Abstract: As the local herbs of southwest of Hubei, Magnolia officinalis Rehd.etWils is valued for its medicinal properties on the bark.The leaves of Magnolia officinalis are ignored in the perspective of pharmaceutics.It was found that the leaves of Magnolia officinalis have the peroxidase activity in the previous studies. Regarding the compelling effect of peroxidase in process of phenols biodegradation,the purification and properties of the peroxidase from the leaves of M.officinalis were studied to fully develop the value of the leaves and to improve the resource utilization efficiency.Based on that,its function of removing bisphenol A was further investigated.The results showed that,after ammonium sulfate precipitation and DEAE-cellulose ion-exchange chromatography,the yield of peroxidase purified from the leaves of M.officinalis was 14%,and purification fold was 52.8 with specific activity of 184140 U/mg.The optimal pH was 6.0.The Km value of POD was 4.23 mmol/L on H₂O₂, and 57.86 mmol/L on guaiacol,respectively.The optimal temperature was 80 ℃.The activity of the enzyme could be maintained for a long time below 75 ℃ (good thermal stability).Its activity was significantly inhibited by ferrous sulfate.M.officinalis leaves peroxidase had good scavenging ability on BPA.Under the conditions of pH 4-9, 25-65 ℃ and H₂O₂/BPA 0.8,the clearance rate of 0.2 mmol/L BPA derivatives for 4000U / L M.officinalis leaves peroxidase was 95% in 3 hours later. M.officinalis leaves peroxidase had convincing future in researches of phenols biodegradation.

Key words: peroxidase;purification;BPA, Magnolia officinalis Rehd.et Wils