Thiolysis-HPLC characterization of apple procyanidins covering a large range of polymerization states.
Procyanidins from the cortex of two cider apple varieties (Malus domestica; Kermerrien and Avrolles) were extracted by solvents. After a solid-phase extraction step, they were fractionated by normal- or reversed-phase HPLC at the semipreparative scale to obtain a series of purified fractions covering a wide range of polymerization states. Freeze-dried fractions were characterized by reversed-phase HPLC following thiolysis. Elution on normal-phase HPLC gave oligomeric procyanidins fractions with (average degree of polymerization) values varying from 2 to 8, whereas polymeric fractions ( values varying from 7 to 190) were obtained by reversed-phase HPLC. Constitutive units were mainly (-)-epicatechin with a proportion above 95% for all fractions. Thiolysis yields were wholly homogeneous with an average value of 75%, which indicates that the efficiency of the reaction did not depend on the polymerization state of the procyanidin fractions.
Guyot
S
S
Laboratoire de Recherches Cidricoles, Biotransformation des Fruits et Légumes, Institut National de la Recherche Agronomique, BP 29, 35650 Le Rheu, France. guyot@rennes.inra.fr
Marnet
N
N
Drilleau
J
J
D000975:Antioxidants / Q000032:analysis*; D044946:Biflavonoids; D002392:Catechin / Q000032:analysis*; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005419:Flavonoids; D005638:Fruit / Q000737:chemistry*; D010636:Phenols; D011108:Polymers / Q000737:chemistry*; D044945:Proanthocyanidins; D013438:Sulfhydryl Compounds / Q000737:chemistry*
D000975:Antioxidants; D044946:Biflavonoids; D005419:Flavonoids; D010636:Phenols; D011108:Polymers; D044945:Proanthocyanidins; D013438:Sulfhydryl Compounds; C017674:procyanidin; D002392:Catechin