PHYS 501 |
| Nuclear magnetic resonance (NMR) can provide molecular-level information on the interactions which govern chiral separations by micellar electrokinetic chromatography (MEKC). Chemical shifts have been studied for R,S 1-1'-binapthyl-2-2'-diylhydrogenphosphate(R,S-BNDHP) interacting with aggregates of cholate and deoxycholate. We have found that BNDHP chemical shifts are sensitive reporters on the primary critical micelle concentrations (CMC) of bile salts, indicating which micellar aggregates are needed to perform successful chiral separations by MEKC. Both NMR chemical shifts and 2D-NOE data demonstrate that OH-12 (on the hydrophilic edge of cholate and deoxycholate) participates in chirally selective interactions between BNDHP and the cholate or deoxycholate micelles. Significantly, MEKC and NMR studies of chenodeoxycholate (lacking OH-12) show that OH-12 is in fact necessary for chiral selection of R,S-BNDHP by cholate and deoxycholate micelles. Using this data, we have developed a structural model for explaining chiral recognition of R,S-BNDHP by cholate and deoxycholate micelles. |
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General Experimental Physical Chemistry
7:30 PM-9:30 PM, Wednesday, August 19, 2009 Walter E. Washington Convention Center -- Hall D, Poster
Division of Physical Chemistry |