Could linear solvation energy relationships give insights into chiral recognition mechanisms? 2. Characterization of macrocyclic glycopeptide stationary phases.
Five parameter linear solvation energy relationships (LSER) are known to have little or no shape recognition ability. However, it is proposed to use LSER studies to get insights into chiral recognition mechanisms. Since the two enantiomers have exactly the same five A-V solute descriptors being still separated by chiral stationary phases (CSPs), it can be considered that they form two different transient diastereoisomers with the CSP. It is then possible to perform LSER studies on the enantioselectivity factors taken as the two enantiomer retention factor ratios. In a first step, the five a-v system parameters of four CSPs of the macrocyclic glycopeptide types were determined using a set of test solutes with known A-V descriptors, both in the reversed phase and the normal phase modes. In a second step, the A-V descriptors of 18 enantiomeric pairs were tentatively established using five achiral columns with known a-v parameters. This was successful for the five molecular enantiomers only. It was found that the predicted retention factor for the molecular enantiomers separated on a given CSP corresponded either to retention factor of the first experimentally eluted enantiomer or to the second one or to none of them. Using the enantioselectivity factors it was possible to obtain the Deltaa-Deltav parameters corresponding to the difference in CSP properties seen by the two enantiomers. For the five molecular enantiomeric pairs in the reversed phase mode with a teicoplanin CSP, it was found that there was an elevated contribution by the e coefficient that we interpret as a possible interaction between surface charges on the teicoplanin CSP and solute induced dipoles. Steric effects, seen on the v parameter, are second in magnitude followed by H-bond and polar interactions. Only one solute could be studied in the normal phase mode showing a different mechanism with polar and steric major interactions.
Mitchell
Clifford R
CR
Abbott Laboratories, 1401 Sheridan Road, North Chicago, IL 60064, USA.
Armstrong
Daniel W
DW
Berthod
Alain
A
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods*; D012997:Solvents / Q000737:chemistry*; D013237:Stereoisomerism; D017334:Teicoplanin / Q000737:chemistry
D012997:Solvents; D017334:Teicoplanin
J Org Chem. 2004 Jul 9;69(14):4677-85
15230589
Phys Chem Chem Phys. 2005 Jun 21;7(12):2418-22
15962024
J Chromatogr A. 2004 Feb 13;1026(1-2):77-89
14763735
J Chromatogr A. 2002 Jul 5;961(2):195-215
12184619
J Mass Spectrom. 2004 Feb;39(2):177-87
14991687
J Chromatogr A. 2004 Jul 9;1042(1-2):37-48
15296386
Anal Chem. 1994 May 15;66(10):1690-5
8030783
Anal Chem. 1996 Aug 1;68(15):2501-14
8694258
Chirality. 1994;6(6):496-509
7946976
J Chromatogr A. 2006 Sep 8;1126(1-2):143-94
16889784
J Chromatogr A. 1999 Sep 10;855(2):455-86
10519086
J Chromatogr A. 2003 Jun 6;1000(1-2):757-78
12877199
J Chromatogr A. 2002 Jul 5;961(2):217-36
12184620
J Chromatogr A. 1996 Apr 19;731(1-2):123-37
8646327
J Chromatogr A. 2004 Feb 13;1026(1-2):91-100
14763736
J Chromatogr A. 2004 May 28;1037(1-2):29-47
15214659