We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our epidemiological study and animal study. Samples of these vegetabl...We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our epidemiological study and animal study. Samples of these vegetables were quantitatively examined by highperformance liquid chromatography (HPLC) on a C-18 reversed-phase column for individual carotenoid content. Pure reference compounds (alpha-carotene, beta-carotent, lycopene, canthaxanthin, and lutein) and internal standard (beta-Apo-8'-carotenal) were employed to quantify xanthophylls and carotenes in these vegetables. The results indicated that fresh, dark-green, leafy vegetables were high in beta-carotene (0.94-9.36 mg/100 g) and oxygenated carotenoids or xanthophylls, primarily lutein (0.94-7.39 mg/100 g),whereas lycopene and alpha-carotene were not prominent and canthaxanthin was non existent in these vegetables. These analyses suggest that consumption of carotenoids such as lutein in addition to beta-carotene may be associated with a lower risk of cancers展开更多
文摘We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our epidemiological study and animal study. Samples of these vegetables were quantitatively examined by highperformance liquid chromatography (HPLC) on a C-18 reversed-phase column for individual carotenoid content. Pure reference compounds (alpha-carotene, beta-carotent, lycopene, canthaxanthin, and lutein) and internal standard (beta-Apo-8'-carotenal) were employed to quantify xanthophylls and carotenes in these vegetables. The results indicated that fresh, dark-green, leafy vegetables were high in beta-carotene (0.94-9.36 mg/100 g) and oxygenated carotenoids or xanthophylls, primarily lutein (0.94-7.39 mg/100 g),whereas lycopene and alpha-carotene were not prominent and canthaxanthin was non existent in these vegetables. These analyses suggest that consumption of carotenoids such as lutein in addition to beta-carotene may be associated with a lower risk of cancers
