title: Concentration and selective fractionation of an antihypertensive peptide from an alfalfa white proteins hydrolysate by mixed ion-exchange centrifugal partition chromatography.
abstract: This article reports a promising use of the mixed ion-exchange centrifugal partition chromatography (MIXCPC) technique in the field of downstream processes. A complex alfalfa white protein concentrate hydrolysate (AWPC hydrolysate) showing anti-hypertensive properties was successfully fractionated by MIXCPC to yield a L-valyl-L-tryptophan (VW) enriched fraction in one run. This dipeptide shows an interesting anti-angiotensin converting enzyme (anti-ACE) activity. An analytical method based on RP-LC/MS-MS was developed to quantify the target VW peptide in both the starting material and the enriched fractions. The best results for the MIXCPC fractionation were obtained by the combined use of the quaternary biphasic solvent system, methyl-tert-butylether/acetonitrile/n-butanol/water (2:1:2:5, v/v) in the descending mode, of the lipophilic di(2-ethylhexyl)phosphoric acid (DEHPA) cation-exchanger with an exchanger (DEHPA)/peptides ratio of 15, and of two displacers: calcium chloride and hydrochloric acid. The complexity of the starting material involved the selectivity optimization by splitting the stationary phase into two sections that differed by their triethylamine concentration. From 1g of AWPC hydrolysate containing 0.26% of VW, 30.7 mg of a VW enriched fraction were recovered with a purity of 10.9%, corresponding to a purification factor of 41 and a recovery of 97%.
authors.affiliation: Institut de Chimie Moléculaire de Reims UMR CNRS 7312, SFR CAP-Santé, Université de Reims Champagne-Ardenne, Reims, France.
authors.forename: Leslie
authors.initials: L
authors.lastname: Boudesocque
authors.forename: Romain
authors.initials: R
authors.lastname: Kapel
authors.forename: Cedric
authors.initials: C
authors.lastname: Paris
authors.forename: Pascal
authors.initials: P
authors.lastname: Dhulster
authors.forename: Ivan
authors.initials: I
authors.lastname: Marc
authors.forename: Jean-Hugues
authors.initials: JH
authors.lastname: Renault
mesh_terms: D000959:Antihypertensive Agents / Q000737:chemistry / Q000302:isolation & purification*; D002138:Calibration; D002498:Centrifugation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods*; D004151:Dipeptides / Q000737:chemistry / Q000302:isolation & purification*; D000455:Medicago sativa / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D000959:Antihypertensive Agents; D004151:Dipeptides; D010940:Plant Proteins; C055060:N-valyltryptophan