SEPARATION OF ENANTIOMERS ON A CHIRAL STATIONARY-PHASE BASED ON PEPSIN .2. STABILIZATION BY A MIXED PROTEIN PHASE WITH CHICKEN OVOMUCOID

A chiral stationary phase (CSP) based on a pepsin from porcine stomach mucosa and chicken ovomucoid (OMCHI) from egg whites has been prepare d for the separation of basic and uncharged enantiomers. The Pepsin an d OMCHI were mixed immobilized onto the same porous aminopropyl-silica materials using an N, N'-disuccinimidyl carbonate reaction. The reten tive and enantioselective properties of the mixed protein phase (MPP), Pepsin-OMCHI CSP, were compared with those of a Pepsin CSP and an OMC HI stationary phase. The Pepsin-OMCHI CSP showed a similar enantiosele ctivity with the Pepsin CSP. In addition, the Pepsin-OMCHI CSP was mor e stable than the Pepsin CSP for repetitive injections of samples and the continuous flow of an eluent. The MPP was further stabilized by cr oss-linking with glutaraldehyde.