This invention is in the field of bio-pharmaceutical technology, specifically involving the new derivatives of puerarin, the biological conversion methods and their pharmaceutical applications. This invention published a new type fructosylated puerarin with structure as shown in Formula (I) below, its preparation method being converting puerarin into fructosyl and fructose oligosaccharyl puerarin in a aqueous phase or nonaqueous phase system by bioconversion method, and at a puerarin concentration of 107.5g/L, the monofructosyl-β (2,6)-puerarin concentration can reach 111.7g/L, and conversion rate of fructosylated puerarin is 90%. By adsorption with AB-8 macroporous resin and gradient elution, product with purity over 97% and complying drug specification can be obtained, with extraction rate over 80%. Tests have shown that fructosylated puerarin is effective to acute myocardio ischemia, and can markedly suppress in vitro the proliferation of human breast cancer cell strain MDA-MB-23 and human chronmyelogenors leukemia cell strain K562, and such oligosaccharylated puerarin has low toxicity, with good application prospects in making drugs to treat cardio-cerebral vascular diseases and/or tumour diseases.
