桦木醇

The effects of extraction temperature, microwave power, extraction time on betulin yield by MAE were discussed and the betulin content was determined by HPLC.

考察了提取温度、微波功率、提取时间对桦木醇收率的影响，并用高效液相色谱法测定了萃取物中桦木醇的含量。

To harmful microflora white part of birch bark is obliged precisely to betulin.

稳定有害菌群白桦树皮部分恰恰有义务为桦木醇。

Betulin and betulinic acid , the triterpenes of the lupane family, are considered to be potential agents against tumoral cancer and HIV .

桦木醇、桦木酸是具有羽扇烷结构的三萜化合物，目前的研究发现，它们具有较高的抗肿瘤、抗HIV病毒活性，它们的衍生物也有较高的生物活性。

The microwave-assisted extraction of betulin from Betula platyphylla Suk. bark was optimized using uniform design.

利用均匀设计法优化了微波辅助提取白桦树皮中桦木醇的工艺。

The results showed that in acetone and ethanol, solubilities of 3, 28-di-O-glutaryl-betulin were 33.52 and 22.65 times of those of betulin respectively; In water, solubility of 3, 28-di-O-glutaryl-betulin was 0.0021 g (100 mL water), and in PBS, solubility of 3, 28-di-O-glutary-betulin was 0.0015 g (100 mL PBS), the hydrophilicity of 3, 28-di-O-glutaryl-betulin was significantly increase.

结果表明，在丙酮和无水乙醇中，桦木酐戊二酸酯的溶解度是桦木醇的33.52和22.65倍；在水中，桦木醇戊二酸酯的溶解度为0.0021g（100mL水）；在PBS中，桦木醇戊二酸酯的溶解度约为0.0015g(100mL PBS)，目标产物的亲水性有了显著的改善。

Its structure was characterized by FT-IR, 1H NMR and MS. Solubility data of betulin and 3, 28-di-O-glutaryl-betulin in acetone, ethanol, water and phosphate-buffered saline (PBS, pH value 7.4) were determined by equilibrium method.

采用FT-IR、1H NMR和MS对产物进行结构表征，并且选用平衡法测定了桦木醇和桦木醇戊二酸酯在丙酮、无水乙醇、水和磷酸盐缓冲溶液（PBS， pH值7.4，）等不同溶剂中的溶解度。

The results showed a betulin yield of 25.43%, a purity of 59.19% was achieved from 1g powder of B. platyphylla bark under the extraction temperature of 72℃, microwave power 67W, and extraction time 100s.

试验结果表明，1g白桦树皮粉末，在提取温度72℃、微波功率67W，提取时间100s的条件下，微波辅助提取的桦木醇收率达到25.43%，纯度达到59.19%。

To improve water solubility of betulin, two acyl groups were introduced at C-3 and C-28 hydroxy groups of betulin. 3, 28-di-O-glutaryl-betulin was synthesized with pyridine as solvent and DMAP as catalyst from betulin and glutaryl anhydride.

为了增强桦木醇的亲水性，对桦木醇的C-3位、C-28位羟基进行修饰，在吡啶作溶剂、二甲基氨基吡啶作催化剂的条件下，与戊二酸酐反应合成桦木醇戊二酸酯。

This paper reviewed the study situation of several forest chemical products associated with medical and health such as sterols,paclitaxel, betulinic acid and hinokitol.

综述了植物甾醇、紫杉醇、桦木酸、桧木醇等几种与医药保健品有关的林产化学品的研究开发现状。

PA-457 was not just another Taxol, the anticancer drug that required the controersial felling of rare yew trees until a semisynthetic substitute was found. Panacos did not need a steady source of Taiwanese herbs. Betulinic acid could be extracted from ubiquitous plane and birch trees, and a subsequent processing step yielded the desired molecule.

PA-457不像抗癌药物太平洋紫杉醇：在太平洋紫杉醇的合成代替品出现前，砍伐罕见的太平洋紫杉一直引发争议；Panacos并不需要有稳定供应的台湾药草，桦木酸能从普遍存在的悬铃树和桦树中提炼，并且只要一个后续处理步骤，就可以制造出所需的分子。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了