Mini Review: Advances in 2-Haloacid Dehalogenases

The 2-haloacid dehalogenases (EC 3.8.1.X) are industrially important enzymes that catalyze the cleavage of carbon–halogen bonds in 2-haloalkanoic acids, releasing halogen ions and producing corresponding 2-hydroxyl acids. These enzymes are of particular interest in environmental remediation and environmentally friendly synthesis of optically pure chiral compounds due to their ability to degrade a wide range of halogenated compounds with astonishing efficiency for enantiomer resolution. The 2-haloacid dehalogenases have been extensively studied with regard to their biochemical characterization, protein crystal structures, and catalytic mechanisms. This paper comprehensively reviews the source of isolation, classification, protein structures, reaction mechanisms, biochemical properties, and application of 2-haloacid dehalogenases; current trends and avenues for further development have also been included.

Polysaccharide- and β-Cyclodextrin-Based Chiral Selectors for Enantiomer Resolution: Recent Developments and Applications

Polysaccharides, oligosaccharides, and their derivatives, particularly of amylose, cellulose, chitosan, and β-cyclodextrin, are well-known chiral selectors (CSs) of chiral stationary phases (CSPs) in chromatography, because they can separate a wide range of enantiomers. Typically, such CSPs are prepared by physically coating, or chemically immobilizing the polysaccharide and β-cyclodextrin derivatives onto inert silica gel carriers as chromatographic support. Over the past few years, new chiral selectors have been introduced, and progressive methods to prepare CSPs have been exploited. Also, chiral recognition mechanisms, which play a crucial role in the investigation of chiral separations, have been better elucidated. Further insights into the broad functional performance of commercially available chiral column materials and/or the respective newly developed chiral phase materials on enantiomeric separation (ES) have been gained. This review summarizes the recent developments in CSs, CSP preparation, chiral recognition mechanisms, and enantiomeric separation methods, based on polysaccharides and β-cyclodextrins as CSs, with a focus on the years 2019–2020 of this rapidly developing field.

Research progress of chiral ligand exchange stationary phases in the enantiomer resolution

The structure of chiral drugs contains at least one asymmetric center. When the enantiomers act on the human body, they are recognized by chiral receptors and enzymes in vivo, which will show different physiological effects and even adverse reactions. Therefore, it is very important for the development of chiral pharmacy to obtain chiral enantiomers with a single configuration by racemic resolution. Some general impurities will be introduced in the production of chiral drugs, thus the detection of impurities is also a crucial step in the quality control of chiral medicines. The chiral ligand exchange stationary phase has a strong recognition effect on enantiomer analytes with multiple chelating sites, and is very suitable for the separation and control of biological samples such as amino acids. In this work, the development of chiral ligand exchange stationary phases in enantiomeric resolution is reviewed, which is expected to provide a basis for the quality control of complex chiral drug components.

Drug Stereochemistry: A Prodigy For Pharmacology and Drug Development

Stereochemistry has evinced the importance of many chiral drugs with respect to drug designing and development. A literature review was conducted for several chiral drugs involving pharmacokinetic and pharmacodynamic parameters of their enantiomers along with their uses in certain diseased conditions. This article mainly includes the pharmacological profile review of some chiral drugs and the aspects due to which the single enantiomer is of importance as compared to the racemic mixture of the drug. This was achieved by moderating the side effects or toxic effects; or by the potentiated activity of the single enantiomer. Resolution deals with the separation of racemic compounds which shows up the credibility to obtain the desired enantiomeric properties. As isomers vary in their pharmacokinetic and pharmacodynamic profiles, chiral drugs have showcased considerable importance in the drug development process. Both the enantiomers have a different pharmacological profile in the treatment of a disease, which differentiates them from drug racemates.