High performance liquid chromatography of phenolic choline ester fragments derived by chemical and enzymatic fragmentation processes: analysis of sinapine in rape seed.
High-performance liquid chromatography methods based on reversed-phase chromatography (RPC) and normal phase chromatography (NPC) were introduced for the separation of some representative phenolic acids, choline and betaine, which are the fragments of phenolic choline esters. Sinapine, which is the major phenolic choline ester found in rape seed, was quantitatively hydrolyzed to choline and sinapic acid upon treatment with a solution of sodium hydroxide at room temperature. Choline was further converted to betaine by incubating the base hydrolyzate with choline oxidase. Both sinapic acid and betaine formed the basis for the quantitative determination of sinapine in rape seed by RPC and NPC, respectively. The amounts of sinapine found in rape seed via either of the two fragments (i.e., sinapic acid or betaine) were in very close agreement.
Li
Juan
J
Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078-3071, USA.
El Rassi
Ziad
Z
D001622:Betaine / Q000032:analysis / Q000737:chemistry; D029741:Brassica rapa / Q000737:chemistry*; D002794:Choline / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003373:Coumaric Acids / Q000032:analysis; D006868:Hydrolysis; D010636:Phenols / Q000032:analysis / Q000737:chemistry; D012972:Sodium Hydroxide / Q000737:chemistry; D013053:Spectrophotometry
D003373:Coumaric Acids; D010636:Phenols; C005685:sinapine; D001622:Betaine; D012972:Sodium Hydroxide; C073734:sinapinic acid; D002794:Choline