熊果苷和红景天苷都是重要的酚类衍生物,存在于多种植物中.熊果苷具有显著的美白、抗氧化、抑菌、抗炎等多种生物活性.红景天苷是红景天的重要药用成分之一,具有抗癌、抗炎、抗氧化等多种药理作用.以熊果苷的苷元(对苯二酚)和红景天苷苷...熊果苷和红景天苷都是重要的酚类衍生物,存在于多种植物中.熊果苷具有显著的美白、抗氧化、抑菌、抗炎等多种生物活性.红景天苷是红景天的重要药用成分之一,具有抗癌、抗炎、抗氧化等多种药理作用.以熊果苷的苷元(对苯二酚)和红景天苷苷元(酪醇)的同系物3-(4-羟基苯基)-1-丙醇为原料,对其进行结构修饰,分别与吗啉、N-甲基哌嗪、N-Boc-乙二胺进行偶联并脱除保护基,得到8种新的中间体和4种新的目标产物,并利用IR、1 H NMR和ESI-MS波谱技术对其结构进行了表征.对中间体和目标产物进行了抑制酪氨酸酶活性的测试.结果显示,p-HQ-6b、p-HQ-7a、p-HQ-7b、L-3、L-4b、L-4c和L-5a的活性优于阳性对照物α-熊果苷(IC50=3.60±0.153),其中,p-HQ-7a对酪氨酸酶抑制作用最佳(IC50=0.288±0.051).展开更多
The authors investigate monsoon change in East Asia in the 21st century under the Special Report on Emissions Scenarios (SRES) A1B scenario using the results of a regional climate model, RegCM3, with a high horizontal...The authors investigate monsoon change in East Asia in the 21st century under the Special Report on Emissions Scenarios (SRES) A1B scenario using the results of a regional climate model, RegCM3, with a high horizontal resolution. First, the authors evaluate the model's performance compared with NCEP-NCAR reanalysis data, showing that the model can reliably reproduce the basic climatology of both winter and summer monsoons over East Asia. Next, it is found that the winter monsoon in East Asia would slightly weaken in the 21st century with spatial differences. Over northern East China, anomalous southerly winds would dominate in the mid-and late-21st century because the zonal land-sea thermal contrast is expected to become smaller, due to a stronger warming trend over land than over ocean. However, the intensity of the summer monsoon in East Asia shows a statistically significant upward trend over this century because the zonal land-sea thermal contrast between East Asia and the western North Pacific would become larger, which, in turn, would lead to larger sea level pressure gradients throughout East Asia and extending to the adjacent ocean.展开更多
文摘熊果苷和红景天苷都是重要的酚类衍生物,存在于多种植物中.熊果苷具有显著的美白、抗氧化、抑菌、抗炎等多种生物活性.红景天苷是红景天的重要药用成分之一,具有抗癌、抗炎、抗氧化等多种药理作用.以熊果苷的苷元(对苯二酚)和红景天苷苷元(酪醇)的同系物3-(4-羟基苯基)-1-丙醇为原料,对其进行结构修饰,分别与吗啉、N-甲基哌嗪、N-Boc-乙二胺进行偶联并脱除保护基,得到8种新的中间体和4种新的目标产物,并利用IR、1 H NMR和ESI-MS波谱技术对其结构进行了表征.对中间体和目标产物进行了抑制酪氨酸酶活性的测试.结果显示,p-HQ-6b、p-HQ-7a、p-HQ-7b、L-3、L-4b、L-4c和L-5a的活性优于阳性对照物α-熊果苷(IC50=3.60±0.153),其中,p-HQ-7a对酪氨酸酶抑制作用最佳(IC50=0.288±0.051).
基金supported by the National Basic Research Program of China(2012CB955401 and 2009CB421406)the National Natural Science Foundation of China(41175072)
文摘The authors investigate monsoon change in East Asia in the 21st century under the Special Report on Emissions Scenarios (SRES) A1B scenario using the results of a regional climate model, RegCM3, with a high horizontal resolution. First, the authors evaluate the model's performance compared with NCEP-NCAR reanalysis data, showing that the model can reliably reproduce the basic climatology of both winter and summer monsoons over East Asia. Next, it is found that the winter monsoon in East Asia would slightly weaken in the 21st century with spatial differences. Over northern East China, anomalous southerly winds would dominate in the mid-and late-21st century because the zonal land-sea thermal contrast is expected to become smaller, due to a stronger warming trend over land than over ocean. However, the intensity of the summer monsoon in East Asia shows a statistically significant upward trend over this century because the zonal land-sea thermal contrast between East Asia and the western North Pacific would become larger, which, in turn, would lead to larger sea level pressure gradients throughout East Asia and extending to the adjacent ocean.
