Rapid determination of the enantiomeric excess of sulfoxides

ORGN 772

Christopher M. Sprout, Chriss@ensbio.com, R&D, ENS, 675 Massachusetts Avenue, Cambridge, MA 02139 and Christopher T. Seto, Department of Chemistry, Brown University, 324 Brook St. Box H, Providence, RI 02912.
Previous reports have established that chiral sulfoxides can inhibit horse liver alcohol dehydrogenase (HLADH) oxidation of ethanol with greater efficiency when using the (S)-enantiomer. HLADH is a NAD dependent enzyme and therefore the rate of the enzymatic oxidation can be conveniently monitored by observing the formation of NADH at 340 nm. (S)-Methyl p-tolyl sulfoxide produced an IC50 value against HLADH of 40 µM, while the (R)-enantiomer was 970 µM. A series of enzyme-catalyzed oxidations of ethanol were conducted at constant methyl p-tolyl sulfoxide concentration, but at variable stereochemical composition of the sulfoxide, 100% (R) to 100% (S). The rate of NADH formation was found to decrease linearly as the enantiomeric excess of the (S)-enantiomer increased. The %ee of many sulfoxide samples of unknown stereochemical composition can be analyzed in a high-throughput manner.
 

Asymmetric Reactions, Molecular Recognition, Self Assembly, Bioorganic Chemistry, Process R&D
8:00 PM-10:00 PM, Wednesday, 16 March 2005 Convention Center -- Hall D, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, 14 March 2005 Convention Center -- Sails Pavilion, Sci-Mix

Division of Organic Chemistry

The 229th ACS National Meeting, in San Diego, CA, March 13-17, 2005