Glucopyranosyl sinapate

Amarowicz, R. and Shahidi, F. 1994. Chromatographic Separation of Glucopyranosyl Sinapate from Canola Meal../. American Oil Chem. Soc., 71, 551-552. 

Cis- and trans-sinapine (the choline ester of sinapic acid), sinapic acid, sinapoyl glucose, Kaempferol-sinapoyl-trihexoside 1 -0-P-D-glucopyranosyl sinapate, Sinapoyl-hexoside, Disinapoyl hexoside, trisinapoyl-dihexoside and sinapoyl conjugate... 

Sinapic acid, an important hydroxydnnamic acid is the most significant phenolic compound in rapeseed and forms 70.2-85.4% of free phenolic adds in defatted canola meals. Esterified forms of these phenolic acids constitnte abont 99% of total phenolics in rapeseed flour of which the sinapine, the choline ester of sinapic acid, is the main ester. A phenolic glucoside namely glucopyranosyl sinapate is also reported in canola (Amarowicz and Shahidi, 1994). Figure 2.1 shows the structures of sinapic acid, sinapine and glucopyranosyl sinapate. 

Amarowicz R, Shahidi F. 1994. Chromatographic separation of glucopyranosyl sinapate from canola meal. Journal of American OH Chemists Society, 71 551-552. 

The main phenolic compounds of rapeseed meal are commonly sinapic acid (Figure 15.3a) and its derivatives—sinapine the choline ester of sinapic acid (Figure 15.3b), or as the glucosidic ester, glucopyranosyl sinapate. About 80-90% of all the phe-nolics in the meal are sinapic acid esters (SAEs) as discussed earlier. Thus, 70% methanolic rapeseed meal extracts of the meal have been classified into free-pheno-lics, esterifled phenolics and released-phenolics according to Krygier et al. (1982). Krygier et al. (1982) extracted free and esterified phenolics, which were methanol soluble and demonstrated that only a small fraction of the total phenolic compounds of rapeseed occurs as free sinapic acid (Koski et al., 2002 Vuorela et al., 2003). 

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