Applications of Cellulose-Based Chiral Stationary Phases in Resolution of Drug Racemates a Mini Review

Responsive circularly polarized ultralong room temperature phosphorescence materials with easy-to-scale and chiral-sensing performance

Circularly polarized room temperature phosphorescence materials represent a state-of-the-art frontier of optical materials and exhibit promising applications in various fields. Herein, we fabricate a series of full-color circularly polarized room temperature phosphorescence materials, based on anionic cellulose derivatives and achiral luminophores. The ionic achiral substituents promote the spontaneous formation of chiral helical structure of cellulose derivatives via the electrostatic repulsion effect. There are multiple interactions between anionic cellulose derivatives and the doped luminophores, thus the chirality is transferred to luminophores and the non-radiative transition is inhibited. The resultant materials can be easily processed into large-scale film and flexible 3D objects with repeatable folding and curling properties. In addition, their phosphorescence performance shows to be excitation-dependence, time-dependence, visible-light excitation, and multi-responsiveness to humidity, temperature as well as pH value. Importantly, they recognize many enantiomers in an instrument-free visual mode, including amino acids, hydroxyl acids, organic phosphate and hydrobenzoin. These results provide insights into design of advanced optical materials which can be applied in multilevel information handling and chiral sensing.

Chiral resolution of the enantiomers of 7-chloro-3-methyl-3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxide using high-performance liquid chromatography on cellulose-based chiral stationary phases

Analytical high-performance liquid chromatography (HPLC) methods using derivatized cellulose chiral stationary phases (CSPs) were developed for the separation of the enantiomers of 7-chloro-3-methyl-3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxide ((+/-) IDRA21). In previous studies, (+/-) IDRA21 has been found to have an interesting inhibitory effect on the desensitization of alpha-amino-2,3-dihydro-5-methyl-3-oxo-4-isoxazolepropanoic acid (AMPA) receptor and improve cognition in animals. This compound possess one chiral carbon atom, but very little information has been reported on the stereoselectivity of his activity. Therefore resolution of the enantiomers of this compound and subsequent identification of stereospecificity in his pharmacological actions are clearly matters of interest. The resolution were made under normal- and reversed-phase conditions using a mobile phase consisting of n-hexane:2-propanol (70/30, v/v) and water:acetonitrile (60/40, v/v) respectively, and a CSP of silica-based cellulose tris-3,5-dimethyl-phenylcarbamate (Chiralcel OD and Chiracel OD-R). The enantiomeric nature of eluates was confirmed by circular dichroism (CD) spectra. A baseline separation (R(S) > 1.5) was obtained in both cases. Furthermore the isolation of optical isomers of (+/-) IDRA21 was performed using a semipreparative column packed with the same cellulose OD CSP.