白桦树羽扇豆烷型三萜类化合物与抑制PTP1B活性研究

Lupane-Terpenoids Isolated from Betula platyphylla Suk of Protein Tyrosine Phosphatase 1B Inhibitory Activity

蛋白酪氨酸磷酸酯酶1B(Protein tyrosine phosphatase1B;PTP1B)在胰岛素信号传递过程中起负调控作用,亦是研究治疗2型糖尿病的重要靶点。利用PTP1B生物活性导向分离方法,从白桦树皮的正己烷提取物中分离得到7个羽扇豆烷型三萜类化合物。经过光谱分析和文献比较,确定分离得到的7个化合物为:羽扇烯酮(1),羽扇豆醇(2),桦木酸(3),白桦脂醛(4),白桦脂酸(5),算盘子酮醇(6)和白桦脂醇(7)。其有效抑制PTP1B活性值(IC50)分别为:5.6±0.3μmol/L,4.1±0.2μmol/L,7.2±0.3μmol/L,12.6±0.4μmol/L,11.6±0.3μmol/L,9.6±0.4μmol/L和13.6±0.5μmol/L。

Protein tyrosine phosphatase 1B plays an importance role in the negative regulation of insulin signaling, and thus considered as an attractive therapeutic target for diabetes. Bioassay guided fractionation of the hexane soluble extract of the seeds of Betula platyphylla Suk afforded seven protein tyrosine phosphatase 1B （ PTP1 B） inhibitory Lupane-triter- penoids 1 4. Isolated compounds （1-7） were identified as lupenone （ 1 ）, lupeol （2）, betulinic acid （ 3 ）, betulinalde- hyde （4） ,betulini （S） ,glochidonol （6） and lup-20/29-ene-1β3β-diol （7）. Compounds 1-7 inhibited PTP1B activity in a dose dependent manner,displaying ICs0values of 5.6 ± 0.3 μmol/L,4. 1 ± 0.2 μmol/L,7.2 ± 0.3 μnol/L, 12.6 ± 0.4 μmol/L,11.6 ± 0.3 μmol/L,9.6 ±0.4 μmol/L and 13.6 ±0.5 μmol/L respectively.