红曲霉菌对姜黄素的转化及产物自由基清除和抗脂质过氧化作用的研究

Effects of Curcumin Metabolites Transformed by M.purureus Went in Radical Scavenging and Anti-oxidation in Hyperlipoidemia Mices

目的研究红曲霉菌对姜黄素的微生物转化及转化总产物的自由基清除和抗脂质过氧化的作用,并对转化产物进行了初步分析。方法用本实验室保存的红曲霉菌对姜黄素进行微生物转化,同时设立菌株对照和底物对照;研究转化总产物对DPPH自由基的清除能力;研究转化总产物对食饵性高脂血症小鼠肝脏和血清MDA、SOD、GSH-Px等过氧化脂质的影响。用乙酸乙酯提取转化产物,用TLC、HPLC-DAD(Agilent Zorbax Extend C18柱,0.1%乙酸和乙腈梯度洗脱,流速1.0mL·min-1)对转化产物进行了初步分析。结果姜黄素转化总产物在10000～400mg·mL-1(相当于含姜黄素100～4mg·mL-1)内有很强的自由基清除能力,总产物浓度在100mg·mL-1还保留了47.46%的清除能力;而底物对照物在10000、2000mg·mL-1时有一定的清除能力,但浓度在400mg·mL-1时自由基清除能力已明显减弱,100mg·mL-1以下已基本消失。转化总产物500,200,100mg·kg·d-1(相当于姜黄素5,2,1mg·kg·d-1)均能降低高脂血症小鼠肝脏和血清的过氧化脂质,而菌株对照组(500mg·kg·d-1)和底物对照组(500mg·kg·d-1,相当于姜黄素5mg·kg·d-1)抗脂质过氧化作用不明显。研究超氧化物歧化酶、谷胱甘肽过氧化物酶,发现姜黄素转化产物对此二酶的作用不明显,其抗氧化作用可能并非通过改变此二酶的活性。转化产物经HPLC-DAD分析,发现可能存在6个转化产物,其保留时间分别为16.3,22.1,23.2,28.0,33.0,36.1min,其光谱图与姜黄素存在明显差异。结论姜黄素经红曲霉菌转化后形成了由6个代谢产物组成的新组合型天然姜黄素类似物群,其自由基清除能力和抗脂质过氧化作用显著增强。

OBJECTIVE To study the radical scavenging and anti-oxidation properties of microbial transformed curcumin by M.purureus went. METHODS A strain of M.purureus went was used for microbial transformation.The DPPH radical scav-enging ability of the transformed curcumin was studied,comparing to the ability of strain culture and substrate control.The anti-oxidation activity of the metabolites in hyperlipoidemia mices was assessed by the change of MDA, SOD, GSH-Px in liver and serum.The metabolites of curcumin extracted were separated and assayed by TLC and HPLC-DAD （Agilent Zorbax Extend C18 column, eluted by a gradient mixture of 0.1% acetic acid solution and acetonitric with flow rate of 1.0 mL＇min^-1）. RESULTS The radical scavenging activity of curcumin was improved after being transformed.The transformed curcumin can reduce lipid perox-ides in hyperlipoidemia mices at dosage of 500, 200, 100 mg＇kg-d^-1 （Corresponding to curcumin 5, 2, 1 mg-kg-d^-1） while strain culture control and substrate control seemed no effects. The transformed curcumin had no significant effect on the activity of the enzyme SOD and GSH-Px.Analysis of the metabolites showed that there were 6 me-tabolites, with retention times of 16.3, 22.1, 23.2, 28.0, 33.0, 36.1 min respectively.The spectra of these metabolites were all different but similar to that of curcumin. CONCLUSION Six metabolites of curcumin were transformed by M.purureus went and became a new combinatorial natural curcumoids group. The radical scavenging and anti-oxidation properties were improved.