Studies On Flavonoids In The Bract Of Zea Mays L

Zea mays.L belongs to gramineae annual herb grass, mainly used for food crops, and there is only one kind in the whole world. The Zea mays.L originated in Latin America, and it is mainly distributed in twenty four provinces, municipalities and autonomous regions in China, including Heilongjiang, Jilin, Liaoning, Hebei, Shangdong, Shangxi, He'nan, Shanxi, Sicuan, Guizhou, Yunnan, Guangxi, etc.The planting area of the Zea mays.L in china is about 24.4983 million ha, and the yields of Zea mays.L are more than 100 million tons, and we can extract 10-15 kg husk from per ton of Zea mays.L. The bract of Zea mays.L resource is very rich but not well used in China. Only a small amount of bracts are used to produce starch and a large number of them are used as fuel or thrown away. The bract of Zea mays.L is usually used to make straw mat, cushion, basket, etc.So far, the chemical structures of flavonoids compounds known are eight thousand types, and five thousand of them derived from flavonoids. With the development of extracting technologies, the research on the Zea mays.L is more considerable and we have extracted some compounds from Zea mays.L, including flavonoids, polysaccharides, sterols, organic acids, etc, which have been paid attention from native and abroad scholars. The "Compendium of Medica" and "Famous Physicians recorded" recording that the Zea mays.L and its by-products including straw, root, axis, etc are available for drug, and extracted more than ten types flavonoids compounds from Zea mays.L. Although domestic scholars have been studying on the use of the bract of Zea mays.L actively, however, most studies remained immature. Recently, the active ingredients on the bract of Zea mays.L research has not been reported, this article will finish the following three areas work in order to search for more extensive medical resources:1. Overview the chemical compounds of Zea mays.L plants and the role of pharmacological profile.2. Reference on the methods of the same kind plants, making up a systematic and pre-experimental method on the bract of Zea mays.L.3. Extract flavonoid compounds from the bract of Zea mays.L and identify their structures.The bract of Zea mays.L has been chosen as raw material which is cheap and easy to collect from July 2007 in Jilin, which has been identified as the bract of Zea mays.L by Professor Wang of College of Pharmacy in Jilin University.The ethanol 95% has been chosen as the extraction solvent. Meanwhile the AB-8 macroporous adsorption resin chromatography, silica gel column chromatography, Sephadex column chromatography, and recrystallization methods are adopted to separate four flavonoids from the bract of Zea mays.L through 95% ethanol. Through the spectral analysis we identified the structures of four compounds are:5,7,4'-trihydroxy-3',5'-dimethoxy-flavone (tricinⅠ),7,4'-dihydrox y-3',5'-dimethoxy-5-O-β-D-glucosyloxy-flavone(5-O-β-D)-glu-tricinⅡ)5,4'-dihydroxy-3',5'-dimethoxy-7-O-β-D-glucosyloxy-flavone,(7-O-β-D-glu-tr-icinⅢ)5,4'-dihydroxy-3'5'-dimethoxy-7-O-β-D-apiofuran osyl-(1→2')-glucosyloxy-flavone (7-O-β-D-apio-(1→2')-glutricinⅣ). compoundⅠ,Ⅱ,Ⅲwere isolated from this plant for the first time, compoundⅣis a new compound 5,7,4'-trihydroxy-3',5'-dimethoxy-flavone(tricin I),7,4'-dihydroxy-3', 5'-dimethoxy-5-O-β-D-glucosyloxy-flavone(5-O-β-D-glutricinⅡ) 5,4'-dihydroxy-3',5'-dimethoxy-7-O-β-D-glucos yloxy-flav-one, (7-O-β-D-glu-tricinⅢ) 5,4'-dihydroxy-3', 5'-dimethoxy-7-O-β-D-apiofuranosyl-(1→2')-glucosyloxy-flavone(7-O-β-D-apio-(1→2')-glu-tricinⅣ). compoundⅠ,Ⅱ,Ⅲwere isolated from this plant for the first time, compound IV is a new compound. At present, the sweet corn beverage processing technology has matured in china, and the corn beverage has been exposed to marketing. The study about medicinal value of Corn and its by-products (straw, roots, axis) will develope a whole new area about corn refiners. Corn is rich in China, and we should fully use and develop these rich plant resources. It is believed that the medicinal food and health products which are made from corn and its by-products will come into being in the near future.In summary, corn and its by-products resources has great value of development. Surveys on flavonoids in the bract of Zea mays L will provide the scientific basis for the development of new, effective and safe drugs.