Studies on Extraction and Purification of Flavonoids from Leaves of Jasminum nudiflorum Lindl.and Their Antifreeradical Activity

The extraction and purification conditions of flavonoids from leaves of Jasminum nudiflorum Lindl.(FLJN) and their abilities of eliminating free radicals were researched.The results of orthogonal experiment showed the optimum extraction conditions were: material with 15-fold ethanol of 75% as solvent was refluxed in water-bath for three times,each for 40min.The crude extract was treated with active carbon to obtain purified product with flavonoids content of 97.6%.Experiments in vitro showed FLJN could scavenge free radicals such as DPPH· and ·OH.The IC50(the amount of sample needed to eliminate 50% of free radical) were 8.40 and 2.24mg/L,respectively.Its antifreeradical ability was nearly the same as that of rutin and slightly weaker than that of dibutyl hydroxy toluene(BHT).