability is poor and ketamine is vulnerable to pharmacokinetic drug interactions. Sublingual and nasal formulations of ketamine are being developed, and especially nasal administration produces rapid maximum plasma ketamine concentrations with relatively high bioavailability.