Applied Circular Dichroism: A Facile Spectroscopic Tool for Configurational Assignment and Determination of EnantiopurityReport as inadecuate




Applied Circular Dichroism: A Facile Spectroscopic Tool for Configurational Assignment and Determination of Enantiopurity - Download this document for free, or read online. Document in PDF available to download.

Journal of Analytical Methods in Chemistry - Volume 2015 2015, Article ID 865605, 6 pages -

Research ArticleDepartment of Chemistry, Doane College, 1014 Boswell Avenue, Crete, NE 68333, USA

Received 29 October 2014; Revised 7 January 2015; Accepted 8 January 2015

Academic Editor: Juan F. Garcia-Reyes

Copyright © 2015 Macduff O. Okuom et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In order to determine if electronic circular dichroism ECD is a good tool for the qualitative evaluation of absolute configuration and enantiopurity in the absence of chiral high performance liquid chromatography HPLC, ECD studies were performed on several prescriptions and over-the-counter drugs. Cotton effects CE were observed for both S and R isomers between 200 and 300 nm. For the drugs examined in this study, the S isomers showed a negative CE, while the R isomers displayed a positive CE. The ECD spectra of both enantiomers were nearly mirror images, with the amplitude proportional to the enantiopurity. Plotting the differential extinction coefficient versus enantiopurity at the wavelength of maximum amplitude yielded linear standard curves with coefficients of determination greater than 97% for both isomers in all cases. As expected, Equate, Advil, and Motrin, each containing a racemic mixture of ibuprofen, yielded no chiroptical signal. ECD spectra of Suphedrine and Sudafed revealed that each of them is rich in 1S,2S-pseudoephedrine, while the analysis of Equate vapor inhaler is rich in R-methamphetamine.





Author: Macduff O. Okuom, Raychelle Burks, Crysta Naylor, and Andrea E. Holmes

Source: https://www.hindawi.com/



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