[Separation and purification of the main glucosinolate from rapeseeds].

A procedure for the preparative isolation of 1-S-[(1Z)-3-hydroxy-1-[(sulfooxy) imino]-4-pentenyl]-1-thio-beta-D-glucopyanose, potassium salt (progoitrin) from Brassica oleracea is reported. The major steps in this procedure were: (1) extraction of glucosinolates with methanol from Brassica oleracea; (2) separation and purification of glucosinolates by chromatographic column on alumina support; and (3) a follow-up reversed-phase separation by octadecyl (C18) silica support yielding progoitrin as the main content of glucosinolate. The structure of progoitrin was identified on its physicochemical properties by ultraviolet absorption spectrometry, infrared absorption, 'H nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis. Spectroscopic data of the sample isolated were in agreement with those reported in the literature. The purity of progoitrin obtained was determined to be 99% by high performance liquid chromatography. The simplicity of the separation and purification procedure for glucosinolates and the high purity of progoitrin isolated would make the method an important reference for future research on glucosinolates and a favorable technique for future development.