Structural characterization of a broccoli polysaccharide and evaluation of anti-cancer cell proliferation effects

Broccoli is a widely consumed vegetable with abundant amount of nutrients, which bring numerous beneficial effects on human health. The structural information of water-soluble polysaccharides in broccoli was eludicated for the first time in this work. A purified polysaccharide fraction (BPCa) was obtained by column chromatography. It comprised of arabinose (Ara), galactose (Gal), rhamnose (Rha) with a molar ratio of 5.3:0.8:1.0. Nuclear magnetic resonnance spectra data revealed that α- l -1,5-Ara f and α- l -1,3,5-Ara f are present in the backbone, while α- l -Ara f terminal was attended in side chain. α- l -1,2-Rha p was found to be linked to α- l -1,5-Ara f in heteronuclear multiple bond correlation spectra. The presences of β- d -1,4-Gal p and α- d -1,4-Gal p A were also detected. Furthermore, BPCa showed significant anti-cancer cell proliferation activities against HepG2, Siha and MDA-MB-231 carcinoma cell lines. The results indicated that BPCa had a good potential to be applied as functional food additives.